灌水方式对水稻灌浆期光合物质运转与分配的影响

Effect of Different Irrigation Modes During Grain Filling of Rice on Translocation and Allocation of Carbohydrate in Rice

在可控条件下设计了水稻灌浆期间灌溉稻田旱作的3 种灌水方式,形成3 种土壤含水量。研究不同灌水方式对亚种间杂交水稻协优9308 和两优培九碳水化合物的运转与分配的影响。试验结果表明,水植与干-湿条件下,茎鞘的贮藏物质或剑叶的光合产物运输率分别为60%与90%,旱作条件下碳水化合物输出率明显降低(P<0.01)。水植与干-湿处理间差异不明显。水稻灌浆成熟期间籽粒是吸收碳水化合物的主要器官,籽粒吸收叶鞘贮藏标记物50%和叶片光合物质80%。但在旱作条件下,籽粒摄取力显著下降,分别下降约10%和20%。干旱胁迫致使杂交组合劣势粒碳水化合物摄取能力的下降,是稻株结实率和充实度下降的主要原因之一。

Intersubspecific hybrid rice Xieyou 9308 and Liangyoupeijiu were used as the test materials, three levels of soil water content were designed during grain filling in irrigated field to study their effects on translocation and allocation of carbohydrate. The results showed that in conventional flooding or non–flooding cultivation, the exported rates of stored carbohydrate from stem and photosynthate from the leaves were 60 % and 90 %, respectively. The exported rate of carbohydrate was decreased significantly (P<0.01) in the non-flooding cultivation. There was no significant difference between the conventional flooding and dry–wet alternation treatments in term of carbohydrate export rate. The filling grains were the major sink for carbohydrate storage during grain filling stage. Grains received nearly 50 % of stored carbohydrate from leaf sheath and 80 % of photosynthate from leaves. At the non-flooding conditions, the absorbing capacity of grains significantly decreased by 10 % and 20 % from leaf sheath and from leaves photosynthate, respectively. Dry stress caused much decrease in absorbing capacity for inferior grains, which might be one of the main reasons for low seed-setting rate in non flooding cultivation.