Study On Chromosome And Systematics Of Acridoidae

Along with the mutual influence of the borderline subjects, thetraditional taxonomy is continually changed and improved in its theoryand method. Cytotaxonomy is an important part of integrated taxonomyand provides a new method for further systematic research. It putsknowledge of cytology for using in taxonomy. Relations betweenbiological groups which is revealed by cytotaxonomy can be regarded asan evidence taxonomy.In this paper, the chromosomal conventional karyotypes and C-bandingpatterns on 18 species belonging to 14 genera and 6 Families ofOrthoptera were studied. Squashing and BSG method were used in thepreparation of slides for microscopical examination. The cells inmetaphase of mitoses or meioses were selected and the relational datawere analyzed by Excel and Microsoft SPSS. The results are as follows:1. The useful of cytotaxonomy marks in Acridoidea: The results of thispaper showed that the chromosome number, the chromosome groups andthe chromosomal behaviours can be used in the comparison of families,and the chromosomal C-banding karyotypes can be used for thecomparison of genera and species. There were marked C-bandingkaryotype in genera, such as there were marked C-banding in L2chromosome in Oxya genera, the different C-bands in different species ofL2 chromosome in this Oxya, this features could be used for thecytotaxonomy in this genera.2. A new species in Oxya and its significanceIn this paper, a species collected from Tengchong City of YunnanProvince has been founded. This species has the different morphologicalfeatures with the other species in this Genus. This species is similar toOxya intricate, but the tegmina is shorter than the Oxya intricate. By the chromosomal C-banding parttens, there are paracentric centromereC-band and telomere C-band in L2 chromosome of this species, thisfeature are different with other species of Oxya genera, so, it can be a newspecies in Oxya. This result further justifies the fact that Oxya L2chromosome can be regarded as the distinctive chromosome indifferentiating between the species in this genera.3. The study on the genetic relation of the representative population ofOxya chinensisThe results show that the Oxya chinensis forms a species; themorphological differences between different populations have closerelation to the environmental factors and ecological conditions. However,the basic structure of male genitalia keeps constant and can be used toidentify species. The karyotype and C-band structure of differentpopulations in Oxya chinensis keeps constant and also shows thatchromosome structure can mirror the basic characteristics of the geneticstructure of species in general, which can be considered as an importantprinciple for the species identification and comparison. From the angle ofthe highly constant genetic structure Oxya chinensis and the gradientchanges of its morphological differences, it is concluded that the Oxyachinensis is a successful widely distributed species. During the process ofevolution, this species continuously adapt to their living environment, sothe distribution of this species extends to different geographical regions.4. The quantitative study of chromosome with the advanced computersoftware systemIn this paper, the author attempts to use the software SPSS to makeANOVA analysis of the relative length, C-band relative length, chiasmafrequency and chiasma location, as well as the comparisons of S-N-K andDuncan between two groups. Based on these researches, the results turnout to be more accurate and convincing compared with those in theprevious researches. The research method is of great significance for the accurately interpreting the changes of chromosome morphologicalstructure, as well as the quantitative study on the regular pattern ofchromosome structural changes. This method is applicable not only to theclassification of Locusts cell, but also the chromosomes of different ofspecies.5. The significance of study the evolution of Locusts chromosomeFrom the results of this study, we come to a conclusion that theintegrated analysis of the conventional chromosome and banding patternsplay an important role in making the comparison between the differenttaxonomic groups and further clarifying its phylogenetic relationship. Ingeneral, the phylogenetic relationship abstracted from the chromosomeindicators accords with the evolutionary relationship of Acridoideabranch morphological studies. Based on the study of family evolutionaryrelationship, it is concluded that pamphagidae with the fewerchromosomes can be categorized the inferior group, on the other hand,the Catantopidae and Oedipodidae with the same number ofchromosomes and similar chromosome groups, can be categorized thesimilar groups. The chromosomes of Arcypteridae can be divided intotwo kinds, one is 2n((?))=23(such as Ceracris), together withCatantopidae and Oedipodidae belonging to the similar groups; the otheris 2n((?))=17 (such as Euchorthippus and Omocestus), the chromosomesgroups containing three pairs of chromosomes with the centromericchromosomes. Due to the centromeric fusion, the decrease ofchromosomes of this group is induced, which can be categorized thesuperior group. The basic chromosome number of Gomphoceridae andAcrididae is 2n((?))=23, compared with Catantopidae and Oedipodidae,these two groups, Gomphoceridae and Acrididae are superior to them, butthere may exist some genetic relationships with them.