The Screeing And Comprehensive Identification Of Melon (Cucumis Melo L.) Varieties For Salt-Alkaline Tolerance During Germination

Soil salinization is one of the factors that affect global environment, society and economy, so it is very important to clarify the salt tolerance mechanism of plant under salt stress for the development of global environment, society and economy.Melon (Cucumis melo L.) is a medium salt-tolerant plants. Seldom study has been done on the salt-alkaline tolerance of Melon, so it is very important to identify and screen the salt-alkaline tolerance of melon for the rational utilization of soil and high yield and quality of melon. In this experiment,50mmol·L-1solution (NaCl:Na2SO4:NaHCO3:Na2CO3=9:1:1:9pH=10.80) was used to simulate the typical salt stress condition. Distilled water treatment was used as control.50mmol·L-1salt-alkaline solution was used on20varieties of melon. Germination potential was tested after treated3days, germination rate, germination index, average germination speed, vitality index, radicle longth, radicle weight, contents of MDA and proline, and soluble protein, activities of peroxidase (POD) and superoxide dismutase (SOD) and catalase (CAT) and other antioxidant enzyme activity. Variance, clustering and stepwise regression analysis of multiple index variable of20cultivars was analyzed to evaluate their salt tolerance.The results are as follows:1. Analysis of D-value and total value of membership function showed that, germination energy, germination rate, average germination rate, vigor index, radicle length, radicle fresh weight, soluble protein content and catalase activity coefficients can be the main evaluation index of germination of melon under salt-alkaline stress.2.With cluster analysis, we can divide20melons into three categories:Lingtian Fourth,Halima Fourth,Zhimami,Yipintianxia208, Lingtian Third and Tian-jiao are cultivars sensitive to salt-alkaline stress stress. Yipintianxia No.108, ShaanxitianNo.l,Jinhui First, Qianyu First, Baixiangmi,Lingtian First, Yulu and wutaishan No.3are cultivars with high tolerance to salt-alkaline stress. Shantian No.3,Xuelian,Guifeixuemi,Ruixuexinzaomi Jingtian No.208and Baiyuxiang are cultivars which showed medium sensitivity and tolerance to salt stress.