Genetic Improvement of New Mexico Acala Cotton Germplasm and Their Genetic Diversity

Abstract

ods. In Tennessee, genetic gain in yield improvement was 7.2 kg ha Ϫ1 yr Ϫ1 as calculated by Culp and GreenThe New Mexico cotton breeding program was established in 1926 (1992) on the basis of the data from Hoskinson and Stewand has been led by five generations of breeders and geneticists. The program has released more than 30 Acala 1517 cotton (Gossypium hir- art (1977). In South Carolina, genetic gain in yield imsutum L.) cultivars and numerous germplasm lines known for high fiber provements was 10.5 kg ha Ϫ1 yr Ϫ1 for commercial cultiquality and Verticillium wilt (caused by Verticillium dahliae Kleb.) tolvars and 15.1 kg ha Ϫ1 yr Ϫ1 for Pee Dee germplasm lines erance that have made substantial contributions to cotton breeding in from 1945 to 1978 (Culp and Green, 1992). For Califorthe USA. The present project was initiated in 2003 to evaluate the genia Acala cotton, Bassett and Hyer (1985) estimated netic improvement of Acala 1517 cultivars and lines released over the the genetic gain of 8.0 kg ha Ϫ1 yr Ϫ1 from 1930 to 1980. past 75 yr in yield, boll size, seed index, lint percentage, fiber length, fiber In the Mississippi Delta, genetic gain in lint yield imstrength, and micronaire. Their genetic divergence was also estimated by provements averaged 9.1 to 10.2 kg ha Ϫ1 yr Ϫ1 from 1922 simple sequence repeat (SSR) markers. On the basis of the data availto 1966 and 8.5 to 9.5 kg ha Ϫ1 yr Ϫ1 from 1910 to 1978; able from annual yield trials, lint yield and lint percentage in Acala however, the rate was shown to be decreased when a 1517 cotton have steadily increased since the 1930s, while boll size and seed index have gradually decreased since the 1960s. Fiber strength has longer period was included in the analysis: 5.4 kg ha Ϫ1 been enhanced since the 1960s, which has been accompanied by steady yr Ϫ1 from 1938 to 1993 and 4.7 kg ha Ϫ1 yr Ϫ1 from 1938 to increase in micronaire. However, fiber length in Acala 1517 cultivars 1999. The genetic gain was further decreased to 3.5 kg tended to shorten from 31.0 to 30.0 mm from 1960 to 1990, whereas ha Ϫ1 yr Ϫ1 from 1983 to 1999 (Bridge et al., 1971; Bridge newly released Acala 1517 cultivars (Acala 1517-95, 1517-99, 1517-02, and Meredith, 1983; Meredith 2000). The slowed ge-1517-03, and 1517-04) have fiber greater than 30.5 mm. Genetic distance netic gain in cotton yield improvement was thought to among Acala 1517 genotypes ranged from 0.06 to 0.38 with an average be due to narrow genetic base of upland cotton and of 0.18 on the basis of 189 SSR marker alleles, indicating a substantial repeated use of a few upland cotton germplasm in major genetic diversity among Acala 1517 cotton germplasm. Divergent germcommercial cotton breeding programs (May et al., 1995; plasm introgression in the program has contributed to genetic diver-Meredith, 2000; Lewis, 2001). sity of Acala cotton germplasm and continuous genetic gain in Acala cotton cultivar improvement.

Proteomic and Virus-induced Gene Silencing (VIGS) Analyses Reveal That Gossypol, Brassinosteroids, and Jasmonic acid Contribute to the Resistance of Cotton to Verticillium dahliae

“…The cotton seedlings were removed from the soil and dip-infected with the liquid containing V. dahliae spores. The seedlings were incubated at 25°C under a 14 h/10 h light/dark photoperiod, and the roots were harvested at 1,6,12,24,48, and 72 h after inoculation. Seedlings treated with sterile distilled water in the same manner were used as a Mock treatment.…”

Assessment of Genetic Improvement in Grain Yield Potential and Related Traits of Kabuli Type Chickpea (Cicer arietinum L.) Varieties in Ethiopia (1974-2009)

“…Progress made in genetic yield potential and associated traits produced by different crops improvement program and the benefits obtained have been evaluated and documented in different countries concluded that genetic improvement in those crops have produced modern cultivars with improved yield potential [11][12][13][14][15][16][17]. This is also true for some crops in Ethiopia [18][19][20][21][22][23][24].…”

Broadening the Genetic Base of Upland Cotton in U.S. Cultivars – Genetic Variation for Lint Yield and Fiber Quality in Germplasm Resources

“…Similar to Pee Dee germplasm, Acala germplasm also has genetic background of triple hybrids (G. arboretum L. × G. thurberi Todaro × G. hirsutum L.) (Smith et al, 1999). These germplasm populations are characterized by high fiber quality and Verticillium wilt tolerance and perform well in semiarid and hot regions in the southwestern of U.S. according to Zhang et al (2005a). Genetic diversity was maintained within Acala germplasm population.…”