Whole-genome re-sequencing reveals genome-wide variations between the peach variety Green No. 9 and its bud mutant Daifei

Whole-genome sequencing technologies provide opportunities to further understand genetic variation among different varieties. Some related genes that are useful for the breeding process could be identified by sequencing technologies. In this study, two peach varieties, Green No. 9 and its bud mutant Daifei, were analyzed with whole-genome re-sequencing. Approximately 109 million total reads were generated, which covered ~89% of the peach reference genome. A total of 1143757 SNPs, 169827 InDels, 17132 SVs and 5040 CNVs were detected in Green No. 9 and Daifei. Variant genes were classified by GO and KEGG metabolic pathway analyses. Detected genes such as LOC18768059 (carbohydrate metabolism) and LOC18785045 (anthocyanin biosynthesis), were good candidate genes for exploring the phenotypic variations between Green No. 9 and Daifei. Green No. 9 and its bud mutant Daifei showed obvious differences in phenotypes and variant genetic loci. The detected genomic variations will contribute to explorations of important functional genes and to understanding the genetic basis of peach bud mutations.

Histological and Molecular Characterization of Grape Early Ripening Bud Mutant

An early ripening bud mutant was analyzed based on the histological, SSR, and methylation-sensitive amplified polymorphism (MSAP) analysis and a layer-specific approach was used to investigate the differentiation between the bud mutant and its parent. The results showed that the thickness of leaf spongy tissue of mutant (MT) is larger than that of wild type (WT) and the differences are significant. The mean size of cell layer L2 was increased in the mutant and the difference is significant. The genetic background of bud mutant revealed by SSR analysis is highly uniform to its parent; just the variations from VVS2 SSR marker were detected in MT. The total methylation ratio of MT is lower than that of the corresponding WT. The outside methylation ratio in MT is much less than that in WT; the average inner methylation ratio in MT is larger than that in WT. The early ripening bud mutant has certain proportion demethylation in cell layer L2. All the results suggested that cell layer L2 of the early ripening bud mutant has changed from the WT. This study provided the basis for a better understanding of the characteristic features of the early ripening bud mutant in grape.