Botrytis sinoallii: a new species of the grey mould pathogen on Allium crops in China

Abstract

A study was conducted to identify Botrytis spp. isolated from bulb onion, green onions, garlic, and garlic chives grown in Hubei Province of China. Based on colony morphology and conidial characteristics, 367 strains of Botrytis spp. were identified as five distinct species, namely, B. cinerea, B. squamosa, B. porri, B. byssoidea, and an undescribed Botrytis species (Botrytis sp.), which accounted for 64.3, 29.9, 3.3, 0.3, and 2.2%, respectively. The previously undescribed species is herein described as a new species, B. sinoallii sp. nov., which is characterized by production of numerous small sclerotia on potato dextrose agar. Phylogenetic analysis using partial sequences of three nuclear genes (G3PDH, HSP60, and RPB2) showed that B. sinoallii forms a unique lineage, which is closely related to B. squamosa, a well-known species on Allium crops, but distantly related to the other species of Botrytis on Allium crops, including B. cinerea, B. porri, B. aclada, B. allii, B. byssoidea, B. globosa, and B. sphaerosperma. Results of inoculation tests showed that B. sinoallii is a newly identified agent that can cause leaf blight of green onion, garlic, and garlic chives. Potential impact of B. sinoallii on production of Allium crops in China is discussed.

Botrytis pseudocinerea Is a Significant Pathogen of Several Crop Plants but Susceptible to Displacement by Fungicide-Resistant B. cinerea Strains

“…A similar cooccurrence of different Botrytis spp. has been described for onion fields in China, which were found to be infected by B. porri, B. sinoallii, B. squamosa, B. byssoidea, and B. cinerea (32). On oilseed rape, gray mold can be a major disease under wet and cool weather conditions, for example, in winter rape.…”

Characterization of a Novel Bipartite Double-Stranded RNA Mycovirus Conferring Hypovirulence in the Phytopathogenic Fungus Botrytis porri

“…Pathogenicity of each strain was determined by inoculating detached leaves of garlic (A. sativum cultivar Feng Suan No. 1) with agar plugs of actively growing mycelia according to the procedures of Zhang et al (57,58).…”

“…Individual conidia on the PDA surface were picked up using a sterilized fine glass needle under a light microscope and transferred to fresh PDA plate at one conidium per plate. The plates were incubated at 20°C for 5 days, the resulting cultures were identified, and those belonging to B. porri were individually tested for the mycelial growth rates on PDA (20°C), pathogenicity on detached garlic leaves (20°C, 72 h), and the presence of the two dsRNA segments in mycelia using previously described methods (51,57,58). The hypovirulent strain Bc-72 and the virulent strain Bc-16 of B. porri were used as controls in this experiment.…”

“…The isolates were designated 72-38-1, 72-38-2, and 72-38-3 for derivatives from strain Bc38, 72-35-1, 72-35-2, and 72-35-3 for derivatives from strain SC35, and 72-95-1, 72-95-2, and 72-95-3 for derivatives from strain Bc-95. All of these derivative isolates were individually tested for the mycelial growth rates on PDA (20°C), pathogenicity on detached garlic leaves (20°C, 72 h), and the presence of dsRNA in mycelia (51,57,58). The parental strains Bc-72, Bc-38, Bc-95, and SC35 were included as controls in this experiment.…”

“…Gray mold disease caused by Botrytis spp., including B. porri, is one of the most important ecological factors limiting both the yield and the quality of these Allium crops (33,57,58). Previous studies indicated that B. porri can cause garlic clove rot (12), garlic leaf blight (57), and leek leaf rot (3).…”