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Grape berry shape is an important agricultural trait. Clarifying its genetic basis is significant for cultivating grape varieties that meet market demands. However, the current study by forward genetics has not achieved in-depth results. Here, a high-density map was constructed to identify quantitative trait loci (QTLs) for berry shape. A total of 358 709 polymorphic SNPs were obtained using whole-genome resequencing (WGS) based on 208 F2 individuals derived from round grape 'E42-6' and oblong grape 'Rizamat'. The 1 635.65 cM high-density map was divided into 19 linkage groups with an average distance of 0.37 cM. Using this map, three significant QTLs for fruit shape index (ShI: ratio of berry length to berry width) identified over three years were mapped onto LG4 and LG5, including one stable QTL on Chr5 with the genomic region of 0.47e1.94 Mb. Combining with gene annotation and expression patterns based on RNA-seq data from two contrasting F2 individuals with round and oblong berry (their average ShI was 1.89 and 1.10, respectively) at four developmental stages, four candidate genes were selected from the above QTLs. They were mainly involved in DNA replication, cell wall modification, and phytohormone biosynthesis. Further analysis of RNAseq data revealed that several important phytohormone synthesis and metabolic pathways were enriched based on differentially expressed genes (DEGs), which was consistent with the results of QTL mapping for genes related to plant hormone biosynthesis in the F2 population. Furthermore, a comparison of plant hormone content showed that there were significant differences in IAA and tZ content between the two contrasting F2 individuals at different developmental stages. Our findings provide molecular insights into the genetic variation in grape berry shape. Stable QTLs and their tightly linked markers offer the possibility of marker-assisted selection to accelerate berry shape breeding. [ABSTRACT FROM AUTHOR]

Cabbage has significant heterosis and most commercial cultivars are hybrids. To explore genetic basis of cabbage heterosis and promote cabbage heterosis utilization, we constructed two populations by crossing 100 DH lines derived from a cabbage hybrid 01-20 ×96-100 with two female parents. Hybrids exhibited different extents of heterosis, the mean value of economic yield was 2.6 times bigger than parents. We identified 66 and 73 QTLs associated with mid-parent heterosis and transgressive heterosis of twelve yield-related traits, respectively. Some QTLs could be detected under the two-year experiment existed in two populations with different testers, showing relatively high phenotypic contribution rate (15.8%-20.0%). Heterosis QTLs exhibited clustered distribution in several cabbage chromosome regions. Two dominant genetic regions, mk300-316 and mk258-268, originated from the elite parent 01-20, exhibited significant genetic effects for yield-related heterosis, which were first identified. Three elite DH lines (D22, D46, D83) harboring these two dominant regions were selected as having strong heterosis in cabbage production. Candidate gene analysis revealed that some genes participating in biosynthetic processes of carbohydrates and some responses to auxin might affect cabbage yield heterosis. QTL identification and genetic dissection of yield-related traits provide new insights into the genetic effects of cabbage heterosis. [ABSTRACT FROM AUTHOR]