Risterucci A M, Paulin D, Ducamp M, N'Goran J A K, Lanaud C
CIRAD, Centre de Cooperation Internationale en Recherche Agronomique pour le Développement, UMR 1096, avenue Agropolis, BP 5035, 34398, Montpellier cedex 5, France.
Theor Appl Genet. 2003 Dec;108(1):168-74. doi: 10.1007/s00122-003-1408-8. Epub 2003 Sep 13.
This study aimed to compare the genetic control of cacao resistance to three species of Phytophthora: Phytophthora palmivora, Phytophthora megakarya and Phytophthora capsici. The study was conducted on 151 hybrid progenies created in Côte d'Ivoire and grown in a green-house in Montpellier. Phytophthora resistance was screened by leaf-test inoculation with two different strains per species. Selection of the best individuals for resistance to P. palmivora at a 10% selection rate, would lead to a genetic progress of 47% in the disease evaluation for this species and a genetic progress of 42% and 21% for the two other species. A genetic map with a total length of 682 cM was built with 213 markers, 190 AFLPs and 23 microsatellites. QTLs were identified using composite interval mapping. QTLs were found located in six genomic regions. One of these was detected with five strains belonging to the three Phytophthora species. Two other regions were detected with two or three strains of two different species. Three additional QTLs were detected for only one species of Phytophthora. Each QTL explained between 8 to 12% of the phenotypic variation. For each strain, between 11.5% to 27.5% of the total phenotypic variation could be explained by the QTLs identified. The identification of multiple QTLs involved in resistance to Phytophthora offers the possibility to improve durability of resistance in cocoa by a possible cumulation of many different resistance genes located in different chromosome regions using marker-aided selection.
本研究旨在比较可可对三种疫霉菌的抗性遗传控制，这三种疫霉菌分别是棕榈疫霉、大果疫霉和辣椒疫霉。该研究在科特迪瓦创建并在蒙彼利埃温室中种植的151个杂交后代上进行。通过对每个物种用两种不同菌株进行叶片接种试验来筛选疫霉抗性。以10%的选择率选择对棕榈疫霉抗性最佳的个体，将导致该物种在病害评估中的遗传进展为47%，另外两个物种的遗传进展分别为42%和21%。利用213个标记构建了总长为682厘摩的遗传图谱，其中包括190个扩增片段长度多态性（AFLP）标记和23个微卫星标记。使用复合区间作图法鉴定数量性状位点（QTL）。发现QTL位于六个基因组区域。其中一个区域是用属于三种疫霉菌的五个菌株检测到的。另外两个区域是用两种不同物种的两株或三株菌株检测到的。另外三个QTL仅在一种疫霉菌中检测到。每个QTL解释了8%至12%的表型变异。对于每个菌株，所鉴定的QTL可解释总表型变异的11.5%至27.5%。对参与疫霉抗性的多个QTL的鉴定，为通过利用标记辅助选择，将位于不同染色体区域的许多不同抗性基因进行可能的累积，从而提高可可抗性的持久性提供了可能性。
