A highly virulent cotton wilt pathogen, Fusarium oxysporum f. sp. vasinfectum VCG0114 (race 4) was found in West Texas in 2017, after being known in California since 2001. Isolates obtained from wilted plants collected in 2017 from Texas, in 2015 from China, and during 2001 to 2014 from California and isolates from historical collections including the race 4 reference isolate were characterized by soil-infestation pathogenicity assays, DNA sequence analysis, and vegetative compatibility analysis. All obtained F. oxysporum f. sp. vasinfectum isolates belonged to VCG0114. All of these isolates, except one isolate from China, caused disease in a soil-infestation assay without nematodes. Thus, they belong to the nematode-independent pathotype. Texas isolates were significantly more virulent than were isolates from China or California on Gossypium barbadense ‘Pima S-7’. Four different genotypes (N, T, MT, and MiT) were identified based on the transposable element Tfo1 insertion into the PHO gene and independent MULE or MITE insertions into the Tfo1 transposon. Some significant differences in virulence were detected among the genotypes in some locations. No differences in pathogenicity were observed between the California and China collection isolates on Pima S-7, and the virulence of the major genotypes was similar on the Gossypium hirsutum cultivar ‘Stoneville 474’ or the Barbren 713 germplasm line. Simple polymerase chain reaction (PCR) methods were developed to specifically determine and detect the four genotypes within VCG0114. A specific PCR method to detect all VCG0114 isolates was also developed. These methods will facilitate the timely identification of infested fields and seed lots and the elucidation of evolutionary relationships among the isolates. This should help to closely monitor the movement of the pathogen and reduce dissemination of these devastating pathogens.

From soils exposed to anthropogenic load, a bacterial strain resistant to pollutants was isolated and characterized. The strain was identified as Pseudomonas trivialis 381 based on morphological, cultural, physiological and biochemical characteristics, as well as MALDI-TOF and 16S rRNA analysis. Its sequence was submitted to the NCBI GenBank (OR234684.1). Studies were conducted to evaluate the influence of the strain on seed germination and plant growth qualities. Laboratory studies have shown the stimulating effect of P. trvialis 381 on tomato seeds; seeds treated with the bacterial cultural liquid increased the energy of germination and seed germination to 100% (with the control being 64% and 60%), and also led to an increase in the length of the stem and root, and the number of roots. Microvegetation experiments have shown the stimulating effect of P. trivialis 381 on the growth of tomatoes and rice, with the particularly noticeable development of the root system, which enabled plants to absorb nutrients more quickly and made them more resistant to adverse conditions. The cultivation of seeds treated with cultural liquid on artificially saline soils (by adding 10% NaCl) enhanced the plants’ resistance to salinity, resulting in better growth of primed plants and an increase in chlorophyll content to more than 3 times in the leaves.