Screening And Evaluation Of Salt-tolerance Rootstock Of Watermelon

Due to the long term protected cultivation of watermelon, the secondary soil salinity has been a very serious problem. In this study the salt-tolerance rootstock of watermelon was screened and evaluated among seventy-five rootstocks belonged to Lagenaria, Cucurbita, Citrullus and Benincasa four types separately, we owned, using the seeds, self-root plant and grafted plant of rootstock. The standard evaluation system of solt-tolerance was also discussed here. we owned.1. Regarding to the seed salt-tolerance, among all types of rootstock we evaluated, Cucurbita type rootstock was identified as the highest one, Lagenaria and Citrullus types showed the moderate level, and no significant difference was detected between them, and Benincasa type was the worst one. While the significant difference in the seed salt-tolerance was detected among the same type of rootstock.2. Comparison of the survival rate of rootstock self-root plant in salt stress, no significant difference in the salt-tolerance was detected among different type of rootstock. The salt-tolerance difference in self-plant was getting less than which in seed, and the significant difference in the self-plant salt-tolerance was still existed among the same type of rootstock. Comparing of the salt injury index of self-root rootstock, we found that Citrullus type rootstocks showed the strongest salt-tolerance, and Cucurbita , Lagenaria and Benincasa types were less. Although this result was different from the seed salt-tolerance experiment, we got some rootstocks showed the similar salt-tolerance result in both experiments.3. Different results were observed between the self-root plant and grafted plant of watermelon in salt stress. Some rootstocks improved the salt-tolerance of grafting, and some rootstocks did not, which indicated that the effect of rootstock on salt-tolerance of grafting was uncertain.4. The effect of the selected salt-tolerance rootstock on grafting survival rate, plant growth, yield and quality of watermelon'8424'were evaluated. The results not only showed that J03, Z0617 and JTT were excellent, but also showed the potential use of Lagenaria type rootstock in grafting salt-tolerance applications.