Flament M H, Kebe I, Clément D, Pieretti I, Risterucci A M, N'Goran J A, Cilas C, Despréaux D, Lanaud C
Centre de coopération internationale en recherche agronomique pour le développement, Programme Biotrop, Montpellier, France.
Genome. 2001 Feb;44(1):79-85. doi: 10.1139/gen-44-1-79.
Phytophthora palmivora causes pod rot, a serious disease on cocoa widespread throughout the producing regions. In order to ascertain the genetic determination of cocoa resistance to P. palmivora, a study was carried out on two progenies derived from crosses between a heterozygous, moderately resistant Forastero clone, T60/887, and two closely related and highly susceptible Forastero clones, one completely homozygous, IFC2, and one partially heterozygous, IFC5. The cumulative size of both progenies was 112 individuals. Plants were subjected to natural and artificial inoculation of P. palmivora in C te d'Ivoire. The genetic maps of T60/887 and of IFC5 were constructed using amplified fragment length polymorphism (AFLP) markers and microsatellites. The map of T60/887 comprised 198 markers assembled in 11 linkage groups and representing a total length of 793 cM. The map of IFC5 comprised 55 AFLP markers that were assembled into six linkage groups for a total length of 244 cM. Ratio of rotten over total number of fruit under natural infection was measured for each tree over two harvests. Artificial inoculations were performed on leaves and pods. These tests were weakly correlated with the pod rot rate in the field. Five quantitative trait loci (QTLs) of resistance were detected for T60/887 but none were common between the three traits measured. Stability and reliability of the experimental procedures are discussed and revealed the difficult use of these artificial tests on adult trees for a good prediction of field resistance.
棕榈疫霉会引发豆荚腐烂病，这是一种在可可种植产区广泛传播的严重病害。为了确定可可对棕榈疫霉抗性的遗传决定因素，对两个后代群体进行了研究，这两个群体来自一个杂合的、具有中度抗性的弗拉斯特罗克隆T60/887与两个亲缘关系密切且高度易感的弗拉斯特罗克隆之间的杂交，其中一个是完全纯合的IFC2，另一个是部分杂合的IFC5。两个后代群体的总数为112株植株。在科特迪瓦，对植株进行了棕榈疫霉的自然接种和人工接种。利用扩增片段长度多态性（AFLP）标记和微卫星构建了T60/887和IFC5的遗传图谱。T60/887的图谱包含198个标记，组装成11个连锁群，总长度为793厘摩。IFC5的图谱包含55个AFLP标记，组装成6个连锁群，总长度为244厘摩。在两个收获季中，测量了每棵树在自然感染下腐烂果实数与总果实数的比例。对叶片和豆荚进行了人工接种。这些测试与田间的豆荚腐烂率相关性较弱。在T60/887中检测到5个抗性数量性状位点（QTL），但在所测量的三个性状之间没有共同的QTL。讨论了实验程序的稳定性和可靠性，结果表明在成年树上进行这些人工测试很难准确预测田间抗性。
