The Assessment For Subgenomic Heterotic Performance And FAE1 Analysis Of Fingerprint In New Type Brassica Napus

As one of edible oil crops and raw materials for biodiesel in the world, B.napus is taken account of importance increasingly. Although the planting area is leading all the time, due to its limited historical domestication and narrow genetic foundation, the utilization of heterosis is stagnant. We replaced the An and Cn genome in traditional B. napus by introgressing Ar genome from B. rapa (ArAr) and Cc genome from B. carinata (BcBcCcCc) partially and led to develop the first new type B.napus whose ArCc exogenous content is 30-50%, and strong heterosis were exhibited in the hybrids resulted from the the first new type B.napus and the traditional B.napus. Also we found the law that as the exogenous content improved, the heterosis is stronger. Later we continued to use interspecific hybridization, genetic recombination, molecular assisted markers and other techniques to develop the second new type B.napus with improved agronomic traits and higher introgressed subgenomic component. The intersubgenomic hybrids resulted from the second new type B.napus and domestic nucleic male sterile lines exhibited great heterosis in seed yield and agronomic traits.Based on the above achievements, we crossed the second new type B.napus with four German male sterile lines in this study. In consecutive two-year field experiment, strong heterosis was found not only in agronomic traits but also in yield traits related to seed yield and biomass. Almost one half of the hybrids showed over check heterosis and all of them showed over parental heterosis, while the MSL101C'×m5R059 hybrid ranked first both in two years for seed yield, even achieving the 1% significant level as for control. Apart from the trait for seeds per pod, other traits exhibited over control heterosis in some sense:the hybrids made from new type B.napus with winter male sterile line MSL012C' perform better with an average value of 129.93 cm for plant height; the main inflorescence length for hybrids focused on 50-65 cm and the hybrid MSL012C'×DH23 was the longest; there's an obvious gap in the hybrids resulted from winter male sterile lines or spring male sterile lines for ten-pod length, while the former is 4 cm longer than the latter; all the hybrids exhibited over control heterosis for thousand-seed weight because the seeds were large and full excluding MSL522C×m5R156, and the economic coefficient for elite hybrids is equal to commercial control. For the quality traits which were measured by near-infrared reflectance spectroscopy, we hoped to use molecular assisted selections to reduce the glucosinolate content in order to lay the foundations for application in the future. In addition, we used the correlation analysis to confirm that as the ArCc exogenous content improved, the subgenomic heterosis is more obvious. At the same time, the second new type B.napus was used as recurrent parents to backcross with the materials from different countries, such as Germany and Australia in order to broaden the germplasm resource and extend the subgenomic heterosis in new type B.napus.The erucic acid in the new type B.napus differs from 0-60%, which belongs to long-chain fatty acid and exists in the seeds of Brassica species with twenty-two carbon. In 1995, James inserted maize transposon into Arabidopsis FAE1 to make it mutate and found the erucic acid content reduced, finally supposed that FAE1 is a key gene to control erucic acid synthesis. As lots of research results released, FAE1 has two copies in chromosome A8 and chromosome C3 in traditional B.napus, and the two copies located in the peak of two major QTL. According to the alignment about FAE1 between different erucic acid content new type B.napus and high erucic acid traditional B.napus cultivar Ningyou 7 after sequencing, we find there is no difference in high erucic acid new type B.napus and high erucic acid traditional B.napus, and there is no difference in low erucic acid new type B.napus and low erucic acid traditional B.napus, but there is SNP polymorphism in different erucic acid content new type B.napus.This result can lay the foundation for broadening the subgenomic heterosis in new type B.napus to some extent.