Research On Relationship Of Color And Oil Content Of Seeds And Analysis Of Genetic Diversity In Brassica Napus L.

This research provided 602 accessions rape breeding of Brassica napus L. germplasm, from College of Agronomy, Northwest A & F University, were provided as tested materials.We used traditional methods for grading the seed color of Brassica napus L. and made assay of its husk content, seed oil content, husk oil content and embryo oil content,then analyzed about their correlation, carries on the path analysis with seed oil content as the goal character. Genomic DNA was isolated with method of CTAB extraction, and we established a suitable amplification system through optimizing PCR reaction factors. Then, 48 Brassica napus L. materials were PCR amplified using 26 polymorphic primer pairs screened from 150 RAPD primers, and we used Un-weighted Pair Group Mathematics Average method (UPGMA) analysis the genetic diversity of selected rapeseed germplasm. We elucidated hereditary basis and evolutionary history of Brassica napus L. germplasm for the rape breeding at the molecular level, and the results provided basis for breeding, parent selection, species identification and resource conservation.The results are as follows:1. According to the Colors of Brassica napus L. were divided into eight grades, three color types. One grading contained 14 materials; two grading contained 61 materials; three grading contained 58 materials;4 grading contained 68 materials; 5 grading contained 65 materials; 6 grading contained 166 material; 7 grading contained 66 materials; 8 grading contained 104 materials. 1, 2, 3 grading belong to yellow color type; 4, 5, 6 grading belong to red type; 7, 8 grading belong to black type; value larger seed color deeper.2. Average husk rate of yellow seeds is 12.85%, red seeds was 14.04%, black seeds was 15.90%; embryo oil content of yellow seeds was 51.55%, red seeds was 50.04%, black seeds was 51.04%; husk oil content of yellow seeds was 9.70%, red seeds was 8.31%, black seeds was 6.48%; seed oil content of yellow seeds was 39.32%, red seeds was 36.09%, black seeds was 36.13%. Yellow-seeded Brassica oil content was significantly higher than the oil content of black seed.3. Correlation coefficient of seed color and seed oil content was -0.8519 **, correlation coefficient of seed color and husk content was 0.9208 **, correlation coefficient of seed color and husk oil content was-0.9192 **, correlation coefficient of seed color and embryo oil content was -0.3284. The direct path coefficient about seed color and seed oil content was - 0.7117, husk content, husk oil content, embryo oil content of direct path coefficient were -0.3929,-0.3749,0.3747; seed color through the husk of the the indirect effects of seed oil content was -0.3618, through the husk oil content of the indirect path coefficient was 0.3446; seed color, husk content, husk oil content through embryo oil content of the indirect path coefficient were-0.1230,-0.1507,0.0418.4. 26 primers with sharp and polymorphic bands amplified were selected from the 150 RAPD markers. There there were procuded 211 amplified bands and 130 bands were polymorphic. The average polymorphic percentage was 61.61 %, with an average 8.1 per primer band, polymorphic bands 5.0.5. The 48 accessions of Brassica napus L. Genetic similarity coefficient (GS) ranged from 0.52-0.89, with a Un-weighted Pair Group Mathematics Average method (UPGMA) cluster analysis, the cluster can be divided into three groups at genetic distance of 0.58 and clustering results are largely related to types of materials. Brassica napus L. has a multiplex genetic background and has plenty of genetic variation.Groupsâ… including 11 accessions and main are yellow-seeded materials which were contained 8 yellow seed materials, 1 red seed materials and 2 black seed materials; Groupsâ…¡including 10 accessions and main are red-seeded materials which were contained 2 yellow seed materials, 6 red seed materials and 2 black seed materials; Groupsâ…¢including 27 accessions and main are black-seeded materials which were contained 6 yellow seed materials, 9 red seed materials and 12 black seed materials.