School of Natural Sciences and ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tasmania, 7001, Australia.
School of Natural Sciences, University of Tasmania, Hobart, Tasmania, 7001, Australia.
Plant Cell Environ. 2020 Jan;43(1):103-115. doi: 10.1111/pce.13649. Epub 2019 Sep 9.
Drought is a major stress impacting forest ecosystems worldwide. We utilized quantitative trait loci (QTL) analysis to study the genetic basis of variation in (a) drought resistance and recovery and (b) candidate traits that may be associated with this variation in the forest tree Eucalyptus globulus. QTL analysis was performed using a large outcrossed F mapping population from which 300 trees were phenotyped based on the mean performance of their open-pollinated F progeny. Progenies were grown in a glasshouse in a randomized complete block design. A subset of seedlings was subjected to a drought treatment after which they were rewatered and scored for damage and growth postdrought. Nondroughted seedlings were assessed for growth traits as well as lignotuber size and resprouting following severe damage to the main stem. QTL were detected for most traits. Importantly, independent QTL were detected for (a) drought damage and plant size, (b) drought damage and growth recovery, and (c) lignotuber size and resprouting capacity. Such independence argues that trade-offs are unlikely to be a major limitation to the response to selection and at the early life history stage studied; there are opportunities to improve resilience to drought without adverse effects on productivity.
干旱是影响全球森林生态系统的主要胁迫因素之一。我们利用数量性状位点（QTL）分析来研究（a）抗旱性和恢复力以及（b）可能与桉树（Eucalyptus globulus）这一变异相关的候选性状的遗传基础。QTL 分析使用了一个大型杂交 F 作图群体进行，该群体中有 300 棵树根据其自由授粉 F 后代的平均表现进行表型鉴定。这些后代在温室中以随机完全区组设计进行种植。一部分幼苗在遭受干旱处理后进行浇水，并在旱灾后对其损伤和生长情况进行评分。未受干旱影响的幼苗则评估其生长特性、以及在主茎严重受损后的木质块茎大小和萌蘖能力。大多数性状都检测到了 QTL。重要的是，（a）干旱损伤和植物大小、（b）干旱损伤和生长恢复以及（c）木质块茎大小和萌蘖能力之间都检测到了独立的 QTL。这种独立性表明，权衡不太可能成为对选择响应的主要限制因素，而且在研究的早期生活史阶段，有机会在不影响生产力的情况下提高对干旱的适应能力。
