蝴蝶兰种质资源倍性鉴定及育性相关性研究OA北大核心CSTPCD

To explore the relationship between ploidy and fertility in Phalaenopsis germplasm resources,this study employed a combination of chromosome counting and flow cytometry to identify the ploidy levels of 33 varieties(species or variants)within the Phalaenopsis.Additionally,a series of complete diallel crosses were conducted to investigate the fertility of Phalaenopsis germplasm resources with different ploidy levels.The results of chromosome counting revealed that there were 5 diploid and 5 triploid Phalaenopsis,each accounting for 15.15%,while there were 10 tetraploid Phalaenopsis,constituting 30.30%.Furthermore,there were 13 aneuploid Phalaenopsis,making up 39.39%.Variations in chromosome size and constitution were observed among different varieties of Phalaenopsis.Flow cytometry results indicated that the estimated ploidy levels of 25 varieties(species or variants)of Phalaenopsis matched the chromosome counting results.The flow cytometry histograms of the tested materials all exhibited 3 to 4 peaks,with cycle values greater than 0.1.The results of hybrid fertility show that the tetraploid Phalaenopsis used as parents for hybridization has the highest fruit set and germination rate.Among the triploid and aneuploid Phalaenopsis,there is a large difference in fertility.The same variety used as a male or female parent for hybridization and self-fertilization also has a large difference in fertility.The above results suggest that the ploidy of most hybrid Phalaenopsis is polyploid or aneuploid,and the fertility of Phalaenopsis is related to its ploidy level and chromosome size and constitution.Flow cytometry ploidy estimation is suitable for Phalaenopsis hybrids with small and uniform chromosomes.All tested Phalaenopsis leaves exhibited endopolyploidization with significant variation in patterns among different ploidy Phalaenopsis leaves.This study provides valuable insights for the identification of Phalaenopsis germplasm resources,parental selection,genetic improvement,and polyploid breeding.