The Breeding of Hybrid Rape Variety Youyan 924 with Strong Heterosis and High Oil

The rape project of ＂Development and Application of Cabbage Type Rape Hybrids with Strong Heterosis＂ which belongs to National 863 Program aimed to breed the rape variety whose rapeseed yield or oil yield increased more than 10% compared with check （CK） variety, or oil yield increased more than 3 percentage points compared with CK. In the regional trial in the middle react,es of the Yangtze River for two years, the average rapeseed yield and oil yield of Youyan 924 which is a hybrid rape variety respectively reached 2 695.95 and 1 264.35 kg/hm2, which respectively increased by 5.22% and 13.4% compared with those of the other test- ing varieties in the same group, and respectively increased by 10.06% and 23.68% compared with those of Zhongyouza 2 which belongs to CK, thus reaching the standard of hybrid rape variety with strong heterosis; the average oil percentage of the variety in the two years was 46.63%,which increased by 3.44 percentage points compared with that of all the other testing varieties in the same group, and in- creased by 5.14 percentage points compared with that of Zhongyouza 2, and the oil percentage of it in the production testing reached 49.21%. Thus Youyan 924 is a variety with strong heterosis and high oil, moreover, its contents of erucic acid and glucosinolate are 0,25% and 20.27 μmol/g, respectively. From the data aggregation of national regional trial, it has the advantages of high oil yield, high yielding ability, reaching the standards of low erucic acid and low glucosinolate, strong lodging re- sistance, good disease resistance aqd moderate mature period.

Diversity and association analysis of important agricultural trait based on miniature inverted-repeat transposable element specific marker in Brassica napus L.

Miniature inverted-repeat transposable elements(MITEs)are a group of DNA transposable element(TE)which preferentially distributed with gene associated regions.Tens of MITEs families have been revealed in Brassica napus genome,they scatter across the genome with tens of thousands copies and produce polymorphisms both intra-and inter-species.Our previous studies revealed a Tourist-like MITE,Monkey King,associated with vernalization requirement of B.napus,however there are still few studies reveal MITE association with agricultural traits in B.napus.In the present study,80 polymorphic markers were developed from 55 MITEs,and used to evaluate genetic diversity in a panel of B.napus accessions consisting of 101 natural and 25 synthetic genotypes.Five agricultural traits,oil content,glucosinolate content,erucic acid content,weight of thousand seeds(WTS)and plant height,were investigated across 3-years field experiments,in addition,two traits,hypocotyl length and root length,were evaluated at the 4-leaf stage in the laboratory.Correlations between the MITE-based markers and seven traits were analyzed,finally,10 polymorphic markers produced by 6 pairs of MITE specific primers were revealed relatively high correlation with 5 traits.Two polymorphic markers were anchored with two candidate genes,BnaA02g13530D and BnaA08g20010D,respectively,which may contribute to glucosinolate content and WTS.This research may contribute to genetic improvement through utilization of MITE-induced polymorphisms in Brassica species.