Genetic study on fruit storage life in a disconnected factorial mating population of Actinidia chinensis (kiwifruit).

摘要

The purpose of this study was to examine inheritance of storage life (estimated by fruit firmness (FF)) in a population of Actinidia chinensis, to select parents for improving the storage life of red-fleshed kiwifruit. A total of 708 female vines were sampled in 2010, from a disconnected mating factorial, with 2x6 and 2x2 sub-factorials and a total of 16 full-sib families. To maximize accuracy of the prediction of breeding values, best linear unbiased prediction (BLUP) was performed with pedigree information, using ASReml-R. The coefficients of co-ancestry for the 16 full-sib families were 0, whereas the coefficients for disconnected families (not crossed) were from 0 to 0.625. Seedlings were sequentially harvested from April to June as their soluble solids concentration (SSC) reached 10%. FF was measured after 56-164 days of storage at 1.5 degrees C. Narrow-sense heritabilities and BLUPs of FF for each vine at 120 days in storage were estimated, using a mixed model in analysis of covariance in ASReml-R, with 'days in storage' as a fixed effect covariate. There was significant general combining ability (P<0.01) for both female and male parents. Parents useful for improving storage life were identified. Heritability was relatively high (0.62), which indicated that fruit storage life could be improved through selection. The response to selection of FF was 0.32 kgf at 1% selection pressure. FF also had a positive genetic correlation with dry matter (DM) and SSC. The relative selection efficiencies of indirect selection for FF using DM and SSC were 0.32 and 0.33, suggesting that selection using DM/SSC could be a convenient and efficient alternative to direct selection for improving storage life. Our results showed that the disconnected factorial design using BLUPs can be an efficient and economic procedure for identifying superior parents.