温度对杂交中籼稻灌浆期淀粉体发育及胚乳透明度的影响

Effect of Temperature on the Starch Grain Development and Endosperm Transparency of Medium Indica Hybrid Rice during the Period of Grain Filling

以E优540和Ⅱ优162两杂交中籼稻为材料,通过人工控温处理,研究了不同温度条件下籽粒灌浆期中的含水率、淀粉合成、可溶性糖转化、Q酶活性,以及淀粉体发育的形态特征。结果表明,稻米淀粉体发育及胚乳透明度,既受品种遗传因素控制,又与环境温度密切相关。适温条件下(26℃22℃,平均24℃),主要由品种遗传特性决定;而高温条件下(36℃30℃,平均33℃),则明显受温度的影响。高温加速了籽粒含水率下降,使淀粉合成和Q酶活性峰值比适温下的分别提前10d和5d;可溶性糖转化,呈现灌浆中、前期加速,中、后期抑制的状况;同时,在不同温度下,花后10d的水稻籽粒胚乳中央的淀粉体,其形态发育出现明显差异。这表明高温改变了稻米淀粉体的发育进程,导致了稻米淀粉体(粒)结构疏松,折光率下降,胚乳透明度降低。

Two medium indica hybrid rice,E-you 540 and Ⅱ-you 162,were cultured in two pots at different temperatures in growth chamber for the analyses of grain water content, the starch content, the soluble sugar content change, Q enzyme activity, and the morphological characteristics of starch grain development during grain filling. The results indicated that rice starch grain development and endosperm transparency were not only controlled by heredity but also affected by environmental temperature. They were mainly controlled by heredity at normal temperature (26℃/22℃) and affected by high temperature (36℃/30℃) when the cultivated rice was the same. The water content was lower, the Q enzyme activity and starch content reached the peak at 5 and 10 days earlier respectively under high temperature than under normal temperature. An abnormal change of soluble sugar content under high temperature was found too. The differences of starch grain morphological development in the central part of grain endosperm were about 10 days after blossom under different temperatures. In conclusion, high temperature changes the starch grain developmental process and makes starch grain construction loose, decreases the refractive index and endosperm transparency in rice grain.