小麦早熟高产品种光合生理特性分析

Analysis on Photosynthetic and Physiologic Characters in Early Maturing and High Grain Yield Wheat Cultivars

对陕西关中地区当前推广的早、中、晚三种熟性 8个高产小麦品种的光合生理特性进行了研究 ,以探明参试的早熟小麦品种高产的光合生理机能和进一步提高早熟小麦品种产量潜力的性状改良途径。结果表明 ,参试早熟高产小麦品种的光合生理特性是 :1 灌浆高峰期蒸腾速率高 ;2 花期至灌浆高峰期有持续稳定的高净光合速率 ;3 花前同化产物对子粒干物质累积贡献潜势大 ;4 花后单株生物增长量远高于中、晚熟品种 ;5 花前同化产物转流系数高 ,花后干物质增长系数高 ,光合产物分配性能好 ,收获指数高。同时也进一步明确早熟高产小麦品种的生物学产量低于中、晚熟品种 ,其原因主要在于拔节期至开花期的生物学增长量少。进一步提高早熟小麦品种产量潜力的途径是在保持或提高收获指数的同时 。

Photosynthetic and physiologic character was studied on eight high grain yield wheat cultivars which popularized in Guanzhong area belonging to early,medium and late maturing,respectively,to find out the photosynthetic and physiologic mechanism of the high grain yield of early maturing wheat cultivars,and the way of characteristic improvement further increasing in yield potential.The result show that early maturing and high grain yield wheat cultivars tested have following characters:1.Transpiration rate is higher during peak filling stage;2.From anthesis to the peak filling stage,net photosynthetic rate is higher and steadier;3.The contribution potential of photoassimilates to dry matter of kernels is larger prefloral;4.Biomass increased per plant is fairly higher than that of medium and late maturing postfloral;5.Higher photoassimilates trans current coefficient prefloral,higher dry matter increasing coefficient postfloral,better photoassimilates distribution character and higher harvest index.At the same time,biomass of early maturing and high grain yield cultivars is lower than that of medium and late maturing cultivars,the principal cause is that increased biomass is less from jointing to anthesis.The way of further improving early maturing cultivars yield potential is keeping or raising harvest index and at the same time largely increasing it′s prefloral biomass.