Background: In the breeding of new horticultural crops, fruit shape is an important selection characteristic. A variety of fruit shapes appeared during the gradual process of selection and domestication. However, few studies have been conducted on grape berry shape, especially studies related to mining candidate genes. To discover candidate genes related to grape berry shape, the present study first took the berry shape parameters analyzed by Tomato Analyzer as the target traits and used a genome-wide association analysis to analyze candidate genes. Results: In total, 122 single-nucleotide polymorphism (SNP) loci had significant correlations with multiple berry shape traits in both years, and some candidate genes were further mined. These genes were mainly related to LRR receptor-like serine/threonine-protein kinase (At1g05700 and At1g07650), transcription factors (GATA transcription factor 23-like, transcription factor VIP1, transcription initiation factor TFIID, and MADS-box transcription factor 6), ubiquitin ligases (F-box protein SKIP19 and RING finger protein 44), and plant hormones (indole-3-acetic acid-amido synthetase GH3.6 and ethylene-responsive transcription factor ERF061). In addition, some important SNP loci were associated with multiple berry-shape traits. The study further revealed some genes that control multiple traits simultaneously, indicating that these berry shape traits are subject to the coordinated regulation of some genes in controlling berry shape. Conclusions: In the present work, we identified interesting genetic determinants of grape berry shape-related traits. The identification of molecular markers that are closely related to these berry-shape traits is of great significance for breeding specific berry-shaped grape varieties.

Global warming will significantly affect grapevine growth and development. To analyze the effects of high temperature on the leaf tissue structure of grapevines in the field, 19 representative cultivars were selected from the grapevine germplasm resources garden in Turpan Research Institute of Agricultural Sciences, XAAS. Twelve tissue structure indexes of grapevine leaves, including the thickness of the upper epidermis (TUE), the thickness of palisade tissue (TPT), leaf vein (LV), the thickness of spongy tissue (TST), the thickness of the lower epidermis (TLE), stoma (St), guard cell (GC), cuticle (Cu), leaf tissue compactness (CTR) and leaf tissue porosity (SR), were measured during the natural high-temperature period in Turpan. The results showed significant differences in the leaf tissue structure of the 19 grapevine cultivars under natural high temperature. Based on the comprehensive comparative analysis of the leaf phenotype in the field, we identified that the leaves of some cultivars, including ‘Zaoxia Wuhe’, ‘Centennial Seedless’ and ‘Kyoho’ showed strong heat tolerance, whereas grapevine cultivars ‘Golden Finger’, ‘Shine Muscat’, ‘Flame Seedless’, ‘Bixiang Wuhe’ and ‘Thompson Seedless’ showed sensitivity to high temperature. We further evaluated the heat tolerance of different grapevine cultivars by principal component analysis and the optimal segmentation clustering of ordered samples. These findings provide a theoretical basis for adopting appropriate cultivation management measures to reduce the effect of high temperatures and offer fundamental knowledge for future breeding strategies for heat-tolerant grapevine varieties.

High temperatures significantly affect the growth and development of grapevines, cause irreversible damage to plants, and severely impact grape production and quality. Biostimulants can promote the growth of plants and enhance their resistance to adverse stress. However, the effects of biostimulants on grapevines under high temperatures have not been studied in detail. To analyze the effects of various biostimulants on the growth and development of grape seedlings under high temperatures, we measured chlorophyll fluorescence parameters with observed seedling phenotypes under high temperatures in open field conditions in Turpan. We conducted a comprehensive analysis of the effects of different biostimulants on the growth, development, and photosynthesis of grapevine seedlings. Our study aimed to provide scientific evidence to improve cultivation methods for grapevines under high-temperature stress. The results revealed that biostimulants have a positive effect on promoting the growth of grapevine seedlings under high-temperature stress conditions. They also positively affect the accumulation of chlorophyll components in grapevine leaves, inhibiting chlorophyll degradation and maintaining photosynthesis. However, the effects of different biostimulants were inconsistent. A comprehensive analysis revealed the following effectiveness order: T2 > T1 > T3 > Control. These findings suggest that T2 is the most effective in alleviating high-temperature stress and promoting grapevine growth. We recommend the use of T2 to improve the cultivation of grapevine seedlings during high-temperature periods. This has implications for grape production in hot and arid climatic areas.