亚种间重穗型杂交稻光合产物的运转特性及其生理机制

 利用14 C、3 2 P同位素示踪技术 ,研究了籼粳亚种间重穗型杂交稻Ⅱ优 16 2、两优培九的光合产物运转特性及其生理机制。结果表明 ,两组合在籽粒形成期的各个阶段 ,其14 C 光合产物的单株生产总量明显高于汕优 6 3,但光合产物运输至穗中的速度皆不如汕优 6 3快 ,最终分配至穗中的比率也比汕优 6 3低 ,且14 C 光合产物在这两个组合的茎鞘中有明显的积累和滞留现象发生。随稻穗发育进程 ,供试亚种间重穗型杂交稻叶片蔗糖磷酸合成酶活性和根系活力由齐穗期、乳熟期、蜡熟期逐步大幅度下降 ,这种蔗糖磷酸合成酶活性和根系活力下降的特性与光合产物运转分配效率较差有一定的内在联系。

Transportation Characteristics of Assimilate and Physiologic Mechanisms in Subspecific Heavy Ear Hybrid Rice (Oryza sativa L.)

The transportation characteristics of assimilate and physiologic mechanisms in two subspecific heavy ear hybrid rice combinations, Eryou162 and Liangyoupeijiu, were studied by using 14 C and 32 P isotope tracer techniques. The results showed that during the different stages in grain filling period, the total amount of photosynthetic product of a plant of the intersubspecific hybrid rice was remarkably more than in Shanyou63, but the speeds of 14 C assimilate transported to spike were significantly slower. The proportions of 14 C assimilate distributed to grains were lower in the two combinations than in Shanyou63 and the obvious accumulation and stagnation of 14 C assimilate in the stems of plant were occurred in the two combinations. Furthermore, the activities of SPS and the activities of root of the combinations decreased sharply and falled step by step from heading stage to milky and dough stage. The decrease of activities of SPS and the decrease of activities of root has relation with the effects on transportation and distribution of assimilate in these intersubspecific hybrid rice combinations.