R436与6个不育系杂交的F_(1)种子抗老化能力的差异及其与母本的相关性

Differences in Anti-aging Ability of F_(1) Seeds Produced by Crossing R436 with Six Male Sterile Lines and Their Correlation with Maternal Inheritance

杂交稻杂种优势利用极大地增加了水稻产量,但杂交稻种子普遍抗老化能力差、不耐贮藏的问题一直备受关注。为了解杂交稻亲本对F_(1)种子抗老化能力和贮藏耐性的影响及其生理生化机制,本文通过种子人工老化法、萌发率和相关生理指标的测定及数据统计分析,对恢复系R436、6个不育系母本(龙S、凤S、中丰S3、中丰S2、株712S和广8A)及其F_(1)种子的抗老化能力和相关生理指标进行了比较和相关性分析。结果表明:未老化的种子中,R436、龙S、凤S、中丰S3、中丰S2和所有F_(1)种子活力高,株712S和广8A种子活力低;除凤S/R436种子外,其他杂交稻种子在老化8 d后的活力指数均高于亲本,暗示绝大多数F_(1)种子的抗老化能力优于亲本种子,表现出超亲优势。多数F_(1)种子老化处理前后的相对电导率皆低于母本种子;多数F_(1)未老化种子的丙二醛(malondialdehyde,MDA)含量均高于亲本种子,而老化后MDA上升幅度与母本种子基本一致。与未老化种子相比,多数老化种子的过氧化氢酶(catalase,CAT)、超氧化物歧化酶(superoxide dismutase,SOD)和过氧化物酶(peroxidase,POD)的活性上升;其中,F_(1)种子老化处理前后SOD活性的变化模式与母本种子十分相似。基于种子老化处理前后萌发率与生理指标相关性分析结果推测,选用种子活力高,且CAT和POD活性低,而SOD活性高的不育系和恢复系配组,可能生产出耐贮藏、抗老化的杂交稻种子。

Utilization of hybrid rice heterosis has greatly increased the rice yield,but the poor aging resistance and storage intolerance of hybrid rice seeds have always been problems of common concern.To understand the effects of hybrid rice parent lines on the anti-aging ability and storage tolerance of F_(1)seeds and the physiological and biochemical mechanisms,the unaged and artificially aged seeds of restorer line R436,six male sterile lines(Long S,Feng S,Zhongfeng S3,Zhongfeng S2,Zhu 712S and Guang 8A)and their F_(1)lines were used as materials,and seed germination rate and related physiological indexes were measured and analyzed statistically.The results showed that unaged R436,Long S,Feng S,Zhongfeng S3,Zhongfeng S2and all F_(1)seeds had high vigor,while Zhu 712S and Guang 8A seeds had low vigor,and except Feng S/R436 F_(1)seeds,the vigor index of other hybrid rice F_(1)seeds was higher than that of their parents after 8days of aging,which means the anti-aging ability of most F_(1)seeds is superior to that of their parents,i.e.heterobeltiosis.The relative conductivity values of the soaking solution of most F_(1)seeds before and after aging treatment were lower than that of the maternal seeds.The malondialdehyde(MDA)content in most unaged F_(1)seeds was higher than that in the parental seeds,and the rise level of MDA after seed aging was basically the same as that in the maternal seeds.Compared with unaged seeds,most aged seeds had increased activities of antioxidant enzymes including catalase(CAT),superoxide dismutase(SOD)and peroxidase(POD).The SOD activities in F_(1)seeds before and after aging treatment were very similar to that in maternal seeds.Based on the correlation analysis between germination rate and physiological indexes before and after seed aging treatment,it was speculated that the combination of restorer lines and sterile lines with high seed vigor,low CAT and POD activities,and high SOD activity,may produce storable and anti-aging hybrid rice seeds.