**Abbreviations**

the introduction of Bt cotton varieties. Thus a number of varieties, not properly bred, have been released in a very short time period, which accelerated the varietal replacement rate. All

The low germination of most cotton varieties, particularly in the post-Bt cotton era, is another area of concern for growers, regulators and policy makers. The germination rate can be improved by avoiding the use of early opened bolls and seed cotton exposed to excessive rain. Similarly, proper control of the moisture content of seed and proper storage conditions can

For Bt-cotton, the mixing of various types, mixing of non-Bt seed with the Bt variety, and the expression level of Bt genes in different varieties are the major issues which need to be addressed. The marketing of earlier released cotton varieties/strains under different names in the market is another area of concern which has affected the reputation of the cotton seed industry. In this regard, FSC&RD must ensure the distinctness of each of the newly developed varieties and or advanced strains with authenticated pedigree that may be verified by the use

The deterioration of a cotton variety leads to reduced seed cotton yield. One of the major causes of this is a high natural cross pollination rate, largely by honeybees, in the Bt cotton era due to a reduction in the number of insecticide applications. Most of the breeding centers are located near urban areas where farmers also grow fodder and vegetable crops which provide alter‐ native hosts for pollinators. Under such circumstances, selfing of plants is recommended on the representative plants of the variety/genotype which would help in maintaining the typical

Cultivation of hybrid cotton showing heterosis for seed cotton yield has remains a major challenge in Pakistan. Conventional methods of hybrid seed production (manual emasculation of floral buds), low seed setting, high cost of production resulting in high cost of seed and purity of seed are the major issues for cultivating hybrid cotton on significant area. Though limited efforts by the private sector (Mr Siddique Akbar Bukhari spent ~30 years; Guard and Four Brothers Seed Corporation Pakistan.) and public sector organizations (CCRI Multan, CRI Faisalabad, NARC Islamabad etc.) have been made, but are unable to provide seed which can cover even one percent of the total cotton growing area of Pakistan. In this regard, the development of male sterile and restorer lines, deployment of new genomic tools (such as RNAi technology), and also chemical emasculation, are the most plausible approaches for

Cultivated cotton has a narrow genetic base which limits future breeding progress. The selection and crossing of well adapted cotton varieties for developing new varieties are the main causes of the narrow genetic base. This problem can be partly overcome by involving genetically diverse parent genotypes in the genealogy of a new variety. For example, genes conferring resistance to abiotic stresses, particularly drought, and biotic stresses, particularly resistance to CLCuD, can be introgressed into *G. hirsutum* L. from *G. arboreum* L. and or *G. herbaceum*L. Tissue culture tools may help in overcoming the phyletic barriers. Preliminary steps have already been taken for introgressing useful genes into the cultivated cotton varieties

overcoming the issue surrounding the widespread adoption of hybrid seed.

these issues hampered the process of production of certified seed.

also ensure the good health of cotton seed.

of DNA fingerprinting.

160 World Cotton Germplasm Resources

features of the variety.



breeding cotton varieties and unraveling the genetics of various traits of cotton using conven‐

, Abid Mahmood2

1 Plant Genomics & Molecular Breeding (PGMB) Lab, National Institute for Biotechnology

3 Textile Industry Division, and Pakistan Central Cotton Committee (PCCC), Islamabad,

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[2] Fryxell PA. The natural history of the cotton tribes. Texas A and M University Press

[3] Fryxell PA. A revised taxonomic interpretation of *Gossypium L. (Malvacea*). Rheedea.

[4] Hutchinson JB. The application of genetics to cotton improvement. Empire Cotton

[5] Hutchinson JB, Silow RA, Stephens SG. The evolution of *Gossypium* and the differen‐

[6] Gerstel DU. Chromosome translocations in interspecific hybrids of the genus *Gos‐*

[7] Gerstel DU, Sarvella PA. Additional observations on chromosomal translocations in

[8] Phillips LL. The cytogenetics of speciation in Asiatic cotton. Genetics 1961; 46 77–83.

tiation of the cultivated cottons. Oxford University Press, London 1947.

Growing Corporation. University Press, Cambridge, 1959.

, Khalid Abdullah3

and

Cotton Germplasm of Pakistan http://dx.doi.org/10.5772/58620 163

tional approaches over the last six decades.

, Zainab Rahmat1

& Genetic Engineering (NIBGE), Jhang Road Faisalabad, Pakistan

4 Permanent Mission of Pakistan to the IAEA, Vienna, Austria

chaeological Science 2002; 29(12) 93–1401.

College Station. USA; 1979. XVII p 245.

*sypium*. Evolution 1953; 7 234–244.

cotton hybrids. Evolution 1956; 10 408–414.

1992; 2(2) 108–165.

2 Ayub Agricultural Research Institute (AARI), Faisalabad, Pakistan

**Author details**

Yusuf Zafar4

Pakistan

**References**

Mehboob ur-Rahman1
