Collinearity Analysis of AllotetraploidGossypium TomentosumandGossypium Darwinii

Abstract: G. tomentosum and G. darwinii are wild allotetraploid cotton species, characterized with many excellent traits including finer fiber fineness, drought tolerance, Fusarium wilt and Verticillium wilt resistance. Based on construction of F 2 linkage groups of G. hirsutum × G. tomentosum and G. hirsutum × G. darwinii, two genetic linkage maps were compared. As a result we found a total of 7 inversion fragments on chr02, chr05, chr08, chr12, chr14, chr16 and chr25, 3 translocation fragments on chr05, chr14 and chr26. Further comparing the inversion and translocation fragments, we noticed four of seven markers orientation of G. tomentosum consistent with G. hirsutum or G. raimondii, one of seven inversion markers orientation of G. darwinii consistent with G. hirsutum ; meanwhile one of three translocation marker orientation of G. tomentosum consistent with G. raimondii. The result indicate, compare G. darwinii, G. tomentosum has closer genetic relationship to G. hirsutum. This study will play an important role in understanding the genome structure of G. tomentosum and G. darwinii, and open the doors for further in-depth genome research such as fine mapping, tagging genes of interest from wild relatives and evolutionary study.