Arid Zone Research ›› 2021, Vol. 38 ›› Issue (2): 469-478.doi: 10.13866/j.azr.2021.02.18

• Plant and Plant Physiology • Previous Articles     Next Articles

Response of growth and root morphological characteristics of Reaumuria soongorica seedlings to drought-rehydration

YANG Biaosheng(),SHAN Lishan(),MA Jing,XIE Tingting,YANG Jie,WEI Changlin   

  1. College of Forestry, Gansu Agricultural University, Lanzhou 730070, Gansu, China
  • Received:2020-06-16 Revised:2020-08-23 Online:2021-03-15 Published:2021-04-25
  • Contact: Lishan SHAN E-mail:990640315@qq.com;shanls@gsau.edu.cn

Abstract:

Plant adaptation to drought includes drought resistance during drought stress and recovery after rehydration following drought stress. Therefore, it is essential to understand the physiological mechanism of plant drought resistance by studying changes in seedling growth and root morphological characteristics under drought and rehydration conditions. In this experiment, drought stress and rehydration were emulated by controlling the soil moisture of potted plants. The basal diameter, plant height, biomass, and root morphological indices of Reaumuria soongorica seedlings under drought-rehydration conditions were determined, and the responses of their growth, biomass distribution, and root morphological characteristics to drought-rehydration were analyzed. Compared with the appropriate water content, the relative increment of basal diameter and plant height, the aboveground, underground, and total biomass of R. soongorica seedlings were significantly reduced under drought stress (P<0.01). The relative increment of the basal diameter of R. soongorica seedlings under drought stress showed a decreasing trend with time. The relative increments of the basal diameter and plant height of R. soongorica seedlings were larger under moderate and severe stress after rehydration, which indicated that the aboveground part of R. soongorica seedlings grew faster after rehydration under severe drought stress. Additionally, compared with the suitable water, the specific root length of R. soongorica seedlings increased significantly under drought stress (P<0.01), indicating that R. soongorica seedlings could adapt to drought stress by elongating their roots. After rehydration, the total root length, root surface area, and total root volume of R. soongorica seedlings decreased, while the root diameter of R. soongorica seedlings increased (P<0.01), indicating that the root resilience of R. soongorica seedlings was weakened under severe stress. In summary, during drought stress, R. soongorica seedlings responded to the stress environment by accelerating the growth of their basal diameter and roots and storing more substances, showing stronger resistance. After rehydration, R. soongorica seedlings were restored by accelerating the growth of their overground parts and increasing root diameter and specific root length, which was helpful to improve their strong recovery ability.

Key words: Reaumuria soongorica, drought stress, rehydration, growing development, root morphology