黄独珠芽生长期内源激素及糖类物质含量的变化

Variation of Endogenous Hormone and Carbohydrate Contents in Growing Bulbils of Dioscorea bulbifera

测定了不同生长阶段的黄独(Dioscorea bulbifera)珠芽内源激素IAA,ZR,DHZR,GA3和ABA的含量,以及可溶性糖、淀粉和干物质的含量,研究其变化规律。结果表明,在珠芽嫩绿到表皮完全变褐的生长过程内源激素IAA,ZR,DHZR,GA3和ABA呈不同的变化曲线增加,表皮完全变褐时达到最高值[分别为516.1,1 525.4,417.5,1 068.2,855.7 ng/g(FW)],到珠芽成熟时这些激素含量又下降。可溶性糖、淀粉和干物质含量在珠芽从嫩绿到生长停止的过程中以不同轨迹增加,到珠芽生长停止时达到最高值(分别为18.0 mg/g,13.6%和27.0%)。以上结果说明,促进珠芽生长的内源激素IAA,ZR,DHZR和GA3的增加过程持续到珠芽表皮完全变褐,而ABA含量也到珠芽表皮完全变褐时才急剧上升到最高值,所以在珠芽表皮完全变褐时生长未停止,到茎蔓枯黄时可溶性糖、淀粉和干物质的含量才达最高值。本研究结果为珠芽的生长调控和适时采摘提供参考。

Contents of endogenous hormones IAA,ZR,DHZR,GA3,ABA,soluble sugar,starch and dry matter in bulbils of Dioscorea bulbifera were tested over developmental cycle.The results showed that the contents of endogenous IAA,ZR,DHZR,GA3 and ABA rose in different curve before the bulbils browned completely.The contents of IAA,ZR,DHZR,GA3 and ABA reached the peak[516.1,1 525.4,417.5,1 068.2,855.7 ng/g(FW),respectively] once the bulbils became brown completely,then those contents declined when the bulbils became mature.The contents of soluble sugar,starch and dry matter increased during the developing stage,and those content climbed the peak(18.0 mg/g,13.6% and 27.0%,respectively)at last.The results indicated that the content of IAA,ZR,DHZR and GA3(endogenous hormones promoting bulbils grow) did not decrease until the bulbils became mature,while at the same time the content of ABA was the maximum.Therefore the content of soluble sugar,starch and dry matter did not decrease and the bulbils did not stop growing until the vines on which the bulbils grew were dry.This result will direct regulating bulbil growth and harvesting bulbil at proper time.