|May Iii, Oscar|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/1995
Publication Date: N/A
Technical Abstract: We assessed diversity among 126 Upland cotton (Gossypium hirsutum L.) cultivars released between 1980 and 1990 by use of coefficient of parentage (CP). In computing CP, we utilized assumptions appropriate for a self-pollinated crop. Mean CP among the 126 cultivars was 0.07, implying a genetically diverse group. However, cluster analysis revealed 12 distinct gene pools, with mean within-cluster CP=0.25 and between cluster CP=0.04. The CP analysis indicates that Acala-type cultivars are more diverse than those bred in the Mississippi Delta or southeastern USA. Cultivar development efforts in the late 1980s emphasized the repeated mating of genetically related material, or reselection within germplasm. To ensure continued progress in cotton improvement and forestall the decline in the genetic base, we suggest that cotton breeders consider the pedigree of parents prior to population synthesis.