玉米耐低钾的根系吸收机制初探

探讨玉米耐低钾的根系生理机制。以筛选出的典型耐低钾的玉米自交系T1、T2和不耐低钾玉米自交系S1、S2为试材,利用4个水平钾浓度(0、0.625、1.250和2.500 mmol/L)的水培方法,研究低钾胁迫对不同耐性玉米自交系根系形态和吸收能力的影响差异。低钾胁迫下,耐低钾玉米自交系的根数、总根长、根表面积、根体积和根干重均大于钾敏感玉米自交系,而根平均直径明显小于钾敏感玉米自交系。从钾吸收效率来看,不同耐性自交系间存在显著差异,而钾利用效率方面差异不显著,相对于不耐低钾自交系S1和S2,耐低钾自交系T1和T2对缺钾的抗性主要表现在低钾条件下,根系具有较强的钾吸收能力。低钾胁迫下耐低钾玉米自交系具有较强的吸钾能力。

Preliminary Study on Root Absorption Mechanism of Low-potassium Tobleranee in Maize

The aim of the research was to discuss the root physiological mechanism of low-potassium tolerance in maize.With maize inbred lines T1 and T2(tolerant to low-potassium),maize inbred lines S1 and S2(sensitive to low potassium) as tested materials,water culture method with 4 levels of potassiumconcentrations(0,0.625,1.250 and 2.500 mmol/L)was used to study the difference in the effects of low-potassium stress on the root morphology and ab-sorption capacity of maize inbred lines with different tolerances.Under low-potassium stress,the root number,total root length,root surface area,root volumeand root dry weight of maize inbred lines with low-potassium tolerance were all higher than that of maize inbred lines with sensitivity to low-potassium andthe average diameter of root were lower than that of maize inbred lines with sensitivity to low-potassium. For potassium absorption effieiency,maize inbredlines with different tolerances existed significant differenees and the difference of potassium utilization efficiency was not significant.Compared with nmizeinbred lines S1 and s2 with sensitivity to low-potassium,the resistance of maize inbred lines T1 and T2 with low-potassium tolerance to potassium deficiencymainly represented that the maize root had the stranger potassium absorption capacity under low potassium conditions.Maize inbred lines had stronger ab-sorption capacity to potassium.