ABSTRACT Previously, the zoosporicidal activity and control of Pythium root rot of flower bulbs by Pseudomonas fluorescens SS101 was attributed, in part, to the production of the cyclic lipopeptide surfactant massetolide A. The capacity of strain SS101 and its surfactant-deficient massA mutant 10.24 to suppress populations and root infection by complex Pythium spp. communities resident in orcha...

Transgenic ethylene-insensitive tobacco (Tetr) plants spontaneously develop symptoms of wilting and stem necrosis when grown in nonautoclaved soil. Fusarium oxysporum, F. solani, Thielaviopsis basicola, Rhizopus stolonifer, and two Pythium spp. were isolated from these diseased Tetr plants and demonstrated to be causal agents of the disease symptoms. Pathogenicity of the two Pythium isolates an...

ABSTRACT Traditional methods of quantifying Pythium spp. rely on the use of selective media and dilution plating. However, high variability is inherent in this type of enumeration and counts may not be representative of the pathogenic population of Pythium spp. Variable regions of the internal transcribed spacer of the rDNA were used to design species-specific primers for detection and quantifi...

The bacterium Pseudomonas aureofaciens 63-28 is antagonistic to several plant pathogenic fungi, including Pythium spp. The bacterium produced at least four antifungal metabolites active against Pythium ultimum and Phytophthora cryptogea when tested in culture for antifungal activity. Two of these compounds were identified as the novel butyrolactones (Z)-4-hydroxy-4-methyl-2-(1-hexenyl)-2-buteno...

Pythium species are the most common seedling disease pathogens isolated from rice in producers’ fields in Arkansas. These studies examined the value of Pythium resistance in breeding lines with cold tolerance in early-season planting environments. These lines show promise for reliable stand establishment in Arkansas. The breeding line RU0701124 had more plants/acre and greater relative root wei...

Carbohydrate-active enzymes (CAZymes) are involved in the metabolism of glycoconjugates, oligosaccharides, and polysaccharides and, in the case of plant pathogens, in the degradation of the host cell wall and storage compounds. We performed an in silico analysis of CAZymes predicted from the genomes of seven Pythium species (Py. aphanidermatum, Py. arrhenomanes, Py. irregulare, Py. iwayamai, Py...

Stand problems consistently cause significant production and management losses in Arkansas rice fields. In 2002, many fields in Arkansas had severe stand losses. Three control practices are being examined in this project for managing stand losses due to seedling diseases: 1) seed treatment fungicides, 2) development of cold-tolerant cultivars, and 3) the use of disease-suppressive production sy...

The genus Pythium was erected by Pringsheim in 1858 and placed in the family Saprolegniaceae. By the end of 19th century taxonomic details of the genus had been clarified and many new species had been described. The relationship with other Oomycetes was established and the genus was included in a new family, Pythiaceae, by Schroter in 1897. The fungus Pythium belongs to the subdivision Mastigom...

pythium species are cosmopolitan, fungus-like oomycotes which may cause diseases in plants, animals and even human beings. some of the species, however, are saprophytes and also well-proven biological control agents of plant pathogenic fungi. since 1968, when the first pythium species was reported from iran, ca 44 species, two varieties, and five groups of this genus have been reported from dif...

The influences of Gaeumannomyces graminis var. tritici (which causes take-all of wheat), Rhizoctonia solani AG-8 (which causes rhizoctonia root rot of wheat), Pythium irregulare, P. aristosporum, and P. ultimum var. sporangiiferum (which cause pythium root rot of wheat) on the population dynamics of Pseudomonas fluorescens 2-79 and Q72a-80 (bicontrol strains active against take-all and pythium ...