Rakesh Sanabam

Chilli is infected by at least 65 viruses globally, with a mixed infection of multiple viruses leading to severe losses being a common occurrence. A simple diagnostic procedure that can identify multiple viruses at once is required to track their spread, initiate management measures and manage them using virus-free planting supplies. The present study, for the first time, reports a simplified and robust multiplex PCR (mPCR) assay for the simultaneous detection of five RNA viruses, capsicum chlorosis orthotospovirus (CaCV), chilli veinal mottle virus (ChiVMV), large cardamom chirke virus (LCCV), cucumber mosaic virus (CMV), and pepper mild mottle virus (PMMoV), and a DNA virus, chilli leaf curl virus (ChiLCV) infecting chilli. The developed mPCR employed six pairs of primer from the conserved coat protein (CP) region of the respective viruses. Different parameters viz., primer concentration (150–450 nM) and annealing temperature (50 °C), were optimized in order to achieve specific an...

Diverse chilli genetic resources of North East India occupy a unique niche in the Nation's chilli gene pool. Widely cultivated chilli landraces (King chilli: , bird eye chilli: and ) of North East India in general and Manipur in particular suffer from decline complex due to high incidence of viral diseases. With this background and the known prominent distribution of (ChiVMV) in Asian region, we studied its prevalence and association with diverse symptoms of chilli landraces. Molecular indexing of samples from 40 chilli plantation groves of Manipur using reverse transcription (RT)-PCR targeting the coat protein (CP) region of ChiVMV genome revealed a high incidence and wide prevalence. Out of a total of 127 chilli samples collected from different groves of Manipur, 81 chilli samples (63.78%) were positive for ChiVMV. Interestingly, ChiVMV infection rate was comparatively higher in the hilly groves (69.23% samples positive) compared to the valley groves (60% samples positive). Pr...

Citrus indica Tanaka is a wild endangered and one of the progenitor species of citrus endemic to North East (NE) India, which is reported in Nokrek Biosphere Reserve in the Garo hills of Meghalaya. A wild orange morphologically claimed to be C. indica was encountered in the Dailong forest of Tamenglong district, Manipur which is located in the Indo-Burma biodiversity hotspot region. Surveys were conducted to establish the exact identity of possible C. indica and study the natural habitat in Dailong forest area. The traditional morpho-taxonomic description for the identification of the plant is performed along with the molecular characterization using three chloroplast regions (trnL-F, psbK-I, matK-5′trnK spacer) and one nuclear (ITS) region. Phylogenetic analysis revealed that the C. indica found in Dailong Forest is monophyletic with the earlier reported C. indica sequence from Garo hills, Meghalaya. Both morphological and molecular data support the identity of C. indica that has b...

ABSTRACT This study was carried out to produce viral disease free scion bank of 'Khasi' mandarin (Citrus reticulata Blanco) using four Citrus species namely 'Kachai' lime (Citrus jambhiri Lush), Champra maounthabi (Citrus jambhiri Lush), Solom (Citrus sps.) and Phouheiree (Citrus sps) through micrografting techniques as viral disease affects the longevity of citrus orchards and quality of fruits. Success of micrografting depended on the type of cut for scion insertion, age of seedlings used as rootstock, conditions of light or darkness, concentration of sucrose used and also on rootstock types used for micrografting. Frequency of success improved considerably from 33.62% at 3% sucrose to 51.62% at 6% sucrose with 0.5 mg/L benzyl amino purine (BAP) in Murashige and Tucker (MT) liquid media using 0.5 mm scion size. Response of micrografting was significantly improved when inverted-T type cut was used for scion insertion giving 37.59% compared to 28.38% success in that of wedge type of cut. The highest rate of success was obtained when scions were grafted onto 'Champra maounthabi' with success rate of 40.74% followed by 'Phouheiree', 'Solom' and 'Kachai' lime, with rates of 34.26, 32.24 and 27.53%, respectively. Analysis of 8-10 months old micrografted plants for the presence of the graft transmissible Citrus tristeza virus (CTV) following double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA) was performed, giving negative results for the virus. INTRODUCTION Citrus, an important horticultural crop is widely distributed in various forms in almost all the NorthEast region of India. Among the Citrus crops available in the region, 'Khasi' mandarin (Citrus reticulata Blanco) is the most economically important one and plays an important role in the socioeconomic development of the peoples in this region. The agro-climatic set up as well as the physiographic condition of the region is comparable with the frontline citrus growing regions of the world (Hazarika, 2012). However, Citrus species of the region once known for its quality and productivity suffer from low productivity and various stages of decline. This low productivity is of major concerned and it is caused by different factors among which the plantation of nucellar plantlets and absence of rootstock plays significant roles. In an author's recent survey, it was found that the plantations are mostly done in hilly terrain and there is evidence for improper management as farmer's lack of skill and knowledge for maintenance of the orchards. The farmer's random selection of seeds from mother plants of unknown performance and raise of seedlings without proper care further lead to the decline of productivity. High rainfall and humidity conditions for long period and forest type of landscape of the region favors the growth and multiplication of pests and pathogens (Hazarika, 2012). The high incidence of insects makes havoc to the Citrus industry of the region as they feed on Citrus crops and also act as vectors of certain diseases present in the NorthEast region, such as greening or Huanglongbing (Das et al., 2007) and CTV (Kishore et al., 2011). The plantation of nucellar origin plantlets commonly followed in this region leads to a long unproductive juvenile phase and young plants are prone to abiotic and biotic