文章采取盆栽试验，外源应用5个不同浓度ABA（0、10-7、10-6、10-5、10-4 mol·L-1)浇注玉米幼苗根系，测定幼苗地上部鲜重、地下部鲜重、根冠比、根表面积、根体积、根长、根干重变化。结果表明，同一低温胁迫时间下， ABA使用表现出低促高抑效应（表现为10-5 mol·L-1>10-6 mol·L-1>10-7 mol·L-1>0 mol·L-1），其中10-5 mol·L-1处理达到显著水平；同一ABA浓度处理下，幼苗增长率表现为低温处理中期（2~4 d和4~6 d）大于前期（0~2 d）和后期（6~8 d）。说明在一定低温胁迫时间范围内，适宜浓度ABA通过对玉米幼苗根系生长调控，能缓解一定程度低温胁迫，提高作物抗寒性。%Setting treatment of ABA at five levels (0, 10-7, 10-6, 10-5, 10-4 mol·L-1) and watering the roots of maize seedlings to measure changes in fresh weight of shoot and root, root/shoot ratio, root surface area, root volume, root length, root dry weight of seedling. The results showed that the application of exogenous ABA presented a promoting effect at low concentration and al inhibiting effect at high concentration at the same time under low temperature stress (performance for 10-5 mol·L-1>10-6 mol·L-1>10-7 mol·L-1>0 mol·L-1), the 10-5 mol·L-1 treatment which had reached significant level. Under the same concentration of ABA treatment, the growth rate of seedling under the middle of low temperature stress(2-4 d and 4-6 d) was greater than the prophase of low temperature stress(0-2 d) and the late stage of low temperature stress(6-8 d), above results indicated that, within a certain range of low temperature stress, appropriate concentration of ABA could regulate the root growth of maize seedling, could al eviate low temperature stress in some degree, so as to improve the cold resistance of maize.
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