Judith K Brown
Work Summary
Unravel the phylodynamics and transmission-specific determinants of emerging plant virus/fastidious bacteria-insect vector complexes, and translate new knowledge to abate pathogen spread in food systems.
Unravel the phylodynamics and transmission-specific determinants of emerging plant virus/fastidious bacteria-insect vector complexes, and translate new knowledge to abate pathogen spread in food systems.
Abstract:
Morphological characters of whiteflies, Bemisia spp., from 17 populations from disparate locations worldwide were compared. Historically, characters of 4th instars (pupae) are used for separating Bemisia spp. We assessed variability in the following characters of the 4th instar: anterior submarginal setae, anterior and posterior was fringes, dorsal setae, posterior submarginal setae, caudal setae, and tracheal folds. Anterior submarginal setae 4 (ASMS 4) were generally, but not always, absent in B. argentifolli Bellows & Perring and B biotype populations, and in most non-A/ non-B biotype (E, K, L, P, and Q). However, ASMS 4 were found in A biotype, in the N biotype, and in B. hancocki. Dorsal setal pair 4 was absent in most populations, and the lenghts of dorsal setal paris 1, 2, 3, 5, and 6 varied on individuals from several populations. Anterior was fringes were highly variable in length and width in all populations. With the exception of the Nepal (P biotype) population, posterior was fringes extended beyond the borders of the caudal setae in all individuals examined. Although posterior submarginal setal pair 5 (PSMS 5) was short in most individuals examined, these setae were elongated in a few individuals from 5 populations. Phylogenetic analysis did not resolve most-parsimonious trees. Our obsrvations indicate that morphological characters of pupae are not useful alone for classifying individuals from B. tabaci or B. argentifolii populations.
PMID: 19757008;Abstract:
The complete DNA-A component sequence of Desmodium leaf distortion virus (DeLDV, Begomovirus) isolated in Yucatan was determined to be 2569 nucleotides (nt) in length, and it was most closely related to Cotton leaf crumple virus-California (CLCrV-[Cal]), at 76%. The complete DNA-B component sequence was 2514 nt in length, and shared its highest nucleotide identity (60%) with Potato yellow mosaic Trinidad virus (PYMTV). Phylogenetic analyses group the DeLDV DNA-A component in the SLCV clade, whereas, the DeLDV DNA-B was grouped with the Abutilon mosaic virus clade, which also contains PYMV, suggesting that the DeLDV components have distinct evolutionary histories, possibly as the result of recombination and reassortment. © 2009 Springer Science+Business Media, LLC.
Idris, A.M., Hernández-Zepeda, C. and Brown, J.K. A defective putative promoter region upstream of the PepGMV-D movement protein gene is associated with viral-induced tissue tropism and PTGS/TGS induction leading to host recovery. J. Virol. (re-submitted).