The Studying On Relativity Of Diapause And Population Genetic Diversity Of Colaphellus Bowringi Baly

The leaf beetle,Colaphellus bowringi Baly is a serious pest of crucifers,aestivating and hibernating as adults in the soil.Four Populations of C.bowringi fromLongnan,Xiushui of JiangXi provence,Taian of ShanDong provence,Haerbin ofHeiLongJiang provence,were studied to explore the diapause diversity by differenttemprature and photoperiod,and estimate the genetic structure and genetic diversityby different DNA marker technologies,and compaired them with diapause diversity.Temperature and photoperiodic adjustment of diapause in populations of C.bowringiAt differente constant temperature (18-30℃),the photoperiodic response ofdiapause induction of the four populations of C.bowringi from Longnan of JiangXiprovence(JXL),Xiushui of JiangXi provence(JXX),Taian of ShanDong provence(SDT),Haerbin of HeiLongJiang provence(HEB),undergoing winter diapause weretested with daylight of 8-16 h.The result suggest that geographical diversity wasoccurred with the increasing of latitude and depressing of temperature.The responseon photopreiod and temperature is differente between the JXL and SDT or HEB,but itis similar to that of JXX.Temperature play a Crucial role in diapause induction for C.bowringi.Whateverphotoperiod,100% diapause occurred at (?)18℃in JXL,at (?)20℃in JXX,at (?)25℃in SDT,at (?)28℃in HEB.The effect of photoperiod on diapause induction is adjusted by temperature.JXLof C.bowringi is typical short-daylight insects.The effect of diapause control ofshort-daylengths enhance with the increasing temperature at＞18℃;The population ofXiushui are also short-daylight insects.The diapause rate induced under differenteshort-light decreases with increasing temperature at＞20℃,and decreases underdifferent long-daylengths with increasing temperature distinctly at＞22℃;For SDT, the diapause rate is 69.23%～90.91% at 28℃.But its photoperiodic responses curve isanomalous wavilness at 30℃,showing the photoperiodic responses didn't occured.HEB don't responce on photoperiod,the diapause induction was decided bytemperature completely.More,The examination showed the different diapausecharacters results in the different life-cycles in the four population of C.bowringi.Genetic diversity analyse of four populations of C.bowringi by mtDNA COIsequence,RAPD and PCR-RFLP1.A total of 30 mutation loci,25 polymorphic loci,37 haplotypes,weredetected among four populations,64 individuals by analyzing the sequences datafrom mtDNA COI gene about 335bp.The content of A+T (63.68%) is obviouslyhigher than that of G+C (36.32%).The nucleotide diversity index were 0.0056(JXL),0.0023 (JXX),0.0093 (SDT),0.0151 (HEB),respectively.The result ofpairwise Fst and Neutrality tests revealed significant genetic differentiation amongfour populations,and evolution of mtDNA COI gene incompliance with the Neutralitytheory。The genetic distance was the biggest between HEB and JXL,and was thesmallest between SDT and JXL among the 4 populations.While the genetic distancebetween JXL and JXX is bigger than that between SDT and JXX.The geneticdistance ofpopulaions dismatch with their geographic distance.2.Four geographical populatios of C.bowringi were amplified using 11 primersselected from 80 random primers.There were 53 polymorphic loci based on 65amplification loci obtained by RAPD analysis.Polymorphisms,genetic similarityindices and genetic diatance were calculated.The results suggesting:the percent ofpolymorphisms was ranging 36.92%～67.69%.Nei genetic diversity was ranging from0.1049～0.20611.And Shannon diversity was ranging from 0.1641～0.3167.Tthegenetic variation within SDT was the highest,while that within JXL is the lowest.Thegenetic distance between JXL and JXX was the smallest,that between JXL and HEBwas the biggest.While the genetic distance between HEB and SDT was smaller thanthat between HEB and JXX.The genetic distances of C.bowringi populations matchtheir geographic distances between the sources of each population,and werecorrelated with their biologic comparability.3.Seven endonucleases were used to analyze the amplified products of COI gene.The result showed that AseⅠ,MboⅠ,NlaⅢ,RsaⅠdidn't produce restrictionfragment-length polymorphism among C.bowringi populations.The polymorphismwas detected among the 4 populations with the enzymes AluⅠand DraⅠ.Whereas,the restriction fragment-length polymorphism was found eihter among 4 populationsor within SDT with HaeⅢ.Four restriction types were found in all individuals.Obviously,the populations could be distinguished with unique restriction type.According to the porportion of restriction fragments shared,the genetic distancesamong the 4 populations were calculated with popgene3.2,and a cladogram wasproduced with MEGA3.1.The result showed that the genetic variance dismatch withtheir diapause variance.