不同发育时期黄皮种子脱水敏感性的研究

STUDIES ON DESICCATION SENSITIVITY OF WAMPEE SEED IN DIFFERENT DEVELOPMENT STAGES

摘要:

自花后４６ｄ到８８ｄ果实成熟．黄皮种子的发芽率由０升至１００％．而活力指数逐渐上升，到花后７４ｄ达到最大值，之后略有下降．每粒种子的呼吸强度在花后４６－６７ｄ持续增加，此后则渐渐减弱，但湿藏２ｄ后又回升．黄皮种子的发育明显超前于果实．花后７４ｄ时．每粒种子的干重已接近最大值，这时种子活力最大．而果实的鲜重虽然已接近最大值．但其干重却只有成熟时的７３％。花后４６－５３ｄ的种子，其发芽率小于１００％，轻微脱水能提高种子的发芽率及活力指数，花后６０ｄ至果实成熟．种子发芽率均为１００％．这时任何程度的脱水都会引起活力指数的下降，但不同发育时期的黄皮种子耐脱水力有差别．其中以花后６７ｄ的耐脱水力最强．花后８８ｄ果实成熟时种子的耐脱水力最弱。

Abstract:

When wampee seeds developed from 46 days after anthesis (DAA) to fruit maturation,the germination Percentage rose from zero to 100%, while the visor index rose from zero and attained maximum value at 74 DAA, and then dropped down slightly. The respiratory rate pergram dry weight decreased continuously, but that on per seed basis increased constantly during 46-67 DAA and fell afterwards, then rose again after wet-storage for one day. The seeds developed ahead of the fruit, the dry weight Per seed reached nearly maximum value at 74 DAA with maximum vigor index, meanwhile, the fresh weight Per fruit reached nearly maximum value, but its dry weight was only 73% of that at ripening stage. The germination percentage of the seeds during 46-53 DAA was less than 100%. Mild desiccation could improve the seed germination percentage and vigor index, and the germination percentage from 60 DAA to the days of fruit maturation were all 100%. In this Period any degree of the seed desiccation could decrease the vigor index. However, the desiccation-sensitivity of seeds during various development stages was different, among which, seeds at 67 DAA had the lowest desiccationsensitivity, while seeds at 88 DAA (maturation) had the highest.