Effects of Two Pilosity Alleles on Agronomic and Fiber Traits in Upland Cotton1
- Joshua A. Lee2
The pilosity alleles H2 and Pilose impart dense pubescence to various plant parts of upland cotton (Gossypium hirsutum L.). The effects of the two alleles on selected agronomic and fiber traits were studied in 1982 in two environments on the background of ‘Empire’, a cultivar which displays a normal density of pubescence. Four entries were compared, i.e., i) homozygous Pilose; ii) normally pubescent siblings of Pilose, designated as C-l; iii) homozygous H2; and iv) normally pubescent siblings H2, designated as C-2. The density of pubescence on leaves of Pilose and H2 did not differ, and both were about 2.5 times more pubescenthan the controls. Pilose did differ from the other three entries in having pubescent bolls. Boll weight was virtually the same for all entries, as was lint percentage. Fiber length varied among entries. C-I had 21% greater 2.5% span length than Pilose (28.4 vs. 23.4 mm). C-2 displayed 4% greater 2.5% span length than H2 (27.8 vs. 26.7 ram), a difference not significant at the 0.5 probability level. The 50% span length of the entries correlated closely with 2.5% span length (r = 0.89**), and Pilose differed significantly from the other entries in fiber length uniformity index. Micronaire was significantly greater for Pilose than for the other three entires (5.2 vs. 4.4 to 4.5), and the coarser fiber of Pilose was accompanied by a small loss in fiber tensile strength. There were no significant differences in fiber elongation. The possible uses for H2 in breeding for insect resistance were discussed.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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