2013 Annual Report
1a.Objectives (from AD-416):
Collaborate with ARS researchers to provide germplasm for Cotton Leaf Curl Virus (CLCuV) screening and transfer resistance identified into adapted cotton lines. Transferring traits from diploid to cultivated tetraploid cotton is a difficult process. ARS at Stoneville, MS, and Texas A&M University, College Station, TX, are the two locations in the U.S. successfully transferring genes from diploid lines into tetraploid cotton. These groups will cooperate to transfer the resistance genes as quickly and efficiently as possible. The lines will be advanced more rapidly by using DNA markers to verify successful transfer of the resistance gene(s) in each generation of the introgression process. The efficiency will be improved by cytogenetic analyses to confirm the lines produced are cytogenetically stable with a complete set of chromosomes.
1b.Approach (from AD-416):
The university collaborator will work with ARS to increase seed of exotic diploid species and provide technical support for increase of germplasm and preparation of seed for CLCuV resistance screening. Lines identified as resistant will be used as donor parents in crosses to transfer the resistant trait (genes) into adapted cotton lines. The transfer of the trait will be tracked using DNA markers and resistant progeny from the crosses will be cytogenetically evaluated to select lines with a complete set of chromosomes and no chromosomal abnormalities.
The funding for this project originates from project 6402-21310-003-09R where additional details can also be found. The main objective is introgression of wild cotton (Gossypium) species into cultivated cotton, with the goal to incorporate resistance to cotton leaf curl virus (CLCuV).
Established relevant methods for high quality mitotic and meiotic chromosome preparations from cotton tissues. These can be applied to introgression or genetic materials for breading lines that might be resistant to CLCuV due to alien germplasm, or mapped regions, e.g., to determine the size of the molecular region to which a resistance gene or Quantitative trait locus (QTL) is localized.
Processe potentially CLCuV resistant lines materials genernated from early generation G. longicalyx introgression materials grown in 2012 summer. Seedcotton harvested, was ginned, and linted seed were acid-delinted, rinsed, dried, for shipment to Pakistan via ARS scientists, Stoneville, MS. In early 2013, specific instructions were obtained on how to finish up the preparation of seeds that were shipped to Pakistan for CLCuV testing.
Maintained vegetative clones of synthetic hexaploid plants under greenhouse conditions, where they flowered under short-day photoperiods.
The funding for this project comes from project 6402-21310-003-09R, Pakistan Cotton Productivity Enhancement Program, where additional details can be found.