Studies On Speciation Of Liriomyza Sativae (Diptera: Agromyzidae)

Liriomyza sativae is one of the three main pests in Liriomyza, whitch is ranked in the quanrantine pest in many countries and regions. We clonged and sequenced the rDNA-ITS & -tubulin gene of the populations collected from different districts and the populations feeded on different hosts about L sativae. Through different bio-soft of DNAStar (Lasergene 501) and Clustal X1. 8 & Mega2.1, we compared the identity and diversity of gene sequence between different population of L. sativae.By soft of DNAStar (Lasergene 501) and Clustal X1.8 & Mega2.1, we compared the rDNA-ITS 1, rDNA-ITS2 and rDNA-ITS sequence of the populations feeded on the different hosts. The results show that there are the different host populations of L. sativae in Yangzhou district. The different host populations of L sativae could be divided into three classes. The populations feeded on hobby host--Solanaceae (Lycopersicon esculentum), Leguminosae (Vigna sinensis) and Cucurbitaceae (Cucumis sativus) are the first class, the sequence divergence among them is not evident, the identity and divergence of sequence between them are 99.5-1 00%(by DNAStar) and 0.000-0. 003(by Clustal) respectively; the populations feeded on distasteful host-Malvaceae (Gossypium hirsutum) is the second class, the sequence identity and divergence between the population feeded on host-Malvaceae and the populations feeded on hobby host are 15. 8-5 1.1% and 0.697-1.140 respectively; the population feeded on host-Cruciferae (Brassica chinensis) was the third class, the population feeded on host-Cruciferae was among the the first two class. Among the three classes, the sequence identity between the population feeded on Cruciferae-host and the first class , the second class are 79.0-98.3% and 16.3-50.6% respectively, the sequence divergence are 0.007-0.045 and 0.727-1.181 respectively; it shows that the sequence identity between the population feeded on host-Cruciferae and the first class is more closely than the sequence identity between the population feeded on host-cruciferae and the second class.By the same soft, we analyse the 5.8S rDNA sequence. We find that there is little divergence among the 5.8S rDNA sequence, but the result of the analysis was similar to the results of the above mentioned. The identity and divergence between the populationsfeeded on hobby-host are 99.2% and 0.000 respectively; the identity and divergence between the populations feeded on hobby-host and distasteful-host are 86.3-92.2% and 0.0678 respectively; the sequence identity between the population feeded on host-Cruciferae and the populations feeded on hobby-host , distasteful-host are 96.2-98.3% and 90.2% respectively, the sequence divergence are 0.022 and 0.092 respectively.By the same soft, we compared the rDNA-ITS1, rDNA-ITS2, rDNA-ITS and 5.8S rDNA sequence of the populations collected from different geographic area. The outcome is that there is geographic speciation about L. sativae in our country. According to the results of study about the six province(or district), the populations could be divided into three classes. The first class are the populations collected from Guangdong province (Guangzhou) , Guangxi province (Nanning) and Guizhou province (Tongren), there is little divergence between them, the sequence identity and divegence are 96.0-100% and 0.000-0.007 respectively; the second class are the populations collected from Jiangsu province (Yangzhou) and Zhejiang province (Hangzhou), the sequence identity and divergence are 93.9-100% and 0.000-0.036 respectively; the population collected from Hainan(Danxian) is the third class. Among the three classes, the sequence identity and divergence between the population collected from Hainan(Danxian) and populations collected from Jiangsu province (Yangzhou) , Zhejiang province (Hangzhou) 's are 67.4-100% and 0.000-0.391 respectively, the sequence identity and divergence between the population collected from Hainan(Danxian) and the first class are 26.2-52.3% and 0.478-1.233 respectively; it shows that the homogenous betwe...