Novel stable QTLs identification for berry quality traits based on high-density genetic linkage map construction in table grape

Abstract

Backgroud: Aroma, berry firmness and berry shape are three main quality traits in table grape production, and also the important target traits in grapevine breeding. However, limited information about their genetic determinants leads to low accuracy and efficiency of quality breeding in grapevine. Mapping and isolation of quantitative trait locus (QTLs) based on the construction of genetic linkage map is a powerful approach to decipher the genetic determinants of complex quantitative traits in grape.Results: In the present work, a final integrated map consisted of 6,436 SLAF markers on 19 linkage groups (LGs) spanning 3,365.41 cM in genome size with an average distance of 0.52 cM between adjacent markers was generated using the specific length amplified fragment sequencing (SLAF-seq) technique. Total 16 significant QTLs were identified on six linkage groups based on phenotypic data of Muscat flavor, berry firmness and berry shape among the hybrids analyzed over three consecutive years from 2016 to 2018. Notably, new QTLs for berry firmness and berry shape were found on LG 8 respectively for the first time, which had the strongest and most stable effects over 2-3 years. Based on biological function and expression profiles of candidate genes in the major QTL regions, 3 genes (VIT_08s0007g00440, VIT_08s0040g02740 and VIT_08s0040g02350) related to berry firmness and 3 genes (VIT_08s0032g01110, VIT_08s0032g01150 and VIT_08s0105g00200) linked to berry shape were highlighted. Overexpression of VIT_08s0032g01110 in transgenic Arabidopsis plants caused the change of pod shape.Conclusions: A new high-density genetic map with total 6634 markers was constructed with SLAF-seq technique, and thus enabled the detection of narrow interval QTLs for relevant traits in grapevine. VIT_08s0007g00440, VIT_08s0040g02740 and VIT_08s0040g02350 were found to be related to berry firmness, and VIT_08s0032g01110, VIT_08s0032g01150 and VIT_08s0105g00200 were linked to berry shape.

Post-Veraison Water Stress and Pruning Level on Merlot Grapevine (Vitis vinifera L.): Effects on Berry Development and Composition

“…Generally, the accumulation of total soluble solids per berry decreased with increasing the pruning level from minimal to severe, while increased with postveraison water stress from none to an intense. is result is in agreement with recently published works [18,33,[40][41][42][43], where higher crop loads per grapevine resulted in a limitation in the final sugar level attainable in the fruit at harvest. is phenomenon was also demonstrated by the studies in [44,45], who found that water deficit combined with increased crop load led to a significant reduction in the rate of sugar accumulation.…”

“…In this study, the results indicate that, where water stress does cause an increase in berry anthocyanin and phenol concentration, this is more likely to be due to a physiological response to the berry volume and weight effect. A similar observation [33,41,46] were made that a water stress treatment brought about an increase in anthocyanin and phenolic concentration in the berry skin.…”

“…is finding is in line with other authors [40,42,46] whom reported that the increase in total anthocyanins and phenols under heavy pruning was due to an increase in grape berry weight and biochemical response of the anthocyanin and phenol metabolic pathway to the induced signals caused by water stress which led to increase the total anthocyanin and phenolic concentration per gram and contents per berry. In other previous studies [26,41,45], correlation analysis of potential factors contributing to altered metabolism in the anthocyanin pathway showed that color was negatively correlated with vigour indices, canopy density, and stomatal conductance and positively correlated with light penetration into the canopy.…”

“…TA in severely pruned and adequately irrigated grapevine was higher by 49.07% compared with minimally pruned grapevines under intense water stress (Figure 9). Other authors [1,26,[41][42][43]45] have also observed higher TA content in heavy pruned grapevine with well-irrigated grapevines probably related to a delay in ripening at which the bunches will not be able to reach target ripeness levels due to a restricted carbon allocation from the canopy and reduction of sugar accumulation.…”

Hyperspectral signatures and reflectance models related to the ripening index in four grape varieties

“…They concluded that grapes with higher skin breaking forces produce extracts with a higher total content of anthocyanins. Further, according to Wang et al (2020) aroma, firmness, and berry shape are three important quality traits that are perceived for table grape berries. On the other matter, throughout the development of the berry, the transverse and longitudinal diameters gradually increase, tending to certain regularity at the end of its maturation (Zhang et al 2021).…”