Widely distributed variation in tolerance to Phytophthora palmivora in four genetic groups of cacao
Widely distributed variation in tolerance to Phytophthora palmivora in four genetic groups of cacao
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DOI：
10.1007/s11295-019-1396-8
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发表时间：
2019-12-05
影响因子：
2.4
通讯作者：
Guiltinan, Mark J.
中科院分区：
文献类型：
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作者：
Fister, Andrew S.;Leandro-Munoz, Mariela E.;Guiltinan, Mark J.
热带树木可可树是巧克力的来源，其种子是中美洲、南美洲、非洲和亚洲许多生产国的主要出口产品。每年因病害损失收获前产量的30-40%。寄主植物抗性是最有效和最环保的病害管理方法。从历史上看，可可种质资源一直没有充分利用的努力引入新的抗病来源育种计划。可可种质资源的维持也依赖于无性繁殖的活体采集，因为可可种子没有休眠，不能储存超过几周。在这项研究中，我们使用90个SNP阵列来验证哥斯达黎加CATIE国际可可收藏中的一组克隆的遗传身份，并将这些克隆分配到已知的遗传群中。我们还使用离体叶片接种技术测定了60个基因型对棕榈疫霉（一种具有全球重要性的可可主要病原体）的敏感性。我们鉴定出24个基因型与标准耐受性品种（SCA6）具有统计学上相似的疾病耐受性，另外24个基因型与标准易感品种（ICS1）相似。我们的结果表明，四个被纳入的遗传群中每一个都表现出对棕榈芽孢杆菌的数量抗性的变异性。这些结果为未来CATIE领域疾病耐受性和易感性的基因组和转录组学分析奠定了基础，并为育种者寻找可引入育种计划的新耐受性来源提供了指导。
The tropical tree Theobroma cacao is the source of chocolate, and its seeds are a major export from many producing countries in Central and South America, Africa, and Asia. Every year, 30-40% of pre-harvest yield is lost due to disease damage. Host plant resistance is the most efficient and environmentally friendly approach for disease management. Historically, cacao germplasm resources have been underutilized in efforts to introduce novel sources of disease tolerance into breeding programs. Maintenance of cacao germplasm also relies on clonally propagated live collections, as cacao seeds do not exhibit dormancy and cannot be stored for more than a few weeks. In this study, we use a 90 SNP array to verify genetic identity of a set of clones in the International Cocoa Collection at CATIE, Costa Rica, and assign the clones into known genetic groups. We also used a detached leaf inoculation technique to measure the susceptibility of 60 genotypes to Phytophthora palmivora, a major cacao pathogen with global importance. We identified 24 genotypes with disease tolerance statistically similar to a standard tolerant variety (SCA6) and another 24 which performed similarly to a standard susceptible variety (ICS1). Our results indicate that each of the four included genetic groups show variability for quantitative resistance to P. palmivora. These results provide a foundation for future genomic and transcriptomic analysis of disease tolerance and susceptibility in the field at CATIE and provide guidelines for breeders searching for novel sources of tolerance that can be introduced into breeding programs.