干旱胁迫与复水对苦荞生长及叶片内源激素含量的影响

以耐旱型苦荞(迪庆苦荞)和旱敏感型苦荞(黑丰一号)为试验材料,采用盆栽人工控水试验,研究了干旱胁迫与复水对不同耐旱型苦荞品种的生理及形态指标的影响,为苦荞的抗旱稳产栽培提供理论依据。结果表明:干旱胁迫显著影响了苦荞生长,表现为株高、茎粗、叶面积、茎叶干重、根系体积、根系表面积、根系平均直径、根系干重、根系活力、根系可溶性蛋白含量均显著低于对照;花期复水后影响得到缓解,表现为各项指标均有所恢复。其中,茎叶干重恢复最佳,干旱胁迫下的迪庆苦荞与黑丰一号相比,茎叶干重增加了54.81%,复水处理与干旱处理相比,迪庆苦荞和黑丰一号分别显著增加了83.78%、47.28%。根系超氧化物歧化酶活性、过氧化物酶活性、丙二醛含量、迪庆苦荞的根系可溶性糖含量和游离脯氨酸含量均显著高于对照处理。干旱胁迫下苦荞叶片生长素(indole-3-acetic acid,IAA)含量显著降低,脱落酸(abscisic acid,ABA)含量显著升高,复水处理与干旱胁迫相比,迪庆苦荞和黑丰一号的IAA含量分别显著增加了25.50%、21.19%,ABA含量分别降低了20.15%、18.18%,表明复水有效地缓解了干旱对内源激素的影响。干旱抑制了苦荞的生长,但复水使两个品种的苦荞均产生了等量补偿效应和部分补偿效应,且耐旱品种(迪庆苦荞)的恢复程度比旱敏感品种(黑丰一号)更好。

Effects of Drought Stress and Rehydration on Growth and Content of Endogenous Hormone in Leaves of Fagopyrum tataricum

In order to provide theoretical basis for drought resistance and stable yield of Fagopyrum tataricum and explore the effect of drought stress and rehydration on the physiological and morphological indexes of drought-tolerant F. tataricum (Diqing) and drought-sensitive F. tataricum (Heifeng1), pot experiments were conducted under greenhouse condition. The results showed that: drought stress significantly affected the growth of F. tataricum. Compared with control, drought stress significantly reduced the plant height, stem diameter, leaf area, shoot dry weight, root volume, root surface area, and root average diameter, root dry weight, root activity, root soluble protein content. Rehydration at florescence could effectively alleviate the effects of drought stress on various physiological and morphological indexes of F. tataricum, and among them, the shoot dry weight recovery was most obvious. Under drought stress, shoot dry weight of Diqing increased by 54.81% compared with that of Heifeng1. Compared with drought treatment, the dry weight of Diqing and Hefeng1 significantly increased by 83% and 47.28%, respectively. However, the SOD, POD, MDA, soluble sugar and free proline content of Diqing were significantly higher than those in the control root. Under drought stress, the IAA content in F.tataricum leaves was significantly decreased, and the ABA content was significantly increased. After the rehydration, the IAA content of Diqing and Heifeng1 significantly increased by 25.5 % and 21.19% compared with the drought stress. The ABA content greatly decreased by 20.15% and 18.18%. The results showed that rehydration reduced the impact of drought on endogenous hormone. Drought inhibits the growth of F. tataricum, but both varieties of F. tataricum produced equal compensation effect and partial compensation effect after the recovery of water. The recovery of drought-tolerant varieties (Diqing) was better than that of drought-sensitive varieties (Heifeng1).