干旱-复水对菊芋苗期根、茎、叶形态特征的影响

Effect of drought stress and re-watering on the morphological characteristics of root,stem,and leaf in Helianthus tuberosus

通过盆栽试验研究干旱-复水对菊芋(Helianthus tuberosus)苗期根、茎、叶、茎叶比、根冠比和物质积累量的影响,探讨菊芋苗期干旱适应机制,干旱半干旱地区菊芋栽培管理提供参考。结果表明:干旱-复水处理菊芋根、茎、叶生物量和总生物量均低于正常水分管理;干旱-复水增加了主根和须根的直径;干旱-复水过程中除复水第16天外,处理须根长度均高于对照;处理前期主根长度高于对照,后期主根长度低于对照;干旱-复水处理提高了菊芋平均叶面积,降低了叶片数量,抑制新叶片的形成;干旱胁迫第2天测定的茎叶比对照高于处理,而其他取样时间处理均高于对照;干旱-复水过程中菊芋根冠比胁迫第2天高于对照,胁迫第4天、第8天和复水第8天处理根冠比低于对照,复水第16天处理高于对照。

Using pot experiments,we examined the effects of drought stress and re-watering on root,stem,leaf,stem/leaf ratio,root/shoot ratio,and biomass in Helianthus tuberosus The following results were obtained.Root,stem,leaf biomass,and total biomass in treated plants were lower than those in control plants.The diameter of the taproot and fibrous roots was increased.During drought stress and re-watering,the lengths of fibrous roots were greater than those in control plants,and the length of the taproot was greater than the control during drought stress but lower than the control during re-watering.The mean leaf area of treated plants was higher than that of control plants,and the number of leaves were lower than that in control plants.The stem/leaf ratios of treated plants were all higher than those of control plants,except on the second day of measurement.During drought stress and re-watering,the root/shoot ratio of treated plants under drought stress on the second day of measurement and re-watered plants at 16 days was higher than that of the control plants,but lower than that of control plants on the fourth and eighth days under drought stress and eighth day under re-watering.