干旱对蚕豆植株自叶部施加的P^(32)的运输和分配的影响

Ieaves of Broad Bean Plant(Vitta faba L.).

一、前言在干旱地区自然分布的植物,多具有大的根系和矮小的地上部。栽培作物在遭受土壤干旱时,地上部的生长亦显著地受到抑制,而根系则相对地比较发达;不过植株的总的生长量要减少很多。这是一种对干旱的反应。其物质基础不外是:1)干旱使植物光合作用降低了;2)干旱使光合作用产物的运输方向发生比例上的变化。干旱对光合作用的影响,已有若干报导(2);但对光合作用产物的运输,则研究较少。

The absorption of foliar applied P^(32)-phosphate by broad bean plants is decreased afterdrought treatment.But the proportion of p^(22) translocated into plant body still remains the same.Under conditions of serious drought,absorbed p^(32)is distributed relatively more to roots than inshoots.During severe drought,the translocation of absorbed p^(32)into the upper level leaves andterminal buds is decreàsed to a lowest degree.After severe drought,if water supplied,p^(32)absorption and translocation may recover.As theresult of the severe drought the growth decreases,although the specific activity of P^(32)has in-creased,and the total amount of p^(32)in upper shoots is,however,lower than the control treatment.We call this fact“retarding effect of drought”Drought has almost the same effect on the translocation and distribution of foliar absorbedp^(32),as on vegetative growth.