Characterization of Bunch Compactness in a Diverse Collection of Vitis vinifera L. Genotypes Enriched in Table Grape Cultivars Reveals New Candidate Genes Associated with Berry Number.

Abstract

Bunch compactness (BC) is a complex, multi-trait characteristic that has been studied mostly in the context of wine grapes, with table grapes being scarcely considered. As these groups have marked phenotypic and genetic differences, including BC, the study of this trait is reported here using a genetically diverse collection of 116 Vitis vinifera L. cultivars and lines enriched for table grapes over two seasons. For this, 3D scanning-based morphological data were combined with ground measurements of 14 BC-related traits, observing high correlations among both approaches (R 2 > 0.90-0.97). The multivariate analysis suggests that the attributes 'berries per bunch', 'berry weight and width', and 'bunch weight and length' could be considered as the main descriptors for BC, optimizing evaluation times. Then, GWASs based on a set of 70,335 SNPs revealed that GBS analysis in this same population enabled the detection of several SNPs associated with different sub-traits, with a locus for 'berries per bunch' in chromosome (chr) 18 being the most prominent. Enrichment analysis of significant and frequent SNPs found simultaneously in several traits and seasons revealed the over-representation of discrete functions such as alpha-linolenic acid metabolism and glycan degradation. In summary, the utility of 3D automated phenotyping was validated for table grape backgrounds, and new SNPs and candidate genes associated with the BC trait were detected. The latter could eventually become a selection tool for grapevine breeding programs.

Plant phenotyping relevance

ブドウ房のコンパクトネスを対象に、3Dスキャンによる自動形態計測を地上測定と比較・検証し、育種利用可能な表現型評価法として実証しているため、方法が中心的です。

Code and data availability

The paper's phenotype/trait measurements (14 ground-measured and 8 3D-inferred bunch compactness traits over two seasons for 116 genotypes) and GBS-derived SNP dataset are not deposited in any public repository. The MDPI supplement contains only summaries (plant material list, descriptive statistics, GWAS signal lists,

No evidence-backed public reproduction asset is currently recorded.