Study On Agronomic Characters, Fiber Quality And Uisease Resistance Of Pest-Resitant Transgenic Cotton

These experiments were conducted to investigate the yield characters, growth and development of plant, resistance to diseases and fiber quality of hybrid and conventional cotton varities (lines) with and without pest-resistant gene Bt, including some Bt-transgenic materials and their receptor. The results showed that:1. Compared with cotton without pest resistance, the transgenic cotton germinated later 0.6d, as well as anthesis being postponed for 0.4d, the whole growing period increasing by 0.4d. Not only the seedling growth is weaker but also the yield and its components decreased to different degrees, in particular in lint percentage.2. Compared with cotton without post resistance, lower resistances to FUSARIUM and VERTICILLIUM wilt and to red leaf and stem wilt were found in transgenic cotton, but the difference in the disease in indexes did not significontly exist between two types of cottons.3. Compared with conventional with pest resistance, transgenic hybrid cotton not only germinated earlier 1.04d but also bloosmed earlier 0.49d. It grew better at late growth stage. Its fruit branch position was lowered by 0.24 and the boll number increased by 0.93 per plantwhile the lint percentage also by 1.1 points. However, the fruit branch number and boll weight were significantly different from those of conventional cotton.4. Compared with conventional cotton with pest resistance, the diseases indexes of hybird cotton with Bt gene to FUSARUIM and verticillium wilt were 8.6% and 21.9%, respectively, indicating that the resistance to this disease was weaker. The thinness and strength of fiber increased but the length and maturing degree of fiber decreased.5. Compared with receptor without pest resistance, transgenic cotton had some changes in main characters with Bt gene being transformed in, for erample, leaf color deepening, seedling germigation being postponed for about 1d, plant growing weaker at early and medium stages, plant height being shorter, boll number per plant reducing by 0.64, boll weight being down 0.03g, line percentage being lowered by 0.17 point, discase indexes to two diseases rising by 1.93 and 5.11 points, fiber thinness increasing and fiber length decreasing.6. According to these results, comprehensive it was concluded that though transgenic cotton had a good pest resistance, some changes in its other characters were found, such as weak growing abiliity, lower resistance to diseases, etc.