**3. Status of cotton germplasm preservation in China**

Funding for maintenance of the collections was provided by the Chinese government under the National Key Technology Research and Development Program, and the National Key Basic Research and Development Program, Funds primarily provided by the National Science Foundation of China, the Ministry of Science and Technology, and the Ministry of Agriculture. There are five full-time staff members assigned to the maintenance and conservation of the germplasm collection. The total collection consists of 8,868 accessions that represent cultivated species (*G. arboreum*, *G. herbaceum*, *G. hirsutum*, *G. barbadense*) and 32 wild species (Table 4 and


Table 5). In these collections, most of the accessions were originated from all China, and the other accessions were imported from 52 countries (Table 6).

**Table 4.** Cotton germplasm in the medium-term germplasm bank

**Years Collection Issues**

Import 9 wild species from Czechoslovakia Prague tropical subtropical Agricultural Research Institute of Kasetsart University, including *G. australe Mueller, G. trilobum ( DC. ) Skovsted, G. tomentosum, G. bickii, G. sturtianum, G. davidsonii, G. klotzschianum, G. davidsonii, G. herbaceum var africanum*

Import 21 wild species from USA, including *G. nandewarense* Derera, *G. capitis-viridis* Mauer, *G. armourianum* Kearn, *G. gossypioides* (Ulbr) Standl, *G. longicalyx* J.B*.*Hutch & Lee, *G. triphyllum* (Harv, Sond) Hochr, *G. incanum* (Schwartz) Hillc, *G. aridum* (Rose&Standley) Skovsted, 3 wild species from French including *G. turneri* Fryx, *G. laxum* Phillips, *G. nelsonii* Fryx.

Import 6 wild species from The Commonwealth Scientific and Industrial Research Organisation in Australia, including *G. cunninghamii* Todaro, *G. costulatum* Todaro, *G. populifolium* (Bentham) Mueller ex Todaro

from Pakistan

*mustelinum* Miers &Watt

Barbados

<sup>1987</sup> Import 79 GP lines and 3 wild species including *G. bickii*, *G. triphyllum*, *G. anomalum*, and 11 lines

<sup>1989</sup> Import 3 wild species from Cote d'Ivoire, including *G. incanum* (Schwartz) Hillc, *G. turneri* Fryx, *G.*

<sup>1991</sup> Import 55 lines from USA, 8 lines from French, 5 line from Egypt, 1 line from Burma, 1 line from

1990-1995 Import 8 *G. hirsutum* landraces and 4 wild species from Mexico including *G. schw endimanii* Fryxell)

Funding for maintenance of the collections was provided by the Chinese government under the National Key Technology Research and Development Program, and the National Key Basic Research and Development Program, Funds primarily provided by the National Science Foundation of China, the Ministry of Science and Technology, and the Ministry of Agriculture. There are five full-time staff members assigned to the maintenance and conservation of the germplasm collection. The total collection consists of 8,868 accessions that represent cultivated species (*G. arboreum*, *G. herbaceum*, *G. hirsutum*, *G. barbadense*) and 32 wild species (Table 4 and

1980 Import 50 genetic stocks from USA, and 7 *G.hirsutum* landraces from Mexico

1983 Import 27 PD lines from USA, and 33 lines from French 1984 Import 6 wild species from Mexico, including *G. aridum* and *G. laxum* 1986 Import 38 lines from Pakistan, including 6 wild species and 7 *G. arboreum* L.

1990 Import 52 lines, including 3 wild species

 Import 35 lines from Mexico Import 36 MAR lines from USA Import 418 *G. hirsutum* landraces from USA Import 100 lines from Uzbekistan 2009-2013 Import 990 lines from Russia

**Table 3.** Cotton germplasm importing and collection from foreign country

**3. Status of cotton germplasm preservation in China**

1992 Import 94 lines from Australia, including 16 wild species

1977

40 World Cotton Germplasm Resources

1982

1986

7,221 accessions were preserved for long-term in Beijing at-18°C under 57% relative humidity. The collection in Anyang, considered the working collection, contains 8,868 accessions and is maintained at 0°C under 50% relative humidity. The Hainan Island nursery site maintained an *in vivo* collection of 391 wild species and *G. hirsutum* landrace stock accessions in a garden under natural field conditions [18-19]. Over time, the Chinese collection has grown through international germplasm exchange and expeditions. The germplasm expeditions covered most of southern China (Hainan Island, Guangxi, and Guangzhou) and the mountainous areas of Yunnan and west Sichuan provinces. *G. hirsutum* landrace germplasm has also been collected from southern Mexico.

The seeds of germplasm accessions in the working collection were renewed according to individual accession germination rates. When germination rates fell under 65%, or the weight of individual accession was no more than 150g, these accessions would be increased and renewed for the maintaining of the viability, genetic integrity and releasing for the research. 50-100 seedlings of each individual should been kept in the field for the harvest of enough healthy seeds. The field was chose according to the environments of origins of the accessions for propagation. The *G. hirsutum* L. has been propagated in Anyang, Nanjing, Kuche, and Liaoyang, in the past years. The *G.barbadence* L. has been grown in Kuche or Turpan of Xinjiang because of low rainfall and high temperature weather. The lines sensitive to the Verticillium wilt and Fusarium wilt were grown in disease free field. Some lines that were photoperiod and temperature sensitive were grown in Sanya of Hainan province. The main agronomic traits were checked according to the database descriptors in the germplasm bank, and the mixed seedlings were weeded out for keeping the purity of the accessions and the true accuracy of the database. Cotton germplasm preserved in the local institutes last century were renewed for enough seeds with purity and vitality. Every year more than 300 accessions were renewed for better seed vitality (Table 7).


**Origin**

*G. hirsutum L.*

*G. barbadence L.*

*G. arbareum L.*

Afghanistan 1 Kenya 5 Albania 1 3 Mali 2

Argentina 7 Nepal 5 Australia 154 Nicaragua 1 Brazil 4 Nigeria 3 Bulgarian 14 North Korea 3

Burma 1 Peru 1 Burundi 1 Portuguesa 1 Cambodia 1 Somalia 2

Canada 1 Spain 3

Cameroon 2 Sweden 1

Czech 1 Tanzania 5 Egypt 1 41 Turkey 6 France 29 Uganda 11

Greece 6 Uzbekistan 11 Hungary 1 Vietnam 5 India 15 1 Yemen 1 Indonesia 2 Yugoslavia 2 Iran 1 Zambia 1 Japan 4 1 Other 4

**Table 6.** The Collections from different countries in the medium-term germplasm bank

Cote d'Ivoire 10 Soviet Union 355 135

Chad 1 Sudan 8 1

Cuba 4 Syria 7 3

Ghana 1 USA 1200 13 11

*G. herbaceum L.*

Angola 1 Mexico 17 1

Burkina Faso 2 Pakistan 99 1

**Origin**

*G. hirsutum L.*

*G. barbadence L.*

*G. arbareum L.*

Cotton Germplasm Resources in China http://dx.doi.org/10.5772/58595

*G. herbaceum L.*

43

**Table 5.** Wild species in the germplasm bank in China


**Species Origin**

*G. nandewarense* Derera Nandeware, New South Wales, Australia

*G. thurberi* Tod Arizona, USA; Sonora and Warburg, Mexico

*G. armourianum* Kearn San Marcos and Baja California, Mexico

*G. sturtianum* Willis Centre and South Australia

*G. robinsonii* Muell West Australia *G. costulatum* Tod Kimberley, Australia *G. cunninghamii* Tod North Australia *G. populifolium* (Benth) Muell ex Tod Kimberley, Australia *G. australe* Muell Centre and North Australia

42 World Cotton Germplasm Resources

*G. bickii* Prokhanov Centre Australia *G. nelsonii* Fryx Centre Australia

*G. davidsonii* Kell Baja California, Mexico *G. klotzschianum* Anderss Galapagos islands

*G. harknessii* Brandg Baja California, Mexico *G. turneri* Fryx Sonora, Mexico *G. gossypioides* (Ulbr) Standl Warburg, Mexico

*G. trilobum* Skov Mexico

*G. aridum* (Rose & Standley) Skov Mexico *G. schwendimanii* Fryx Mexico *G. lobatum* Gentry Mexico

*G. anomalum* subsp*.senarense* (Wawra & Peyr)

*G. laxum* Phillips Guerrero, Mexico *G. raimondii* Ulbr Centre and West Peru

*G. capitis-viridis* Mauer cape verde islands

*G. incanum* (Schwartz) Hillc Yemen

*G. tomentosum* Nutt & Seem Hawaii *G. mustelinum* Miers &Watt Brazil

**Table 5.** Wild species in the germplasm bank in China

*G. darwinii* Watt Galapagos islands

Vollesen Niger, Chad, Sudan, Ethiopia

*G. somalense* (Gürke) J.B.Hutch Sudan, Ethiopia, Somalia, Kenya *G. stocksii* Mast in Hook Somalia, Oman, Pakistan *G. longicalyx* J.B*.*Hutch & Lee Sudan, Uganda, Tanzania *G. triphyllum* (Harv, Sond) Hochr Angola, Botswana, Namibia

**Table 6.** The Collections from different countries in the medium-term germplasm bank


**Table 7.** Seed propagation of cotton germplasm in recent years

#### **4. Evaluation of cotton germplasm in China**

For the utilization of the cotton germpasm, all the accessions in the germplasm bank were evaluated with different method, including the main agronomic traits and mutant beneficial genes. We took charge of some national projects such as "*Propagation, Identification, evaluation and utilization of cotton germplasm"*, "*Construction molecular map of cotton germplasm and molecular marker for the genes with important traits"*, "*Germplasm enhancement and utilization of cotton"* etc., for elite germplasm evaluation. All these projects were in cooperative with provincial cotton research institutes and national universities. We are seeking to have some chances to make international cooperation on collection and evaluation.

Central Asia grew very well in Xinjiang province, but these from Brazil and Africa produce only in Yunan. This provided a guidance for the further introduction germplasm in different area. Some better fiber quality lines were screened after the evaluation in different environ‐ ments, such as Chuan77-1, Acala1517-70, Acala1517-77, LineF, upland, FJA, Zaoshuchan‐ grong7, ITMA96497, Hopical. Now Nanjing, Anyang, Kuerle, Kuche and Shijiazhuang were chosen as the appointed locations for the environment adaption evaluation of the cotton

**Salt**

1957-1990 2943 2344 2345 2844 2888 365 364 359 1 1991-2000 1242 888 897 1053 1064 337 356 337 346 2001-2005 491 470 485 477 484 198 202 208 207 2006-2009 501 416 500 487 500 284 499 500 498

**Boll -worm** **Aphid** **Pink worm**

Cotton Germplasm Resources in China http://dx.doi.org/10.5772/58595

> **Tetranychid mite**

45

The *G.arboreum* L in China was selected to evaluate for special agronomy traits, such the fiber quality, abiotic resistance, specific follower color and leaf. Some important traits were classified into different types including oil and protein contents in the seeds, fiber fineness, and boll

The genetic diversity of main sources germplasm of Upland cotton were studied on the basis of simple sequence repeat (SSR) markers. These germplasm of Upland cotton included the cultivars bred in different periods and grown in different ecological areas, the lines transferred with genes and exotic DNA, and the introgression lines from interspecific hybridization [13]. Meanwhile, SSR fingerprinting analysis were set up to indentify the elite germplasm with high yield and good fiber quality, and QTLs mapping were carried out to screen the markers linked or associated with the beneficial genes [21-24]. Those studies presented an overview of the genetic diversity of the cotton germplasm in China, and provided a guideline for breeders to

The introgression *G.hirsutum* lines were created by different institutes and collected in the germplasm bank in the past years, which possessed some important beneficial genes from the wild species. Our research showed that there were specific SSR loci among the different exotic *G.hisutum*. Around 45.2% of 155 interspecific lines possessed specific SSR loci [13]. The percentage of the lines with exotic specific SSR loci among the exotic *G.hirsutum* which may be transferred from *G. barbadense* and *G. thurberi* was highest, reached 62.1% and 71.1% respectively. The second was those with the specific SSR loci of *G*. *anomalum* and *G*. *bickii* etc.,

germplasm in China.

**Years** **Fiber quality** **Fusarium wilt**

**Verticillium wilt**

**Table 8.** Evaluation of the main traits in cotton during the past years

**Drought**

maturity based on the evaluation of all the germplasm.

**4.2. Evaluation with molecular method**

develop new cultivars efficiently.

*4.2.1. Evaluation of introgression G.hirsutum lines*

#### **4.1. Evaluation of agronomic traits**

Germplasm accessions were evaluated by field investigation according to "*Descriptors and Data Standards for Cotton Germplasm"* utilizing the IPGRI description standards for cotton [20]. Sixtysix agro-economic characters were evaluated, including 41 morphological and agronomic characters, 13 fiber quality, 4 seed quality, 8 disease, insect, multi-adversity resistance charac‐ ters among 6372 accessions. The main characters were early maturity, mid-maturity, late maturity, clustering of bolls, dwarfness, pubesence, naked seeds, big boll, high lint percentage, long fiber, strong fiber, high oil content, high protein content, low gossypol content, high gossypol content, high Fusanrium wilt resistance, high Verticillium wilt resistance, root disease resistance, aphids resistance, bollworm resistance, red pink boll worm resistance, spider resistance, draught resistance, salinity resistance, humidity resistance, cold resistance, color of fiber, male sterility, and genetic markers (Table 8). The Chinese Crop Germplasm Information System (CGRIS) served as a central repository for all germplasm accession characterization and evaluation information for China and was freely available at http:// icgr.caas.net.cn/ cgrisintroduction.html (verified on July 17th 2009). Cotton germplasm evaluation and characterization data was first stored on an offline, internal database and then periodically deposited onto the CGRIS online database.

The evaluation of environment adaptation was also carried out in the past years. All germ‐ plasms from the foreign origins were divided into three types based on the latitude, including tropical type, subtropical type and temperate zone type, and were grown in Lujiang in Yunan province, Nanjing in Jiangsu province, Yuncheng in Shanxi province, Kuerle in Xinjiang province. It was found that the germplasm from USA were adaptable in Yellow River area and Yangtze River area because of the similar latitude and weather, and the germplasms from


**Table 8.** Evaluation of the main traits in cotton during the past years

**Years** 2001 2002 2003 2004 2005 2006 2007 2008

For the utilization of the cotton germpasm, all the accessions in the germplasm bank were evaluated with different method, including the main agronomic traits and mutant beneficial genes. We took charge of some national projects such as "*Propagation, Identification, evaluation and utilization of cotton germplasm"*, "*Construction molecular map of cotton germplasm and molecular marker for the genes with important traits"*, "*Germplasm enhancement and utilization of cotton"* etc., for elite germplasm evaluation. All these projects were in cooperative with provincial cotton research institutes and national universities. We are seeking to have some chances to make

Germplasm accessions were evaluated by field investigation according to "*Descriptors and Data Standards for Cotton Germplasm"* utilizing the IPGRI description standards for cotton [20]. Sixtysix agro-economic characters were evaluated, including 41 morphological and agronomic characters, 13 fiber quality, 4 seed quality, 8 disease, insect, multi-adversity resistance charac‐ ters among 6372 accessions. The main characters were early maturity, mid-maturity, late maturity, clustering of bolls, dwarfness, pubesence, naked seeds, big boll, high lint percentage, long fiber, strong fiber, high oil content, high protein content, low gossypol content, high gossypol content, high Fusanrium wilt resistance, high Verticillium wilt resistance, root disease resistance, aphids resistance, bollworm resistance, red pink boll worm resistance, spider resistance, draught resistance, salinity resistance, humidity resistance, cold resistance, color of fiber, male sterility, and genetic markers (Table 8). The Chinese Crop Germplasm Information System (CGRIS) served as a central repository for all germplasm accession characterization and evaluation information for China and was freely available at http:// icgr.caas.net.cn/ cgrisintroduction.html (verified on July 17th 2009). Cotton germplasm evaluation and characterization data was first stored on an offline, internal database and then

The evaluation of environment adaptation was also carried out in the past years. All germ‐ plasms from the foreign origins were divided into three types based on the latitude, including tropical type, subtropical type and temperate zone type, and were grown in Lujiang in Yunan province, Nanjing in Jiangsu province, Yuncheng in Shanxi province, Kuerle in Xinjiang province. It was found that the germplasm from USA were adaptable in Yellow River area and Yangtze River area because of the similar latitude and weather, and the germplasms from

997 1058 574 700 586 1336 404 400

**Accession Number**

44 World Cotton Germplasm Resources

**Table 7.** Seed propagation of cotton germplasm in recent years

**4. Evaluation of cotton germplasm in China**

international cooperation on collection and evaluation.

periodically deposited onto the CGRIS online database.

**4.1. Evaluation of agronomic traits**

Central Asia grew very well in Xinjiang province, but these from Brazil and Africa produce only in Yunan. This provided a guidance for the further introduction germplasm in different area. Some better fiber quality lines were screened after the evaluation in different environ‐ ments, such as Chuan77-1, Acala1517-70, Acala1517-77, LineF, upland, FJA, Zaoshuchan‐ grong7, ITMA96497, Hopical. Now Nanjing, Anyang, Kuerle, Kuche and Shijiazhuang were chosen as the appointed locations for the environment adaption evaluation of the cotton germplasm in China.

The *G.arboreum* L in China was selected to evaluate for special agronomy traits, such the fiber quality, abiotic resistance, specific follower color and leaf. Some important traits were classified into different types including oil and protein contents in the seeds, fiber fineness, and boll maturity based on the evaluation of all the germplasm.

#### **4.2. Evaluation with molecular method**

The genetic diversity of main sources germplasm of Upland cotton were studied on the basis of simple sequence repeat (SSR) markers. These germplasm of Upland cotton included the cultivars bred in different periods and grown in different ecological areas, the lines transferred with genes and exotic DNA, and the introgression lines from interspecific hybridization [13]. Meanwhile, SSR fingerprinting analysis were set up to indentify the elite germplasm with high yield and good fiber quality, and QTLs mapping were carried out to screen the markers linked or associated with the beneficial genes [21-24]. Those studies presented an overview of the genetic diversity of the cotton germplasm in China, and provided a guideline for breeders to develop new cultivars efficiently.

#### *4.2.1. Evaluation of introgression G.hirsutum lines*

The introgression *G.hirsutum* lines were created by different institutes and collected in the germplasm bank in the past years, which possessed some important beneficial genes from the wild species. Our research showed that there were specific SSR loci among the different exotic *G.hisutum*. Around 45.2% of 155 interspecific lines possessed specific SSR loci [13]. The percentage of the lines with exotic specific SSR loci among the exotic *G.hirsutum* which may be transferred from *G. barbadense* and *G. thurberi* was highest, reached 62.1% and 71.1% respectively. The second was those with the specific SSR loci of *G*. *anomalum* and *G*. *bickii* etc., reached 57.1% and 42.9% respectively (Table 9). Because the numbers of exotic gene transfor‐ mation were different, the specific SSR loci detected were very different. The *G. hirsutum* with exotic *G. barbadense* genes possessed 1-4 specific SSR loci, and those with *G. thurberi* had 1-5 specific loci. Through analysis of the agricultural traits of the introgression lines with specific SSR loci, the correlation between specific SSR loci and the main elite traits of the introgression lines was found. The results showed that the more specific SSR loci of exotic species, the better the fiber length and strength, the more tolerance of drought stress etc., and the elite strains with resistance to Verticillium wilt maybe selected from the germplasm with specific SSR loci (Table 10). This indicated that there were desirable markers and genes related to high fiber quality, tolerance to draught, resistance to Verticillium wilt etc. among these exotic *G. hirsutum* lines. For example, the variety Shenmian 5 in *G.hirsutum* with exotic genes of *G. barbadense* had 5 specific SSR loci. This caused its high fiber quality with length 34.1 mm and strength 24.3 Cn/tex, which indicated the high fiber quality of *G. barbadense* may be transferred into Shenmian 5. Similarly, the character of resistance to Verticillium wilt of *G. hirsutum* variety Shenmian 718 maybe resulted from *G. barbadense* since it had 2 specific SSR loci of *G. barba‐ dense.* The high fiber quality traits of *G. hirsutum* variety Acala SJC-1, FJA and J line with consanguinity of *G. thurberi* maybe also resulted from potential high quality genes of *G. thurberi.* Moreover, the similar molecular and agronomic characters of exotic *G. hirsutum* of *G. barbadense* and *G. thurberi* indicated *G. barbadense* may be originated from *G. thurberi* [13]*.*

330 cultivars have been assigned with the "Decimal string code", and more lines will be done

**Verticillium Wilt tolerance (%)**


Strength (cN/tex)

0.215 0.192 0.438\* 0.319 0.100

Specific SSR loci 0.521\*\* -0.051 -0.100 -0.068 0.026

Specific SSR loci 0.185 0.020 0.085 -0.009 -0.139

**Fusarium Wilt Resistance (%)**

Cotton Germplasm Resources in China http://dx.doi.org/10.5772/58595

> Elongation (%)

**Bollworm resistance (%)** 47

Micronaire

For further finding and using the potential beneficial genes, QTLs mapping and cloning of genes were carried out using the mutant lines that were developed through physical and biologic methods or/and collected from other institutes. A new fiber developmental mutant *G. hirsutum* line GZnn with fuzzless-seed was analyzed by traditional genetics methods and SSR marker analysis. It was found that GZnn possessed a qualitative trait of naked seed that was controlled by one recessive gene. Using SSR marker technology, we located this fuzzlessgene on chromosome 10 and named it n4, which was different from N1 (on chromosome 12), n2 (on chromosome 26) and n3 (found in USA in recent years). This gene was closely linked with SSR marker S1495-120. Some other novel fiber quality QTLs were also detected using genetic population of the interspecific crossed line J02-508 which was segregated for fiber length and fiber strength. The fiber length of line Su7235 was found to be controlled by one major gene and many minor genes. A dwarf gene which was thought to be caused by the absence of gibberellin (GA) and recovered by spraying GA in the seedling stage, was also found and mapped[22]. Other genes about the big boll, high lint percent, brown fiber, resistance to *Verti*cillium wilt, and glandless in the seedling [21-24]. Some important genes controlling the drought and salt tolerance, yield, fiber quality and boll opening stage, were screened with the

The purpose of the collection and evaluation of cotton germplasm is to release and utilization for the improvement of breeding based on the screening of the beneficial genes. The procedures

*4.2.2. Identification of the genes or QTLs in the specific germplasm*

**Drought tolerance (%)**

\* showed significance at 5%, \*\* showed significance at 1%

Length (mm) Uniformity

**Salt tolerance (%)**

(%)

**Table 10.** Correlation coefficient between SSR loci and fiber traits and stress resistant traits

method of association mapping using a germplasm resources.

**5. Germplasm release and utilization**

in the future [25].

Lines with specific loci(%)

Lines with specific loci(%)


**Table 9.** The specific SSR loci of introgression genes among some exotic *G. hirsutum*

For confirming the detail information of each accession, the database of fingerprints was set up to describe and distinguish some lines. "Decimal string code" was given to each individual based on the fingerprints after running gel with SSR markers, and then the information of the code as an identification number was integrated with the existent database. This helped to keep the uniformity of the accessions in the germplasm bank and the releasing lines. Till now


\* showed significance at 5%, \*\* showed significance at 1%

reached 57.1% and 42.9% respectively (Table 9). Because the numbers of exotic gene transfor‐ mation were different, the specific SSR loci detected were very different. The *G. hirsutum* with exotic *G. barbadense* genes possessed 1-4 specific SSR loci, and those with *G. thurberi* had 1-5 specific loci. Through analysis of the agricultural traits of the introgression lines with specific SSR loci, the correlation between specific SSR loci and the main elite traits of the introgression lines was found. The results showed that the more specific SSR loci of exotic species, the better the fiber length and strength, the more tolerance of drought stress etc., and the elite strains with resistance to Verticillium wilt maybe selected from the germplasm with specific SSR loci (Table 10). This indicated that there were desirable markers and genes related to high fiber quality, tolerance to draught, resistance to Verticillium wilt etc. among these exotic *G. hirsutum* lines. For example, the variety Shenmian 5 in *G.hirsutum* with exotic genes of *G. barbadense* had 5 specific SSR loci. This caused its high fiber quality with length 34.1 mm and strength 24.3 Cn/tex, which indicated the high fiber quality of *G. barbadense* may be transferred into Shenmian 5. Similarly, the character of resistance to Verticillium wilt of *G. hirsutum* variety Shenmian 718 maybe resulted from *G. barbadense* since it had 2 specific SSR loci of *G. barba‐ dense.* The high fiber quality traits of *G. hirsutum* variety Acala SJC-1, FJA and J line with consanguinity of *G. thurberi* maybe also resulted from potential high quality genes of *G. thurberi.* Moreover, the similar molecular and agronomic characters of exotic *G. hirsutum* of *G. barbadense* and *G. thurberi* indicated *G. barbadense* may be originated from *G. thurberi* [13]*.*

**Exotic species**

46 World Cotton Germplasm Resources

*G*. *hirsutum race mexicanum*

introgression lines

Total

**No. of accessions** **No. of specific loci**

**Table 9.** The specific SSR loci of introgression genes among some exotic *G. hirsutum*

*G*. *barbadense* 29 8 62.1 2.6 1-4 *G*. *arboreum* 21 2 4.8 2.0 2 *G*. *thurberi* 45 15 71.1 1.7 1-5 *G*. *sturtianum* 12 2 25.0 2.0 2 *G*. *bickii* 7 1 42.9 1.0 1 *G*. *anomalum* 7 3 57.1 1.8 1-3

*G*. *raimondii* 5 2 40.0 1.0 1

For confirming the detail information of each accession, the database of fingerprints was set up to describe and distinguish some lines. "Decimal string code" was given to each individual based on the fingerprints after running gel with SSR markers, and then the information of the code as an identification number was integrated with the existent database. This helped to keep the uniformity of the accessions in the germplasm bank and the releasing lines. Till now

**Percentage of lines with specific loci(%)**

5 1 20.0 1.0 1

155 25 45.2 1.8 1-5

**Average specific loci**

**Range of specific loci**

**Table 10.** Correlation coefficient between SSR loci and fiber traits and stress resistant traits

330 cultivars have been assigned with the "Decimal string code", and more lines will be done in the future [25].

#### *4.2.2. Identification of the genes or QTLs in the specific germplasm*

For further finding and using the potential beneficial genes, QTLs mapping and cloning of genes were carried out using the mutant lines that were developed through physical and biologic methods or/and collected from other institutes. A new fiber developmental mutant *G. hirsutum* line GZnn with fuzzless-seed was analyzed by traditional genetics methods and SSR marker analysis. It was found that GZnn possessed a qualitative trait of naked seed that was controlled by one recessive gene. Using SSR marker technology, we located this fuzzlessgene on chromosome 10 and named it n4, which was different from N1 (on chromosome 12), n2 (on chromosome 26) and n3 (found in USA in recent years). This gene was closely linked with SSR marker S1495-120. Some other novel fiber quality QTLs were also detected using genetic population of the interspecific crossed line J02-508 which was segregated for fiber length and fiber strength. The fiber length of line Su7235 was found to be controlled by one major gene and many minor genes. A dwarf gene which was thought to be caused by the absence of gibberellin (GA) and recovered by spraying GA in the seedling stage, was also found and mapped[22]. Other genes about the big boll, high lint percent, brown fiber, resistance to *Verti*cillium wilt, and glandless in the seedling [21-24]. Some important genes controlling the drought and salt tolerance, yield, fiber quality and boll opening stage, were screened with the method of association mapping using a germplasm resources.

#### **5. Germplasm release and utilization**

The purpose of the collection and evaluation of cotton germplasm is to release and utilization for the improvement of breeding based on the screening of the beneficial genes. The procedures were made to fit for the normal release and utilization for the research. Since recorded files, a large number accessions have been released and helped to promote the yield, quality and resistance in the development of cotton breeding in China.

**5.2. Germplasm utilization**

*5.2.1. Utilization of basic germplasm*

Huai 910 and Chuanmian 243.

All these accessions shared with the researchers have helped to develop some import cultivars. Some basic accessions have made important contribution to the improvement of cotton breeding, which could be summarized in three stages in the development of cotton germplasm. In the first stage, the germplasm imported from USA, such as TX 53, Stone‐ ville 4, Stoneville 4B, Stoneville 2B, Coker 100, D.P.L 14, D.P.L 15, and Empire, were the main basic lines to promote the breeding level in China [15-17,26-27]. More than one thousand new lines were bred based on these basic lines. Guannong No.1 is the typical cultivar that was bred using the basic line King, and also was used as new basic line for the new cultivar breeding. In the second stage, the cultivars and germplasm selected by the Chinese breeders, such as Yishuhong, Jingmian 1, Ganmian 1, Xuzhou 209, Xuzhou 1818, Dongting 1, Zhongmiansuo 2, Zhongmiansuo 3, Zhongmiansuo 4, Zhongmiansuo 7, Jiangsumian 1, Jiangsumian 2 and Jiangsumian 3, became the new basic lines, which were commercialized and grown in larger areas. Some lines with resistant genes also were used as the basic lines, such as Liaomian 1, Liaomian 3, Shanmian 3, Shanmian 4, Shanmian 5, 52-128, 57-681, and D.P.L 16 from USA, as well as 24-21 and KK1543 from the Soviet Union. New cultivars that were created using these basic lines, replaced the varieties imported from foreign countries in commercialization. In the third stage, the basic lines with the resistant to the disease, early maturity, high lint percentage and male sterility, were used that resulted in the resistant lines 86-1 and Zhongmiansuo 12, early mature lines Heishan mian 1 and Zhongmiansuo 10, high lint percent and heterotic line Jimian 1, and male sterile line Dong A. The glandless lines such as Lambright GL-5 and Mcnair 210 introduced from USA, helped to create new type of cultivars in China. The basic germplasm lines of *G*. *barbadense* were fewer than the *G.hirsutum*. Only seven lines were most frequently-used in the breeding of *G*. *barbadense*, such as C6022, 8763 I and 9122 i from the Soviet Union,

Cotton Germplasm Resources in China http://dx.doi.org/10.5772/58595 49

Menoufi from Egypt, Xinhaimian, Junhai and Changrong 3 from China.

Some important cultivars have been bred after the basic lines were introduced to the breeders in China. Zhongmiansuo 12 was from the crossing of Uganda 3 and Xingtai 6871, which was the first high yielding cultivars that was resistant to Fusarium wilt and was ever grown in nearly 50% cotton area in China during 1992-1996. Lines 52-128, 57-681-52-128 and 57-681 were selected from D.P.L 15 and Texas 531 bred by Sichuan cotton institute, and became the important lines that provided the gene source of resistance to Fusarium wilt. In China, Liaomian 1 and Liaomian 2 were the pioneer varieties with Verticillium wilt. Resistance. Two varieties of Zhong 8004 and Zhong 8010 resistant to Verticillium wilt were produced. Lines Shan 1155 and Zhong 3474 with resistance to Fusarium and Verticillium wilt provided resistant genes for seven varieties. In the 1990s, almost 111 varieties had the resistant genes of Verticil‐ lium wilt from the lines 86-6, Chuan 737, Chuan 2802, Shan 2234, Shan 6192, Chuanmian 239,

#### **5.1. Germplasm release**

Formal germplasm seed requests within China are needed to provide to the Cotton Research Institute of the Chinese Academy of Agricultural Sciences. A Material Transfer Agree‐ ment is required to distribute seeds of requested germplasm. Seed requests from outside of China require a complex procedure for approval. Cotton characterization and evalua‐ tion database is linked with Chinese Germplasm Resource System (CGRIS: http:// icgr.caas.net.cn). More than 11241 accessions cotton germplasm have been released for the customers in China and a few foreign counties till 2006 (Table 11). Since 2007, different accessions have been grown in the field every year and have been arranged for demonstra‐ tion in the boll opening stage for the selection and utilization of the researchers. Through this way, the researchers could visually recognize and know the lines in the germplasm bank, and decide what they want to choose for the breeding and other research. There‐ fore, the numbers of accessions released in recent years which were selected by the researchers themselves increased dramatically every year.


**Table 11.** The accessions released in the different areas during the past years

#### **5.2. Germplasm utilization**

were made to fit for the normal release and utilization for the research. Since recorded files, a large number accessions have been released and helped to promote the yield, quality and

Formal germplasm seed requests within China are needed to provide to the Cotton Research Institute of the Chinese Academy of Agricultural Sciences. A Material Transfer Agree‐ ment is required to distribute seeds of requested germplasm. Seed requests from outside of China require a complex procedure for approval. Cotton characterization and evalua‐ tion database is linked with Chinese Germplasm Resource System (CGRIS: http:// icgr.caas.net.cn). More than 11241 accessions cotton germplasm have been released for the customers in China and a few foreign counties till 2006 (Table 11). Since 2007, different accessions have been grown in the field every year and have been arranged for demonstra‐ tion in the boll opening stage for the selection and utilization of the researchers. Through this way, the researchers could visually recognize and know the lines in the germplasm bank, and decide what they want to choose for the breeding and other research. There‐ fore, the numbers of accessions released in recent years which were selected by the

> **Province/ Country**

**Accession number**

**Number of organizations**

resistance in the development of cotton breeding in China.

researchers themselves increased dramatically every year.

**Number of organizations**

Hubei 542 15 USA 204 Jiangxi 422 9 Brazil 52 Hunan 356 11 Russia 50 Sichuan 330 5 Vietnam 18 Shanxi 314 8 Australia 12 Zhejiang 257 4 Ethiopia 10 Liaoning 256 6 Pakistan 15 Anhui 122 16 Marcello 6 Shanxi 101 5 Kazakhstan 3 Gansu 52 5 India 1 Hainan 28 4 Others 190 Chongqin 25 2 Total 11241

**Table 11.** The accessions released in the different areas during the past years

Henan 2525 27 Shanghai 20 4 Xinjiang 1803 21 Tianjin 11 3 Jiangsu 981 22 Jilin 4 1 Hebei 863 24 Xizang 3 1 Beijing 862 15 Guangdong 1 1 Shandong 573 18 Yunnan 1 1

**5.1. Germplasm release**

48 World Cotton Germplasm Resources

**Province/ Country**

**Accession number**

#### *5.2.1. Utilization of basic germplasm*

All these accessions shared with the researchers have helped to develop some import cultivars. Some basic accessions have made important contribution to the improvement of cotton breeding, which could be summarized in three stages in the development of cotton germplasm. In the first stage, the germplasm imported from USA, such as TX 53, Stone‐ ville 4, Stoneville 4B, Stoneville 2B, Coker 100, D.P.L 14, D.P.L 15, and Empire, were the main basic lines to promote the breeding level in China [15-17,26-27]. More than one thousand new lines were bred based on these basic lines. Guannong No.1 is the typical cultivar that was bred using the basic line King, and also was used as new basic line for the new cultivar breeding. In the second stage, the cultivars and germplasm selected by the Chinese breeders, such as Yishuhong, Jingmian 1, Ganmian 1, Xuzhou 209, Xuzhou 1818, Dongting 1, Zhongmiansuo 2, Zhongmiansuo 3, Zhongmiansuo 4, Zhongmiansuo 7, Jiangsumian 1, Jiangsumian 2 and Jiangsumian 3, became the new basic lines, which were commercialized and grown in larger areas. Some lines with resistant genes also were used as the basic lines, such as Liaomian 1, Liaomian 3, Shanmian 3, Shanmian 4, Shanmian 5, 52-128, 57-681, and D.P.L 16 from USA, as well as 24-21 and KK1543 from the Soviet Union. New cultivars that were created using these basic lines, replaced the varieties imported from foreign countries in commercialization. In the third stage, the basic lines with the resistant to the disease, early maturity, high lint percentage and male sterility, were used that resulted in the resistant lines 86-1 and Zhongmiansuo 12, early mature lines Heishan mian 1 and Zhongmiansuo 10, high lint percent and heterotic line Jimian 1, and male sterile line Dong A. The glandless lines such as Lambright GL-5 and Mcnair 210 introduced from USA, helped to create new type of cultivars in China. The basic germplasm lines of *G*. *barbadense* were fewer than the *G.hirsutum*. Only seven lines were most frequently-used in the breeding of *G*. *barbadense*, such as C6022, 8763 I and 9122 i from the Soviet Union, Menoufi from Egypt, Xinhaimian, Junhai and Changrong 3 from China.

Some important cultivars have been bred after the basic lines were introduced to the breeders in China. Zhongmiansuo 12 was from the crossing of Uganda 3 and Xingtai 6871, which was the first high yielding cultivars that was resistant to Fusarium wilt and was ever grown in nearly 50% cotton area in China during 1992-1996. Lines 52-128, 57-681-52-128 and 57-681 were selected from D.P.L 15 and Texas 531 bred by Sichuan cotton institute, and became the important lines that provided the gene source of resistance to Fusarium wilt. In China, Liaomian 1 and Liaomian 2 were the pioneer varieties with Verticillium wilt. Resistance. Two varieties of Zhong 8004 and Zhong 8010 resistant to Verticillium wilt were produced. Lines Shan 1155 and Zhong 3474 with resistance to Fusarium and Verticillium wilt provided resistant genes for seven varieties. In the 1990s, almost 111 varieties had the resistant genes of Verticil‐ lium wilt from the lines 86-6, Chuan 737, Chuan 2802, Shan 2234, Shan 6192, Chuanmian 239, Huai 910 and Chuanmian 243.

#### *5.2.2. Utilization of germplasm with beneficial traits and genes*

Germplasm with beneficial agronomic traits were utilized in the past year for purpose of the good quality, high yield, and multiple resistance in the cotton breeding. Nine PD lines with good fiber quality, such as PD 4548 and PD 2164, have been the origin of eleven new cultivars including Emian 21, Lumian 14, and Wanmian 10. The new varieties Xinluzao 6, Xinluzao9 and Xiangzamian 9 came from the contribution of line Bellsiro with good fiber quality [24, 26]. Lumian 9 had the pedigree of Acala. In the field of resistant research, Simian 3 that was important and popular in commercialization, was devoloped by importing the Fusarium wilt resistant genes from the line Yankang 76-75. Also Liaomian 5 was the origin of Verticillium wilt resistant gene and contributed to the breeding of six new varieties including Zhongmian‐ suo 20 and Lumian 7. Chuanmian 109 that possessed the gene of resistance to aphid, helped to create the cultivars Chuanmian 109-1 and Jingmian 1 with the resistant to the aphid. In recent years, more and more varieties were bred through composing different kinds of powerful genes from the special germplasm lines. For example, Chuang 075 was from the lines Zhong‐ miansuo 12, Yumian 19 and Zhnongmiansuo 21 with Verticillium wilt resistance. Zhongmian‐ suo 44 developed from the line Zhong 2369 with Fusarium wilt resitance, the line Tamcot CD3Hal with drought tolerance and the line Zhongmiansuo 17 with high yield. Zhongmiansuo 49 derived from the early mature line Jing 444 and the line Zhongmiansuo 35 with salt tolerance and high yield. Zhongmiansuo 48 with good fiber quality, big boll and high yield, was from the big boll line Su9108.

Zhong 163, Zhongmiansuo 51, Xincai 3, Xiangcaimian and Zhongmiansuo 81, and green fiber

Cotton Germplasm Resources in China http://dx.doi.org/10.5772/58595 51

Wild species possess many beneficial genes that have been swept in the domestication of cotton. Researchers in China started to study and untilize the wild species very early. The most famous variety was Shiyuan 321 from the hybridization of *G.thurberi*, *G.barbadense* and *G.hirsutum* by the institute of Genetic and Developmental Biology, Chinese Academy of Sciences(CAS) and Shijiazhuang Academy of Agricultural Sciences. Jinmian 2 was the second commercialized variety from the *G.thurberi*, *G.anomalum* and *G.hirsutum*, which possessed the traits such as resistance to Verticillium wilt, Fusarium wilt and bollworm, early maturity, high yield, and good fiber quality. Qinyuan 4 was commercialized with the multiple cross of *G. sturtianum* and two *G. hirsutum* (Zhongmiansuo 12 and Acala SJ-1), which is resistant to Fusarium wilt and tolerant to drought. Other lines were also created by different institutes in China, such as the line HST2 from the hybridization of *G. sturtianum* and *G. hirsutum* with the resistant to Verticillium wilt, Fusarium wilt, pinkworm and drought, line HAS from *G. sturtianum*, *G. hirsutum*, and *G. arboretum*, line 92-26-2 from *G. hirsutum* and *G. anomalum*, line 92-48-1 from *G. thurberi*, *G. barbadense* and *G. hirsutum*, line BZ201 from *G. thurberi*, *G. hirsutum* and *G. hirsutum* landrace, line BZ401 from *G. hirsu‐ tum* and *G. anomalum*, line JSCG7235 from *G. hirsutum* and *G. anomalum* with long fiber

In future, further research need to be carried out based on the current result of cotton germplasm in China for providing the development of cotton breeding. First, expeditions to the origin sites should be emphasized in the following stage of collection, especially expeditions in the origin sites of wild species and landraces. Exchange with the countries that had special and more diversity germplasm should be continued for enriching the diversity of cotton in China. Second, the method of evaluation should be renewed, and new methods such as the association analysis with new generation sequencing technology should be used in the procedure of screening of important germplasm carrying beneficial genes. The genes with drought and salt tolerance that are required urgently in North-west China cotton production suffering from water deficiency and salinity, should be identified accurately with high throughput methods. Third, new lines should be created through comprehensive techniques using the current germplasm resources. One novel line could significantly change the reputation of cotton breeding. Forth, high efficient database should be set up for recording all the information of the cotton germplasm, including the agronom‐

cultivars Lv 4560 and Zhongmiansuo 82.

*5.2.4. Utilization of wild species*

length and strong fiber strength.

ic traits and molecular data.

**6. Future perspectives and suggestions**

#### *5.2.3. Utilization of special germplasm with specific traits*

Some special cotton germplasm showed different characteristics to the standard lines in the traits of leaf shape, flower color, bract shape, absence of nectarines, fiber color etc. The first special trait used in the breeding was okra leaf, which reduced the vegetative growth for keeping well light ventilation, and was resistant to *Syllepte derogata Fabricius*. The varieties with okra leaf were very popular in the cotton growing areas. The oldest cultivar with okra leaf used in china was Okra leaf TX 8207 selected from normal leaf TX 8207, which was the important variety before 1958. The second famous cultivar with okra leaf was Biaoza A1, a hybrid commercialized in Xinjiang. The virescent trait was also used in the breeding for indentifying the false hybrid in the seedling stage. Frego-bract providing the resistance to the bollworm, pink bollworm and boll weevil through the narrow and twisted bract, helped to create the new cultivar Zhongmiansuo 33. The absence of nectary in the leaf and bract could reduce the attraction to insects, and was used in the breeding of morphological resistance to insects such as Zhong 5909 and Ji U82-3[28]. The glandless trait attracted the researchers when it was found to be lower poisonous to the health of people for the oil and protein consumption. Many varieties with glandless such as Zhong 13 and Yumian 6 have been selected in the past years and were grown in some special areas. The cultivars with brown and green fiber were also created. The first two colored cotton cultivars in China were Zhongxu 1 and Lvxu 1, which genes were transferred from the wild cotton. In recent years, more and more colored cotton cultivars were bred by different researchers, such as the brown fiber cultivars Zhong 263, Zhong 163, Zhongmiansuo 51, Xincai 3, Xiangcaimian and Zhongmiansuo 81, and green fiber cultivars Lv 4560 and Zhongmiansuo 82.

#### *5.2.4. Utilization of wild species*

*5.2.2. Utilization of germplasm with beneficial traits and genes*

the big boll line Su9108.

50 World Cotton Germplasm Resources

*5.2.3. Utilization of special germplasm with specific traits*

Germplasm with beneficial agronomic traits were utilized in the past year for purpose of the good quality, high yield, and multiple resistance in the cotton breeding. Nine PD lines with good fiber quality, such as PD 4548 and PD 2164, have been the origin of eleven new cultivars including Emian 21, Lumian 14, and Wanmian 10. The new varieties Xinluzao 6, Xinluzao9 and Xiangzamian 9 came from the contribution of line Bellsiro with good fiber quality [24, 26]. Lumian 9 had the pedigree of Acala. In the field of resistant research, Simian 3 that was important and popular in commercialization, was devoloped by importing the Fusarium wilt resistant genes from the line Yankang 76-75. Also Liaomian 5 was the origin of Verticillium wilt resistant gene and contributed to the breeding of six new varieties including Zhongmian‐ suo 20 and Lumian 7. Chuanmian 109 that possessed the gene of resistance to aphid, helped to create the cultivars Chuanmian 109-1 and Jingmian 1 with the resistant to the aphid. In recent years, more and more varieties were bred through composing different kinds of powerful genes from the special germplasm lines. For example, Chuang 075 was from the lines Zhong‐ miansuo 12, Yumian 19 and Zhnongmiansuo 21 with Verticillium wilt resistance. Zhongmian‐ suo 44 developed from the line Zhong 2369 with Fusarium wilt resitance, the line Tamcot CD3Hal with drought tolerance and the line Zhongmiansuo 17 with high yield. Zhongmiansuo 49 derived from the early mature line Jing 444 and the line Zhongmiansuo 35 with salt tolerance and high yield. Zhongmiansuo 48 with good fiber quality, big boll and high yield, was from

Some special cotton germplasm showed different characteristics to the standard lines in the traits of leaf shape, flower color, bract shape, absence of nectarines, fiber color etc. The first special trait used in the breeding was okra leaf, which reduced the vegetative growth for keeping well light ventilation, and was resistant to *Syllepte derogata Fabricius*. The varieties with okra leaf were very popular in the cotton growing areas. The oldest cultivar with okra leaf used in china was Okra leaf TX 8207 selected from normal leaf TX 8207, which was the important variety before 1958. The second famous cultivar with okra leaf was Biaoza A1, a hybrid commercialized in Xinjiang. The virescent trait was also used in the breeding for indentifying the false hybrid in the seedling stage. Frego-bract providing the resistance to the bollworm, pink bollworm and boll weevil through the narrow and twisted bract, helped to create the new cultivar Zhongmiansuo 33. The absence of nectary in the leaf and bract could reduce the attraction to insects, and was used in the breeding of morphological resistance to insects such as Zhong 5909 and Ji U82-3[28]. The glandless trait attracted the researchers when it was found to be lower poisonous to the health of people for the oil and protein consumption. Many varieties with glandless such as Zhong 13 and Yumian 6 have been selected in the past years and were grown in some special areas. The cultivars with brown and green fiber were also created. The first two colored cotton cultivars in China were Zhongxu 1 and Lvxu 1, which genes were transferred from the wild cotton. In recent years, more and more colored cotton cultivars were bred by different researchers, such as the brown fiber cultivars Zhong 263,

Wild species possess many beneficial genes that have been swept in the domestication of cotton. Researchers in China started to study and untilize the wild species very early. The most famous variety was Shiyuan 321 from the hybridization of *G.thurberi*, *G.barbadense* and *G.hirsutum* by the institute of Genetic and Developmental Biology, Chinese Academy of Sciences(CAS) and Shijiazhuang Academy of Agricultural Sciences. Jinmian 2 was the second commercialized variety from the *G.thurberi*, *G.anomalum* and *G.hirsutum*, which possessed the traits such as resistance to Verticillium wilt, Fusarium wilt and bollworm, early maturity, high yield, and good fiber quality. Qinyuan 4 was commercialized with the multiple cross of *G. sturtianum* and two *G. hirsutum* (Zhongmiansuo 12 and Acala SJ-1), which is resistant to Fusarium wilt and tolerant to drought. Other lines were also created by different institutes in China, such as the line HST2 from the hybridization of *G. sturtianum* and *G. hirsutum* with the resistant to Verticillium wilt, Fusarium wilt, pinkworm and drought, line HAS from *G. sturtianum*, *G. hirsutum*, and *G. arboretum*, line 92-26-2 from *G. hirsutum* and *G. anomalum*, line 92-48-1 from *G. thurberi*, *G. barbadense* and *G. hirsutum*, line BZ201 from *G. thurberi*, *G. hirsutum* and *G. hirsutum* landrace, line BZ401 from *G. hirsu‐ tum* and *G. anomalum*, line JSCG7235 from *G. hirsutum* and *G. anomalum* with long fiber length and strong fiber strength.

## **6. Future perspectives and suggestions**

In future, further research need to be carried out based on the current result of cotton germplasm in China for providing the development of cotton breeding. First, expeditions to the origin sites should be emphasized in the following stage of collection, especially expeditions in the origin sites of wild species and landraces. Exchange with the countries that had special and more diversity germplasm should be continued for enriching the diversity of cotton in China. Second, the method of evaluation should be renewed, and new methods such as the association analysis with new generation sequencing technology should be used in the procedure of screening of important germplasm carrying beneficial genes. The genes with drought and salt tolerance that are required urgently in North-west China cotton production suffering from water deficiency and salinity, should be identified accurately with high throughput methods. Third, new lines should be created through comprehensive techniques using the current germplasm resources. One novel line could significantly change the reputation of cotton breeding. Forth, high efficient database should be set up for recording all the information of the cotton germplasm, including the agronom‐ ic traits and molecular data.

### **Author details**

Yinghua Jia\* , Junling Sun and Xiongming Du

State Key Laboratory of Cotton Biology/ Institute of Cotton Research of Chinese Academy of Agricultural Sciences (ICR, CAAS),Anyang, Henan, China

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