杂交稻种子在不同处理下的抗老化能力及其生理生化变化的研究

AGING TOLERANCE OF HYBRID RICE SEEDS UNDER DIFFFRENT TREATMENTS AND THE PHYSIOLOGICAL AND CHEMICAL CHANGES IN THE AGED SEEDS

用４种含水量（９．６％，１１．４％，１３．１％，１４．６％）和２种包装处理（塑料袋密封、纱布袋）研究了灿型杂交稻种子在人工加速老化条件下的抗老化能力及生理生化变化。结果表明，在纱布袋包装条件下，经５０℃，ＲＨ１００％老化１０ｄ后，其发芽势、发芽率和发芽指数除含水量为１４．６％的明显较低外，其它３种含水量间差异不大；而塑料袋密封包装的种子，不同含水量间差异明显，其发芽势、发芽率和发芽指数随着含水量的增加而下降。保持种子含水量在１１％甚至１０％以下，有利于延缓和控制杂交稻种子的衰老，提高耐藏性。试验还表明，过氧化物酶（ＰＯＤ）、过氧化氢酶（ＣＡＴ）活性与种子活力保持相同的变化趋势，而种子浸泡液电导率和丙二醛（ＭＤＡ）含量则与活力呈显著负相关。）和０．８７９２￣（）。过氧化物酶活性变化与过氧化氢酶基本相同，酶活性与发芽率和发芽指数的相关系数分别为ｒ＝０．８７６４￣（）和０．９１２５￣（）。２．３电导率的变化表３是将种子浸泡１０ｈ，１８ｈ和２４ｈ测定的浸泡液的电导率。结果表明，人工老化处理后增加了种子浸泡液的电导率，说明杂交稻种子经人工老化后，细胞膜的完整性受到损伤，膜透性增大，电解质外渗增加，导致浸泡液导电性增大?

Hybrid rice seeds with four levels of moisture content (9.6%,11.4%,13.1%,14.6%)and two kinds of packs(gauze,plastic film)were artificially aged at 50℃RH100%for 10 days so as to study their aging tolerance and physiological and biochemical changes during their aging.The results indicated:When seeds were sealed in gauze pockets,the germination energy,germination percentage,germination index of seeds with M.C.14.6%were obvi-ously lower,but there were less difference among those with other M.C.When seeds were sealed in plastic film pockets,the differences in germination performance were significant.They decreased with the increase in seed moisture content.It' s advantageous to the retarda-tion of aging of hybrid rice seeds and their storability to keep the moisture content lower than 11%even 10 %.The changes in the POD and CAT activity were similar to those in the seed vigour,but the electrical conductivity and MDA content were negatively correlated to the vigour of the aged seeds