遮光对不同穗型粳稻叶片光合特性和叶绿体超微结构的影响

Shading Effects on Photosynthesis and Chloroplast Ultra-Structure Characteristics of leaves in Japonica Rice with Different Panicle Types in Northern China

为了明确遮光对北方不同穗型粳稻叶片光合作用的影响,以直立穗型粳稻品种沈农9741、半直立穗型粳稻品种盐丰47和弯穗型粳稻品种辽盐16为材料,研究了抽穗期遮光对不同穗型粳稻叶片净光合速率(Pn)、叶绿素含量、叶绿素荧光特性及叶绿体超微结构的影响。结果表明:遮光均导致了不同穗型粳稻品种叶绿素含量的增加和Pn的降低,其中叶绿素含量的增加表现为沈农9741(10.55%)>辽盐16(7.30%)>盐丰47(7.01%),而Pn的降低表现为沈农9741降幅最大,盐丰47次之,辽盐16最小;遮光对北方粳稻叶片原初光能转化效率(Fv/Fm)的影响不大,但显著降低了抽穗后4d内的叶片实际光化学效率(Yield);遮光后细胞内的叶绿体外形肿胀,与对照相比出现了较多的嗜锇颗粒,类囊体垛叠程度增高且紧密,淀粉粒数目有所减少。遮光后不同穗型粳稻品种都表现了一定的耐荫性,抽穗期遮光对直立穗型粳稻品种的影响大于对半直立穗型和弯穗型粳稻品种的影响。

In order to understand the shading effects during heading period on the net photosynthetic rate(Pn), chlorophyll content,chlorophyll fluorescence characteristics and chloroplast ultra-structure of japonica rice with different panicle types,Shennong 9741(erect panicle), Yanfeng 47(semi-erect panicle) and Liaoyan 16(curved panicle) were used as materials. The results showed that the increase of chlorophyll content of Shennong 9741 was the maximum with 13.27%, and that of Yanfeng 47 was the minimum with 7.01% under shading. However, the biggest decline of Pnwas in Shennong 9741, and the smallest of that was in Liaoyan16.There was no obvious effect of shading on Fv/Fmof rice leaf, but the Yield of flag-leaf was significantly decreased under shading within 4 days after heading. The shape of intracellular chloroplast swelled slightly under shading. Meanwile, there were more numbers of osmphore, fewer numbers of starch granule and thylakoids stacking in chloroplast. Our studies indicatd that there are different degrees of shading tolerance in japonica rice with different panicle types under shading stress, and the influences of shading on Shennong 9741 is greater than that of Yanfeng 47 and Liaoyan16.