Molecular characterization of chickpea chlorotic dwarf virus and peanut witches’ broom phytoplasma associated with chickpea stunt disease and identification of new host crops and leafhopper vectors in India

Abstract

An investigation was carried out to identify and characterize the phytoplasma and viruses associated with the chickpea varieties showing severe stunting, leaf reddening, yellowing and phyllody symptoms during the summer season of 2018–2019 and 2019–2020 in eight states of India. The average disease incidence was recorded from 3 to 32% in different states. The presence of chickpea chlorotic dwarf virus (CpCDV) was confirmed in thirty-seven chickpea samples by amplification of CpCDV coat protein gene and sequence comparison analysis. No record of association of luteovirus, polerovirus and cucumovirus could be detected in any of the symptomatic chickpea samples by RT-PCR assay. Brassica nigra, B. juncea, Lens culinaris, two weeds (Heteropogan contartus, Aeschynomene virginica) and one leafhopper (Amarasca biguttula) were identified as new putative hosts for CpCDV. Association of peanut witches’ broom phytoplasma was confirmed in twenty-eight chickpea samples, Sesamum indicum, five weeds hosts and two leafhopper species (Exitianus indicus, Empoasca motti) using nested PCR assays with primer pairs P1/P7 and R16F2n/R16Rn. The results of phytoplasma association in plants and leafhopper samples were further validated by using five multilocus genes (secA, rp, imp, tuf and secY) specific primers. Sequence comparison, phylogenetic and virtual RFLP analysis of 16S rRNA gene and five multilocus genes confirmed the identity of association of 16SrII-C and 16SrII-D subgroups of phytoplasmas strain with chickpea samples collected from Andhra Pradesh (AP), Telangana, Karnataka, Madhya Pradesh, Uttar Pradesh and New Delhi. Mixed infection of phytoplasma (16SrII-D) and CpCDV was also detected in symptomatic chickpea samples from AP and Telangana. The reports of association of 16SrII-C subgroup phytoplasma in chickpea and 16SrII-D subgroup phytoplasma in C. sparsiflora and C. roseus are the new host records in world and from India, respectively.

Temperature influence on leafhopper population and its potential distribution in predicting spread of chickpea stunt disease in India

“…Among major biotic stresses, chickpea stunt is the major disease caused by different groups of viruses, e.g. cucumovirus, mastrevirus and polerovirus, reported in many chickpea growing countries worldwide (Akram et al, 2016;Abraham et al, 2006;Chalam et al, 1986;Kanakala et al, 2013;Kanakala and Kuria, 2019;Shreenath et al, 2020;Reddy et al, 2021). The chickpea chlorotic dwarf virus (CpCDV) is widespread in all chickpea growing states of India (Horn et al, 1993;Kanakala et al, 2013;Shreenath et al, 2020).…”

“…CpCDV and phytoplasma are reported to be transmitted by the leafhopper Orosius albicinctus in a persistent manner (Horn et al, 1993;Akhtar et al, 2011). In a recent study, CpCDV was identified in two species of leafhoppers, Amarasca (Sundapteryx) biguttula and O. albicinctus feeding in chickpea fields, suggesting that these leafhopper species may be potential source of natural vectors of CpCDV infection (Reddy et al, 2021).…”

“…Earlier, O. orientalis was identified as the main leafhopper vector for natural transmission of chickpea phyllody phytoplasma in India and Pakistan (Pallavi et al, 2012). Reddy et al (2021) identified two leafhopper species (Exiantus indicus, Emposca motti) feeding on symptomatic chickpea plants from Andhra Pradesh and New Delhi as putative vectors for the presence of 16SrII-D subgroup of phytoplasma. Distribution of leafhopper population in terms of its abundance, particularly in chickpea growing regions is an important feature and has direct connection with epidemics.…”

Occurrence, Distribution and Molecular Characterization of Phytoplasma Infecting Chickpea (Cicer arietinum L.) from Tamil Nadu

“…The crop is cultivated with an area of 9.93 Mha and a productivity of 935.34 kg/ha in India (Merga and Haji, 2019). The major chickpea growing states are Madhya Pradesh (MP), Rajasthan, Maharashtra,Uttar Pradesh (UP), Andhra Pradesh (AP), Karnataka, Chhattisgarh, Bihar, Tamil Nadu and Jharkhand.These states contribute more than 95% of the chickpea production in India (Pradipa et al, 2018;Gurivi Reddy et al, 2021).In Tamil Nadu, the crop is cultivated in districts of Coimbatore, Tiruppur, Dindigul, Thiruvallur, Kancheepuram, Erode, Salem, Namakkal, Perambalur, Tiruchirappali, Madurai, Virudhunagar, Ramanathapuram, Thoothukkudi, Tirunelveli and Dharmapuri (Pradipa et al, 2018). The crop loss due to biotic and abiotic stress has been reported for several years.…”

“…The chief symptoms reported by several workers associated with phytoplasma disease include stunting of plants, dwarfing, bushy appearance and leaf reddening. The plants infected in the early stages, it produced severe stunting symptoms (Shreenath et al, 2020;Gurivi Reddy et al, 2021).…”