Preliminary Genetic Analysis In Heterotic Groups Of Chinese Semi-Winter Brassica Nupus

Strong heterosis of Chinese semi-winter rapeseed was observed with spring and winter rapeseed. The objectives of this study were to genetically analyze heterotic groups of Chinese semi-winter rapeseed with spring rapeseed and winter rapeseed from Germany. The main results were as follow:1. Semi-winter lines and hybrids derived from semi-winter and spring rapeseed flower early than hybrid between semi-winter and winter rapeseed.2. Strong heteriosis was found for seven agronomic traits among hybrids, but was not even between two heterotic groups, semi-winter×spring and semi-winter×winter, i. e. all of hybrids derived from some Chinese semi-winter accessions had stronge heterosis, while the hybrids between some of Chinese accessions and spring rapeseed were stronger than those of winter rapeseed, vice versa.3. A positive and significant correlation of plant height was found with height of banch, amount of banches, seed yield and seeds per pod, while negetive correlation of length of inflorescence was found with amount of banches and seeds per pod.4. Hereotic groups were classified according combining ability. Benefitly,22 Chinese lines were classed into heterotic group of spring rapeseed, because the hybrids between them and spring rapeseed have postive special combining ability (SCA) and stronger for seed yield than hybrid between spring and winter rapeseed. Ten Chinese lines were classed into heterotic groups of winter rapeseeed due to postive SCA between them and winter rapeseed, while 31 Chinese accessions were classed into spring and winter groups due to postive general combining ability.5. Among 110 SSR primers used to evaluate 65 inbred lines including two testers and 63 Chinese accessions,101 SSR primers detect polymorphic bands. The number of polymorphic bands for SSR primer varied from 1 to 5, with an average of 1.95. Average GD of semi-winter rapeseed was 0.53±0.07 for winter rapeseeds and 0.51±0.07 for spring rapeseeds. Forty-five and 22 loci were relative to seed yield at the significant level of 0.05 and 0.01, respectively.6. No clear relationship for hetortic groups was found in principal component analysis using polymorisms in all of loci detected or loci significantly related to seed yield. No clear relationship was found between genetic distance calculated with molecular markers and heterosis.