Valentini Nadia, Portis Ezio, Botta Roberto, Acquadro Alberto, Pavese Vera, Cavalet Giorsa Emile, Torello Marinoni Daniela
Dipartimento di Scienze Agrarie, Forestali e Alimentari (DISAFA), University of Turin, Turin, Italy.
Front Plant Sci. 2021 Dec 23;12:749394. doi: 10.3389/fpls.2021.749394. eCollection 2021.
An increasing interest in the cultivation of (European) hazelnut () is driving a demand to breed cultivars adapted to non-conventional environments, particularly in the context of incipient climate change. Given that plant phenology is so strongly determined by genotype, a rational approach to support these breeding efforts will be to identify quantitative trait loci (QTLs) and the genes underlying the basis for adaptation. The present study was designed to map QTLs for phenology-related traits, such as the timing of both male and female flowering, dichogamy, and the period required for nuts to reach maturity. The analysis took advantage of an existing linkage map developed from a population of F progeny bred from the cross "Tonda Gentile delle Langhe" × "Merveille de Bollwiller," consisting in 11 LG. A total of 42 QTL-harboring regions were identified. Overall, 71 QTLs were detected, 49 on the TGdL map and 22 on the MB map; among these, 21 were classified as major; 13 were detected in at least two of the seasons (stable-major QTL). In detail, 20 QTLs were identified as contributing to the time of male flowering, 15 to time of female flowering, 25 to dichogamy, and 11 to time of nut maturity. LG02 was found to harbor 16 QTLs, while 15 QTLs mapped to LG10 and 14 to LG03. Many of the QTLs were clustered with one another. The major cluster was located on TGdL_02 and consisted of mainly major QTLs governing all the analyzed traits. A search of the key genomic regions revealed 22 candidate genes underlying the set of traits being investigated. Many of them have been described in the literature as involved in processes related to flowering, control of dormancy, budburst, the switch from vegetative to reproductive growth, or the morphogenesis of flowers and seeds.
对（欧洲）榛子种植的兴趣日益浓厚，这推动了对适应非传统环境的品种培育的需求，特别是在气候变化初现的背景下。鉴于植物物候学在很大程度上由基因型决定，支持这些育种工作的合理方法将是识别数量性状基因座（QTL）以及适应基础的潜在基因。本研究旨在绘制与物候相关性状的QTL图谱，如雄花和雌花开花时间、雌雄异熟以及坚果成熟所需时间。该分析利用了从杂交组合“Tonda Gentile delle Langhe”דMerveille de Bollwiller”培育的F子代群体构建的现有连锁图谱，该图谱由11个连锁群组成。总共鉴定出42个含有QTL的区域。总体而言，检测到71个QTL，其中49个在TGdL图谱上，22个在MB图谱上；其中，21个被归类为主要QTL；13个在至少两个季节中被检测到（稳定主要QTL）。详细来说，鉴定出20个QTL对雄花开花时间有贡献，15个对雌花开花时间有贡献，25个对雌雄异熟有贡献，11个对坚果成熟时间有贡献。发现LG02含有16个QTL，而15个QTL定位于LG10，14个定位于LG03。许多QTL彼此聚集在一起。主要簇位于TGdL_02上，主要由控制所有分析性状的主要QTL组成。对关键基因组区域的搜索揭示了22个潜在基因，这些基因是所研究性状的基础。其中许多基因在文献中被描述为参与与开花、休眠控制、芽萌发、从营养生长向生殖生长的转变或花和种子的形态发生等相关过程。
