Study On The Genetic Diversity And The Low Temperature Tolerance Of Spinach Germplasm

Spinach is an important and secondary hardy vegetable. In this experiment, we could identifygenetic relationship and genetic resemblance of 24 spinach cultivars, the study would be able toprovide the theory to genetic classification and spinach breeding. Meanwhile, it determined theindexes at different stages of spinach to study the theory of low temperature tolerance frommorphology, metabolism and physio-biochemistry, to institute an integrative appraisement system;it redounded to impose the course of breeding. The mean results were as fellow:1. 24 spinach accessions were clustered into three groups based on morphological marker.Spinach accessions in different modalities and from different regions could be divided well.24 spinach accessions were clustered into five groups based on RAPD maker, and the fifthgroup could be clustered into four litter groups again. According to the study, spinach accessions indifferent modalities, tolerance and from different regions could be divided well, too. Its result wasconcordance to morphological marker.2. 24 primers producing qualified fragments were selected from 120 RAPD primers. 24informative RAPD primers were studied among 24 spinach accessions. The results showed: Mostof RAPD productions were polymorphic. The method of RAPD marker used to assessing thegenetic diversity of spinach is feasible and reliable.3. Germination ability of spinach was lower and lower with the temperature dropping. 5℃wasset as the identification temperature of low temperature tolerance of spinach. The POD activity andMDA content of spinach radicle were higher than controls at 5℃.4. With the process of the low temperature treatment at seedling stage (10℃/5℃), the PODactivity and the soluble protein content rised at begin then dropped at last, MDA content, theconductivity percentage rised, the content of Ch1 dropped, R/T rised, the leaf area was increasedslowly. The soluble sugar content and Pro content had no obvious tendency.5. The correlation of spinach existed among different growth stages. The germination index at5℃could be used as identification indexes of low temperature tolerance of spinach; the leaf area ofseedling stage could be used as subsidiary indexes of low temperature tolerance of spinach. ThePOD activity and the soluble sugar content of leaf in seedling stage could be used as referenceindexes of low temperature tolerance of spinach.6. The linear equation of low temperature tolerance for spinach: y=1.7068x+137y:cold-resistant coefficient; x:germination index at 5℃. 7. The screening result was 2 extreme hardy varieties, 3 hardy varieties, 3 fairly hardyvarieties, 15 un-hardy varieties, 1 extreme un-hardy variety.