Genetic Analysis And QTL Mapping Of Genes Controlling Seed Number Per Pod In Brassica Napus L.

Seed number per pod is one important component of rapeseed yield. Two parentmaterials which are 8-8520 and yu 102 were sliced up by paraffin secting.The P₁,P₂,F₁ (reciprocal),F₂ (reciprocal),BC₁ generations of 8-8520 and yu 102 wereconstructed to study the inheritance of the traits of seed number per pod, and the QTLcontrolling the trait was located by using SSR and AFLP markers. At the meantimetwo parents were pured by microspore culture technique.With the work,animmortalized F₂ population would be constructed to map the seed number per podgenes.The main results were summarized as followes:1. There is only one embryo cultured and doubled successfully in yu102; 89embryoes were got and 57 doubled successfully in 8-8520, and the ratio ofdoubling is 64%. The results indicate that different genotypes have differentembryo efficiency.2. Paraffin secting, slit and crosscut of ovary pollinated or unpollinated indicatesthere is no multicapsular degradation (crosscut) and yu102 has more ovules than8-8520(slit).3. The genetic model of the seed number per pod estimated was accored withaddition-domination models and the main genetic effect was addition sffects.4. The formula of Castle-Wright was used to calculate the number of genescontrolling the trait,and the minum was 1.5.5. A genetic map of Brassica napus L. was constructed with F₂ population. It wasdevided into 12 linkage groups, including 43 markers and covering 535.4cM andaverage distance was 12.5 cM.6. For the identification of QTL for the seed number per pod, there was only 1 QTLdectected.It was mapped on linkage group 4, and it can explain variations 15.6%.By analysis of variance,there are two markes linked with QTL of seednumber per pod.