Research, Evaluation And Utilization On Partial Germplasm Resources Of Brassica Napus L.

Rapeseed is an important oil crop in China. At present, Brassica napus L. (2n=4x=38, AACC) is the main type of cultivated rapeseed in China. Studying on rapeseed germplasm resources is significant for guiding to rapeseed production and germplasm innovation. In this study, 93 B. napus L. from different regions were assessed using agronomic traits, quality traits and SSR markers. The main results were as follows:1. The coefficient of variation of eleven agronomic traits ranged from 10.2% (plant height) to 37% (yield per plant), which indicated the diversity of materials was significant. Using nine indexes (excluding silique density and yield per plant), cluster analysis was performed. The result showed that all materials were classified into three groups at genetic distance 1.91. Groupâ… performed that first branch position was high and other traits were moderate. Groupâ…¡performed that yield per plant was high and other traits were moderate. Groupâ…¢performed that both plant height and yield per plant were low. Further classified, such subgroups as high plant or long pod were showed.2. SSR analysis showed: 103 bands were amplified by 20 pairs of primers in 93 B. napus L., in which 85 bands were polymorphic, and polymorphic ratio was 82.5%. Through UPGMA cluster analysis, all materials were divided into seven groups at genetic distance 0.37, and there were different subgroups in the seven groups. 15 sterile materials were consisted in subgroup ii of groupâ… and in subgroupiii of groupâ…£. Genetic distance between wp27 and wp28 was zero, and others were longer than zero. Average genetic distance was 0.23. It was indicated that genetic diversity of investigated materials was higher.3. Quality indexes of rapeseed: protein, oil, erucic acid and glucosinolate were analyzed by NIRS. The results showed that main quality traits of investigated materials were basically up to the standard of high protein, high oil and double low through primary selection, and the structure of first-class rapeseed were basically formed. But materials used for industry such as high erucic acid were few.4. Based on the data of geographical regions, agronomic traits, quality traits and SSR molecular markers, by multiple clusters, random sampling and systemic sampling, a pre-core collection of B. napus L. with a total of 31 accessions was established, which was 33.3% of the entire collection. Comparison between character eigenvalues of pre-core collection and whole collection indicated that pre-core collections could effectively represent whole collection. Meanwhile, DNA fingerprints of 31 pre-core collections were established.