The yellow mosaic viruses (YMV) infecting legumes are considered to be the most devastating begomoviruses as they incite considerable yield loss. The yellow discoloration of pods and seeds of infected plants and symptom emergence in the very first trifoliate leaf of the plants in the field were suggestive that the virus may be seed borne, which was investigated in the present study. The distribution of the virus in various parts of the seeds of black gram (Vigna mungo L. Hepper) plants naturally infected in the field was determined by polymerase chain reaction (PCR), Southern blot analysis, and sequencing. Nucleotide sequencing of the PCR amplicons from the seed parts from groups of ten seeds revealed the presence of mung bean yellow mosaic virus (MYMV) in the seed coat, cotyledon, and embryonic axes. The presence of virion particles was confirmed through double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) and immunosorbent electron microscopy (ISEM) even in a single whole seed. In confocal microscopy, positive fluorescent signals were obtained using coat protein gene-specific primers in the embryonic axes. However, in the growth tests performed with the same batch of seeds, there was no symptom development in the seedlings though the virus (both DNA A and B components) was detected in 32 % of tested seedlings. In this study, the MYMV was detected in seed coat, cotyledon, and embryo. This study revealed that the MYMV is a seed-borne virus.

Diverse endophytes with multiple functions exist in different banana cultivars. However, the diversity of cultivable bacterial endophytome that contributes to antifungal activity against Fusarium oxysporum f.sp. cubense (Foc) in resistant and susceptible banana cultivars is mostly unknown. In the present study, we isolated bacterial endophytes from resistant Yengambi KM5 (AAA) and susceptible banana cultivar Ney Poovan (AB) to determine the diversity of cultivable bacterial endophytes. Our study revealed the presence of 56 cultivable bacterial endophytes and 6 nectar-associated bacteria in YKM5 and 31 cultivable bacterial endophytes in Ney Poovan. The identified cultivable bacterial genera in YKM5 included

Grapes downy mildew caused by obligate oomycete plant pathogen Plasmopara viticola is a devastating disease worldwide, resulting in significant yield and quality losses. A field survey was conducted in two major grapes cultivated areas of Tamil Nadu for the incidence of grapevine downy mildew. The disease incidence was 43.42%–76.69%, and the highest disease incidence of 76.69% was observed in the Theni district. Totally eight P. viticola isolates were collected from different places in Coimbatore and Theni districts. These isolates were confirmed through microscopic observation and sequencing of COX 2 gene, and the phylogenetic tree was developed to study their phylogenetic relationship among the isolates which shows 97–100% sequence similarity with other P. viticola isolates and less sequence similarity with Plasmopara species. The loop‐mediated isothermal amplification (LAMP) assay was developed based on the CesA4 gene sequence of P. viticola. The assay developed was more sensitive as it detected P. viticola genomic DNA up to 20 fmg. LAMP assay specificity was proved by carrying out the assay with genomic DNA extracted from other Oomycetes and fungal plant pathogens. Finally, LAMP assay was validated by testing seventy‐eight grapevine leaf samples collected from seven different locations. LAMP assay showed a positive reaction in sixty‐two samples tested out of seventy‐eight samples tested. Therefore, the LAMP assay described should helpful for early and specific detection of downy mildew pathogen and help in mitigating disease incidence.

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