根际通气状况对盐胁迫下棉花幼苗生长的影响

以溶液培养的棉花(Gossypium hirsutum)幼苗为材料,测定了不同盐胁迫程度和不同通气状况下棉花幼苗株高、根系体积、根系和茎叶生物量以及灰分含量的变化,以探索根际通气状况对盐胁迫下棉花生长的影响。结果表明,盐胁迫抑制棉花植株生长,表现为植株变矮、叶面积减小和干物质积累下降;根际环境通气不良也会导致棉花幼苗生长受抑制、干物质积累下降和矿质元素吸收减少等。进一步比较盐胁迫和根际通气状况及两者组合作用对棉苗生长的影响,发现盐胁迫对株高和总生物量的影响较大,而根际通气状况对根系体积、根系生物量、根冠比和矿质元素吸收的影响较大。总体表现为:盐胁迫对茎叶生长的不利影响较大,而根际通气状况对根系生长的不利影响较大。同时,在根际环境通气良好的条件下,不同程度盐胁迫导致的棉花幼苗株高、根系体积、叶面积、根系生物量和总生物量的变化程度远小于根际环境通气不良条件下的变化程度。实验结果表明,根际环境通气良好可以减弱盐胁迫对棉花生长发育的抑制作用,而根际环境通气不良则会加重盐胁迫的不利影响。

Effect of Rhizosphere Ventilation on Growth of Cotton Seedlings Under Salt Stress

We examined the effect of rhizosphere ventilation and salt stress on the growth of cotton seedings cultivated in nutrient solution. The changes in plant height, root volume, shoot and root biomasses as well as ash content in cotton seedlings were examined to investigate the effect of rhizosphere ventilation on the growth of cotton under salt stress. Salt stress inhibited the growth of cotton and led to decreased plant height, leaf area and dry weight; poor ventilation also decreased plant height, dry weight and mineral element absorption. A further comparison of the effect of rhizosphere ventilation and the combined effect of rhizosphere ventilation with salt stress showed a prominent effect of salt stress on plant height and total biomass, with a striking effect of rhizosphere ventilation on root volume, root biomass, root-to-shoot ratio and mineral element absorption (i.e., the adverse effect of salt stress was mainly exhibited on stems and leaves, and that of rhizosphere ventilation on root growth). In addition, the variation in cotton seedlings in terms of plant height, root volume, leaf area, root biomass and total biomass in the rhizosphere ventilation conditions was smaller than those in seedlings without ventilation. Rhizosphere ventilation could increase plantlet height, leaf area, dry weight, thereby alleviating the adverse effect of salt stresses.