Celton Jean-Marc, Kelner Jean-Jacques, Martinez Sébastien, Bechti Abdel, Khelifi Touhami Amina, James Marie José, Durel Charles-Eric, Laurens François, Costes Evelyne
Institut National de la Recherche Agronomique (INRA), UMR 1334, AGAP CIRAD-INRA-Montpellier SupAgro Team «Architecture et Fonctionnement des Espèces Fruitières», Montpellier, France; Institut National de la Recherche Agronomique (INRA), UMR1345 Institut de Recherche en Horticulture et Semences (IRHS), AgroCampus-Ouest, Université d'Angers, SFR 4207 QUASAV, Beaucouzé, France.
Institut National de la Recherche Agronomique (INRA), UMR 1334, AGAP CIRAD-INRA-Montpellier SupAgro Team «Architecture et Fonctionnement des Espèces Fruitières», Montpellier, France.
PLoS One. 2014 Mar 13;9(3):e91016. doi: 10.1371/journal.pone.0091016. eCollection 2014.
In apple (Malus×domestica Borkh), as in many fruiting crops, fruit maintenance vs abscission is a major criteria for production profitability. Growers routinely make use of chemical thinning agents to control total fruit load. However, serious threats for the environment lead to the demand for new apple cultivars with self-thinning properties. In this project, we studied the genetic determinism of this trait using a F1 progeny derived from the cross between the hybrid INRA X3263, assumed to possess the self-thinning trait, and the cultivar 'Belrène'. Both counting and percentage variables were considered to capture the fruiting behaviour on different shoot types and over three consecutive years. Besides low to moderate but significant genetic effects, mixed models showed considerable effects of the year and the shoot type, as well as an interaction effect. Year effect resulted mainly from biennial fruiting. Eight Quantitative Trait Locus (QTL) were detected on several linkage groups (LG), either independent or specific of the year of observation or the shoot type. The QTL with highest LOD value was located on the top third of LG10. The screening of three QTL zones for candidate genes revealed a list of transcription factors and genes involved in fruit nutrition, xylem differentiation, plant responses to starvation and organ abscission that open new avenues for further molecular investigations. The detailed phenotyping performed revealed the dependency between the self-thinning trait and the fruiting status of the trees. Despite a moderate genetic control of the self-thinning trait, QTL and candidate genes were identified which will need further analyses involving other progenies and molecular investigations.
与许多结果作物一样，在苹果（Malus×domestica Borkh）中，果实的留存与脱落是决定生产效益的主要标准。种植者通常使用化学疏果剂来控制总果量。然而，对环境的严重威胁促使人们需要具有自疏特性的新苹果品种。在本项目中，我们利用一个F1后代群体研究了该性状的遗传决定性，该群体来源于假定具有自疏性状的杂交种INRA X3263与品种‘贝雷纳’的杂交。我们考虑了计数变量和百分比变量，以捕捉不同枝条类型在连续三年中的结果行为。除了低到中等但显著的遗传效应外，混合模型还显示出年份和枝条类型的显著效应以及交互效应。年份效应主要源于隔年结果。在几个连锁群（LG）上检测到了8个数量性状位点（QTL），这些位点要么独立，要么特定于观察年份或枝条类型。LOD值最高的QTL位于LG10的上三分之一处。对三个QTL区域进行候选基因筛选，揭示了一系列转录因子和参与果实营养、木质部分化、植物对饥饿的反应以及器官脱落的基因，为进一步的分子研究开辟了新途径。详细的表型分析表明，自疏性状与树木的结果状态之间存在相关性。尽管自疏性状的遗传控制程度中等，但已鉴定出QTL和候选基因，这需要涉及其他后代群体的进一步分析和分子研究。
