粳稻根系与叶片早衰的关系及其对籽粒灌浆的影响

以衰老程度不同的品种为试材,对根系和叶片衰老的生理机制、根系与叶片衰老的关系、根系和叶片衰老对籽粒灌浆结实的影响进行了研究.结果表明:(1)抽穗后根系和叶片MDA含量持续上升,而SOD活性却先上升然后再持续下降,说明MDA含量上升最初并不是由SOD活性下降引起的.(2)根系和叶片衰老受ZRs和ABA平衡关系的调控,ZRs含量的下降和

Relation between Root and Leaf Senescence and their Effects on Grain-filling in Japonica Rice

The varieties with different senescence degree used as materials, the physiological mechanism of root and leaf senescence, relations between root senescence and leaf senescence and their effects on grain-filling were studied. The results showed that: (1)The MDA content continued increasing, but the SOD activity first rose then declined in root and leaf after heading, which showed that increasing of MDA content was not caused by declining of SOD activity originally. (2)Senescence of root and leaf was regulated by the balance of ZRs and ABA content, but the balance in root was different from that in leaf. Reducing of ZRs content and increasing of ABA content would quicken senescence. (3)Root senescence was closely related to leaf senescence. According the change of MDA content during senescence, it was found that root senesced earlier than leaf, so root senescence initiated and aggravated leaf senescence, but declining of metabolizing activity in root was not always earlier than that in leaf. (4)Root and leaf senescence could affect grain-filling obviously mainly through weakening inferior grain filling, and the inferior grain filling was the main factor affecting seed-setting percentage.