杂交水稻种子萌发中ATP杂种优势初探

A Preliminary Study on ATP Heterosis in Hybrid Rice Seed During Germination

本文以两种杂交水稻及其亲本为材料,研究了28℃下种子萌发过程中ATP杂种优势表现及ATP水平的变化与水分吸收,呼吸速率和胚生长等生理活动间的关系。结果表明:干种子的ATP含量很低,吸胀初期有一个快速增长的初始阶段。24h后ATP量的增加变缓,但仍呈上升趋势,无明显的停滞阶段。ATP水平的变化与种子吸水量和呼吸速率的关系甚为密切,其与两者的相关系数(r)均达极显著水平。杂交稻种子在萌发过程中其ATP水平一直处于父母本的中间,ATP杂种优势分别达19.9％(威优64)和8.5％(汕优6号)。说明F_1的ATP水平受其亲本遗传的控制,并且倾向于母本不育系。种子萌动速率也表现为中间型,与ATP水平有较好的相关性,但胚的生长却明显超过其父母本,超亲优势达20.3％。

ATP heterosis and dynamics of ATP level of two hybrid rice and their parents at 28℃ during 0-60 hours of seed germination were studied.The dry seeds contained ATP to a certain extent. After the seed was soaked, ATP level was characterized by an initial rapid increase at the beginning of seed imbibition. After 24-60 hours of germination the augmentation rate of ATP level decreased progressively without any lag phases. The magnitude of the ATP level was highly correlated to the increase of the water uptake by the seeds and to the respiratory rate with highly significant correlation coefficients (p<0.01). As being compared to the parents, the ATP level of hybrid rice seeds tended to be intermediate between parents during the germination. The ATP level of hybrid vigor was 19.9% and 8.5% for Wei-You 64 and Shan—You 6 respectively, indicating that the ATP level of F_1 was controlled by parental heredity and tended to the ATP level of parents sterile line. The seed germination rate of hybrid rice belonged to the intermediate type, and correlated to the ATP level. However, the embryo growth was faster than its parents with a transgression of 20.3%.