Department of Horticulture, PMAS-Arid Agriculture University, Rawalpindi, Pakistan.
National Center of Industrial Biotechnology, PMAS-Arid Agriculture University, Rawalpindi, Pakistan.
PLoS One. 2022 Sep 13;17(9):e0274387. doi: 10.1371/journal.pone.0274387. eCollection 2022.
The narrow genetic base of modern cultivars is becoming a key bottleneck for crop improvement and the use of wild relatives is an appropriate approach to improve the genetic diversity of crops to manage the sustainable production under different abiotic and biotic constraints. In Pakistan, wild germplasm of grapevine viz Dakh, Toran, and Zarishk belong to Vitis vinifera subsp. sylvestris and Fatati belong to Vitis vinifera subsp. sativa is naturally present in humid and sub-humid areas of mountainous and sub-mountainous regions and showed varying level of tolerance against drought stress but have not been evaluated as rootstock. In this study, different tolerant behavior of wild grapevines as rootstock in grafted scion varieties were explored under different levels of PEG-6000 mediated drought stress i.e., -4.00, -6.00, and -8.00 bars. In response to drought stress, wild grapevines evoked several non-enzymatic and enzymatic activities. Among non-enzymatic activities, total chlorophyll contents of commercial varieties were sustained at higher level when grafted on wild grapevines Dakh and Fatati which subsequently reduced the damage of cell membrane via MDA. Whereas, to cope the membranous damage due to excessive cellular generation of ROS, wild grapevines triggered the enhanced activities of SOD to dismutase the free oxygen radicals into H2O2, then CAT enzyme convert the H2O2 into water molecules. Higher accumulation of ROS in commercial scion varieties were also coped by wild grapevines Dakh and Fatati through the upregulation of POD and APX enzymes activities. Based on these enzymatic and non-enzymatic indices, biplot and cluster analysis classified the wild grapevines as rootstock into three distinct categories comprises on relatively tolerant i.e., Dakh (Vitis vinifera subsp. sylvestris) and Fatati (Vitis vinifera subsp. sativa), moderate tolerant i.e., Toran (Vitis vinifera subsp. sylvestris) and relatively susceptible category i.e., Zarishk (Vitis vinifera subsp. sylvestris).
现代栽培品种的遗传基础狭窄，正成为作物改良的关键瓶颈，而利用野生近缘种是提高作物遗传多样性的一种适当方法，可用于管理不同非生物和生物胁迫下的可持续生产。在巴基斯坦，葡萄野生种质资源如 Dakh、Toran 和 Zarishk 属于 Vitis vinifera subsp. sylvestris，Fatati 属于 Vitis vinifera subsp. sativa，自然存在于山区和次山区的湿润和半湿润地区，对干旱胁迫表现出不同程度的耐受性，但尚未被评估为砧木。在这项研究中，不同耐旱性的野生葡萄作为砧木在不同 PEG-6000 介导的干旱胁迫水平下对嫁接品种的影响，即-4.00、-6.00 和-8.00 巴。在应对干旱胁迫时，野生葡萄会引发多种非酶和酶促活动。在非酶活性中，当商业品种嫁接到野生葡萄 Dakh 和 Fatati 上时，总叶绿素含量保持在较高水平，随后通过 MDA 减少细胞膜的损伤。然而，为了应对由于细胞内 ROS 过度产生而导致的膜损伤，野生葡萄会触发 SOD 活性的增强，将游离氧自由基歧化为 H2O2，然后 CAT 酶将 H2O2转化为水分子。野生葡萄也通过提高 POD 和 APX 酶活性来应对商业接穗品种中 ROS 的积累。基于这些酶和非酶指标，双标图和聚类分析将野生葡萄作为砧木分为三个不同的类别，包括相对耐旱的 Dakh（Vitis vinifera subsp. sylvestris）和 Fatati（Vitis vinifera subsp. sativa）、中度耐旱的 Toran（Vitis vinifera subsp. sylvestris）和相对敏感的 Zarishk（Vitis vinifera subsp. sylvestris）。
