|08-380 Project Manager: D. C. Jones|
TRANSITIONING TO TRUE MOLECULAR BREEDING IN COTTON: WHOLE-GENOME ASSOCIATION MAPPING TO IDENTIFY MARKERS FOR PHOTOPERIODIC FLOWERING IN GOSSYPIUM HIRSUTUM L.
Alan E. Pepper, Texas A&M Research Foundation
Wild, exotic and primitive Gossypium hirsutum germplasm resources harbor economically useful genes that could be used to confer improved fiber quality, disease resistance, and tolerance to abiotic stresses such as drought. A major obstacle to the use of this 'exotic' germplasm in breeding arises from the fact that many of the wild accessions exhibit strict short-day photoperiod flowering and remain vegetative during the long days of summer cultivation in the high latitudes of the U.S. cotton belt. Wild germplasm stocks can be converted to photoperiod-independent flowering through extensive backcrossing to a photoperiod-independent parent. However, such conversion efforts are expensive, time consuming, and the genetic compositions of the resulting converted lines are often poorly characterized. The availability of highly reliable molecular markers linked to day-neutral alleles—employed as part of a high-throughput marker-directed selection strategy—would greatly accelerate the speed and greatly reduce the costs of photoperiodic primitive race-stock conversions. In theory, the conversion process could be accelerated from 10+ generations down to just two or three.
We are seeking to identify these reliable genetic markers through a 'candidate gene' approach. We are using a suite of candidate genes that have been previously been implicated as being important for photoperiodic flowering in the model plant species Arabidopsis thaliana, and in other crop species such as wheat, sorghum, soy and rice. We will use computational and molecular tools to compare molecular-genetic data with phenotypic data in order to identify candidate gene markers that are strongly associated with photoperiodic flowering (these may be the genes that have undergone genetic change during the domestication process). Recently, this method has emerged as the preeminent tool for the identification of genes that play roles in human diseases, leading to reliable diagnostic tools and promising new therapies. Unlike the piecemeal accession-by-accession approach of standard quantitative trait locus (QTL) analysis, this candidate-gene approach extraordinary power to simultaneously query a very large number of germplasm accessions in order to identify valuable genes.
A Cotton Incorporated Fellow, Ms. Carla Logan-Young, was supported on this project.
|Project Year: 2012|
Search 2012 Projects:|
▸ New Mexico
▸ North Carolina
▸ South Carolina
▸ Cotton Incorporated Fellow
▸ Crop Improvement
▸ Production Efficiency
▸ Sustainable Cotton
▸ Variety Improvement
▸ All Project Nos.