| The cotton Verticillium wilt is one of the obstacle that affected cotton area in China, Breeding varieties resistance to disease, the first step is identifying resistance to cotton wilt, is a most important method to prevention and cure cotton Verticillium wilt. No people studied the resistance to Verticillium wilt in transgenic cotton from the transgenic cotton had planted in China. The author collected 45 transgenic anti-pest cotton varieties (lines) from China and foreign countries that were used to study their resistance to cotton Fusuarium wilt, Verticillium wilt and cotton bollworm resistance with methods of field nursery, the standard of identifying resistance to cotton wilt based on relative index of resistance (IR). The results showed, the resistant, tolerant and susceptible cotton varieties (lines) accounted for 6.7%, 51.1% and 42.2% of the total. The infection and development regularity of Verticillium wilt was different in varieties (lines).The disease resistance of varieties (lines) from foreign countries was lower than that from China, there were obvious difference in resistance among varieties (lines) from different provinces. The CK of identification in transgenic cotton was singled out, which was J103. The results of correlation analysis showed, there was significant coefficient between Verticillium wilt percentage and the first fruit-branch nodes or the height of the first fruit-branch. There was significant coefficient between disease index and boll per plant or lint yield or the first fruit-branch nodes or the height of the first fruit-branch. There was significant coefficient between disease index and boll weight or disease index of Fusarium wilt or bolls per plant or lint percentage or seed cotton yield or pre-frost seed cotton yield or lint yield or pre-frost lint yield by the analysis of the data of regional test in Hebei province.There was no significant difference on set eggs but there was significant difference on the regularity of the bollworm larvae between transgenic cotton and conventional cotton. The transgenic cotton varieties (lines) had highly resistance to pest (mainly resistance pest is cotton bollworm), particularly on the second generation, and decreased on the third generation, and part of these have very strong pest resistance with over 90% control efficiencies to the third generation. There was coefficient between the level of the resistance pest and the bolls or yield. |
