GERMPLASM ENHANCEMENT AND GENETIC IMPROVEMENT OF COTTON
Location: Genetics and Precision Agriculture Research
Title: Genetic effects of nine Gossypium barbadense L. chromosome substitution lines in topcrosses with five elite Upland cotton G. hirsutum L. cultivars
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 2, 2011
Publication Date: April 1, 2012
Citation: Jenkins, J.N., McCarty Jr, J.C., Wu, J., Hayes, R.W., Stelly, D. 2012. Genetic effects of nine Gossypium barbadense L. chromosome substitution lines in top crosses with five elite Upland cotton G. hirsutum L. cultivars. Euphytica. 187:161-173.
Interpretive Summary: Gossypium barbadense has superior fiber properties to G. hirsutum which is called upland cotton and is the primary cotton of commerce. Attempts to transfer superior fiber properties to upland cotton from G. barbadense have generally not been highly successful. Chromosome substitution lines have been used in many crops to more easily move desirable alleles from one species to another. Several chromosome substitution lines have been developed in cotton. This study utilized nine of these lines in crosses with five upland varieties and determined the genetic effects of these crosses. Results showed that several chromosome substitution lines carried alleles for agronomic or fiber improvements that could be transferred to upland cotton. Using these chromosome substitution lines should provide a better way to transfer specific desirable alleles into upland cotton than crosses between the two species. Specific desirable alleles were identified in each chromosome substitution line.
Crosses between Gossypium barbadense L. and Upland (G. hirsutum L.) have produced limited success in introgressing fiber quality genes into Upland cotton. Chrosome substitution lines (CSL) have chromosomes or arms from G. barbadense, line 3-79, substituted for the corresponding chromosome or arm in G. hirsutum in a near isogenic background of TM-1. For the purpose of simplicity, both chromosome substitution (CS-B) lines and chromosome translocation (NTN) lines were called chromosome substitution lines (CSL). We top crossed nine CSL and their parents (TM-1 and 3-79) with five, diverse cultivars and grew parental lines and their F2 populations in four environments and measured agronomic and fiber quality traits. The CSL and their F2 hybrids showed wide ranges for both agronomic and fiber traits of economic importance. Genetic analysis showed that additive effects were more important than dominance effects for lint percentage, boll weight, lint yield, fiber length, strength, elongation, micronaire, and yellowness; whereas, dominance effects were more important that additive effects only for fiber length uniformity and reflectance. For all traits, except boll weight and lint yield, significant additive effects for one or more chromosomes from 3-79 in TM-1 background were greater than the corresponding TM-1 chromosome. In addition, we identified specific 3-79 chromosomes that carry alleles useful for improvements of specific fiber quality traits in Upland cotton. Favorable additive effects from chromsome or chromosome segments from 3-79 that are superior to corresponding chromosomes for chromosome segments from TM-1 were identified in this study as follows: lint percentage 10, 16-15; long fibers 01, 11sh, 26Lo; more uniform fibers 01, 11sh, 10, 17-11; stronger fibers 01, 11sh, 12sh, 26Lo, 17-11; fiber elongation 01, 11sh, 26Lo, 10, 17-11; reduced fiber micronaire 01, 12sh, 4-15, 16-15, 17-11; fibers with more reflectance 10, 4-15, 16-15, 17-11; fiber with less yellowness 4-15, 17-11. From our study, we concluded that by using CSL, favorable fiber quality alleles can be introgresssed into Upland, which greatly improves the breeder's probability of success. These data should provide useful genetic information to the cotton breeding industry at large.