GENOME-WIDE IDENTIFICATION OF RECOMBINATION RATES OF MALE VERSUS FEMALE GAMETES IN INTERSPECIFIC POPULATION OF COTTON

Abstract

Based on the established SSR-based BC1 genetic linkage map, 2 genetic maps covered with 313 markers have been developed for 2 more backcross populations which was aimed to study the difference of recombination rates between male and female gametes. The total lengths of genetic maps for male and female were 4532.9cM and 4464.4cM respectively, and the average marker distances were 14.48cM and 14.26cM respectively. The results showed that there was no difference for the recombination rates between male and female gametes on the total map length and the average marker interval. There were 6 linkage groups showing significant differences between the 2 populations, which indicated that the gamete recombinant rates can only influence some chromosomes in cotton. Although a lot of marker intervals showed difference between maps, only 17 marker intervals were caused by the male and female gametes recombination rates. Further investigation showed that the male gamete mainly resulted in a longer genetic distance between markers, and increased the recombination rates; while the female gamete usually resulted in a shorter genetic distance of marker interval, and decreased the recombination rates. The present results will give us some useful instructions in cotton genetics and breeding.