摘要
在控制条件下研究了锌营养状况对几种双子叶植物(向日葵、莱豆、苹果、棉花和番茄)根分泌低分子量有机化合物如氨基酸、糖类和酚类的影响。缺锌导致根分泌物增加,随着介质供锌浓度的增加,根分泌有机物质的量逐渐减少,充分征明锌在细胞膜稳定性方面的重要作用。与对照植物相比较,缺锌植物的根分泌物能够使石灰性土壤中铁和锰的活化率提高1.6～2.1和2.7～3.5倍,而对锌的活化作用却不明显。
The effect of zinc nutritional status on root exudation of lowmo- lecular-organic substances was studied in sunflower,bean,apple,cotton and tomato grown in nutrient solutions under controlled environmental conditions. Zinc deficiency increased root exudation of amino acids,sugar and phenolics in various dicotylenous plants studied.With the increase in the supply concen- trations of zinc the release of amino acids,sugar and phenolics was decreased. Root exsudates of zinc deficient sunflower and tomato plants mobilized 1.6～2.1 and 2.7～3.5 times more iron and manganese from a calcarous soil (luvisol)than that of zinc sufficient plants,but the zinc mobilization rates remained no diffe- rent.The role of root exudates in the plant nutrition was also discussed.
关键词
双子叶植物
根分泌物
活化作用
锌
dicotylenous plants
root exudation
mobilization
zinc
