旱种水稻结实期茎中碳同化物的运转及其生理机制

Remobilization of Carbon Assimilates in the Stems during Grain Filling and Its Physiological Mechanism in Dry-cultivated Rice

以杂交水稻汕优 6 3和籼稻扬稻 6号为材料 ,研究了旱种 (地膜覆盖栽培 )水稻结实期茎中碳同化物的运转及其生理机制。结果表明 ,抽穗至成熟期旱种水稻标记1 4C从茎中向籽粒的再分配、茎中非结构性碳水化合物 (NSC)的运转率及其对籽粒的贡献率均显著高于水种 (常规栽培 )水稻。水稻旱种后籽粒中的蔗糖合成酶和酸性转化酶活性、茎中α 淀粉酶和 β 淀粉酶活性均增加 ,以蔗糖合成酶和α 淀粉合成酶尤为明显。茎中α 葡萄糖苷酶和淀粉磷酸化酶活性在旱种和水种间无显著差异。茎中淀粉和1 4C向籽粒的运转量与籽粒中蔗糖合成酶活性、茎中α 淀粉酶和 β 淀粉酶活性呈极显著正相关 ,与α 葡萄糖苷酶和酸性转化酶活性相关不显著 ,与淀粉磷酸化酶活性呈显著负相关。表明水稻旱种后促进了茎中NSC向籽粒的运转 ,对籽粒中蔗糖合成酶和茎中α ,β 淀粉酶活性的增加起重要作用。

With the indica hybrid combination of Shanyou 63 and indica cultivar of Yangdao 6 as materials, the remobilization of pre-stored carbon in the stems during grain filling and its physiological mechanism were investigated in dry-cultivated (plastic film mulching cultivation) rice. The results showed that the re-allocation of pre-fixed 14 C from stems to grains, the transfer ratio of nonstructural carbohydrate (NSC) pre-stored in the stems and its contribution to grains from heading to maturity in dry-cultivated rice were very significantly greater than those in moist-cultivated (conventional cultivation) rice. The dry-cultivation enhanced the activities of sucrose synthase and acid invertase in grains and α-, β-amylase in stems, with the activities of sucrose synthase and α-amylase enhanced more. Activities of α-glucosidase and starch phosphorylase were no significant differences between the dry-cultivation and moist-cultivation. The remobilization of starch and 14 C transferred from stems to grains were very significantly and positively correlated with the activities of sucrose synthase in grains and α-, β-amylase in stems, but not significantly correlated with α-glucosidase and acid invertase activities, and negatively correlated with the activity of starch phosphorylase. The results indicate that the dry-cultivation in rice promotes carbon remobilization from stems to grains during grain filling and enhanced activities of sucrose synthase in grains and α-, β-amylase in stems play an important role.