Abstract:

Soil salinization is the main limiting factor in agricultural production. The development of salinized resistant crops has great significance to the efficient development and utilization of salinized land, and the improvement of land increment. Sesame germplasms with significant differences in salt tolerance were used as experimental materials. We used a potting experiment by setting three NaCl treatment concentrations of 0‰, 5‰, and 8‰. To establish a method for identifying and evaluating the salt tolerance during the seedling stage, relative seeding height, relative survival seedlings, seeding and root fresh weight, and dry weight were measured. The results showed that with the increase of NaCl concentration, the growth parameters at the seedling stage decreased gradually. Under 8‰ NaCl stress, the relative seeding and root fresh weight, relative seeding and root dry weight, relative seeding height, and relative survival seedlings were 20.57%-49.12%, 28.26%-48.76%, 8.17%-23.42%, 6.46%-21.10%, 10.91%-45.01%, and 6.83%-53.00%, respectively. Combined with principal component analysis and comprehensive evaluation method of membership function, the salt tolerance of eight sesame varieties was evaluated. The order of salt tolerance of 8 sesame varieties was as follows: ‘G551’>‘G441’>‘LZ 1’>‘Zhong zhi 11’>‘LZ 2’>‘JH1’>‘G358’>‘G452’. Then salt tolerance screening of 126 sesame germplasms was performed using relative survival seedlings under 8‰ NaCl. With the cluster analysis, these 126 sesame varieties were divided into five groups, and 9 high salt-tolerant varieties were screened. The results provide material and technical support for identification of salt tolerance in sesame and the breeding of new salt tolerant varieties.

Key words: sesame, salt tolerance at seedling stage, identification and evaluation, principal component analysis