**Cotton Germplasm of Pakistan**

Mehboob ur-Rahman, Zainab Rahmat, Abid Mahmood, Khalid Abdullah and Yusuf Zafar

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/58620

## **1. Introduction**

[29] Punitha D, Raveendran TS. DNA fingerprinting studies in coloured cotton geno‐

types. Plant Breeding 2004; 123: 101-103.

136 World Cotton Germplasm Resources

The economy of Pakistan relies heavily on cotton, which contributes ~60% of total foreign exchange earnings (US\$ 15 billion in 2012/13). Cotton is grown on about three million hectares annually with average lint production of 670 kg ha-1. Historically the cultivation of cotton can be traced back to 6000 BC with *Gossypium arboreum* L. identified in the ancient remains of Monjadharo (Sindh) [1]. The indigenous cultivated cotton is locally known as Desi cotton, which carries the A-genome [2-3]. Following the industrial revolution in the textile sector, the tetraploid *Gossypium hirsutum* L. gradually replaced *G. arboreum* L., because it generally produces a higher quality lint and has a higher seed cotton yield (SCY) in the Indo-Pak region. These American types originated from New Orleans and Georgia were first introduced in 1818 [4]. This material was primarily a mixture and did not attract the interest of farmers in its initial years of cultivation because of high susceptibility to sucking insects, particularly jassids (*Amarasca devastans* Dist.). Organized selection procedures were adopted to select genotypes suited to the local conditions that laid a concrete foundation for breeding material on the subcontinent.

The four cultivated cotton species can be easily identified based on variations in plant growth habit, leaf shape, boll, flower, seed and fiber features [2-3, 5]. Substantial differences between *G. herbaceum* L. and *G. arboreum* L. have been found based on genetic, cytogenetic, isozyme and genomic data. The two species are easily crossable to produce F1 hybrids that are fertile and vigorous with high pollen fertility (60%). However, in common with other crops species, genetic incompatibility depresses seed viability and affects plant morphology in segregating generations. Consequently resulting plants resemble one of the parents. One reciprocal chromosomal translocation differentiates the two species [6-8]. Recently eight and 13 unique polymorphic loci of *G. arboreum* L. and *G. herbaceum* L., respectively, have been reported [9].

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DNA markers, such as restriction fragment length polymorphism (RFLP), random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP) and simple sequence repeat/microsatellite (SSR), have also been utilized to provide genomic polymorphic markers which can distinguish most cotton species [10-12].

resulted in narrow genetic base of the cultivars/genotypes developed by selecting from a single population. The study conducted on 30 *G. arboreum* L. genotypes, largely originated in Pakistan demonstrated a narrow genetic base [20-21]. In this study, two major cultivars Ravi and FDH-228, showed 90.1% genetic similarity in RAPD assay [20]. It has been demonstrated that the narrow genetic base, like many other cultivated crop species, can impede the future

Cotton Germplasm of Pakistan http://dx.doi.org/10.5772/58620 139

The initial breeding program for developing high yielding varieties involved selection from the available mixture of various *G. arboreum* L. types. Two cotton varieties Z. Mollisoni and 278-Mollisoni were developed through selections which gradually replaced the old types. The first cotton research station was established at Lyallpur (currently Faisalabad, located in Pakistan), and breeding for developing improved types by making selections from the available cotton varieties/genotypes was initiated by Mr. T. Trought and later continued by Mr. M. Afzal. In 1927, 15-Mollisone cotton line was tested in national trials which was approved for cultivation in 1930 on account of its high ginning outturn (GOT) 35% compared to 34% for "Mollisoni" and 33% for the mixture cultivated in the farmer's field. Another variety 39- Mollisoni exhibited 36-37% GOT versus 35% for 15-Mollisoni. The highest wrap count 8'S was

spun by the lint produced of the varieties 39-Mollisoni and 15-Mollisoni (Table 1).

In 1935, efforts for development of elite desi cotton types from the historically cultivated mixture of *G. arboreum* L. biotypes known as "Multani Kapas" for the South West of Punjab— Multan region [22], were initiated through selection. A high yielding variety 119-Sanguineum (119-S), developed in 1936 and approved for cultivation in 1941, demonstrated relatively higher GOT 36.4% compared to 34% of the mixture of various biotypes. Another candidate line 231-R, bred at Hansi Research Center under the administrative umbrella of Cotton Section Lyallpur, was tested in various trials. Testing continued after 1947, and 231-R was ultimately

The Cotton Research Institute (CRI), Faisalabad carried out breeding for desi cotton at two research stations. Haroonabad was a drought prone area and the major cash crop of this region was desi cotton (60,712 hectares in the early 1950s). Breeding efforts at the Cotton Research Station Haroonabad started in 1952. Four candidate lines were identified based on leaf morphology (broad or narrow) and flower color (white or yellow). One of the varieties, 73/3, showed a higher GOT (42%) with staple length of 13.7 mm compared to a 37-38% GOT and 16-19 mm staple length of the already cultivated mixture. However, the newly developed varieties could match the yield of the already cultivated mixture of desi cotton. Thus breeding

The hybridization work at the Cotton Research Station, Faisalabad, started in 1930 to improve fiber quality, especially the staple length, of the existing cultivated desi cotton varieties. Wide crosses were made between 39-Mollisoni and the Chinese variety Million Dollar, resulting in improved strains (called Jubilee strains-D.C.17, D.C.26, D.C.37, D.C.40 and D.C.41). They had improved staple length and a higher GOT but with a lower yield potential over the control variety Mollisoni. Among these, D.C.40 showed improved quality features (staple length=20.3

breeding progress [13].

**2.2. Breeding history of desi cotton cultivars in Pakistan**

approved for general cultivation in 1959 [23].

efforts, through selection, were abandoned.

Breeders, geneticists, cytogeneticists and biotechnologists have made substantial contribution for the improvement of cotton germplasm conferring resistance and/or tolerance to various stresses including biotic and abiotic, through bridging conventional and genomic tools [13]. Breeding for earliness and photoperiod insensitivity has also been accomplished by intro‐ gressing genes from the alien cotton species, which paved the way for not only sustaining cotton production but also provided enough window for cultivating another crop like wheat on the same land, thus laying down a foundation for addressing food security concerns in Pakistan.
