Cytotaxonomic Studies On Eight Spieces Of Spiders In Shanxi (Araneae:Lycosidae)

Lycosidae is one of the five biggest families in Araneae, which has large amount of predation and an extensive feeding habits. Spiders of Lycosidae can prey on a variety of pests, which is of great importance in biological control of agricultural and forest pests. Although there were a large scale researches on the spiders, studies on cytotaxonomic of Lycosidae were seldom reported.In this paper, the optimization of techniques in pretreatment and chromosomal preparation were researched systematically. This experiment drawn its materials from 8 Lycosidae species collected from Shanxi which belong to 3 subfamilies and 4 genera. We made a systematic cytotaxonomy research from the following aspects such as the testis morphology, chromosome karyotype and chromosome behaviors and so on. The main results were as follows:(1) Optimization results of pretreatment:Hypotonic treatments were made with distilled water for 40 min, spiders were then fixed with Carnoy solution for 12h and dissected in 0.067% NaCl would contribute to obtain the full gonads. Meanwhile the chromosome obtained subsequently were clear and suitable concentrated,which were suitable for karyotype and chromosome behavior analysis.(2) Optimization results of method on chromosomal preparetion:Hypotonic treatments were made with distilled water for 15 min, gonads were then fixed with Carnoy solution for 20 min and stained with Giemsa solution (10%, pH 6.8) for 30 min.(3) The comparison in testis morphology of 8 kinds of spieces showed that:There were certain degrees of difference in length, width and area of testis morphology among 8 kinds of wolf spiders. O. qiongzhongensis testis area was minimum, while P. chapini testis area was the maximum, and H. alpigena testis width was maximum. In testis length, O. qiongzhongensis, A. licenti and P. astrigera were significantly shorter than the rest 5 species. In testis width, P. chapini was significantly wider than O.qiongzhongensis and P. astrigera, O.qiongzhongensis was significantly slimmer than others except P.astrigera. In testis area, P.chapini?P. pseudoannulata and P. Luctinosa etsinensis were significantly larger than the other five species. O. qiongzhongensis?P. plumipes and H.alpigena showed significant differences between each other. The morphological differences in the genus of Lycosidae are significant and species in the same genus have much in common.Cluster analysis results showed that:P. Luctinosa etsinensis, P. chapini and H. alpigena gatherred together as a same class, P. plumipes and P. pseudoannulata gatherred together as a branch, O. qiongzhongensis and P. astrigera gatherred together as a class and A. licenti was a single branch. Therefore, spermary can provide relatively stable diagnostic character between genera and species, which has a certain morphology and numerical taxonomic value.(4) The karyotype analysis results showed that:The number of chromosome in 8 species of Lycosidae are mainly (?)2n=28 and (?)2n=26, the sex determining mechanism is X1X2O.All the sex chromosomes are telocentric chromosomes and small-sized, which rank last in genome formula. Most of autosomal chromosomes are telocentric and metacentric chromosomes. The chromosomes karyotype of P. Luctinosa etsinensis, O. qiongzhongensis and H. alpigena are similar, P. plumipes is similar to P. pseudoannulata and P. astrigera is similar to P. chapini, the karyotype formula are:n=6m+sm+8T, n=6m+3sm+6T, n=4m+3sm+7T, and n=m+14T n=m+13T, and n=6m+8T n=8m+7T, respectively. In addition, the karyotype formula of A. licenti is n=3m+M+10T.Of all the chromosomes, the maximum relative length was 13.99±0.32, the minimum relative length was 2.20±0.26. O. qiongzhongensis without large chromosomes, the genome formula is 11M+2S+X1X2; P. astrigera and P. pseudoannulata are the same in genome formula (L+11M+S+X1X2);A. licenti and H. alpigena are the same in genome formula (L+11M+X1X2). P. chapini is similar to P. plumipes and P. Luctinosa etsinensis,the genome formula are 2L+8M+2S+X1X2,2L+10M+X1X2 and L+10M+2S+X1X2, respectively.(5) The analysis of chromosome behavior in mitotic showed that:There was no significant difference in interphase and certain morphological differences in prophase between intergeneric and interspecific of Lycosidae. P. chapini and P. astrigera had obvious euchromatic synapsis phenomenon in metaphase; P. pseudoannulata chromosome appearred red distortion in anaphase. The mitotic metaphase chromosome synapsis and anaphase chromosome distortions can be used as P. chapini, P. astrigera and P. pseudoannulata discriminant features.(6) The results of mitotic chromosome behavior showed that:The crossover forms in diplotene and diakinesis were significantly different among 8 kinds of Lycosidae, which can be used to distinguish between spieces. In leptotene stage, chromosomes of beiwuzhu were slend and arranged loose; nucleolus of P. astrigera, P. plumipes and P. pseudoannulata arranged centre of cell, the remaining were arranged at the edge of side.The chromomere of P. chapini, P. pseudoannulata and H. alpigenawere visible in zygonemaon; the sister chromatids of O. qiongzhongensis were clearly visible in pachytene; two bivalents at pachytene were clearly visible among A. licenti, P.chapini, P. pseudoannulata, P. astrigera, H. alpigena and P. Luctinosa etsinensis; in anaphase I H. alpigena and anaphase ? P. astrigera chromosome appearred parallel movement; P. chapini, P. plumipes, P. astrigera and P. Luctinosa etsinensis got tadpole shaped sperm cells. Thus it can be seen, there are obvious differences in chromosome morphology and behavior between different spieces of wolf spiders, which can be as identification characteristics in genera and species.