珍稀濒危植物珙桐果实中的萌发抑制物质

GERMINATION INHIBITORS IN FRUIT OF RARE AND ENDANGERED DAVIDIA INVOLUCRATA

许多研究表明 ,抑制物的存在是导致种子休眠的重要原因 .珍稀濒危植物珙桐的种子具有很长的休眠期 .通过对果实中抑制物质的初步分离 ,结果显示 ,除内果皮和胚乳外 ,其果肉中也存在大量抑制物 ,其抑制活性分别为果肉>内果皮 >胚乳 .果肉提取物经柱层析得到 2 4个组分 ,绝大部分组分具有抑制作用 .内果皮和胚乳提取物经系统溶剂法分离 ,结果表明 ,内果皮中抑制物质主要存在于乙醚相、乙酸乙酯相和甲醇相中 ,胚乳中抑制物质主要存在于甲醇相和乙醚相中 .大量抑制物质的存在是珙桐种子休眠期长的一个重要原因 .图 4参

Many researches demonstrated that the existence of inhibitor likely caused seed dormantly. There was a long dormant period in seed of rare and endangered Davidia involucrata . It was therefore proposed that there were probably a lot of inhibitors in pulp,as well as in endocarp and endosperm. By isolating the inhibitors in D. involucrata fruit,the results supported the idea that there existed a number of inhibitors in pulp besides endocarp and endosperm. The bioassay revealed the order of inhibitory effect: pulp>endocarp>endosperm. Twenty-four components were isolated from pulp by column chromatography,and most of them could inhibit germination of Blassica chinensis seed and its radical elongation.The inhibitors of endocarp and endosperm were isolated by using a series of solvents. The results indicated that the inhibitors of endocarp were in the phases of methanol,acetic acid ethylester and diethyl ether. However,the inhibitors of endosperm mainly were in methanol and diethyl ether. The existence of inhibitors was possibly one of the important reason,why there was a long dormant period in seed of D. involucrata . Fig 4,Ref 17