再生稻再生芽存活和成苗对高温的响应机理及栽培调控

提高再生季产量是实现再生稻可持续发展的重要途径。再生季有效穗数是影响再生季产量形成的主要因素，而提高有效穗数的关键是增加再生芽的存活和成苗数量。在再生稻主产区，再生芽存活和成苗时期经常遭遇高温胁迫，造成再生芽死亡。目前，有关再生芽存活和成苗对高温的响应机理以及栽培调控机制还不清楚。因此，本项目采用盆栽和大田试验相结合的方法，在4个生育阶段不同温度条件下，测定再生芽存活与成苗动态，再生芽以及叶、茎和穗碳水化合物积累和转运特性，内源激素含量，抗氧化酶活性以及根系活力和根系激素含量。系统解析不同生育阶段高温对再生芽存活和成苗的影响机理，并明确再生芽存活和成苗对高温最敏感的生育阶段；在此基础上，研究应对高温胁迫的栽培调控途径，阐明水分管理对高温胁迫下再生芽存活和成苗的调控效应及其机制。明确上述问题，可以为再生稻抗高温育种与栽培调控提供理论依据和技术支持。

Improving grain yield of ratoon crop is critical to the sustainable development of ratoon rice production. Grain yield of ratoon crop is largely affected by panicle number, which is primarily attributed to the survival and growth of regenerated buds. The survival and growth of regenerated buds are vulnerable to high temperature stress and related heat damage in major ratoon rice producing-region. However, the physiological mechanisms underlying and effects of management optimization on the response of survival and growth of regenerated buds to high temperature are unknown. Therefore, the present project will determine the dynamics of survival and growth of regenerated buds, accumulation and transportation of carbohydrate, endogenous hormones content, and antioxidant enzyme activity in regenerated bud, leaf, stem, and panicle, and root activity and hormone content under different temperature treatments in four stages of development of survival and growth of regenerated buds. The main objectives of this project are to investigate the physiological mechanisms underlying the response of survival and growth of regenerated buds to high temperature in different stages of development so as to determine the stage of development in which survival and growth of regenerated buds are most sensitive to high temperature. Furthermore, this project will explore whether water management optimization could alleviate the effects of high temperature on survival and growth of regenerated buds, and to elucidate the regulatory mechanism of water management on the survival and growth of regenerated buds under high temperature stress. The results of this project will lay the foundation on breeding and crop management to relieve the high temperature stress on ratoon rice.