First Report of Myrothecium Leaf Spot of Common Bean in China Caused by Myrothecium roridum

Abstract

Common bean (Phaseolus vulgaris L.) is an economically important crop in China. In June 2008, a new foliar disease was observed on beans in Shunyi District, Beijing, China. The disease occurred in approximately 15% of the plants in a commercial field. Leaf spots were circular to irregular, reddish brown, zonate, and 8 to 20 mm in diameter. Black sporodochia with white tuffs were present on older lesions and black spore masses were present in moist weather. Ten isolates recovered from lesions produced white, floccose colonies and spore masses after 4 days on potato dextrose agar. The rod-shaped, hyaline conidia had rounded ends and averaged 6.8 × 2.5 μm. All characteristics were consistent with the description of Myrothecium roridum Tode ex Fr. (1). The internal transcribed spacer regions of one isolate were sequenced and deposited in GenBank (Accession No. GQ 381291). Sequences of the isolate from bean in China were 98% similar to sequences of M. roridum in GenBank. To determine pathogenicity, 30 healthy seedlings of common bean were inoculated by spraying a 1 × 105 conidia ml–1 suspension of M. roridum onto the foliage. Ten seedlings were sprayed with sterile water and served as controls. Plants were kept in a humid chamber at 27°C overnight and then placed in a growth chamber. After 6 days, the symptoms described above were observed on leaves in all inoculated plants, whereas symptoms did not develop on the control plants. The pathogen was reisolated from inoculated leaves, fulfilling Koch's postulates. There is one report of M. roridum on soybean in Korea (2). To our knowledge, this is the first report of Myrothecium leaf spot on common bean in China. References: (1) M. Fitton et al. CMI Mycol. Pap. No. 253, 1970. (2) K. J. Yum et al. Plant Pathol. J. 6:313, 1990.

Identification of Paramyrothecium foliicola causing crater rot in eggplant and its potential hosts under controlled conditions

“…States, Brazil, China, Korea, Pakistan, Ghana and Brazil (Tewari & Skoropad, 1977;Tulloch, 1972;Kim et al, 2003;Han et al, 2014, Li et al, 2014, Li et al, 2015Ben et al, 2015;Ben et al, 2016;Ben et al, 2017;Fujinawa et al, 2016;Garibaldi et al, 2016;Chen et al, 2018;Zhao et al, 2010;Alam et al, 2017;Haudenshield et al, 2018;Fish et al, 2012;Sun et al, 2020;Rennberger & Keinath, 2020). Among the several species, P. roridum is the frequently reported causal agent of these diseases.…”

Verrucarin A and roridin E produced on spinach by Myrothecium verrucaria under different temperatures and CO2 levels

“…In the last few decades, a large number of new hosts of Myrothecium spp. have been studied, because new species or varieties have become favorable for the proliferation of this pathogen in new regions (Belisario et al 1999;Garibaldi et al 2016b;Kim et al 2003;Mmbaga et al 2010;Worapong et al 2009;Zhao et al 2010). Plant disease is the result of an interaction between a host plant, a virulent pathogen, and the environment.…”

Antifungal Potential of Indigenous Medicinal Plants against Myrothecium Leaf Spot of Bitter Gourd ( Momordica charantia L.)

“…Our findings are in agreement with the results of earlier workers whom reported M. roridum and M. verrucaria both as plant pathogens while later is a weaker one 7 . Myrothecium species are soilinhabiting fungi but due to facultative parasitic nature also able to cause disease in aerial parts of economically important host plants 6,36,37,38 . However, M. roridum also identified as a virulent seedborne pathogen 15 .…”