Genetic Analysic And Gene Maping Of Pod Length Trait In Brassica Napus L.

The rapeseed is the most important oil-bearing crop, as well as an important origin of edible vegetable oil and high quality protein. Statistics data showed that the rapeseed oil consumption occupied 35% of edible vegetable oil consumption. The rapeseed cake rice dregs consumption took hold of approximately 25% of the plant cake rice dregs consumption. The rapeseed pod no is not only an important storage organ, also is the important photosynthesis organ, it has the dual function of "the storehouse" and "the source". The cultivation of long-pod variety may enhance the output potential. The pod length is controlled by quantitative trait loci of multi-genes. It is a continuous variation, and influenced larger by the environment, therefore the single gene effect can not be separated by the quality character. Currently, genetic crop breeding has been developed with the development of quantity genetics and modern biological technology. Accompanied by the aid of the DNA markers and the QTL localization, the complex quantity character can be divided into certain separate Mendel factor. Subsequently, the pod length controlled genes are allocated onto specific chromosome region and the distances with other genes are easy to be determined.The hybrid obtains generation F₁ and F₂ were used from a cross between long-pod 229836 and short-pot 23P146-3. A linkage map of the pod length was conducted by micro satellite markers (SSRs). Taking the F₂ population as analysis content, the full pod length, pod body length and the pot beak length were carried on the preliminary QTL localization. The results were the followings:1. The variance analysis indicated that, the long-pod parent 229836 and the short-pod parent 23P146-3 showed significant differences in the full pod length, the body length and pod beak length;2. The back cross population F₁ didn't display obvious differences in the full pod length, pod body length and pod beak length, and they showed great similarities instead. This result indicated that these characters were controlled by nuclear genes, and were not affected by maternal DNA;3. The Estimation of heritability of pod length, pod body length and pod beak length were 84.07%, 81.67% and 85.46%;4. The three traits in F₂ population had a continuous normal distribution, indicating the pod length, pod body length and pod beak length were quantitative in nature and controlled by polygenes; 5. SSR markers were used to analyze 186 single plants genotype in F₂ population. A linkage map was produced by JionMap 3.0 software, including 19 linkage groups and a genetic map with 233 loci. The full map length was 1440.4cM, with an average of 6.2cM. The number of locus ranged between 2-38, and the length of linkage groups varied from 12.3 cM to 181.5 cM;6. The three traits were computed by the WinQTLCart2.5, and in total 12 QTLs were detected. These 12 QTLs were allocated in 4 linkage groups among the 19 linkage groups. The genetic effect value of 12 QTLs was situated between 5.51%-19.74%, in which 5 controlled the pod body length and 2 controlled the pod beak length. The QTL total effect separately may explain the corresponding character variation 16.08%-50.05%.