Fruit rot of sweet pepper caused by Stemphylium lycopersici in Japan
A severe rot of postharvest fruits of sweet pepper, a variety of Capsicum annuum, was found in Kagawa Prefecture in southwestern Japan in August 1999. A fungus, isolated repeatedly from the diseased fruits and identified as Stemphylium lycopersici, was demonstrated to be pathogenic to fruits of sweet pepper. The disease was new to Japan, and the fungus was added to the pathogens causing fruit rot of C. annuum.
Potential of Novel Sequence Type of Burkholderia cenocepacia for Biological Control of Root Rot of Maize (Zea mays L.) Caused by Fusarium temperatum
In this study, two Burkholderia strains, strain KNU17BI2 and strain KNU17BI3, were isolated from maize rhizospheric soil, South Korea. The 16S rRNA gene and multilocus sequence analysis and typing (MLSA-MLST) were used for the identification of the studied strains. Strain KNU17BI2, which belonged to Burkholderia cenocepacia, was of a novel sequence type (ST) designated ST-1538, while strain KNU17BI3 had a similar allelic profile with the seven loci of Burkholderia contaminans strain LMG 23361. The strains were evaluated in vitro for their specific plant growth promoting (PGP) traits, such as zinc solubilization, phosphate solubilization, ammonia production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, indole acetic acid (IAA) production, siderophore, and hydrolytic enzyme activity. Interestingly, the strains exhibited a positive effect on all of the tested parameters. The strains also showed broad-spectrum antifungal activity against economically important phytopathogens in the dual culture assay. Furthermore, the strains were evaluated under greenhouse conditions for their in vivo effect to promote plant growth and to suppress the root rot of maize that is caused by Fusarium temperatum on four Korean maize cultivars. The results of the greenhouse study revealed that both of the strains were promising to significantly suppress fusarium root rot and enhance plant growth promotion on the four maize cultivars. This study, for the first time, reported in vitro antifungal potential of B. cenocepacia of novel ST against economically important plant pathogens viz., F. temperatum, Fusarium graminearum, Fusarium moniliforme, Fusarium oxysporum f.sp. melonis, Fusarium subglutinans, Phytophthora drechsleri, and Stemphylium lycopersici. This is also the first report of zinc solubilization by B. cenocepacia. Moreover, the present research work reports, for the first time, about the potential of B. cenocepacia and B. contaminans to control the root rot of maize that is caused by F. temperatum. Therefore, we recommend further studies to precisely identify the bioactive chemical compounds behind such activities that would be novel sources of natural products for biological control and plant growth promotion of different crops.
SPORULATION OF DIVERSE SPECIES OF FUNGI UNDER NEAR-ULTRAVIOLET RADIATION
Cultures of 34 fungi were irradiated at 70° F under continuous exposure to near-ultraviolet light (3100–4000 A) at 76 microwatts per cm2 for periods ranging from 3 to 10 days. Sporulation was initiated or increased in Ascochyta pinnodella, A. pisi, Alternaria chrysanthemi, A. tenuis, A. zinniae, Botrytis cinerea, Coryneum sp., Epicoccum nigrum, Epicoccum sp., Fusarium oxysporum, F. nivale, F. roseum, F. solani, Gliocladium sp., Helminthosporium avenae, Mycosphaerella pinodes, Ophiobolus graminis, Piricularia oryzae, Phoma herbarum var. medicaginis, P. trifolii, Phoma spp., Phyllosticta sp. Pyrenochaeta terrestris, Septoria tritici, Stemphyllium botryosum, S. trifolii, Wojinowicia graminis, and Verticillium albo-atrum. H. oryzae formed conidia only when irradiation was followed by a dark period. Kabatiella caulivora and H. sativum sporulated as well in darkness as under irradiation. Sclerotia of Typhula spp. produced sporophores under a 12-hour dark, 12-hour ultraviolet light cycle at 41° F. When eight ult...