无机磷形态对甜菜生长和磷吸收的效应

采用液培和砂培法,进行了不同基因型甜菜对外源无机磷吸收利用研究。结果表明:1)生长介质中有效性无机磷含量的高低,直接影响各参试甜菜品种磷的吸收效率和利用效率,且表现出明显的基因型差异;2)参试的3个品种对生长介质中不同形态无机磷的吸收表现出明显的生物多样性特点,并主要体现在Ca8-P以上形态的磷;3)在缺磷和足磷条件下,各参试甜菜品种根际周围的pH值均有不同程度的差异,但与品种的抗耐低磷胁迫能力关系不大,相差的pH值不足以显著增加土壤中Ca8-P以上形态磷的有效性。4)各甜菜品种须根系的长度与抗低磷胁迫指数呈高度一致性,是造成不同品种对难溶性无机磷胁迫抗耐能力差异的主要原因。

Effects of Pi Form on the Growth and P Uptake by Sugarbeet

Studies on the uptake,utilization of exogenous inorganic P in different sugarbeet genotypes were conducted by means of liquid and sand culture.The results showed that: 1)the values of inorganic P content in the growing substrates had a direct influence on P efficiency of uptake and utilization in sugarbeet varieties,and demonstrated significantly genetic difference;2) the uptake of different form inorganic P in the 3 varieties varied greatly,mainly presented in Ca8-P or more unavailable P form;3) under sufficient and insufficient P conditions,the pH values in the root vicinity of all 3 varieties used in this trial had some differences,but had little relationships with resistant ability to P stress,i.e.the lowered pH can not significantly affect the availabilities of Ca8-P or more unavailable P form;4) the total length of fibre in each variety was highly coordinated with its resistant ability to P stress,this was the key reason for the difference of resistant ability to P stress in different varieties.