Comparative Analysis of Population Genetic Structure in Bemisia tabaci(Gennadius) Biotypes B and Q Based on ISSR Marker

Bemisia tabaci （Gennadius） biotypes B and Q are two invasive biotypes in the species complex. The comparison of the population genetic structure of the two biotypes is of significance to show their invasive mechanism and to their control. The intersimple sequence repeats （ISSR） marker was used to analyze the 16 B-biotype populations and 4 Q-biotype populations worldwide with a Trialeurodes vaporariorum population in Shanxi Province, China, and a B. tabaci non-B/Qbiotype population in Zhejiang Province, China, was used as control populations. The analysis of genetic diversity showed that the diversity indexes of biotype Q including Nei＇s gene diversity index, Shannon informative index, and the percentage of polymorphic loci were higher than those of biotype B. The high genetic diversity of biotype Q might provide the genetic basis for the excellent ecological adaptation. Cluster analysis suggested that the ISSR could not be used in the phylogenetic analysis though it could easily distinguish the biotypes of B. tabaci. The difference of the population genetic structure between the biotype B and the biotype Q exists based on the ISSR marker. Meanwhile, the results suggested that the molecular marker has its limitation in the phylogenetic analysis among the biotypes of B. tabaci.

Prevalence of Gingival Biotype in a Syrian Population and Its Relation to Tooth Shapes: A Cross-Sectional Study

Background: Gingival biotype is one of the most important factors that impede success in dental treatments;it affects the outcomes of periodontal surgery, and restorative treatments. Researchers classified gingival biotypes into thin biotype and thick biotype. It is crucial to identify tissue biotype before treatment. Aim of Study: To determine the prevalence of gingival biotypes in a Syrian population, in addition, to study the distribution of gingival biotypes according to gender and tooth shape. Material and Methods: This cross sectional study included 500 volunteers (300 males and 200 females) from the patients who had visited the department of periodontology-dental faculty at Damascus University. Gingival thickness was assessed to determine the gingival biotype for the maxillary central incisors using the direct measurement technique (Trans-gingival probing). Shapes of the maxillary incisors were recorded. A written informed consent was taken from each patient. Statistical analysis was done using test k2 p < 0.05. Results: The mean age was 26.8 ± 4.4 years. Thick gingival biotype was detected in 58.4% of the sample and most of patients are men while the prevalence of thin gingival biotype was 41.6% of the sample. It was also observed that patients with thin gingival biotype had triangular tooth shape in 99.5% (p < 0.05). Conclusion: Thick gingival biotype was observed to be more prevalent in a Syrian population than thin biotype. Most Syrian males had thick gingival biotype with square tooth shape while females had thinner biotype and triangular tooth shape.

The biotypes and host shifts of cotton-melon aphids Aphis gossypii in northern China

Aphis gossypfi is a globally distributed species and therefore has a highly variable life cycle. Populations of A. gossypii in northern China exhibit greater genotypic diversity and a broader host range, yet the details of life cycles of different biotypes is still unclear. In this study, the Cytb and 16S gene regions of A. gossypfi collected from 5 common summer hosts and 4 primary hosts were analyzed. A total of 57 haplotypes were obtained from 1 046 individual A. gossyp# sequences. The sequence included 44 variable sites, 27 of which were parsimony informative sites and 17 of which were singleton variable sites. The most frequent 3 haplotypes were found in 896 individuals, representing a total of 85.7% of all individuals and 36 haplotypes were found in 1 individual. A neighbor-joining tree was constructed using 21 haplotypes that were found in more than 2 individuals. Considering the individual host plant, 5 biotypes were identified. Type 1 corresponded exactly to the cucurbit host-race and the other 4 biotypes were found as cotton host-races. Type 3 was the most abundant biotype in cotton fields in northern China.

Comparative Morphology and Morphometry of Six Biotypes of Bemisia tabaci (Hemiptera: Aleyrodidae) from China

Morphology and morphometry of six biotypes （B, Q, Cv, ZHJ-1, ZHJ-2 and ZHJ-3） of Bemisia tabaci （Gennadius） from China on cotton plants were studied by using microscopes. Nymphal body sizes and characters were measured and observed, especially on the 4th instar （pupal case）, including the vasiform orifice, operculum, lingula, length and thickness of anterior and posterior wax margins, width of thoracic tracheal combs. Adult characters of both sexes were investigated including the body size, compound eyes, antennal segments, vasiform orifice, hind tarsi and genitals. The results indicated that differences of some morphological characters or morphometrics were significant among the six biotypes of B. tabaci in China： （1） Pupal sizes of the exotic biotypes （B and Q） were significantly larger than the indigenous biotypes with the following order as B〉Q〉ZHJ-I〉Cv〉ZHJ-3〉ZHJ-2; （2） for both male and female adults, sizes of all characters investigated in the invading biotypes （B and Q）, especially B, were much larger than those of the indigenous ones.

Bemisia tabaci Biotype Dynamics and Resistance to Insecticides in Israel During the Years 2008-2010

The sweetpotato whitefly Bemisia tabaci（Hemiptera：Aleyrodidae）is an extremely polyphagous insect pest that causes significant crop losses in Israel and worldwide.B.tabaci is a species complex of which the B and Q biotypes are the most widespread and damaging worldwide.The change in biotype composition and resistance to insecticide in Israel was monitored during the years 2008-2010 to identify patterns in population dynamics that can be correlated with resistance outbreaks.The results show that B biotype populations dominate crops grown in open fields,while Q biotype populations gradually dominate crops grown in protected conditions such as greenhouses and nethouses,where resistance outbreaks usually develop after several insecticide applications.While in previous years,Q biotype populations were widely detected in many regions in Israel,significant domination of the B biotype across populations collected was observed during the year 2010,indicating the instability of the B.tabaci population from one year to another.Reasons for the changing dynamics and the shift in the relative abundance of B.tabaci biotype,and their resistance status,are discussed.

Studies on the Host Biotypes and Its Cause of Cotton Aphidin Nanjing,China

The fitness of cotton aphid, Aphis gossypii Glover, on different host plants was studied. The results showed that the cotton aphid population in Nanjing formed host preference bio-types on cucumber and cotton. The aphids from cotton and cucumber could not inter-transplant successfully between the two host plants. The apterous and alate offspring of stem mother from hibiscus could not survive, reproduce and form population normally when they were transplanted to cucumber and water melon, but they could form normally when transplanted to cotton and muskmelon. There was no significant difference between the stylet length of cotton aphids from cucumber and cotton, so the stylet length was not the cause of the host preference. When the aphids originated on hibiscus were transplanted to cotton, water melon and muskmelon, the stylet could reach host phloem to absorb host plant’s nutrients, but it couldn’t when transplanted to cucumber. Cotton aphid can feed on muskmelon without secretion of water-soluble saliv

Species and Biotype Analysis of Brucella Strains Isolated from Cattle and Sheep in Xinjiang

[ Objective] The paper aimed to understand the epidemiological characteristics of Brucella strains in Xinjiang and then provide an available integrated measure to prevent and control brucellosis. [ Method ] Eleven suspected Brucella strains were isolated by traditional methods, which were further identified by AMOS-PCR assay. Conventional biochemical tests were carried out to identify the biological subtype of sheep Brucella. [ Result] Nine strains were all B. meliten- s/s, and biological test indicated that all of them were B. melitensis biotype 3. [ Conclusion] B. melitensis biotype 3 was the predominant strain of Brucella in Xin- jiang, and AMOS-PCR assay could be applied safely and quickly as an assistant tool to detect Brucella. The results of molecular epidemiology laid a foundation for updating prevention and control strategy against brucellosis in Xinjiang.

Impact of Rice Stem Borers and Identification of <i>Orseolia oryzivora</i>Harris &Gagné, 1982 (Diptera: Cecidomyiidae) Biotypes in the Southern Cameroon

The study compares the impact due to rice stem borers in two sites (Yaoundé and Ntui). It also shows the diversity of the African Rice Gall Midge (AfRGM) biotypes in southern Cameroon (Santchou, Ndop, Tonga, Ebolowa, Ba?gom, Yaoundé and Ntui). The New Rice for Africa (NERICA) varieties 3, 8, 9 and 13 sown in Ntui were less attacked than those sown in Yaoundé. At both sites, damages ranged from 0.78% to 2.7%. In terms of diversity, the main stem-borer species were O. oryzivora, Diopsis apicalis, D. longiconis and Chilo zacconius. Molecular analyses of Orseolia oryzivora larvae collected in the localities of Santchou, Ndop, Tonga, Ebolowa, Ba?gom and Yaoundé showed the existence of more than one O. oryzivora biotype in southern Cameroon’s rice basins.

Gingival biotype: The probe test utility

Purpose: To evaluate the relevance of the probe test in classifying the gingival biotype and to determine if differences exist between maxillary and mandibular gingival biotypes in the same patient. Materials and Methods: 53 subjects were included. The gingival thickness was evaluated as thick or thin. This evaluation was based on the transparency of the periodontal probe through the gingival margin while probing the sulcus. In another hand, 124 clinicians were asked to identify the gingival biotype in the same 53 subjects based on visual inspection on pictures. For each examiner, the accuracy in identifying the gingival biotype was assessed using the percentage of cases correctly identified. Results: the percentile of agreement is greater than 70% in maxilla as well as in mandible. An imbalance was observed on the maxillary pictures concerning the gingival biotype and on the thin biotype between maxilla and mandible despite there being no statistical difference (p < 0.0001). The percentile of agreement is quite similar in the mandible for both thin (74%) and thick (70%) gingival biotypes. Agreement between mandibular probe and maxilla probe results demonstrates a weak percentile of agreement of gingival biotypes between maxillary and mandibular anterior teeth (57%). Conclusion: The use of probe transparency through the gingival margin is an accurate and simple method for gingival biotype diagnosis to discriminate a thin gingival from a thick gingival. Furthermore, individualizing the gingival biotype for each of the arches appears to be a new outcome that needs further investigation.

Effects of Crown Lengthening on Bi, PLI and PD Levels in Patients with Different Periodontal Biotypes

Objective:To investigate the effect of crown lengthening on patients with different periodontal biological types.Methods:60 patients with different periodontal biotypes treated in our hospital from May 2017 to February 2019 were retrospectively analyzed.According to the different periodontal biotypes,the above-mentioned patients were further divided into control group(thin fan type,30 cases)and observation group(thick flat type,30 cases).The periodontal probing depth(PD),plaque index(PLI),bleeding index(BI)and gingival margin position at 1 week,1 month,2 months and 3 months after operation were compared between the two groups.Results:The PD,Bi and PLI values of the two groups after treatment were lower than those before treatment(P<0.05);There was no significant difference in gingival margin position between the two groups after 1 week to 1 month and 1 month to 2 months(P>0.05);After 2 months to 3 months of treatment,the gingival margin distance of the observation group was larger than that of the control group,and the difference was statistically significant(P<0.05).Conclusion:Crown lengthening can effectively improve the periodontal indexes of different periodontal biotypes,and the gingival margin of thick and flat type patients moves more toward the crown.

Measurement and Clinical Significance of Gingival Biotype in Anterior Teeth

The morphological characteristics of periodontal tissue and tooth tissue in gingival biotype are one of the indicators reflecting the individual differences of periodontal tissue in patients.Gingival biotypes of anterior teeth are often related to the prognosis of smile aesthetic treatment,which is one of the reference indexes for predicting the success rate of aesthetic treatment such as restoration,implant,periodontal,orthodontic and so on.Gingival biotypes have individual differences,so different gingival biotypes have different responses to different external stimuli.In the current clinical work,the correct evaluation of gingival biotype,especially the accurate measurement of gingival thickness,is the basis of reasonable choice of treatment and prognosis evaluation.

MALDI-TOF质谱技术及Biotyper数据库在养殖场空气微生物鉴定中的应用

以16SrRNA测序法为标准方法,利用MALDI-TOF质谱技术及Biotyper数据库对某猪场210株空气分离株进行鉴定及准确率分析。结果显示91.0%的菌株被准确鉴定到种水平,95.7%被准确鉴定到属水平。研究表明MALDI-TOF质谱技术可以快速准确检测空气微生物,为养殖场环境质量监测提供了新的技术支持。

USING RAPD\|PCR TO DISTINGUISH BIOTYPES OF BEMISIA TABACI (HOMOPTERA:ALEYRODIDAE) IN CHINA

Ten populations of the whitefly Bemisia tabaci (Gennadius) collected from eight fieed and ornamental crops from seven provinces/cities in China were determined using RAPD PCR. Results showed that the 10 populations of B.tabaci could be classified into three distinct groups: a Biotype B group, a Guangxi group, and a Fujian group. The whiteflies in the Biotype B group were collected from sweetpotato and cotton in Beijing, tomato in Shandong, poinsettia in Shanghai and Guangdong, cabbage in Fujian, and hemp and eggplant in Xinjiang. The Guangxi group were collected from pumpkin in Nanning, Guangxi, and the Fujian group, from sweetpotato in Fujian. It was notable that B.tabaci specimens collected on cabbage in Fujian belonged to the Biotype B group. It is clear that Biotype B does now occur in China, in Beijing, Shandong, Xinjiang, Shanghai, Fujian and Guangdong. It is likely that the Guangxi and Fujian groups are native to China.

Effects of host, temperature and relative humidity on competitive displacement of two invasive Bemisia tabaci biotypes [Q and B]

Bemisia tabaci shifted unexpectedly in China from a predominance of B biotype to Q biotype during 2005-2008. This observation stimulated an interest in inves- tigating whether environmental factors, including host, temperature and relative humidity （RH） could possibly explain the observed shift in biotypes distribution. Results indicated that all three parameters examined influenced biotype survivability. The percentage of B biotype, when reared together on pepper plants with the Q biotype, decreased significantly from 66.7% in the founder population, to 13.6% and 3.7% in the first and second genera- tions, respectively. When the B （founder at 66.7%） and Q （founder at 33.3%） biotypes were reared together on eggplant alone, or on pepper-plus-eggplant combination, the population size of the B biotype either remained constant, or increased somewhat in the first and sec- ond generations. On eggplant, the effects of RH and temperature on the competitiveness between the Q and B biotypes （3 pairs of Q and 6 pairs of B） were not significant.

Soybean aphid intrabiotype variability based on colonization of specific soybean genotypes

The soybean aphid, Aphis glycines Matsumura （Hemiptera： Aphididae）, is one of the most destructive insect pests on soybeans in the United States. One method for managing this pest is through host plant resistance. Since its arrival in 2000, 4 aphid biotypes have been identified that are able to overcome soybean aphid resistance （Rag） genes. A soybean aphid isolate collected from Moline, Illinois readily colonized soybean plants with the soybean aphid resistance gene Rag2, unlike biotypes 1 and 2, but similar to soybean aphid biotype 3. Two no-choice experiments compared the virulence of the Moline isolate with biotype 3. In both experiments, differences in aphid population counts were not significant （P 〉 0.05） on soybean genotypes LD08-12957a （Rag2） and LD11-5413a （Rag2）, but the aphid counts for the Moline isolate were significantly （P 〈 0.05） lower than the aphid counts for the biotype 3 isolate on the soybean genotypes Dowling （Rag1）, LD05-16611 （Rag1）, LD11-4576a （Rag1）, and P1567598B （raglb and rag3）. The Moline isolate was a variant of aphid biotype 3, which is the first report showing that soybean aphid isolates classified as the same biotype, based on virulence against specific Rag genes, can differ in aggressiveness or ability to colonize specific host genotypes.

Invasive mechanism and management strategy of Bemisia tabaci(Gennadius) biotype B:Progress report of 973 Program on invasive alien species in China

Bemisia tabaci(Gennadius) biotype B,called a "superbug",is one of the most harmful biotypes of this species complex worldwide.In this report,the invasive mechanism and management of B.tabaci biotype B,based on our 5-year studies,are presented.Six B.tabaci biotypes,B,Q,ZHJ1,ZHJ2,ZHJ3 and FJ1,have been identified in China.Biotype B dominates the other biotypes in many regions of the country.Genetic diversity in biotype B might be induced by host plant,geographical conditions,and/or insecticidal application.The activities of CarE(carboxylesterase) and GSTs(glutathione-S-transferase) in biotype B reared on cucumber and squash were greater than on other host plants,which might have increased its resistance to insecticides.The higher activities of detoxification enzymes in biotype B might be induced by the secondary metabolites in host plants.Higher adaptive ability of biotype B adults to adverse conditions might be linked to the expression of heat shock protein genes.The indigenous B.tabaci biotypes were displaced by the biotype B within 225 d.The asymmetric mating interactions and mutualism between biotype B and begomoviruses via its host plants speed up widespread invasion and displacement of other biotypes.B.tabaci biotype B displaced Trialeurodes vaporariorum(Westwood) after 4-7 generations under glasshouse conditions.Greater adaptive ability of the biotype B to adverse conditions and its rapid population increase might be the reasons of its successful displacement of T.vaporariorum.Greater ability of the biotype B to switch to different host plants may enrich its host plants,which might enable it to better compete with T.vaporariorum.Native predatory natural enemies possess greater ability to suppress B.tabaci under field conditions.The kairomones in the 3rd and 4th instars of biotype B may provide an important stimulus in host searching and location by its parasitoids.The present results provide useful information in explaining the mechanisms of genetic diversity,evolution and molecular eco-adaptation of biotype B.Furthermore,it provides a base for sustainable management of B.tabaci using biological and ecological measures.

White Matter Abnormalities in Major Depression Biotypes Identified by Diffusion Tensor Imaging

Identifying data-driven biotypes of major depressive disorder(MDD) has promise for the clarification of diagnostic heterogeneity. However, few studies have focused on white-matter abnormalities for MDD subtyping. This study included 116 patients with MDD and118 demographically-matched healthy controls assessed by diffusion tensor imaging and neurocognitive evaluation.Hierarchical clustering was applied to the major fiber tracts, in conjunction with tract-based spatial statistics, to reveal white-matter alterations associated with MDD.Clinical and neurocognitive differences were compared between identified subgroups and healthy controls. With fractional anisotropy extracted from 20 fiber tracts, cluster analysis revealed 3 subgroups based on the patterns of abnormalities. Patients in each subgroup versus healthy controls showed a stepwise pattern of white-matter alterations as follows: subgroup 1(25.9% of patient sample),widespread white-matter disruption;subgroup 2(43.1% of patient sample), intermediate and more localized abnormalities in aspects of the corpus callosum and left cingulate;and subgroup 3(31.0% of patient sample),possible mild alterations, but no statistically significant tract disruption after controlling for family-wise error. The neurocognitive impairment in each subgroup accompanied the white-matter alterations: subgroup 1, deficits in sustained attention and delayed memory;subgroup 2, dysfunction in delayed memory;and subgroup 3, no significant deficits. Three subtypes of white-matter abnormality exist in individuals with major depression, those having widespread abnormalities suffering more neurocognitive impairments, which may provide evidence for parsing the heterogeneity of the disorder and help optimize typespecific treatment approaches.

Viral infection of tobacco plants improves performance of Bemisia tabaci but more so for an invasive than for an indigenous biotype of the whitefly

The ecological effects of plant-virus-vector interactions on invasion of alien plant viral vectors have been rarely investigated. We examined the transmission of Tomato yellow leaf cur/China virus （TYLCCNV） by the invasive Q biotype and the indigenous ZHJ2 biotype of the whitefly Bemisia tabaci, a plant viral vector, as well as the influence of TYLCCNV-infection of plants on the performance of the two whitefly biotypes. Both whitefly biotypes were able to acquire viruses from infected plants and retained them in their bodies, but were unable to transmit them to either tobacco or tomato plants. However, when the Q biotype fed on tobacco plants infected with TYLCCNV, its fecundity and longevity were increased by 7- and 1-fold, respectively, compared to those of the Q biotype fed on uninfected tobacco plants. When the ZHJ2 biotype fed on virus-infected plants, its fecundity and longevity were increased by only 2- and 0.5-fold, respectively. These data show that the Q biotype acquired higher beneficial effects from TYLCCNV-infection of tobacco plants than the ZHJ2 biotype. Thus, the Q biotype whitefly may have advantages in its invasion and displacement of the indigenous ZHJ2 biotype.

Impacts of transgenic Bt cotton on the stylet penetration behaviors of Bemisia tabaci biotype B Evidence from laboratory experiments

Stylet penetration behaviors of Bemisia tabaci biotype B on two transgenic cotton lines ＂GK12＂ and ＂GK19＂ expressing Bt toxic protein CrylA （Bt cotton） and a non-Bt conventional cotton line ＂Simian-3＂ （CK cotton） were recorded with the direct current electrical penetration graph （DC-EPG） technique. Our results suggested that EPG waveform patterns, types and characteristics [non-probe （NP）, pathway （C）, potential drops （pd） and phloem phase （E（pd））] ofBemisia tabaci biotype B were very similar on the three cotton lines. There were no obvious differences of pathway variables among whiteflies on the three cotton lines. Some phloem variables related to E（pd）l differed. Duration of 1st E（pd）l and mean duration of E（pd）l on both GK12 and GK19 were significantly shorter than that on CK cotton （P 〈 0.05）. Fewer whiteflies on GK have long E（pd）l. Other phloem variables including total duration of E（pd） summed, mean E（pd） duration and percentage of whiteflies reaching the phloem phase were similar among the three cotton lines.