【作者】 钟平安； 刘凯； 况慧云； 冯利； 黄英金；

【Author】 ZHONG Ping-an LIU Kai KUANG Hui-yun FENG Li HUANG Ying-jin~* (Jiangxi Agricultural University,Nanchang 330045)

【机构】 江西农业大学农学院；

【摘要】 将水稻胚乳组织的发育细分为胚乳细胞的增殖和胚乳细胞的充实两个过程,旨在从胚乳组织的发育过程及其穗内不同粒位间的同步性探明籽粒耐高温逼熟的抗性机制。研究结果表明,乳熟期高温胁迫对胚乳细胞增殖速率和增殖持续时间有明显影响。与高温逼熟敏感基因型相比,高温逼熟耐性强的基因型表现为起始增殖势高,最大增殖速率及平均增殖速率大,胚乳的细胞数目多,强、弱势粒达最大增殖速率的时间在粒位间的差异小, 强、弱势粒胚乳细胞增殖的同步性好。乳熟期高温胁迫使胚乳最终重量、起始增重势、最大增重速率及平均增重速率均降低,活跃增重期及增重持续期缩短,到达最大增重速率时间延迟,增重速率为最大时的重量占胚乳最终重量的比值增加,但高温逼熟耐性强的基因型其变化幅度明显小于高温逼熟敏感基因型。根据研究得到的胚乳细胞增殖动态与胚乳干重增重动态的相关性结果,对籽粒耐高温逼熟的育种及栽培调控应着眼于弱势粒胚乳细胞的增殖。更多还原

【Abstract】 Endosperm tissue development of heat-tolerant rice genotype was divided into two stages as pro- liferation and filling in this studies in order to reveal resisting mechanism of grain resisting heat-forced maturity through researching endosperm tissue development and its synchronization of different position grains.The re- sults indicated that,there was an obviously effect of high temperature during milky stage on proliferation rate and the time of reaching the end of proliferation of endosperm cell.Compared to heat-sensitive rice genotype, the characteristics of heat-tolerant rice genotype were as follows:R₀（the initial proliferation potential of en- dosperm cells）,G_max（the maximum rate of proliferation of endosperm cells）,G_mean（the mean proliferation rate of endosperm cells）and the number of endosperm cell were higher,the difference of t_max.G of SG（Superior grains）and IG（Inferior grains）was smaller and the synchronization of their endosperm cell proliferation was better.Under the condition of high temperature stress during milky stage,A（the eventual weight）,R₀（the initial grain-filling potential）,G_max（the maximum increasing rate）and G_mean（the mean increasing rate）all de- creased,D（active increasing duration）and t_99%A（the time of reaching the end of weight）shortened,t_max·G（the time reaching the inflexion）postponed and Ⅰ（the ratio of the weight at the time of reaching the inflexion con- tributed to the final grain weight）increased.While the changing range of heat-tolerant rice genotype was small- er than that of heat-tolerant rice genotype.According to the correlated results studying on the dynamics of en- dosperm cell proliferation and dry weight of endosperm,it should pay attention to proliferation of endosperm cell of IG on breeding and cultivate regulation of grain resisting heat-forced maturity in rice.更多还原