关键词: 绿豆, 生物炭, 盐碱胁迫, 根系, 离子含量

Abstract: In the study,mung bean cultivar Lüfeng 2 was used as test material,and no biochar treatment was regarded as control group (0%,CK). And the other two were 10% and 20% biochar treatments.Three different kinds of sodium bicarbonate solution (0,100,200 mmol/L) were used for root treatment,and then the growth and physical and chemical indicators of mung bean were determined at flowering and pod-forming stage,in order to study the effects of different proportions of biochar on the growth of mung bean seedlings under salt-alkali stress,which would provide a basis for the restoration,exploitation and utilization of saline-alkali land and the high-quality and high-yield cultivation of mung bean in salinealkali land.The results indicated that the mung bean biomass,plant height,leaf area,chlorophyll content,Fv/Fm and root morphological indexes decreased significantly in CK group under salt-alkali stress,and the Na⁺content in mung bean plants increased markedly while the contents of K⁺, Ca²⁺and Mg²⁺significantly reduced.The addition of biochar had a positive effect on the growth and ion accumulation of mung bean plants under salt-alkali stress,especially the 20% biochar treatment in which the root dry mass,aboveground dry weight,plant height and leaf area increased by 75.00%,19.72%,54.82% and 123.10%,and the root length,total root surface area and root tip number increased by 57.85%,488.50%and 227.83% under 200 mmol/L sodium bicarbonate solution,while the average diameter of the roots did not change significantly.In addition,the addition of biochar increased the chlorophyll content and Fv/Fm value of mung bean leaves,and increased the contents of K⁺,Ca²⁺and Mg²⁺ ,and decreased the Na⁺content.Obviously,the addition of biochar can improve the morphology of the roots,shoots and leaves of mung bean plants,improve the leaf photosynthesis and root functions,and promote the accumulation of mung bean biomass,which will lay a foundation for later mung bean yield under saline-alkali stress.Overall,20% biochar treatment was better than 10% biochar treatment.

Key words: Mung bean, Biochar, Saline-alkali stress, Root system, Ion content