First Report of the Bemisia tabaci B Biotype in India and an Associated Tomato leaf curl virus Disease Epidemic

Abstract

In May 1999, in the Kolar district of Karnataka State, Bemisia tabaci numbers on tomato increased by approximately 1,000-fold that observed previously (3). This was associated with an epidemic of severe tomato leaf curl disease that caused complete crop failure. DNAs extracted from 35 symptomatic tomato leaf samples collected within the epidemic region all gave the expected 500 to 600 bp amplicon with begomovirus-specific primers A/B (1). These primers amplify from the conserved nonanucleotide TAATATTAC in the common region of DNA-A to the conserved amino acid sequence CEGPCKYG within the coat protein gene. AluI and TaqI restriction patterns of all 35 polymerase chain reaction (PCR) products were identical. One PCR product from an epidemic (GenBank no. AF321929) and a non-epidemic (AF321930) site (Bangalore) were cloned and sequenced. The two 531-bp inserts showed 96% nucleotide identity to each other and 94% nucleotide identity to the equivalent region of Tomato leaf curl Bangalore virus (ToLCBV-Ban-4) (AF165098), suggesting that the epidemic was caused by an indigenous ToLCBV strain. Adult B. tabaci were collected from tomato plants at nine sites within the epidemic. DNA was extracted from 9 to 13 individuals per site and analyzed by RAPD-PCR using primers OpB20 and OpB11. Eighty to 100% of individuals per site had identical patterns to those of B biotype individuals from Israel and Florida, which were different to the patterns produced by the indigenous Indian B. tabaci. Adult B. tabaci from the epidemic and nonepidemic (Bangalore) regions were cultured separately on zucchini plants (n = 20) vars. Fordhook and Ambassador. Distinct silverleaf symptoms appeared in all plants fed on by the epidemic B. tabaci, but not on those fed on by the nonepidemic whiteflies. Irregular ripening of tomatoes was also a widespread problem in the epidemic area. Cytochrome oxidase I (COI) (720 bp) gene sequences were obtained for epidemic (AF321927) and nonepidemic (AF321928) B. tabaci, which had only 80% nucleotide identity to each other. A GenBank BLAST search showed that the former were most similar to B biotype whitefly from Israel (AF164667; 97%) and Texas (AF164675; 99%). The B biotype transmits Indian ToLCBV (2) and its introduction into India is of great concern as it is already associated with a devastating plant-disease epidemic. References: (1) D. Deng et al. Ann. App. Biol. 125:327, 1994. (2) P. F. McGrath and B. D. Harrison. Ann. App. Biol. 126:307, 1995. (3) H. K. Ramappa et al. Ann. App. Biol. 133:187, 1998.

The third genotypic clusters of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) found in Bangladesh

“…The most likely reason for the similarity of these populations may be the movement of B. tabaci between the countries as a result of human activities. The most recent example of such introduction has been the arrival of the B biotype in India, Pakistan, and China (Banks et al, 2001;Simon et al, 2003;Zhang et al, 2005), and more recently the Q biotype in China (Zhang et al, 2005). The data, which presented here, highlight the real and increasing threat posed by the movement of B. tabaci and potentially new viruses to agriculture in Asia.…”

Identification of mungbean lines with tolerance or resistance to yellow mosaic in fields in India where different begomovirus species and different Bemisia tabaci cryptic species predominate

“…In another study, Asia1 was found to be predominant in the North of India, butin the South a higher diversity of B. tabaci species was found (ChowdaReddy et al 2012;Ellango et al 2015), whereas in this study Asia II 8 was predominant in the south. A first report of B. tabaci MEAM1 in India was from Banks et al (2001) who collected this invasive species from infected tomato in the Kolar district. Further reports of MEAM1 were primarily from the same region (Rekha et al 2005;Shankarappa et al 2007;Ellango et al 2015) with one find in Dabhoi in the West (Chowda-Reddy et al 2012).…”

Host Plant Mediated Population Variations of Cotton Whitefly Bemisia tabaci Gennadius (Aleyrodidae: Homoptera) Characterized with Random DNA Markers

“…Their results suggested that a differentiation of populations has already occurred, mainly according to the host plant, instead of the geographical region where populations are localized and they had reported that there was no grouping of samples collected on different crops in the same state. Among the biotypes of B. tabaci, the B biotypes, in the previous two decades has been distributed widely and caused tremendous losses world wide as a pest and vector of virus diseases [2,10,30,31] . The B biotype has distinctive biological traits, together with esterase and RAPD patterns that showed little variation [2,7,26] .…”

“…Three distinct bands of sizes viz., 350, 800 bp and 1 kb were produced by B11 primer [32] , similar to that in our study clearly distinct bands of 500 bp and 1 kb were produced by the primer OPA 12, while resolved bands were obtained below 500 bp using OPE 04 primer. The B biotype was first recorded in the Kolar district of Karnataka state, South India, during the summer growing season (March-June) of 1999 [30] . In a different study [32] , cluster analyses of RAPD data separated the B. tabaci samples into north and south Karnataka groups.…”