Exploration of the physiological mechanism of two zucchini germplasms responding to cadmium stress

XING Xiaoting; WANG Yong; WANG Longyu; SUN Yayun; CHANG Jingyi; SUN Shouru; ZHU Lei

doi:10.16861/j.cnki.zggc.2024.0629

Abstract：Cadmium,which is the main heavy metal pollutant in agricultural soil,can seriously affect plant growth and development as well as human health.Using zucchini germplasm RL296 and SL379 as materials,this study investigated the changes in physiological parameters of different germplasms under cadmium stress.The results indicated that under treatment with 10 mmol·L-1 CdCl2,there is a significant difference in stress index between the two materials.The inhibitory effect of cadmium stress on plant height in SL379(a decrease of 50％)was significantly stronger than that of RL296(a de-crease of 41.51％).In the treatment group,the chlorophyll a content and chlorophyll fluorescence value in RL296 were significantly higher than those in SL379.Moreover,RL296 exhibited lower relative conductivity and MDA level than SL379,indicating that RL296 had stronger cadmium stress tolerance than SL379.The measurement of proline content,and SOD,POD and CAT activity in the leaves of both germplasms under treatment showed that the antioxidant enzyme activity of both materials increased,with proline content,SOD,and POD activity in RL296 significantly higher than those in SL379.In addition,the cadmium content in the aboveground and underground parts of RL296 seedlings was signifi-cantly lower than that in SL379 under cadmium treatment.In summary,the cadmium-tolerant zucchini genotype RL196 under cadmium stress could accumulate more proline,have stronger antioxidant enzyme activity and accumulate less cad-mium compared to the cadmium-sensitive genotype.This provides a theoretical basis for the study of the mechanism of zucchini response to cadmium stress and for the screening and breeding of low-cadmium accumulation varieties.