Alahakoon Dilmini, Fennell Anne
Agronomy, Horticulture, and Plant Science Department, South Dakota State University, Brookings, SD, United States.
Front Plant Sci. 2023 Feb 2;13:1083374. doi: 10.3389/fpls.2022.1083374. eCollection 2022.
Own-rooted grapevines and grapevine rootstocks are vegetatively propagated from cuttings and have an adventitious root system. Unraveling the genetic underpinnings of the adventitious root system architecture (RSA) is important for improving own-rooted and grafted grapevine sustainability for a changing climate. Grapevine RSA genetic analysis was conducted in an 'VRS-F2' population. Nine root morphology, three total root system morphology, and two biomass traits that contribute to root anchorage and water and nutrient uptake were phenotyped. Quantitative trait loci (QTL) analysis was performed using a high density integrated GBS and rhAmpSeq genetic map. Thirty-one QTL were detected for eleven of the RSA traits (surface area, root volume, total root length, fresh weight, number of tips, forks or links, longest root and average root diameter, link length, and link surface area) revealing many small effects. Several QTL were colocated on chromosomes 1, 9, 13, 18, and 19. QTL with identical peak positions on chromosomes 1 or 13 were enriched for , , , , and transcription factors, and QTL on chromosomes 9 or 13 were enriched for the transcription factor and regulation of autophagy pathways. QTL modeling for individual root traits identified eight models explaining 13.2 to 31.8% of the phenotypic variation. 'Seyval blanc' was the grandparent contributing to the allele models that included a greater surface area, total root length, and branching (number of forks and links) traits promoting a greater root density. In contrast, 'Manitoba 37' contributed the allele for greater average branch length (link length) and diameter, promoting a less dense elongated root system with thicker roots. and the were identified as important candidate genes in the enriched pathways underlying the hotspots for grapevine adventitious RSA. The combined QTL hotspot and trait modeling identified transcription factors, cell cycle and circadian rhythm genes with a known role in root cell and epidermal layer differentiation, lateral root development and cortex thickness. These genes are candidates for tailoring grapevine root system texture, density and length in breeding programs.
自根葡萄树和葡萄树砧木通过扦插进行无性繁殖，具有不定根系。揭示不定根系结构（RSA）的遗传基础对于提高自根和嫁接葡萄树在气候变化下的可持续性至关重要。在一个“VRS - F2”群体中进行了葡萄树RSA遗传分析。对九个根系形态、三个总根系形态以及两个有助于根系固定和水分与养分吸收的生物量性状进行了表型分析。使用高密度整合的GBS和rhAmpSeq遗传图谱进行了数量性状位点（QTL）分析。针对RSA的11个性状（表面积、根体积、总根长度、鲜重、根尖、分叉或连接的数量、最长根和平均根直径、连接长度以及连接表面积）检测到31个QTL，显示出许多小效应。几个QTL共定位在染色体1、9、13、18和19上。在染色体1或13上具有相同峰值位置的QTL富含、、、、和转录因子，而在染色体9或13上的QTL富含转录因子和自噬途径的调控。对单个根系性状的QTL建模确定了八个模型，解释了13.2%至31.8%的表型变异。“白谢瓦尔”是等位基因模型的亲本，这些模型具有更大的表面积、总根长度以及促进更高根系密度的分支（分叉和连接的数量）性状。相比之下，“马尼托巴37”贡献了更大平均分支长度（连接长度）和直径的等位基因，促进形成根系密度较低、根较粗的细长根系。和被确定为葡萄树不定RSA热点区域富集途径中的重要候选基因。综合的QTL热点和性状建模确定了在根细胞和表皮层分化、侧根发育以及皮层厚度方面具有已知作用的转录因子、细胞周期和昼夜节律基因。这些基因是在育种计划中调整葡萄树根系质地、密度和长度的候选基因。
