Montemarani A, Sartori M, Nesci A, Etcheverry M, Barros G
Laboratorio de Ecología Microbiana Ambiental, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ruta Nacional 36, km 601, 5800, Río Cuarto, Córdoba, Argentina.
Lett Appl Microbiol. 2018 Dec;67(6):614-619. doi: 10.1111/lam.13076. Epub 2018 Nov 11.
Northern corn leaf blight (NCLB) caused by Exserohilum turcicum is an endemic foliar disease in the Argentinean maize production area. Before applying a control method, it is essential to focus on factors that lead to the survival and conservation of E. turcicum inoculum. However, there is little information about the life cycle of this emerging pathogen in our country. The objective of the present work was to analyse the growth ability of three E. turcicum isolates under different type and conditions of maize, wheat and soybean residues, matric potential, temperature and their interactions. Statistical analysis demonstrated a significant effect of three factors on growth rate: residues-based media, matric potential and temperature. Among them the major effect was produced by matric potential followed by temperature. Although there were no significant differences in the growth rate among different residues types, the range of conditions in which growth occurred was different. According to these results, soybean residues would allow a better survival of E. turcicum inoculum under no-tillage system and providing an inoculum source for maize infections in subsequent year. SIGNIFICANCE AND IMPACT OF THE STUDY: Exserohilum turcicum is an emerging pathogen in Argentina that has caused significant economic losses in different maize growing areas. However, at present there is a lack of information about the life cycle of this fungal pathogen. The present study shows the influence of abiotic factors such as temperature and water potential on the growth of E. turcicum on different crop residues used in rotations with maize under no-till system cultivation. According to our results, soybean residues allowed the pathogen growth in a wider range of conditions compared to wheat and maize residue, providing an inoculum source for maize infections in subsequent season.
由大斑突脐蠕孢引起的玉米大斑病是阿根廷玉米产区的一种地方性叶部病害。在应用防治方法之前，必须关注导致大斑突脐蠕孢接种体存活和保存的因素。然而，在我国，关于这种新出现病原体的生命周期的信息很少。本研究的目的是分析三种大斑突脐蠕孢分离株在不同类型和条件的玉米、小麦和大豆残体、基质势、温度及其相互作用下的生长能力。统计分析表明，有三个因素对生长速率有显著影响：基于残体的培养基、基质势和温度。其中主要影响因素是基质势，其次是温度。虽然不同残体类型之间的生长速率没有显著差异，但生长发生的条件范围不同。根据这些结果，在免耕系统下，大豆残体将使大斑突脐蠕孢接种体有更好的存活，并为次年玉米感染提供接种源。研究的意义和影响：大斑突脐蠕孢是阿根廷一种新出现的病原体，已在不同玉米种植区造成重大经济损失。然而，目前关于这种真菌病原体的生命周期缺乏信息。本研究表明了温度和水势等非生物因素对免耕系统种植下与玉米轮作使用的不同作物残体上大斑突脐蠕孢生长的影响。根据我们的结果，与小麦和玉米残体相比，大豆残体在更广泛的条件下允许病原体生长，为后续季节的玉米感染提供接种源。
