| The different transgenic upland cotton T4, T5 progenies with resistance to Fusarium Wilt and Verticillium Wilt which has experienced several generations of selection were used in this study. Our main propose was to find out the high disease-resistant plants with an excellent agronomic characteristics by screening high disease-resistant mutants and investigating their main agronomic traits in field. Molecular detection (PCR and southern blotting) and analysis of some physiological indexes fiber quality were done in order to find out the differences between the disease-resistant lines. The main results are as follows:1. Analysis of main agronomic traits of T4 progenies with high disease-resistant transgenic lines.In T4 high disease-resistant lines, all lines were almost with equal disease-resistance, but their height, numbers of fruit branches or bolls per plant are different, some significant difference existed among some lines, and the results indicated that the disease-resistance had no significant relations with plant height, numbers of fruit branches or bolls per plant. We found that the exogenous gene receptor would provide its good agronomic traits to the related transgenic lines. According to the statistical results, about 50%plants' height were significant different from the control, but only 16.67%of transgenic plants showed the significant different in the number of fruit branches or bolls per plant compared with that of control. Thus, the mutation effect of Ac/Ds-enhencer showed a big variation among the different agronomic traits.2. Analysis on molecular detection (PCR and southern blotting) of T4, T5 progenies high or tolerant disease-resistant upland cotton transgenic linesIn T4, T5 progenies high or tolerant disease-resistant lines, more than 50%plants showed a positive PCR results based on Bar and NPTII primers sequence. We also found that 18.65%-23.54%of plants just presented Bar fragment, which was higher than that of 13%in rice,1107 transgenic lines only with Bar fragment are slightly higher than 4105 transgenic lines, meanwhile T5 progenies were higher than T4 generation, it preliminarily indicated that Bar and NPTII genes existed stably in T4, T5 transgenic lines, and is was effective to screen stable genotypic plants with separated Ds element. So some plants with positive results in PCR experiment were used to do southern blotting and found that the Ds sequence was really inserted the cotton genome of the tested lines3. Analysis of main physiological index of T5 progenies with high or tolerant disease-resistant upland cotton transgenic linesIn T5 progenies with high or tolerant disease-resistant lines, during summer fruit stage and bud-boll stage, chlorophyll content, content of soluble protein and soluble sugar of high disease-resistant lines are higher than tolerant disease-resistant lines, perhaps high disease-resistant lines have higher photosynthetic capacity. The trend of different physiological indexes at different developmental phases were as follows:from bud-boll stage to summer fruit stage, there was a slight upward trend of chlorophyll content and downward trend of content of soluble sugar and soluble protein, this might be related to the degree of soluble sugar transferred from "source" to "sink" in developmental periods.4. Analysis of fiber quality of T5 progenies with high or tolerant disease-resistant upland cotton transgenic linesIn T5 progenies with high or tolerant disease-resistant lines, the fiber quality of high disease-resistant lines had no more improvement compared that of the tolerant disease-resistant lines, this indicated that high photosynthetic potential of high disease-resistant lines had no correlation with the fiber quality of cotton. |
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