二代棉铃虫不防治下SGK321与石远321叶片衰老的比较

Leaf Senescence Differences between Cotton Variety SGK 321 and SY 321 without Chemical Control of Second Generation Bollworm

以双价转基因抗虫棉SGK321和非抗虫棉石远321为试验材料,在大田条件下研究了二代棉铃虫不防治条件下两品种叶片衰老方面的差异。结果表明,在二代棉铃虫不防治条件下,非抗虫棉石远321棉铃虫危害严重,幼蕾脱落比SGK321平均每株多6个;受害石远321的单位叶面积载铃量和根冠比显著低于SGK321,叶面积和叶面积系数显著高于SGK321,叶片内细胞分裂素类物质含量在盛花期高于SGK321,而脱落酸含量整个生育期则明显低于SGK321;与SGK321相比,石远321的主茎功能叶具有较高的SOD活性、较高的叶绿素含量和较低的MDA含量。因二代棉铃虫危害而损失部分早期蕾,改变了非抗虫棉的库源关系,在一定程度上延缓了石远321叶片的衰老。

Abs With transgenic Bt ＋ CpTi cotton SGK 321 and its wild type SY 321 as experimental materials, the differences in leaf senescence between the two varieties under field contions without chemical control of the 2nd generation cotton bollworm were investigated. The results showed that SY 321 suffered more bollworm damage with 6 fallen squares per plant more than that of SGK 321. Compared with SGK 321, the fruiting load per leaf area and root to shoot ratio of SY 321 were significantly lower, but the leaf area and leaf area index were significantly higher; the contents of CTKs of SY 321 were higher in the full - bloom stage, but the content of ABA was lower during all the growth period; SY 321 had higher SOD activity, higher chlorophyll content and lower MDA content in stem leaves. It was concluded that the bollworm damage altered the sink - source relation of non - Bt cotton SY 321, and thus delayed the leaf senescence.