AUTHOR=Sayiprathap B. R. , Patibanda A. K. , Prasanna Kumari V. , Jayalalitha K. , Ramappa H. K. , Rajeswari E. , Karthiba L. , Saratbabu K. , Sharma Mamta , Sudini H. K. 

TITLE=Salient Findings on Host Range, Resistance Screening, and Molecular Studies on Sterility Mosaic Disease of Pigeonpea Induced by Pigeonpea sterility mosaic viruses (PPSMV-I and PPSMV-II)

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.838047

DOI=10.3389/fmicb.2022.838047

ISSN=1664-302X

ABSTRACT=<p>Two distinct emaraviruses, <italic>Pigeonpea sterility mosaic virus-I</italic> (<italic>PPSMV-I</italic>) and <italic>Pigeonpea sterility mosaic virus-II</italic> (<italic>PPSMV-II</italic>) were found to be associated with sterility mosaic disease (SMD) of pigeonpea [<italic>Cajanus cajan</italic> (L.) Millsp.]. The host range of both these viruses and their vector are narrow, confined to <italic>Nicotiana benthamiana</italic> identified through mechanical transmission, and to <italic>Phaseolus vulgaris</italic> cvs. Top Crop, Kintoki, and Bountiful (F: Fabaceae) through mite transmission. A weed host <italic>Chrozophora rottleri</italic> (F: Euphorbiaceae) was also infected and tested positive for both the viruses in RT-PCR. Among the wild <italic>Cajanus</italic> species tested, <italic>Cajanus platycarpus</italic> accessions <ext-link ext-link-type="DDBJ/EMBL/GenBank" xlink:href="15661" xmlns:xlink="http://www.w3.org/1999/xlink">15661</ext-link>, <ext-link ext-link-type="DDBJ/EMBL/GenBank" xlink:href="15668" xmlns:xlink="http://www.w3.org/1999/xlink">15668</ext-link>, and <ext-link ext-link-type="DDBJ/EMBL/GenBank" xlink:href="15671" xmlns:xlink="http://www.w3.org/1999/xlink">15671</ext-link>, and <italic>Cajanus scarabaeoides</italic> accessions <ext-link ext-link-type="DDBJ/EMBL/GenBank" xlink:href="15683" xmlns:xlink="http://www.w3.org/1999/xlink">15683</ext-link>, <ext-link ext-link-type="DDBJ/EMBL/GenBank" xlink:href="15686" xmlns:xlink="http://www.w3.org/1999/xlink">15686</ext-link>, and <ext-link ext-link-type="DDBJ/EMBL/GenBank" xlink:href="15922" xmlns:xlink="http://www.w3.org/1999/xlink">15922</ext-link> were infected by both the viruses and mite vector suggesting possible sources of SMD inoculum. Though accession <ext-link ext-link-type="DDBJ/EMBL/GenBank" xlink:href="15666" xmlns:xlink="http://www.w3.org/1999/xlink">15666</ext-link> of <italic>C. platycarpus</italic>, 15696 of <italic>C. scarabaeoides</italic>, and 15639 of <italic>Cajanus lanceolatus</italic> were infected by both the viruses, no mite infestation was observed on them. Phylogenetic analysis of nucleotide sequences of RNA-1 and RNA-2 of <italic>PPSMV-I</italic> and <italic>PPSMV-II</italic> isolates in southern India revealed significant divergence especially <italic>PPSMV-II</italic>, which is closely related to the <italic>Fig mosaic virus</italic> (<italic>FMV</italic>) than <italic>PPSMV-I</italic>. In multilocation testing of pigeonpea genotypes for their broad-based resistance to SMD for two consecutive years, genotypes ICPL-16086 and ICPL-16087 showed resistance reaction (&lt;10% incidence) in all three locations studied. Overall, the present study gives a clear idea about the host range of <italic>PPSMV-I</italic> and <italic>PPSMV-II</italic>, their molecular relationship, and sources of resistance. This information is critical for the development of reliable diagnostic tools and improved disease management strategies.</p>