萌发后回干对种子耐贮藏性和再萌发的影响研究

Study on Re-Germination and Storage Ability on Dehydration Wheat (Triticum aestivum L.) Seeds after Germination

摘要:

小麦是抗旱性、抗寒性非常好的单子叶作物，也是世界性的粮食作物，其种子具备诸多优良特性。种子引发是提高种子活力的有效方法，然而，引发的技术需要严格控制好时间，要在胚根突破种皮以前开始回干，如果引发时间控制不当或回干不及时就可能导致胚根突破种皮或胚芽生长。为了探索小麦种子引发不当产生的后果对小麦的影响，本研究以泰山22和石麦20为试验材料，试验设种子胚根突破种皮、胚芽1~1.5 mm和胚芽2.5~3 mm的再回干三个处理，以种子的发芽率等指标评价小麦种子的再萌发能力，并通过将经处理的种子分组进行不同时长的贮藏对其耐脱水性和耐藏性进行研究。结果表明，短期贮藏对过度引发小麦种子二次萌发能力影响较小，即使胚芽伸长3 mm再贮藏30 d的回干种子依然可以继续发芽和生长，但发芽率和活力指数分别比对照下降。回干对种子的生长状态有明显影响，胚根脱水耐性较差，回干后死亡，需要重新发根，胚芽的耐脱水性较好，回干不会导致胚芽的死亡。此外，过度引发后种子的抗霉菌污染力减弱。综上，过度引发会对小麦种子会产生不良影响，虽然不会致死，但会导致种子种用价值降低。

Abstract: Wheat is a good monocot crop with drought and cold resistance. It is also a worldwide food crop. Its seeds have many excellent characteristics. Seed priming is an effective way to improve seed vitality. However, the technology of seed priming requires strict control of the time. It is necessary to stop the priming before the radicle breaks through the seed coat. If the time is not controlled or returned to the dry, the radicle may break the seed coat or the germ growth. In order to explore the effects of over priming of wheat seeds, Taishan 22 and Shi Mai 20 were used as experimental material after treatment by priming to the seeds radical broke through the seed coats, the germ 1~1.5 mm and the germ 2.5~3 mm to evaluate the germination capacity of the wheat seeds with the germination rate of the seeds, and to research the seed desiccation tolerance and storability through a period of 30 days storage. The results showed that short term storage had less effect on the capacity of re-generation of wheat seeds. Even if the sprout elongating 3 mm was stored to 30 d, the sprout seeds could still continue to germinate and grow, but the germination rate and vigor index were lower than those of the control. The growth of the seeds has an obvious effect on the growth state of the seeds. The elongated seed root is sensitive to dry; all the roots are dead after dehydration. It needs to be re-rooted. The dehydration of the germ is better, rehydration will not lead to the death of elongate buds, and the anti-fungal contamination of the seeds after excessive initiation is weakened. In conclusion, over priming wheat seeds will have bad effects, which will not cause death, but will lead to the reduction of seed use value.