Seed Coat Color Genetics And An AFLP Marker Of Yellow-Seeded Rapeseed (Brassica Napus L.)

The main materials used in this study were yellow-seeded rapeseed (Brassica napus L.) 7500 and 933044, while black-seeded rapeseed(Brassica napus L.) were zhongyou821 , 7512 and zhongshuang No.4. The inheritance of the seed colour gene for two yellow-seeded rapeseed {Brassica napus L.) and the allelic relationship between 7500 and 933044 were studied. AFLP technique was adapted to detect molecular markers linked to the seed coat colour genes. The main results are as follows:1. Two yellow-seeded rapeseed 7500 and 933044 were crossed with three black-seeded rapeseed zhongyou821 , 7512 and zhongshuang No.4 for genetic studies of seed coat colour. In cross (7500, 933044)xzhongyou821, all Fl plants exhibited the character of yellow seed coat and F2 plants had a segeregation ratio of 3:1, all the backcross set seeds between F1 and yellow seeded parent with yellow seedcoat, while the seeds of the backcross between F1 and black seeded parent had a segregation ratio of 1:1. In cross (7500, 933044)×7512, all Fl plants set seeds with black seedcoat and F2 plants had a segregation ratio of 1:3, the seeds of the backcross between Fl and yellow seeded parent had a segregation ratio of 1:1, while all the backcross set seeds between Fl and black seeded parent with black seedcoat. In cross (7500, 933044)×zhongshuang No.4, the seed coat colour of all Fl plants were black and F2 plants had a segregation ratio of 3:13, the seeds of the backcross between Fl and yellow seeded parent had a segregation ratio of 1:1, while all the backcross set seeds between Fl and black seeded parent with black seed coat. The results indicated that the yellow seeded trait of 7500 and 933044 may be controlled by two pairs of dominant genes in an interacted manner. The dominant gene determined yellow seed coat and epistatic dominant gene governed black seed coat.2. The broad sense heritability of seed coat colour trait in the crosses between 7500 and three black-seeded rapeseed was from 66. 5% to 84.8%, the narrow sense heritability was from 60. 7% to 68. 6%, while the broad sense heritability of seed coat colour trait in the crosses between 933044 and three black-seeded rapeseed was from 77. 6% to 90. 0%, the narrow sense heritability was from 69. 8% to 76. 6%. Variance analysis showed that F value was 7.59 and probability was 0. 02; therefore, the difference of the broad sense heritability of seed coat colour character between 7500 and 933044was significant. The broad sense heritability of yellow-seeded rapeseed 933044 was bigger than yellow -seeded rapeseed 7500. The result showed that seed coat colour trait of 933044 more stabilized than 7500, yellow seed trait both of them had little affection by environment, and the genetic transmission capability of the yellow seed coat trait from parent to offspring was strong.4. Seed coat color of Fl plants derived from the cross of 7500x933044 were yellow and black seeds in F2 population plants, x2test value was 0.38,less than x2o.os