Planting period is the main factor for controlling maize rough dwarf disease

Maize rough dwarf virus (MRDV) is one of the main yield-limiting factors of maize in the Mediterranean. However, knowledge about the interactions between the agroecosystem and the virus–vector–host relationship continues to be limited. We used multi-model inference to test a landscape-scale approach together with variables measured in the field, and we estimated the effects of early and late planting on MRDV incidence. The results revealed that the virus incidence increased by 3% when the planting was delayed, and this increase was coincident with the first peak of the vector population. The variables at the field and landscape scales with a strong effect on virus incidence were the proportions of grasses in adjacent crops, in uncultivated areas, and in edges close to maize plants. Grass plant cover in the edges also affected virus incidence, but these effects varied with the planting period. These findings provide new insights into the causes of MRDV incidence and may provide some guidance to growers to reduce losses caused by the virus. Among the recommendations to be prioritized are early planting, management of grasses at field edges, and non-overlapping cultivation of maize and winter cereals in the same area.info:eu-repo/semantics/publishedVersio

First report of Barley yellow mosaic virus in Barley in Spain

The presence of Barley mild mosaic virus (BaMMV) and the weakly serological detection of Barley yellow mosaic virus (BaYMV) were reported in Spain (1); both viruses are members of the genus Bymovirus (family _Potyviridae_). Random and symptomatic surveys were conducted during February and March of 2003 in barley fields in north eastern Spain to determine the occurrence of BaMMV and BaYMV. Leaves from 316 samples collected in 15 fields were analyzed using enzyme-linked immunosorbent assay (ELISA) with commercial antisera specific for BaYMV and BaMMV (Loewe Biochemica, Munich) as well as antisera against both viruses (provided by T Klumen). Positive ELISA samples were further analyzed using reverse transcription-polymerase chain reaction (RT-PCR) with specific primers that amplify 445 bp of BaMMV (1) and 433 bp of BaYMV (2). Complete agreement was observed between the ELISA and RT-PCR results. Mixed infections of BaYMV and BaMMV were detected in 10 samples, BaYMV in 5 samples and BaMMV in 3 samples. Samples positive for both viruses that exhibited clear mosaic symptoms were collected in 2 fields. RT-PCR products from 5 BaYMV-infected samples were cloned and sequenced and showed 96 to 98 per cent identity to BaYMV isolates previously reported from Europe (Genbank Accession Nos. AJ1515479-85 and X95695-7) and 92 to 95 per cent identity with isolates reported from Asia (GenBank Accession Nos. AB023585-96, AJ132268, AJ224619-22, AJ224624-28, AF536944-46, AF536948-58, D01091, D00544, and Z24677). Sequence identity of Spanish isolates was 96 to 99 per cent. To our knowledge, this is the 1st report of BaYMV infecting barley in Spain and illustrates the association of both Bymoviruses infecting barley

Quantitative, high-resolution epigenetic profiling of CpG loci identifies associations with cord blood plasma homocysteine and birth weight in humans

Supplementation with folic acid during pregnancy is known to reduce the risk of neural tube defects and low birth weight. It is thought that folate and other one-carbon intermediates might secure these clinical effects via DNA methylation. We examined the effects of folate on the human methylome using quantitative interrogation of 27,578 CpG loci associated with 14,496 genes at single-nucleotide resolution across 12 fetal cord blood samples. Consistent with previous studies, the majority of CpG dinucleotides located within CpG islands exhibited hypomethylation while those outside CpG islands showed mid-high methylation. However, for the first time in human samples, unbiased analysis of methylation across samples revealed a significant correlation of methylation patterns with plasma homocysteine, LINE-1 methylation and birth weight centile. Additionally, CpG methylation significantly correlated with either birth weight or LINE-1 methylation were predominantly located in CpG islands. These data indicate that levels of folate-associated intermediates in cord blood reflect their influence and consequences for the fetal epigenome and potentially on pregnancy outcome. In these cases, their influence might be exerted during late gestation or reflect those present during the peri-conceptual period