Effects of the Density of Pubescence on Some Traits of Extra-long-stapled Cotton1
- Joshua A. Lee2
Most modern cultivars of extra-long-stapled cotton (Gossypium barbadense L.) display glabrous stems and variable densities of pubescence on leaves. These cottons produce long, strong, and fine fibers. The Tanguis cultivars, and the American Pima Stock, E-2, produce coarse, although lengthy and strong, fibers. Because Tanguis and E-2 have dense tomentum on leaves and stems, there arose the question of whether grade of plant vestiture affected fiber fineness and perhaps other fiber and agronomic traits. Three phenotypes, normally pubescent, hirsute, and glabrous, were fixed in ‘Pima S-5’, Coastland Sea Island, and ‘Seabrook Sea Island’, selection AS-2. The nine resulting entries were grown in replicated experiments at two locations in North Carolina in 1983. Compared with normal, the hirsute phenotype of AS-2 showed significantly increased lint percentage, and glabrousness reduced lint percentage significantly in AS-2 and Pima S-5. Hirsuteness significantly reduced g seed cotton boll-1 and lint index in Coastland. Glabrousness significantly reduced 2.5% span fiber length in AS-2 and length uniformity index was reduced in both hirsute and glabrous Coastland. Fiber tenacity was significantly reduced in glabrous Coastland, and hirsute Coastland showed a significant reduction in fiber elongation. None of the phenotypes affected micronaire values in any of the families. Increased pubescence was associated with fewer deficits in agronomic and fiber traits than glabrousness, and each of the Sea Island cottons showed more significant changes in the traits sampled than Pima S-5.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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