Field pea crops in central Alberta were surveyed for ascochyta blight from 2011 to 2012 and fungal isolates were recovered from foliar lesions on selected plants. Cultural and microscopic characterization of the 275 i...Field pea crops in central Alberta were surveyed for ascochyta blight from 2011 to 2012 and fungal isolates were recovered from foliar lesions on selected plants. Cultural and microscopic characterization of the 275 isolates obtained revealed that 272 were of Mycosphaerella pinodes and three were of Phoma medicaginis var. pinodella. Ascochyta pisi or Phoma koolunga were not identified. Isolates of M. pinodes were divided into two groups,GI and GII, based on visual assessment of culture characteristics. GI isolates(light to dark, mostly gray colony color; pycnidial distribution radial and concentric; conidia10.5–14.5 × 4.2–6.2 μm most with one septum, occasionally two, constricted at the septum;spore mass light buff to flesh color) were predominant(83%), while GII isolates(dark to gray colony color; pycnidia abundant; conidia 8–16 × 3.5–6.2 μm most with 1 septum, constricted at the septum; spore mass light buff to flesh color) were less common(17%). The cultures of GII isolates were similar to recent descriptions of A. pisi, but they differed in spore color. In a host differential study, 13 pathotypes of M. pinodes were identified from 110 single-spore isolates. Pathotype I was predominant(88 isolates) and virulent on all nine differential genotypes. The other pathotypes(pathotypes II–XIII) were rare(1–6 isolates of each).Comparison of the present results with earlier studies suggests that pathotype I has been prevalent for many years, and that its aggressiveness on the host differentials has increased over time. Emphasis should be placed on breeding for resistance to M. pinodes in field pea cultivars intended for deployment in central Alberta.展开更多
Aphanomyces root rot(ARR) of field pea(Pisum sativum), caused by Aphanomyces euteiches, can cause severe root damage, wilting, and large yield losses under wet soil conditions. To identify ways to manage this disease,...Aphanomyces root rot(ARR) of field pea(Pisum sativum), caused by Aphanomyces euteiches, can cause severe root damage, wilting, and large yield losses under wet soil conditions. To identify ways to manage this disease, the effect of A. euteiches inoculum density on field pea was studied under greenhouse and field conditions in 2015 and 2016. Increases in inoculum density reduced seedling emergence, root nodulation, and plant vigor, and resulted in increased root rot severity in both field and greenhouse tests. Seed treatments with the fungicides Apron Advance(thiabendazole + fludioxonil + metalaxyl) + Vibrance(difenoconazole + metalaxylM + sedaxane), INTEGO Solo(ethaboxam), BAS 516F(boscalid + pyraclostrobin), BAS 720F(metalaxyl + pyraclostrobin + fluxapyroxad), and BAS 516F + BAS 720F(3:1) were evaluated for their efficacy against ARR. All seed treatments except Apron Advance + Vibrance reduced root rot severity under controlled conditions. BAS 516F, BAS 720F and INTEGO Solo improved plant vigor and all treatments reduced seedling blight to varying degrees under greenhouse conditions, but not in the field. A collection of 22 pea genotypes was evaluated for resistance to root rot in field plot experiments. Line 00–2067 showed the least severe root rot symptoms,whereas ‘Spring D' showed the lowest reduction in yield. The results suggest that there may be an opportunity to combine partial host resistance and fungicidal seed treatments to adequately manage ARR of field pea.展开更多
基金funded in part by the ACAAF (Advancing Canadian Agriculture and Agri-Food) Program of the Agriculture and Food Council and the Alberta Pulse Growers Commission
文摘Field pea crops in central Alberta were surveyed for ascochyta blight from 2011 to 2012 and fungal isolates were recovered from foliar lesions on selected plants. Cultural and microscopic characterization of the 275 isolates obtained revealed that 272 were of Mycosphaerella pinodes and three were of Phoma medicaginis var. pinodella. Ascochyta pisi or Phoma koolunga were not identified. Isolates of M. pinodes were divided into two groups,GI and GII, based on visual assessment of culture characteristics. GI isolates(light to dark, mostly gray colony color; pycnidial distribution radial and concentric; conidia10.5–14.5 × 4.2–6.2 μm most with one septum, occasionally two, constricted at the septum;spore mass light buff to flesh color) were predominant(83%), while GII isolates(dark to gray colony color; pycnidia abundant; conidia 8–16 × 3.5–6.2 μm most with 1 septum, constricted at the septum; spore mass light buff to flesh color) were less common(17%). The cultures of GII isolates were similar to recent descriptions of A. pisi, but they differed in spore color. In a host differential study, 13 pathotypes of M. pinodes were identified from 110 single-spore isolates. Pathotype I was predominant(88 isolates) and virulent on all nine differential genotypes. The other pathotypes(pathotypes II–XIII) were rare(1–6 isolates of each).Comparison of the present results with earlier studies suggests that pathotype I has been prevalent for many years, and that its aggressiveness on the host differentials has increased over time. Emphasis should be placed on breeding for resistance to M. pinodes in field pea cultivars intended for deployment in central Alberta.
基金funding support received from Agriculture and Agri-Food Canadathe Saskatchewan Pulse Growers Association+1 种基金the Manitoba Pulse and Soybean Growers through the Growing Forward 2the Pest Management and Surveillance Implementation Program
文摘豌豆(Pisum sativum var. arvense L.)是世界上重要的豆科作物。豌豆籽粒蛋白质含量很高,并能提高土壤中有效氮的含量。由一种土传卵菌根腐丝囊霉(Aphanomyces euteiches Drechs.)引起的Aphanomyces根腐病(ARR),在包括加拿大在内的许多地区对豌豆生产构成严重威胁,在潮湿的土壤条件下引起严重的根损伤、萎蔫,造成大幅度减产。在有利于病害发生的条件下,由于病原体卵孢子的寿命长,在豌豆任何生长阶段都可以侵染豌豆植株,传统病害防控措施(如作物轮作和拌种处理)不能完全防治病害的危害。培育部分抗病或耐病豌豆品种可能是分析豌豆中根腐丝囊霉变异性和生理转化性、提高病害防治效果的有效途径。因此,检测抗病数量性状基因座(QTL)对豌豆育种计划至关重要。本文对根腐丝囊霉的致病特点、ARR防控措施以及部分与抗性相关的QTL进行了综述。
基金Funding support from Agriculture and Agri-Food Canada, the Saskatchewan Pulse Growersthe Manitoba Pulse and Soybean Growers through the Growing Forward 2 Program
文摘Aphanomyces root rot(ARR) of field pea(Pisum sativum), caused by Aphanomyces euteiches, can cause severe root damage, wilting, and large yield losses under wet soil conditions. To identify ways to manage this disease, the effect of A. euteiches inoculum density on field pea was studied under greenhouse and field conditions in 2015 and 2016. Increases in inoculum density reduced seedling emergence, root nodulation, and plant vigor, and resulted in increased root rot severity in both field and greenhouse tests. Seed treatments with the fungicides Apron Advance(thiabendazole + fludioxonil + metalaxyl) + Vibrance(difenoconazole + metalaxylM + sedaxane), INTEGO Solo(ethaboxam), BAS 516F(boscalid + pyraclostrobin), BAS 720F(metalaxyl + pyraclostrobin + fluxapyroxad), and BAS 516F + BAS 720F(3:1) were evaluated for their efficacy against ARR. All seed treatments except Apron Advance + Vibrance reduced root rot severity under controlled conditions. BAS 516F, BAS 720F and INTEGO Solo improved plant vigor and all treatments reduced seedling blight to varying degrees under greenhouse conditions, but not in the field. A collection of 22 pea genotypes was evaluated for resistance to root rot in field plot experiments. Line 00–2067 showed the least severe root rot symptoms,whereas ‘Spring D' showed the lowest reduction in yield. The results suggest that there may be an opportunity to combine partial host resistance and fungicidal seed treatments to adequately manage ARR of field pea.
