Molecular characterization and infectivity analysis of tomato leaf curl New Delhi virus isolates infecting potato.

Nucleotide sequence of complete genome of a new isolate (KAN-6) of tomato leaf curl New Delhi virus (ToLCNDV) from Kanpur, Uttar Pradesh, India was determined. Sequence analysis indicated that it shared maximum identity to ToLCNDV isolates from pumpkin and ashgourd. Infectious clones of isolate KAN-6 along with two other ToLCNDV isolates (MOD-21 & FAI-19) obtained from potato fields of Modipuram and Faizabad, India were produced and used in symptom expression studies in N. benthamiana and potato plants through agro-inoculation. These isolates produced different symptoms both in N. benthamiana and potato. Severe symptoms of yellow mottling, downward curling and stunted growth were observed in N. benthamiana plants inoculated with KAN-6. MOD-21-inoculated plants also showed downward curling, stunted growth, but yellow mottling was observed only in older leaves whereas FAI-19-inoculated plants produced only downward curling symptoms. In case of potato, typical symptoms of apical leaf curl disease were observed in cultivar Kufri Pukhraj inoculated with MOD-21 and KAN-6 that are similar to those produced by virus-infected plants in the field. However, MOD-21 produced more prominent yellow mosaic symptoms as compared to KAN-6. FAI-19 produced only restricted yellow spots in Kufri Pukhraj. Only mild symptoms appeared in KAN-6 and no symptoms were observed in MOD-21- and FAI-19-inoculated Kufri Bahar plants which is known to show lowest seed degeneration under field conditions. Analysis of genomic components indicated that these isolates had 94.8-94.9% and 87.9-97.3% identity among them in DNA A and DNA B, respectively. The results of the study indicate the association of ToLCNDV isolates of different symptomatology with apical leaf curl disease of potato. This is also a first experimental demonstration of Koch's postulate for a begomovirus associated with apical leaf curl disease of potato.Author names: Please confirm if the author names (Swarup Kumar Chakrabarti) are presented accurately and in the correct sequence (given name, middle name/initial, family name).Yes. It is correct. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02752-5.

Complete mitogenome mapping of potato late blight pathogen, Phytophthora infestans A2 mating type.

Complete mitochondrial genome of Phytophthora infestans, A2 mating type (MT) with a size of ≅37,767 bp was sequenced. A total of 53 protein-coding genes are predicted on both strands, including 25 tRNA, 2 rRNA, and 18 respiratory proteins. Gene order of A2MT was consistent with that established in A1, despite high level of polymorphism in both coding and non-coding regions. The mtDNA of A2MT was found to have 99.5% and 99.4% homology with Ia and Ib, whereas 94.7% and 94.3% with IIa and IIb, respectively. Study of repeats revealed a dinucleotide (AT)9 specific to A1 and homology of cox1 gene sequence revealed the relationship among 50 Phytophthora species.