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Target And Non-Target Effects Of Different Transgenic Pest-Resistant Cotton Varieties On Bemisia Tabaci Biotype Q And Aphis Gossypii Glover Using EPG And Life Table

Posted on:2013-07-02Degree:MasterType:Thesis
Country:ChinaCandidate:J GaoFull Text:PDF
GTID:2233330395468738Subject:Agricultural Entomology and Pest Control
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With the cultivating and the popularizing of different anti-pesttransgenic cotton varieties, the target and non-target effects of transgenic cotton ondifferent insects were much concerned and the evaluating technologies on transgeniccotton were more needed. In this thesis, the electrical penetration graph (EPG) wasused to evaluate the target and non-target effects of different transgenic pest-resistantcotton varieties on feeding behaviors of Bemisia tabaci biotype Q and cotton aphidAphis gossypii. The host selections of B. tabaci to different transgenic cotton varietieswere tested using Y-tube. The effects of different anti-sap-sucking-pest transgeniccotton varieties on the development of B. tabaci biotype Q were tested. Based on theresults, the target and non-target effects of different anti-pest transgenic cottonvarieties on cotton aphid and B. tabaci biotype Q were discussed. The results weresummarized as follows:(1) The effects of cotton aphid on the feeding behaviors between differentBt+CpTI bivalent transgenic cotton varieties and maternal cotton varieties was testedusing EPG. Results showed all the EPG variants of cotton aphid were not significantdifferences between on the bivalent transgenic cotton “SGK321” and its maternalcotton variety “Shiyuan321” during the6h EPG recording time. Similar to“SGK321”, differences of most EPG variants were not signigficant between on thebivalent transgenic cotton “Zhongmiansuo-41” and on its maternal cotton variety“Zhongmiansuo-23”, but the percentage of E1and E durations in total recording time(E1%and E%, respectvely) of cotton aphid between on “Zhongmian-41” wassignificantly lower than that of the materanl variety “Zhongmian-23”, respectively. So,bivalent transgenic cotton “Shiyuan321” had no non-target effects on cotton aphid,but the bivalent transgenic cotton “Zhongmian-41” seems had target effects on thefeeding behavious of cotton aphid.(2) The effects of3anti-sap-sucking-pest transgenic cotton varieties on thefeeding behavious of cotton aphid and B. tabaci biotype Q were tested. Results showed that all the three anti-sap-sucking-pest transgenic cotton varieties wereresistant to cotton aphid and B. tabaci biotype Q, indicating the target effects weresignificant. The obvious difference of aphids feeding bahavious were that insecs spentmore time and more probing numbers to probe and less time to ingest leaf saps onphloem of transgenic cotton than the maternal varieties. Especially the percentage ofE2and E(E1+E2) duration in total recording duration (E2%and E%each), whichrepresent the duration of ingesting of leaf saps, was significantly lower than that ofthe corresponding maternal cotton variety, respectively. It suggested that theresistance factor of anti-sap-sucking-pest transgenic cotton mainly were being in thephloem juice. Therefore the percentage of E2wave and E wave duration could be asparameters to evaluate the resistance effects of the3anti-sap-sucking-pest transgeniccotton varieties. In addition, the values of each EPG parameter of cotton aphid or B.tabaci biotype Q between on different anti-sap-sucking-pest transgenic cottonvarieties were not always consistent. We deduce the insect species, cotton varietiesand imported genes might contribute to the difference.(3) The host-selection bahaviours of the B. tabaci biotype Q on differentanti-sap-sucking-pest transgenic cotton varieties were tested. Results showed that B.tabaci biotype Q had a significant preference to cotton compared to that of blankcontrol. But non-significant differences of host preference between on transgeniccotton variety and its maternal cotton variety, suggestting that the genes’ importtingdid not significantly affect the cotton volatile components or contents. But the eggnumber of B. tabaci on transgenic cotton A1, B1was sifinificanly lower than that ofits maternal cotton A2, B2, respectively, suggesting the differences of adaptabilitybetween the two transgenic cotton varieties and its maternal variety, respectively. Thedifference of egg numbers between on transgenic cotton C1and its maternal cottonC2was not significantly different.(4)In the laboratory, in order to evaluate the resistant effects of differentanti-piecing-sucking pests transgenic cotton varieties on B. tabaci biotype Q, weinvestigated the differences of developing parameters including body size,developmental duration, survival rate, adult longevity, fecundity and life-tableparameters of B. tabaci biotype Q on3different anti-piecing-sucking pests transgeniccotton varieties and their corresponding maternal cotton varieties. The results showedthat differences in most parameters including body size, developmental duration,survival rate and adult longevity were not significant between on each transgenic cotton variety and on its corresponding maternal cotton variety. But the fecundity offemale adults and net reproductive rate (R0) of population of B. tabaci on transgeniccotton varieties was significantly lower than that of its corresponding maternal line,respectively. The other life-table parameter, population doubling time (t), was higheron each transgenic cotton variety than on the corresponding maternal variety. Theseresults showed that the3anti-piecing-sucking pests transgenic cotton varieties wereresistant to B. tabaci biotype Q. In other words, the arget effects on B. tabaci biotypeQ were obvious.
Keywords/Search Tags:Transgenic pest-resistant cotton, Aphis gossypii Glover, Bemisia tabacibiotype Q, Electrical penetration graph, Life table, Target and non-target effects
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