Association and linkage mapping to unravel genetic architecture of phenological traits and lateral bearing in Persian walnut (Juglans regia L.)
Association and linkage mapping to unravel genetic architecture of phenological traits and lateral bearing in Persian walnut (Juglans regia L.)
复制标题
DOI：
10.1186/s12864-020-6616-y
复制
发表时间：
2020-03-04
期刊：
影响因子：
4.4
通讯作者：
Dirlewanger, Elisabeth
中科院分区：
文献类型：
--
作者：
Bernard, Anthony;Marrano, Annarita;Dirlewanger, Elisabeth
研究背景揭示核桃萌芽期和结果习性等农艺性状的遗传结构对于适应气候变化和提高产量具有重要意义。使用多位点模型的全基因组关联研究（GWAS）在一组170个核桃种质中进行了基因分型，这些核桃种质使用Axiom（TM）J. regia 700 K SNP阵列进行基因分型，其中包括2018年，2019年的物候数据和遗留数据。这些种质来自INRAE核桃种质资源收集，这是世界上许多国家进行的重要勘探工作的结果。同时，对分离的78个物候相关性状个体的F-1代进行基因分型和表型分析，构建连锁图谱，并进行数量性状位点（QTL）检测。结果利用GWAS，我们发现位于1号染色体开始的SNPs与萌芽和雌性开花日期有很强的关联。这些发现得到了在同一基因组区域检测到的QTL的支持。使用GWAS还检测到高度显著相关的SNP，用于异二配生殖和侧生习性，均位于11号染色体上。我们开发了一个竞争等位基因特异性PCR（KASP）标记核桃萌芽日期，并验证了它使用的植物材料从核桃改良计划的加州大学戴维斯分校，证明其有效性的标记辅助选择在波斯核桃。我们发现了几个与核桃开花事件有关的候选基因，包括一个编码糖催化酶的异二配生殖相关基因和一个与雌性开花日期相关的细胞分裂相关基因。结论本研究加深了对核桃雌雄开花和侧结果相关重要农艺性状遗传结构的认识。萌芽期是决定核桃结实的重要性状之一，新的萌芽期标记将有助于筛选和培育适合特定气候条件的核桃新品种。
Background Unravelling the genetic architecture of agronomic traits in walnut such as budbreak date and bearing habit, is crucial for climate change adaptation and yield improvement. A Genome-Wide Association Study (GWAS) using multi-locus models was conducted in a panel of 170 walnut accessions genotyped using the Axiom (TM) J. regia 700 K SNP array, with phenological data from 2018, 2019 and legacy data. These accessions come from the INRAE walnut germplasm collection which is the result of important prospecting work performed in many countries around the world. In parallel, an F-1 progeny of 78 individuals segregating for phenology-related traits, was genotyped with the same array and phenotyped for the same traits, to construct linkage maps and perform Quantitative Trait Loci (QTLs) detection. Results Using GWAS, we found strong associations of SNPs located at the beginning of chromosome 1 with both budbreak and female flowering dates. These findings were supported by QTLs detected in the same genomic region. Highly significant associated SNPs were also detected using GWAS for heterodichogamy and lateral bearing habit, both on chromosome 11. We developed a Kompetitive Allele Specific PCR (KASP) marker for budbreak date in walnut, and validated it using plant material from the Walnut Improvement Program of the University of California, Davis, demonstrating its effectiveness for marker-assisted selection in Persian walnut. We found several candidate genes involved in flowering events in walnut, including a gene related to heterodichogamy encoding a sugar catabolism enzyme and a cell division related gene linked to female flowering date. Conclusions This study enhances knowledge of the genetic architecture of important agronomic traits related to male and female flowering processes and lateral bearing in walnut. The new marker available for budbreak date, one of the most important traits for good fruiting, will facilitate the selection and development of new walnut cultivars suitable for specific climates.