金钟藤种子低萌发率原因探讨

Probing the cause of the low germination rate of Merremia boisiana seed

关键词:  藤本植物  种皮透水性  种子活力  种子内源抑制物  萌发率

Key words:  liana  seed coat permeability  seed vigor  seed endogenesis inhibitor  germination

摘要:

金钟藤种子在室内萌发率很低，为进一步探讨金钟藤种子的特性，阐明其种子萌发率低的主要原因，对金钟藤种皮的透水性、种子解剖结构、种子活力和种子内源抑制物的生物测定进行了研究。结果表明：金钟藤种皮透水性较差，完整种子比破皮种子吸水达到最高水平慢38 h；种子空瘪粒多，占所有种子的30%；种子活力较低，平均活力仅为35%；金钟藤种子甲醇粗提液对白菜种子萌发率、根长和芽长均有较强的抑制作用，其浸提液浓度在25 mg/mL时，严重抑制白菜种子萌发和生长，即金钟藤种子内部含有较高的内源抑制物质。金钟藤种子萌发率低，表明其近年来突发性蔓延成灾主要不是由种子生成新个体造成的，导致其蔓延成灾的关键因素还需要进一步深入研究。

Abstract:

To find out the reasons for its indoor low germination rate，the permeability of seed coat，seed anatomical structure，seed vigor and seed endogenesis inhibitors were examined. The results showed that the permeability of seed coat was poor. Chipped seeds reached the highest value of water absorption in less than 38 h as the intact seeds. The proportion of empty seeds was as high as 30%. Seed vigor was low and averaged at 35%. The germinability，shoot and root growth of cabbage seeds were significantly inhibited by methanol extracts of M.boisiana seeds. When methanol extracts of seeds reached a concentration of 25 mg/mL，germination and growth of cabbage seeds were seriously inhibited，suggesting rather high content of endogenesis inhibitors in M.boisiana seeds. Low germination rate of M.boisiana seeds indicated that seed's generation of a new plant was not the main reason for the outburst overspread disaster in the recent years, and the key factors should be further researched.