Advances in Grape Genetic Analysis, Quality Regulation, and Stress Resistance Research

1. Introduction

Grapes, due to their widespread global distribution and significant commercial value, have become central research subjects in the global fruit industry. The robust development of the grape industry relies heavily on scientific research and technological support [1]. Grapevines possess diverse germplasm resources that exhibit notable variations in fruit quality, environmental adaptability, and resistance to pests and diseases. These variations provide a diverse foundation for industrial upgrading and establish higher technical demands for scientific research and exploration [2,3]. Consequently, an in-depth analysis of the genetic characteristics of various grapevine germplasms, coupled with targeted optimization of cultivation management and storage preservation techniques, is essential for establishing a high-quality grape production system. This Special Issue (New Insights into the Genetic Regulation and Quality Improvement of Grapes) invites researchers to share their research findings on the genetic regulation and quality improvement of viticulture. In order to showcase the latest scientific research achievements in the field of grapes and build an industry academic exchange platform, this Special Issue of grape research has undergone strict multiple rounds of review and finally included nine high-quality academic papers, including one review paper and eight original research papers.

2. Fundamental Research on Grapes

The breakthroughs in gene editing technology have provided precise tools for the targeted breeding of grapevines, enabling efficient improvement of key traits such as fruit quality and stress resistance, thus bypassing the labor-intensive and time-consuming processes of traditional breeding methods. In 2016, successful genome editing using CRISPR/Cas9 was first reported in grapes [4,5]; Ren et al. (contribution 1) outlined the future prospects of grapevine genome editing in model systems, precise genome editing, accelerated trait improvement, and non-transgenic genome editing, emphasizing the significant role of CRISPR/Cas in grapevine genome editing.

A systematic analysis of genetic diversity and the domestication process not only clarifies the evolutionary trajectory of grapevine germplasm resources but also provides a clear genetic map for the identification and utilization of superior genes, aiding in the innovation and selection of high-quality germplasm. Through an analysis of domestication index values, probabilities, and entropy, Fort et al. (contribution 2) found that intermediate domestication values pointed towards hybrid populations, highlighting the critical role of hybridization in the development of modern grapevine varieties. This demonstrates the significant importance of mixed populations as reservoirs of genetic diversity. Climate change is often regarded as the most significant challenge facing the grapevine growing industry in the 21st century. Experts are increasingly emphasizing the need to explore the biodiversity within grapevine varieties, identifying grapevine germplasm resources from the Canary Islands using Simple Sequence Repeat (SSR) markers to uncover genetic diversity (contributions 3 and 4). Additionally, reference SSR markers accepted by the global scientific community were used to identify the population structure of ‘Malvasia’, ensuring the authenticity of high-quality wine (contribution 5).

3. The Quality of Grape Berry

Aroma is one of the core indicators of grape fruit quality, directly determining the flavor experience of table grapes and the sensory value of wine. The related research results will lay a theoretical foundation for breeding high-aroma quality grapevine varieties and optimizing cultivation measures to enhance fruit aroma [6]. Huang et al. (contribution 6) used transcriptomic and metabolomic analysis methods to explore the berries of three grapevine varieties (“Adenauer Rose,” “Mei Xiangbao,” and “Kyoho”) at two developmental stages, successfully identifying and quantifying various metabolites and genes related to grape aroma formation.

4. Research Directions on Stress Resistance

With global warming, high-temperature stress has become a significant factor limiting the stable development of the grapevine industry [7,8]. Analyzing the physiological and molecular regulatory mechanisms of grapes in response to high-temperature stress can provide crucial support for the development of cultivation technologies resistant to high temperatures and the breeding of high-temperature-resistant grapevine varieties. The key role of miRNAs in regulating high-temperature stress was observed by Zhang et al. (contribution 7), who found that high temperatures inhibited the expression of Vvi-miR3633a, leading to increased expression of its potential target genes Vv-Atg36 and Vv-GA3ox2. This resulted in decreased activity of the enzymes SOD and CAT, increased thermal injury, and ultimately weakened the plant’s resistance to high temperatures. Biostimulants are agricultural products that contain substances capable of stimulating physiological and biochemical processes in plants, helping them adapt to various adverse environmental conditions [9]. Wu et al. (contribution 8) found that the BaZFP924 protein (patent number: ZL202110900671.3) is most effective in alleviating high-temperature stress and promoting the growth of grapes.

5. The Distribution of Diseases

The diseases in grapes are a major issue in production. Clarifying their distribution patterns and the causes of outbreaks helps to reduce the impact of diseases and pests on grape yield and quality, promoting the green and high-quality development of the industry [10]. The pathogen of downy mildew can infect all the green organs of grapevines (shoots, leaves, inflorescences, clusters) during warm and humid periods in the growing season, leading to significant losses in a short time. Nityagovsky et al. (contribution 9) identified six different amplicon sequencing variants (ASVs) of the downy mildew pathogen from metagenomic data, and through bioinformatics analysis, obtained information on potential microbial antagonists of P. viticola, which forms the theoretical basis for the development of biological control agents for grape downy mildew.

Overall, this Special Issue gathers cutting-edge achievements in grape research, covering the entire chain of content from basic genetic studies to industrial application technologies. The research conclusions not only hold significant academic value for basic grape research but also provide practical theoretical guidance for variety improvement, cultivation optimization, and disaster prevention in the grape industry. This has remarkable benefits for promoting the coordinated development of grape research and industry.