Prospects for using primitive landrace germplasm for cotton improvement

Long-term cotton genetic improvement is dependent upon the careful introduction and exploitation of new genetic variation. One of the largely untapped reservoirs of genetic diversity available to cotton breeders resides in the primitive Gossypium hirsutum L. landrace collection. Although most accessions are classified as G. hirsutum and reside within the primary upland cotton gene pool, widespread use of these genetic resources has been minimal due to their photoperiodic nature and perennial growth habit. In our research program, we are deploying two different, but related approaches to introduce and use novel genetic variation present within this genetic resource. First, we are developing breeding populations derived from crosses involving a number of day-neutral converted lines developed by the USDA-ARS Mississippi State, MS research program. Second, we are characterizing a set of naturally occurring day-neutral primitive landrace accessions in an effort to identify novel accessions for use as breeding parents. Preliminary results suggest these genetic resources contain beneficial alleles for fiber quality and climate resiliency.