| Teinopalpus has only two sister species,Teinopalpus aureus and Teinopalpus imperialis,The larvae of both sister species were recorded in the wild as oligophagous insects,,feeding only on a few species of Magnoliaceae plants.They show high protection value,and in 1985,T.aureus was listed in the IUCN Red List of protected Species,and in 1989 it was listed as the national "First-class" key protected animal.T.imperialis was listed as the national "Second-class" key protected.For habitat conservation,Magnoliaceae plant resources which Teinopalpus Spp.feed should be protected first.However,due to the special occurrence location of Teinopalpus in the field,often located in high altitude mountains,and often active in the tree canopy or mountain top,ield surveys are difficult and subjective(for example,more attention is paid to Magnoliaceae),so whether the larvae of Teinopalpus eat magnoliaceae plants is still doubted.For this reason,larval feeding selection experiments have been conducted in recent years with Magnoliaceae endogamous plants and non-Magnoliaceae exogamous plants by using the protected area artificial protection study platform to gain direct evidence.According to the two sisters species swallowtail butterflies is a kind of sympatric distribution,regional parts crisscross,and magnoliaceae host plant species and resources constitute a different,and so on,the widely distributed host plant Michelia maudiae in the occurrence area of the Teinopalpus aureus and Manglietia insignis in the occurrence area of Teinopalpus imperialis were selected as the research objects,and plant leaves were collected from multiple butterfly occurrence points.At the same time,the genetic diversity of each geographic population was analyzed by ISSR molecular marker method and DNA(mat K and psb A-trn H chloroplast gene)fingerprinting method,In this way,the quality of the existing host resources of the rare butterfly is evaluated,and the basis for the subsequent introduction of butterfly habitat protection strategies and programs based on the protection of host resources is provided.The main conclusions of the study are as follows:(1)Through the double selection experiment,it was revealed that the larvae of T.aureus preferred to feed on the plants of Magnoliaceae(ingroup).However,the larvae’s sensory recognition response to the host plant is slower than expected,and it needs to feed on a possible "sign stimuli" to fix on the selection target.There was no significant difference between non-Magnoliaceae(outgroup)plants and ingroup plants in the frequency of feeding selection,but in the degree of feeding(leaf-eating area),there were significant differences between Magnoliaceae and outgroup plants.By calculating the selection index and the plant genetic distance based on the mat K gene,an exponential function(subtracting function)model between the genetic distance and the selection index was constructed.It was found that with the increase of the genetic relationship,the selection index dropped sharply.The result supports the view that host plant selection is driven by plant genetic relationships and trade-off hypothesis.(2)The genetic diversity of Magnoliaceae in the occurrence area of Teinopalpus was studied by ISSR molecular markers.The results showed that the effective allele(Ne),gene diversity index(H)and Shannon information index(I)values in the Population of Michelia maudiae were higher than those in the population of Manglietia insignis.The degree of gene exchange among the 10 populations of Michelia maudiae was average,and there is frequent gene exchange in the population of Manglietia insignis.It is speculated that the genetic differentiation of plants has affected the dispersal of Teinopalpus population,leading to the decrease of gene exchange frequency,and producing the species differentiation.(3)Genetic diversity analysis of host plants of Michelia maudiae and Manglietia insignis by combining mat K and psb A-trn H sequences showed that the nucleotide diversity(π)and mean nucleotide variation(K)of Michelia maudiae were higher than those of Manglietia insignis.The results of AMOVA combined with gene sequences showed that the variation of Michelia maudiae was more among the populations,while that of Manglietia insignis was more within the populations.The same haplotype is shared by different populations in both Michelia maudiae and Manglietia insignis.The plant mismatch distribution maps are single-peaked,indicating population expansion or sustained population growth may have occurred. |
