Bt抗虫杂交棉叶片营养元素含量变化及其与产量的关系

为了比较杂交棉不同品种、不同世代棉花叶片营养元素含量的差异，于2003、2004年以Bt抗虫杂交棉NZ62、H64、H16的杂交种一代、二代和三代为材料，在湖南长沙进行了研究。田间试验在湖南农业大学试验基地进行，采用随机区组试验，设4次重复，4行区，小区面积13．4m^2。分别于棉花盛花期、吐絮期两个时期，在每个试验小区连续取10株棉株的倒数第4叶和倒数第2叶，测定棉叶的全量N、P、K、B、Cu、Zn、Fe、和Mn的含量。研究结果表明：不同品种花铃期养分含量除P以外均存在显著差异，且变化趋势基本一致，均以NZ62含量最高，H16次之，H64最低，差异达显著水平（P〈5％）。吐絮期不同品种叶片的N、P、K和B含量均不存在显著差异，而Cu、Zn、Mn营养含量均存在显著差异，NZ62比H16和H64高；不同世代花铃期F1棉株叶片的N、K、Cu、Zn、Fe、Mn和B的含量显著高于F2、F3（P〈5％），而F2、B的含量变化基本一致，F1代棉株对营养元素的吸收与F2、F3代棉株相比具有显著的杂种优势。F2、F3代优势衰退与其叶片营养元素含量减少相符合。但吐絮期不同世代之间没有显著差异。相关分析表明，花铃期棉花叶片含N量、含K量与子棉产量和皮棉产量有显著相关（P〈5％），而吐絮期的这两个元素的含量与棉花产量无显著相关（P〉5％）。无论是花铃期还是吐絮期，B元素的含量与子棉、皮棉产量的相关均达到极显著水平（P〈1％）。

Studies on the nutrition element contents of transgenic Bt cotton hybrid leaves and its relationship with yield

The purpose of this study was to compare the nutrition element contents of leaves and analyze its relationship with the yield of transgenic Bt cotton hybrids F_1, F_2, F_3 of NZ_ 62 , H_ 64 , H_ 16 . The field experiments were conducted with plots at 13.4m~2, 4 rows, the plots were arranged in randomized complete block design with 4 replications. The field experiments were conducted in Changsha experimental base of Hunan Agricultural University in 2003 and 2004. The contents of N, P, K, B, Cu, Zn, Fe and Mn of the fourth and second leaves from the top of main cotton stems were analyzed at flowering and open boll stages. Experiment results showed that there were significant differences in the contents of N, K, B, Cu, Zn, Fe and Mn in the 4~ th leaves at flowering stage among different cotton hybrid combinations. All the element contents of NZ_ 62 plants was the highest, that of H_ 16 was the second and that of H_ 64 was the lowest, the difference was significant (p<5%). There was no significant difference in the element contents of the second leaves among the transgenic Bt cotton hybrids at open boll stage. There were significant differences among the contents of N, K, Cu, Zn, Fe, Mn and B in the 4th leaves of F_1, F_2 and F_3 generations at flowering stage (p<5%), and the contents of F_1 plants were higher than F_2 and F_3, and the difference between F_2 and F_3 was not significant. F_1 plants showed higher hybrid vigor to absorb nutrition elements than F_2 and F_3 plants. The decreased hybrid vigor of F_2 and F_3 were related with the decreasing of nutrition element contents. But there was no significant difference in the element contents of the second leaves of F_1, F_2 and F_3 plants at open boll stage(p<5%). The results of correlation analysis showed that the cotton yields, both seed cotton yield and lint yield, were significantly positive related to N and K contents of the hybrid leaves at flowering stage, but the relationship at open boll stage was not significant(p>5%). The positive correlation of cotton yields and the B contents in cotton plant leaves at flowering and open boll stages were highly significant(p<1%).