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Effects of Plant Smoothness on Agronomic Traits of Upland Cotton—Fiber Properties 1
Author(s) -
Lee Joshua A.
Publication year - 1984
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1984.0011183x002400040021x
Subject(s) - diallel cross , lint , biology , cultivar , allele , fiber crop , fiber , smoothness , horticulture , gossypium , gossypium hirsutum , agronomy , botany , genetics , mathematics , gene , hybrid , composite material , materials science , mathematical analysis
Glabrousness in upland cotton ( Gossypium hirsutum L.) confers resistance to certain insects and decreases trash in ginned lint. Such plant smoothness has been associated with reductions in lint percentage and fiber yield, but there is little information on the effects of the phenotype on fiber properties. Two complete diallel sets involving various combinations of smoothness and pilosity alleles were grown in randomized, complete blocks in North Carolina in 1982 in four replications per location. The first set was generated by intercrossing the allelic pairs, Sm s1 1 and sm 1 , and Sm 2 and sm 2 in all possible combinations, and the second by intercrossing the allelic pairs Sm 2 and sm 2 , and Sm , and sm 4 1 . Increasing the number of Sm alleles in a given cotton increases plant smoothness, whereas the completely recessive phenotype (all sm alleles), imparts normally pubescent, the phenotype of ‘Coker 310’, the cultivar used as background. Within the two diallels 2.5% fiber span length varied from 26.9 to 30.1 mm with the lowest values associated with the Sm 2 allele. Fifty percent span length varied from 13.0 to 14.3 mm but was significantly various only in the first diallel, and the variation for 50% span length in that particular set did not relate to degree of plant smoothness. The entries with the shortest 2.5% span length tended to have the highest fiber uniformity index. Micronaire values above 5 were associated with some of the entries homozygous for Sm 2 and fiber tenacity showed a deficiency where the Sm s1 1 allele was homozygous. There were significant estimates for general and specific effects for some of the traits, particularly with entries harboring the Sm 2 ✕ sm 2 contrasts, and evidence for maternal and reciprocal (maternal ✕ embryonic) effects for some traits. There was no consistent evidence that degree of plant smoothness related to disturbances in any fiber trait, but evidence that specific smoothness alleles were accompanied by fiber quality deficits.