Originally published as Genetics Published Articles Ahead of Print on December 30, 2005.

Genetics, Vol. 172, 1927-1938, March 2006, Copyright © 2006
doi:10.1534/genetics.105.053371

Effects of Chromosome-Specific Introgression in Upland Cotton on Fiber and Agronomic Traits

Sukumar Saha*,1, Johnie N. Jenkins*, Jixiang Wu{dagger}, Jack C. McCarty*, Osman A. Gutiérrez*, Richard G. Percy{ddagger}, Roy G. Cantrell§ and David M. Stelly**

* United States Department of Agriculture–Agriculture Research Service, Crop Science Research Laboratory, Mississippi State, Mississippi 39762, {dagger} Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, Mississippi 39762, {ddagger} United States Department of Agriculture–Agriculture Research Service, Maricopa Agricultural Center, Maricopa, Arizona 85239, § Cotton Incorporated, Raleigh, North Carolina 27513 and ** Department of Soil and Crop Sciences, Texas A&M University, College Station, Texas 77843

1 Corresponding author: United States Department of Agriculture–Agriculture Research Service, Crop Science Research Laboratory, 810 Highway 12 E., P.O. Box 5367, Mississippi State, MS 39762-5367.
E-mail: ssaha{at}msa-msstate.ars.usda.gov

Interspecific chromosome substitution is among the most powerful means of introgression and steps toward quantitative trait locus (QTL) identification. By reducing the genetic "noise" from other chromosomes, it greatly empowers the detection of genetic effects by specific chromosomes on quantitative traits. Here, we report on such results for 14 cotton lines (CS-B) with specific chromosomes or chromosome arms from G. barbadense L. substituted into G. hirsutum and chromosome-specific F2 families. Boll size, lint percentage, micronaire, 2.5% span length, elongation, strength, and yield were measured by replicated field experiments in five diverse environments and analyzed under an additive–dominance (AD) genetic model with genotype and environment interaction. Additive effects were significant for all traits and dominance effects were significant for all traits except 2.5% span length. CS-B25 had additive effects increasing fiber strength and fiber length and decreasing micronaire. CS-B16 and CS-B18 had additive effects related to reduced yields. The results point toward specific chromosomes of G. barbadense 3-79 as the probable locations of the genes that significantly affect quantitative traits of importance. Our results provided a scope to analyze individual chromosomes of the genome in homozygous and heterozygous conditions and thus detected novel effects of alleles controlling important QTL.