草业学报2025，Vol.34Issue(9)：78-86,9.DOI:10.11686/cyxb2024386
寒冷区苏打盐碱生境下紫花苜蓿越冬期根颈的生理特性
Physiological characteristics of the alfalfa root collar during overwintering under soda saline-alkali stress in cold areas
摘要
Abstract
The root collar or crown of alfalfa(Medicago sativa)is a transitional structure connecting roots and stems,and has an important role in alfalfa greening.This research aimed to clarify the physiological characteristics of the alfalfa root collar during overwintering under soda saline-alkali stress in a cold area.Two alfalfa varieties Longmu No.801(over-winter survival rate 96.59%)and Stockpile(over-winter survival rate 83.54%),were tested in Daqing.The activities of superoxide dismutase(SOD)and peroxidase(POD),and the contents of free proline(Pro),soluble protein(SP),total soluble sugar(SS),malondialdehyde(MDA)and tissue water content(TWC)in root collar of two alfalfa varieties were monitored at six time points during overwintering(late September,October,November,December,February and April)in the field.The physiological characteristics of the alfalfa root collar in test plants under combined stresses of soda saline-alkali and low temperature in winter were analyzed using a multivariate procedure.It was found that under the combined stresses of soda saline-alkali and low temperature in winter,alfalfa root collar TWC gradually decreased with increase in the low temperature stress exposure time,and the contents of SS,SP and Pro gradually increased,reaching a peak in February of the following year.The SS content of Longmu No.801 was higher than Stockpile,while the Pro content of Stockpile was higher than Longmu No.801.SOD and POD activities together with MDA content in alfalfa root collars showed a bimodal winter pattern,with peaks in late November and February,and the February peak in the variety Stockpile significantly higher than Longmu No.801 for all three parameters.Compared with Stockpile,Longmu No.801 had stronger SOD activity and less MDA accumulation,and POD activity was higher under cold exposure.In summary,under the combined stress of soda saline and winter cold,Longmu No.801 accumulated more SS in the root collar,maintained a more stable TWC in the root collar,and maintained stronger activities of antioxidant enzymes,than the variety Stockpile,which had lower over-winter survival.These root collar physiological characteristics are therefore indicated by our research to be linked to the variety differences in overwinter survival in saline-alkali conditions.关键词
越冬期/苏打盐碱/苜蓿/根颈/生理特性Key words
during overwintering stage/soda saline-alkali/alfalfa/root collar/physiological characteristics引用本文复制引用
陈宁,包凤轩,赵辉祥,王楠,姜汝玉,李国良,刘香萍,曲善民,杨伟光..寒冷区苏打盐碱生境下紫花苜蓿越冬期根颈的生理特性[J].草业学报,2025,34(9):78-86,9.基金项目
科技创新2030-重大项目(2022ZD04012)和学成、引进人才科研启动计划(XYB202113)资助. （2022ZD04012）
