| Cucumber seed is dry mature seeds of cucurbitaceae. The effect of cucumber seeds is wide, and has both pharmacological effects and the effectiveness of health care. With people’s health consciousness enhancement, the demand for cucumber seed is increasing. On the premise of guarantee the quality of cucumber seeds, there is an urgent need for development new varieties of cucumber. So it is necessary to conduct a comprehensive study on cucumber seed yield.In this study,the seed yield per fruit of 72 accessions of different types of cucumber were tested and correlation and path analysis of the their agronomic traits. Selected high seed yield per fruit(D1158-1、D0328-3、D0103-1-2) and low seed yield per fruit(D0432-3-1、D0435-3-1-1) match the constructed the hybrid combinations, the combination of D1158-1×D0435-3-1-1 construct the six generation. And the F2 generation is analyzed the correlation between pair of characters using both the SSR molecular marker and composite interval mapping which enabled us to construct the genetic linkage map. The main findings from this study are as follows:(1) The results showed that there were obvious variances of the seed yield per fruit different varieties of cucumber germplasm, swinging in the range of 0.47~7.93 g. With 8% yearold open pollination progenies, the high and low accessions are respective 6.(2) The order of 9 related traits influence on the seed yield per fruit was as follows: number of seed per fruit> fruit chamber diameter> hundred-seed weight> per fruit weight> seed length> seed wide> fruit chamber length> proportion of female flowers>node. Multiple regression analysis and Path analysis both showed number of seed per fruit and hundred-seed weight were the major factors to affect the seed yield per fruit.(3) The length of the cucumber seed is a quantitative trait controlled by multi-genes; it followed the additive-dominance(AD) genetic model, in line with the genotype × environment interaction as the dominant effects, so conventional cross-breeding of later generation selection will be effective.the broad sense heritability and environmental-broad heritability are high with respectively, 57.7551%, 16.3979%. So seed yield per fruit is mainly decided by genetic factors, but also influenced by the environment.(4) Special combining ability of combination of D1158-1×D0435-3-1-1 has a high breeding value and can be used as good parents to improve the length of the cucumber seeds.(5) This study has selected D1158-1×D0435-3-1-1 combination and its F2 to construct the population genetic map.Three linkage groups have been constructed and these contain 13 SSR loci, the most long-chain group has 173.9c M,(LG2) and the shortest linkage group(LG3) has 9.6c M. The LG2 is the most densely distributed, it accounted for 53.3% of the marked screened. Linkage groups showed a total length of252.5c M with an average distance of 19.4c M between markers.Composite interval mapping analysis of the cucumber seed yield per fruit has detected 6 QTLs on the linkage groups. These 6 QTLs were shown to increase the length of the cucumber seeds for synergistic addictive effect. QTL1, QTL2 QTL3, QTL4 QTL5, and QTL6 showed respectively, a nearest marked map distance of 15.8c M、0.2c M、8.8c M、10.9c M、9.24 c M、4.0c M; the LOD values of 13.49 、 13.63 、 14.12 、 19.16 、 14.57 、 15.98, and finally, the explained by genetic variations were 13.89%、8.31%、11.19%、18.08%、11.83%、10.77%. |
PDF Full Text Request