Note: Biotype status ofBemisia tabaci from various crops in Cyprus (original) (raw)
Related papers
Pest Management Science, 2014
BACKGROUND: The taxonomy of the species complex Bemisia tabaci, a serious agricultural pest worldwide, is not well resolved yet, even though species delimitation is critical for designing effective control strategies. Based on a threshold of 3.5% mitochondrial (mtCOI) sequence divergence, recent studies have identified 28 putative species. Among them, mitochondrial variability associated with particular symbiotic compositions (=cytotypes) can be observed, as in MED, which raises the question of whether it is a single or a complex of biological species. RESULTS: Using microsatellites, an investigation was made of the genetic relatedness of Q1 and ASL cytotypes that belong to MED. Samples of the two cytotypes were collected in West Africa where they live in sympatry on the same hosts. Genotyping revealed a high level of differentiation, without evidence of gene flow. Moreover, they differed highly in frequencies of resistance alleles to insecticides, which were much higher in Q1 than in ASL. CONCLUSION: Q1 and ASL are sufficiently reproductively isolated for the introgression of neutral alleles to be prevented, suggesting that they are actually different species. This indicates that nuclear genetic differentiation must be investigated within groups with less than 3.5% mtCOI divergence in order to elucidate the taxonomy of B. tabaci at a finer level. Overall, these data provide important information for pest management.
PCR-RFLP identification ofBemisia tabaci biotypes in the Mediterranean Basin
Phytoparasitica, 2006
At least 20 genetic biotypes, with varying degrees of biological characterization, are currently recognized within the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex. Their identification relies on a set of different molecular techniques. However, none of the available markers is completely adequate, due to technical difficulties or lack of reproducibility. We therefore developed a method for rapid biotyping of B. tabaci populations. The five biotypes (B, Q, M, S and T) reported until now in the Mediterranean Basin have been tested by PCR amplification of the cytochrome oxidase I mitochondrial gene followed by restriction with the enzyme Tru9I. The digestion patterns produced by this enzyme were able to identify the five biotypes clearly. Digestion with another enzyme, TaqI, discriminated only between biotypes B and Q. The newly developed method enables rapid biotyping and can be applied in studies aimed at assessing biotype distribution and competition at least in the Mediterranean area.
Only the B biotype of Bemisia tabaci is present on vegetables in São Paulo State, Brazil
Scientia …, 2011
Bemisia tabaci (Genn.) is one of the most important pests in cultivated areas of vegetables and ornamental crops around the world. Based on the mitochondrial cytochrome oxidize I (mtCOI) sequence, there is evidence that B. tabaci should be considered a cryptic species complex of 11 groups containing 24 species. Two of the groups, Middle East-Asia Minor 1 and Mediterranean include biotypes B and Q, respectively. In this study we evaluated the mtCOI sequence of B. tabaci populations collected in sites of the state of São Paulo, Brazil. Using PCR-RFLP with Taq I, a typical biotype B profile was obtained for all specimens. Based on the comparison with mtCOI reference sequences we found four haplotypes all belonging to the Middle East-Asia Minor 1. They occurred in the hosts pepper (Capsicum annuum L.), tomato (Solanum lycopersicum L.), eggplant (Solanum melongena L.) and cucurbitaceae plants.
2020
Problems of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) that increased and escalated in the last 40 years seem to be related to one or more aggressive biotypes that appeared to spread steadily worldwide. As well, some biological characteristics of B. tabaci have led some entomologists to change and multiply their methodology to update with the change in the pest genetic structures. This study is the 1st of its kind in Qassim region in KSA in respect of B. tabaci biotypes. Four identification methods (Squash Silverleaf Symptoms (SSL), cross mating, Cytochrome oxidase subunit I (COI) sequences, and ISSR-PCR analysis) were carried out to determine the biotypes of B. tabaci at Qassim regions. Slight SSL symptoms were observed with varying degrees on squash leaves caused by B. tabaci population at Qassim, KSA. Cross-mating among the populations that have the same or similar genetic structures produced fertilized offspring, females and males with higher sex ratios in favor of fema...
Journal of Pest Science, 2012
The genetic diversity of Bemisia tabaci was investigated in Southern Italy using the mitochondrial cytochrome oxidase I (COI) gene as molecular marker and sampling whiteflies on cultivated plants, weeds and bushes. Phylogenetic analysis of COI sequences and restriction analysis of COI amplicons were used to genotype whitefly populations. A PCR-RFLP method based on digestion with the endonuclease ApoI was set up to identify the B. tabaci genetic variants so far recorded from the Mediterranean region. In general, biotype Q populations were most frequently collected (76.0% of all sampled populations). In greenhouse districts, 87.0% sampled populations were identified as biotype Q, and 13.0% were assigned to biotype B. Outside the greenhouse districts, the biotype B was never collected, whilst biotype Q populations were found on weeds and on plants cultivated in family gardens in different environments, also located in interior plains or in mountain areas distant from intensive cultivations of whitefly host plants. A new genetic variant unrelated to B and Q biotypes, which was named Ru, was collected on Rubus ulmifolius and grapevine. Phylogenetic analysis of COI sequences shown that Ru haplotypes form a wellsupported clade sister to the clade including the Asian/ Australian major genetic groups and the Italy major genetic group. The closest relative of the Ru clade (10.7% pairwise genetic distance) was the Italy group, with this latter so far including only the haplotypes of the T biotype. These results were discussed in the light of the recent B. tabaci species concept.
The sweet potato whitefly, Bemisia tabaci, is a complex species, and many of its biotypes are important agricultural pests. The B and Q biotypes are invasive and coexist with the native Cv biotype on vegetable and ornamental crops in China. In this study, these three biotypes were identified based on their morphological characteristics, RAPD-PCR analysis, and DNA sequences of the COI gene. The anterior and posterior wax fringes of the B, Q, and Cv biotypes significantly differed from each other. Based on this morphological characteristic, the three biotypes can easily be distinguished in greenhouses and fields. Genomic DNA RAPD-PCR band patterns also revealed differences between these biotypes using the H 16 primer. The B biotype has three bright DNA bands between 250 and 600 bp, the Q biotype only has one bright band at 300bp,whiletheCvbiotypehasnobandbetween250and500bp.BoththeCvandQbiotypeshavetwobrightbandsat300 bp, while the Cv biotype has no band between 250 and 500 bp. Both the Cv and Q biotypes have two bright bands at 300bp,whiletheCvbiotypehasnobandbetween250and500bp.BoththeCvandQbiotypeshavetwobrightbandsat750 and 1000 bp while the B biotype has only one band at $1000 bp. Based on the COI gene, the genetic identity between B and Cv, B and Q, and Q and CV was 85.8%, 94.7%, and 86.0%, respectively. The MP tree indicated that the phylogenetic relationship between the B and Q biotypes is much closer than that between the B and Cv or the Q and Cv biotypes. The uses of the morphological, RAPD-PCR, and DNA sequencing methods in biotype identification of B. tabaci are discussed.
Progress in Natural Science, 2009
The sweet potato whitefly, Bemisia tabaci, is a complex species, and many of its biotypes are important agricultural pests. The B and Q biotypes are invasive and coexist with the native Cv biotype on vegetable and ornamental crops in China. In this study, these three biotypes were identified based on their morphological characteristics, RAPD-PCR analysis, and DNA sequences of the COI gene. The anterior and posterior wax fringes of the B, Q, and Cv biotypes significantly differed from each other. Based on this morphological characteristic, the three biotypes can easily be distinguished in greenhouses and fields. Genomic DNA RAPD-PCR band patterns also revealed differences between these biotypes using the H 16 primer. The B biotype has three bright DNA bands between 250 and 600 bp, the Q biotype only has one bright band at 300bp,whiletheCvbiotypehasnobandbetween250and500bp.BoththeCvandQbiotypeshavetwobrightbandsat300 bp, while the Cv biotype has no band between 250 and 500 bp. Both the Cv and Q biotypes have two bright bands at 300bp,whiletheCvbiotypehasnobandbetween250and500bp.BoththeCvandQbiotypeshavetwobrightbandsat750 and 1000 bp while the B biotype has only one band at $1000 bp. Based on the COI gene, the genetic identity between B and Cv, B and Q, and Q and CV was 85.8%, 94.7%, and 86.0%, respectively. The MP tree indicated that the phylogenetic relationship between the B and Q biotypes is much closer than that between the B and Cv or the Q and Cv biotypes. The uses of the morphological, RAPD-PCR, and DNA sequencing methods in biotype identification of B. tabaci are discussed.
Population variability of Bemisia tabaci (Genn.) in different hosts
Genetics and molecular research : GMR, 2013
The silverleaf whitefly, Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae), is a cryptic species complex that contains some of the most damaging pests in tropical and subtropical regions. Recent studies have indicated that this complex is composed of at least 24 distinct and morphologically indistinguishable species that mainly differ in their ability to transmit phytoviruses, adapt to hosts, and induce physiological changes in certain hosts. The importance of this species has been increasing worldwide, because it serves as a phytovirus vector, particularly for geminiviruses, in economically important crops. Here, we aimed to examine the population variability of B. tabaci populations inhabiting 6 agricultural crops grown in 5 regions of Brazil and 1 region of the USA; BRrep [Brasília (DF, Brazil) - cabbage], ILsoj [Urbana (IL/USA) - soybean], BJabo [Bom Jesus da Lapa (BA, Brazil) - pumpkin], CPsoj [Campinas (SP, Brazil) - soybean], UBman [Ubatuba (SP, Brazil) - cassava], and PEmel [P...