T. Giridhara Krishna

Mungbean yellow mosaic India virus is associated with yellow mosaic disease of blackgram (Vigna mungo L.) in Andhra Pradesh, India

To study the variability and to identify the species of Begomovirus associated with yellow mosaic disease of blackgram in Andhra Pradesh, India, infected blackgram samples were collected from six districts belonging to three regions of Andhra Pradesh. The total DNA was isolated by modified CTAB method and amplified with coat protein gene-specific primers (RHA-F and AC abut) resulting in 900 bp gene product. The PCR products were cloned, sequenced and deposited in GenBank. The sequence analysis of six clones showed that the size of amplified CP gene of YMV was 920 bp. Based on nucleotide sequence identity of six isolates representing three regions of Andhra Pradesh, the isolates from Rayalaseema and Telangana region are the same variant of YMV (>99.5% identity) and isolate from coastal Andhra is another variant of YMV (>95.4%) when compared with other region isolates. Comparison of CP gene sequence of YMV-TPT isolate with 27 other isolates in database revealed more than 93.2 and 86.2% identity with MYMIV isolates and less than 80 and 64% identity with MYMY isolates that originate from Indian sub-continent and South-East Asia at nucleotide and amino acid level, respectively. Phylogenetic tree based on CP gene sequences of six isolates with other isolates from GenBank formed unique cluster with MYMIV. Hence the YMV infecting blackgram in Andhra Pradesh is caused by MYMIV rather than MYMY as reported in Tamil Nadu which is adjoining state in southern India.

FIRST REPORT OF GROUNDNUT BUD NECROSIS VIRUS IN JASMINE

Jasmine (Jasminum sambac) is a popular flower and oil-bearing plant in the family Oleaceae. India is the second producer and exporter of jasmine in the world. In April 2012, commercial jasmine fields in the Thiruvallur district of Tamil Nadu (India) showed mosaic and chlorotic spots on the young leaves. Based on symptomatology, the involvement in disease aetiology of Groundnut bud necrosis virus (GBNV, genus Tospovirus, family Bunyaviridae) was suspected. The presence of this virus in symptomatic jasmine leaves was firsrt ascertained by direct antigen coating (DAC)-ELISA (Clark and Joseph, 1984), using a polyclonal antiserum raised to GBNV and it was further confirmed by RT-PCR using primers designed in the nucleocapsid gene (Satyanarayana et al., 1996). The 830 bp amplicon was cloned in pTZ57R/T vector (Fermentas, USA) and sequenced. The nucleotide sequence was deposited in GenBank (accession No. JQ995170). Sequence analysis (BioEdit v. 7.05) showed 99.7% and 100% identity with the nucleocapsid gene of other GBNV isolates at the nucleotide and amino acid levels, respectively. Phylogenetic trees constructed using MEGA version 4.0 confirmed the close relationship of the GBNV isolate from jasmine with another isolate from groundnut (GenBank accession No. HM770020). The infected crop was removed to eradicate the infection. To the best of our knowledge, this is the first report of GBNV on jasmine.

Use of ENSO-Based Seasonal Rainfall Forecasting for Informed Cropping Decisions by Farmers in the SAT India

Dryland agriculture in India is practiced on 97 million ha of the cultivated area that supports 40% of the human population and 60% of livestock population by producing 44% of the food and fodder requirements. Even if India can achieve the full potential of irrigation in 139.5 million ha, still 75 million ha drylands would continue to depend on rainfall from southwest (SW) and northeast (NE) monsoons, characterized by high rainfall variability that cause most of production uncertainties. Thus dryland agriculture continues to play a crucial role in India’s food security. However, productivity gains have been relatively insignificant and risk-averse dryland farmers have to improve agricultural productivity with suitable management options and matching application of farm inputs to maximize crop productivity and income, while minimizing crop failure and input losses against uncertainties of seasonal weather to feed the booming population.