不同水分条件下不同抗旱性苦荞根系生长规律研究

为了探明不同抗旱性苦荞根系形态和生理特性与抗旱性的关系,为干旱胁迫下苦荞高产优质栽培管理及抗旱品种的筛选提供理论依据,采用人工控水的方法,研究并分析了正常供水、重度干旱条件下不同抗旱性苦荞品种迪庆苦荞（耐旱）、黑丰1号（旱敏感）根系生长形态和生理指标变化。结果表明,干旱胁迫显著增加了苦荞根冠比、根系丙二醛（MDA）和脯氨酸（Pro）含量,而最大根长、根体积、根表面积显著降低。随着生育期推进,各处理苦荞最大根长、根体积、根表面积、MDA含量等指标均呈现逐渐增加趋势,根冠比、Pro含量呈现先增后减趋势。品种之间方差分析结果表明,重度干旱胁迫条件下,各测定时期迪庆苦荞的根冠比、最大根长、根体积、根表面积、根系Pro含量均显著高于黑丰1号,MDA含量则显著低于黑丰1号。回归分析表明,不同处理苦荞根表面积、最大根长等指标在测定时期内随时间变化的数学模型均符合指数函数,根体积、MDA含量等指标均符合一元二次方程的规律。干旱胁迫下苦荞根系与地上部分的生长均受到抑制,且表现为对地上部的影响大于对根系;与黑丰1号相比,迪庆苦荞耐旱性更强。

Research on the Root Growth of Different Drought-Resistant Fagopyrum tataricum under Different Water Conditions

The purpose of this study was to find out the relationship between root morphology and physiology and drought resistance of Fagopyrum tataricum, to provide a theoretical basis for high-yield and high-quality cultivation and management and selection of drought-resistant varieties of Fagopyrum tataricum. The method of artificial water-control was adopted. Quantitative indices of root growth for different drought-resistant Fagopyrum tataricum varieties (Diqing tartary buckwheat and Heifeng 1) under normal water supply and severe drought were determined and analyzed, during which the change of root growth of Fagopyrum tataricum was simulated. Results showed that, root-shoot ratio, the contents of malonaldehyde (MDA) and proline (Pro) increase significantly under the drought stress condition, while maximum root length, root volume and root surface area showed adecreasing significantly. Under different water conditions, the root-shoot ratio of Fagopyrum tataricum decreased, the maximum root length, root volume and root surface area increased, MDA content increased, and Pro content increased first and then decreased with the development of growth period. The results of variances analysis showed that under severe drought stress, root-shoot ratio, maximum root length, root volume, root surface area and root Pro content of Diqing tartary buckwheat were significantly higher than Heifeng 1, and MDA content was significantly lower than Heifeng 1. By establishing regression analysis equation, it can be concluded that the mathematical models of root surface area and maximum root length treated with different treatments were the same during the whole growth period, and they all conformed to the exponential model, while the indexes of root volume and MDA content conformed to the unitary quadratic equation. Under drought stress, the growth of the roots and aerial parts of Tartary buckwheat was inhibited, and the effects on the shoots were greater than those of the roots. Compared with Heifeng 1, Diqing tartary buckwheat has stronger drought tolerance.