小麦芒和旗叶叶绿体结构及低温荧光发射

本文对 "京411"和 "京冬8" 两个小麦品种芒和旗叶的叶绿体超微结构及其低温荧光特性等进行了比较研究.结果表明,小麦芒有发育较好的叶绿体,其单个叶肉细胞中叶绿体数较少,体积小,基粒垛叠整齐,基粒片层少,但其片层比旗叶的宽.其中高产品种"京冬8"芒的基粒及其片层均较"京411"多.通过低温(77K)荧光发射光谱分析结果显示,不同品种的芒和旗叶的F686/F734值存在差别,如高产品种旗叶的F686/F734比其芒高,而在对比品种芒中F686/F734的值比旗叶高;两个品种芒的F686/F734值差别不大.本文还讨论了芒的叶绿体结构与功能的关系,从而为研究其在穗部光合中的作用提供了有力的证据.

Comparison of chloroplast ultrastructure and 77K fluorescence emission spectra between awns and flag leaves in wheat

The chloroplast ultrastructure and characteristics of 77K fluorescence emission spectra of awns and flag leaves in wheat ( Triticum aestivum L.) were investigated. The results showed that chloroplasts of awns were well developed, while awns included smaller and fewer chloroplasts when compared with those of the flag leaves. The chloroplasts of awns contained fewer grana and grana lamellae. Nevertheless, the grana lamellae in the awn chloroplasts were stacked well and the grana lamellae were wider than those of the flag leaves. It was further found that the characteristics of fluorescence emission spectra at 77K presented here in the form of F 686 /F 734 ratio of the flag leaves was higher than that of awns in the high yield cultivar, while in the control the result was opposite. When the awns of two cultivars were compared, no significant differences were noticed in terms of F 686 /F 734 ratio. These findings provided strong anatomical and physiological evidence that awns played an unusual role in the yield of wheat.