Gupta Sanjiv, Loughman Robert
State Agricultural Biotechnology Centre, Division of Science and Engineering, Murdoch University, Murdoch, Western Australia 6150, Australia.
Plant Pathology, Agriculture Western Australia, Baron-Hay Court, South Perth, Western Australia 6151, Australia.
Plant Dis. 2001 Sep;85(9):960-966. doi: 10.1094/PDIS.2001.85.9.960.
Studies on variation, occurrence, and distribution of virulence in Pyrenophora teres are helpful to identify effective sources of resistance that can be used for barley breeding in Western Australia. Seventy-nine isolates of Pyrenophora teres were collected from different barley fields of Western Australia in 1995-96. Seventy-four induced net type symptoms (P. teres f. teres) and five induced spot type symptoms (P. teres f. maculata). Net type isolate responses on 47 barley lines were similar to the range of responses induced by nine historical isolates collected in the region between 1975 and 1985. These net type isolates were classified into two distinct groups based on virulence to the cultivar Beecher. Isolates were further classified into eight groups based on minor pathogenic variation among the population. The virulence phenotype present in an eastern Australian isolate was not observed in any isolates collected from Western Australia. An analysis of variance on a subset of 12 net type isolates indicated a significant line × isolate interaction (P < 0.001), with the interaction term variance component four times larger than the error variance. Based on these studies, the virulence among net type isolates has remained stable in Western Australia for the last 19 years. Spot type isolates were collected from a wider geographic area than previously reported and varied in virulence based on response to barley line Herta. Variation in spot-type isolates is reported for the first time from the region. The results from this study are being used in the development of resistant varieties.
对网斑病菌（Pyrenophora teres）毒力的变异、发生及分布进行研究，有助于确定可用于西澳大利亚大麦育种的有效抗性资源。1995 - 1996年，从西澳大利亚不同大麦田收集了79个网斑病菌分离株。其中74个引起网斑型症状（网斑病菌圆斑专化型，P. teres f. teres），5个引起斑型症状（网斑病菌黄斑专化型，P. teres f. maculata）。47个大麦品系上的网斑型分离株反应与1975年至1985年期间在该地区收集的9个历史分离株诱导的反应范围相似。这些网斑型分离株根据对品种比彻的毒力分为两个不同的组。基于群体中的微小致病变异，分离株进一步分为8个组。在从西澳大利亚收集的任何分离株中均未观察到澳大利亚东部一个分离株中存在的毒力表型。对12个网斑型分离株的一个子集进行方差分析表明，品系×分离株存在显著互作（P < 0.001），互作项方差分量比误差方差大四倍。基于这些研究，在过去19年中，西澳大利亚网斑型分离株的毒力一直保持稳定。斑型分离株的收集地理区域比以前报道的更广，并且根据对大麦品系赫塔的反应，其毒力有所不同。该地区首次报道了斑型分离株的变异情况。本研究结果正用于抗性品种的培育。
