Variability in colonization of arbuscular mycorrhizal fungi and its effect on mycorrhizal dependency of improved and unimproved soybean cultivars.

Breeding selection of germplasm under fertilized conditions may reduce the frequency of genes that promote mycorrhizal associations. This study was developed to compare variability in mycorrhizal colonization and its effect on mycorrhizal dependency (MD) in improved soybean genotypes (I-1 and I-2) with differential tolerance to drought stress, and in unimproved soybean genotypes (UI-3 and UI-4). As inoculum, a mixed native arbuscular mycorrhizal fungi (AMF) was isolated from soybean roots, showing spores mostly of the species Funneliformis mosseae. At 20 days, unimproved genotypes followed by I-2, showed an increase in arbuscule formation, but not in I-1. At 40 days, mycorrhizal plants showed an increase in nodulation, this effect being more evident in unimproved genotypes. Mycorrhizal dependency, evaluated as growth and biochemical parameters from oxidative stress was increased in unimproved and I-2 since 20 days, whereas in I-1, MD increased at 40 days. We cannot distinguish significant differences in AMF colonization and MD between unimproved and I-2. However, variability among improved genotypes was observed. Our results suggest that selection for improved soybean genotypes with good and rapid AMF colonization, particularly high arbuscule/hyphae ratio could be a useful strategy for the development of genotypes that optimize AMF contribution to cropping systems.

Whole genome sequence analysis of bovine G6P[11] rotavirus strain found in a child with gastroenteritis.

During the rotavirus strain surveillance in Slovenia, G6P[11] bovine rotavirus strain was detected in a 5 months old boy with gastroenteritis. The strain was enrolled in a whole genome sequence analysis to determine its genome segment composition and genetic characteristics. Genotype composition for the whole genome was G6-P[11]-I2-R2-C2-M2-A13-N2-T6-E2-H3, reflecting similarities with bovine rotavirus strains. The bovine origin of the strain was confirmed in all genome segments, showing the highest nucleotide identity with bovine rotavirus strains and clustering of the RVA/Human-wt/SVN/SI-R56/07/2007/G6P[11] together with bovine rotavirus strains in phylogenetic analysis. This is the first bovine G6P[11] rotavirus strain with the whole genome analysis and the first report on rotavirus G6P[11] genotype detected in humans.