Naegele R P, Granke L L, Fry J, Hill T A, Ashrafi H, Van Deynze A, Hausbeck M K
First author: Research Horticulturalist, United States Department of Agriculture-Agricultural Research Service Crop Diseases, Pests and Genetics Research Unit, Parlier, CA 93720; second author: Associate Research Scientist, Dow Agrosciences, Indianapolis, IN 46268; third author: Former Graduate Research Assistant, Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824; fourth author: Senior Research Associate, Department of Plant Sciences, University of California, Davis 95616; fifth author: Assistant Professor, North Carolina State University, Raleigh 27695-7550; sixth author: Director of Research, Seed Biotechnology Center, University of California, Davis; and seventh author: Professor, Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing 48824.
Phytopathology. 2017 Dec;107(12):1522-1531. doi: 10.1094/PHYTO-02-17-0040-R. Epub 2017 Oct 2.
Incorporating disease resistance into cultivars is a primary focus of modern breeding programs. Resistance to pathogens is often introgressed from landrace or wild individuals with poor fruit quality into commercial-quality cultivars. Sites of multiple disease resistance (MDR) are regions or "hot spots" of the genome with closely linked genes for resistance to different pathogens that could enable rapid incorporation of resistance. An F-derived F recombinant inbred line population from a cross between 'Criollo de Morelos 334' (CMM334) and 'Early Jalapeno' was evaluated in inoculated fruit studies for susceptibility to oomycete and fungal pathogens: Phytophthora capsici, P. nicotianae, Botrytis cinerea, Fusarium oxysporum, F. solani, Sclerotinia sclerotiorum, Alternaria spp., Rhizopus oryzae, R. stolonifer, and Colletotrichum acutatum. All isolates evaluated were virulent on pepper. Significant differences in disease susceptibility were identified among lines for each of the pathogens evaluated. P. capsici was the most virulent pathogen, while R. oryzae and one Sclerotinia isolate were the least virulent. Quantitative trait loci associated with resistance were identified for Alternaria spp. and S. sclerotiorum. Positive correlations in disease incidence were detected between Alternaria spp. and F. oxysporum, F. solani, and C. acutatum, as well as between C. acutatum and Botrytis spp., F. oxysporum, F. solani, and P. capsici. No sites of MDR were identified for pathogens tested; however, positive correlations in disease incidence were detected among pathogens suggesting there may be genetic linkage among resistance genes in CM334 and Early Jalapeno.
将抗病性融入栽培品种是现代育种计划的主要重点。对病原体的抗性通常从果实品质较差的地方品种或野生个体渗入商业品质的栽培品种中。多病害抗性（MDR）位点是基因组中的区域或“热点”，具有与不同病原体抗性紧密连锁的基因，这可能有助于快速整合抗性。在接种果实研究中，对由“克里奥洛·德·莫雷洛斯334”（CMM334）和“早辣青椒”杂交产生的F衍生F重组自交系群体进行了卵菌和真菌病原体易感性评估：辣椒疫霉、烟草疫霉、灰葡萄孢、尖孢镰刀菌、茄腐镰刀菌、核盘菌、链格孢属、米根霉、匐枝根霉和尖孢炭疽菌。评估的所有分离株对辣椒均具有毒性。在所评估的每种病原体的品系之间发现了疾病易感性的显著差异。辣椒疫霉是毒性最强的病原体，而米根霉和一种核盘菌分离株毒性最弱。鉴定出了与链格孢属和核盘菌抗性相关的数量性状位点。在链格孢属与尖孢镰刀菌、茄腐镰刀菌和尖孢炭疽菌之间，以及尖孢炭疽菌与葡萄孢属、尖孢镰刀菌、茄腐镰刀菌和辣椒疫霉之间，检测到了疾病发病率的正相关。在所测试的病原体中未发现MDR位点；然而，在病原体之间检测到了疾病发病率的正相关，这表明CM334和早辣青椒的抗性基因之间可能存在遗传连锁。
