Studies On Taxonomy Status Of "Mayisong" In Liancheng National Nature Reserve Of Gansu

The Picea includes about 40 species to the temperate and boreal regions of the Northern Hemisphere, occurring in Europe, Asia Minor, the Caucasus, Siberia, China, Japan, the Himalayas, and North America. 16 species and 9 varieties make China have the most kinds of plants of Picea than other countries. There are six species in Gansu Province, including P. asperata, P. crassifolia, P. wilsonii, P. neoveitchii, P. brachytyla and P.purpurea, and they are mainly distributed in the central, eastern and southern of Gansu. P. crassifolia, and P. wilsonii are occurring in Liancheng National Nature Reserve of Gansu Province. Mayisong, which is named by the local people, is scattered in Liancheng National Nature Reserve. Some biological experts presumed Mayisong was a hybrid species of P. crassifolia and P. wilsonii, however, further studies need to be conducted to assess whether Mayisong was a hybrid species. In addition, the local people divide P. wilsonii into Heitielan(P. wilsonii) and Baitielan and the relationships between them are also discussed in the study.In this study, the methods of morphology, anatomy, microscopic morphology, protein electrophoresis, chemotaxonomy, cyto-taxonomy, numerical taxonomy and variation of character were employed to study the taxonomic problems of Mayisong. The relationships of/! wilsonii and Baitielan were studied as well. The results of the research were summarized as follows:(1) Morphology: From the phenotypic characteristics of comparison, we found that the slightly difference between P. wilsonii and Baitielan was the bark. Most of the characters among Mayisong, P. wilsonii, and Baitielan were different. Except the impalpable difference between numerical characters, the most evident differences of Mayisong and P. crassifolia were cone and bark. The cone shape coefficient of Mayisong and P. crassifolia was 2.88 and 2.07, individually. The cone shape of Mayisong was longer and narrower than P. crassifolia. The split block of Mayisong was small, tenuis, almost there was no split groove, however, its counterpart of P. crassifolia was big, thick, and the split groove was profound. Through scatterplot visualization we knew that most of all characters of Mayisong, P. wilsonii, and Baitielan were not superposed, although most of all characters between Mayisong and P. crassifolia were superposed, several characters were not superposed, such as bark and cone. It was consistent with the locals who distinguish Mayisong and others by bark. There were some differences of bark between P. wilsonii and Baitielan, but the interlacing phenomena also exist, for example, the fissura transversa of bark about P. wilsonii and Baitielian was 11.00-21.00 mm and 8.00-18.00 mm, individually. So the bark was an unstable character in P. wilsonii. Anderson hybrid index method confirmed that Mayisong was neither the hybrid species of P. wilsonii and P. crassifolia, nor the hybrid species of Baitielan and P. crassifolia, it was possibly the infraspecific pattern of/! crassifolia.(2) Anatomy: The needle leaves' cross section of Baitielan, P. wilsonii and P. crassifolia were nearly square, but that of Mayisong was slightly thin and flat, nearly rhombus; Both of the needle leaves' cross-sectional area of Mayisong and P. crassifolia were bigger than those of Baitielan and P. wilsonii. The structures of resin canals were identical, but the frequency of their appearance was different. The frequency of two resin canals of Baitielan and P. wilsonii occur at the same time was much greater than that of Mayisong and P. crassifolia. Anderson hybrid index method about needle's anatomy and part of tracheid's characters showed that Mayisong was neither the hybrid species of P. wilsonii and P. crassifolia, nor the hybrid species of Baitielan and P. crassifolia.(3) Microscopic morphology: Each pollen structure of four types was composed of one corpus and two sacci. The concavity of Baitielan and P. wilsonii was evident, Mayisong had a little concavity, and concavity of P. crassifolia was not evident. The scan of wood showed that 4 categories of tracheids were all pitted tracheids. The scan of needle leaves showed that the shape of four categories were four prismatic strip, the apexes of Baitielan and P. wilsonii were more acerate than those of Mayisong and P. crassifolia. The number of stoma lines in ventral aspect and back side of Baitielan and P. wilsonii were similar, so do Mayisong and P. crassifolia. The superficial wax of Baitielan and P. wilsonii was less than Mayisong and P. crassifolia. There was no evident difference among seeds were observed.(4) Protein electrophoresis: The results of SDS-PAGE about seeds water-soluble proteins showed that in terms of the color and protein content of the bands, the bands of Baitielan and P. wilsonii were similar. Similar results were also got from the bands of Mayisong and P. crassifolia. There were no evident intermediate bands were observed neither among Mayisong, P. crassifolia and P. wilsonii, nor among Mayisong, P. crassifolia and Baitielan. In addition, Mayisong had the highest dissimilarity value between P. wilsonii and the lowest one between P. crassifolia. Based on the above results it was proper to classify Mayisong as a infraspecific pattern of/! crassifolia. It was hard to distinguish Baitielan and P. wilsonii according to the SDS-PAGE results.(5) Chemotaxonomy: The thin-layer chromatography (TLC) of flavonoids and tannins showed that needles and branches had differences in four categories. The TLC of tannins showed that P. crassifolia and Mayisong had specific blotches. P. wilsonii and Baitielan had slightly difference with each other regardless of the flavonoids or tannins, branch or needle. Mayisong and P. crassifolia had many differences with Baitielan and P. wilsonii. Great differences of flavonoids and tannins in the leaves of P. crassifolia and Mayisong were observed. Therefore, we presumed that Mayisong was the infraspecific pattern of P. crassifolia. The chemical composition of P. wilsonii and Baitielan was so similar that it was difficult to distinguish them.(6) Cyto-taxonomy: Baitielan didn't have the long chromosome L, P. wilsonii had four long chromosomes L, both of Mayisong and P. crassifolia had two ones. All of the four types of Picea had about 8-14 mediocre and long chromosome (M2) and about 6-10 mediocre and short chromosome (Ml). Each Baitielan and P. wilsonii had 4 short chromosomes (S), each Mayisong and P. crassifolia had 2 short chromosomes (S). The karyotypic formula of four types was 2n=2x=24=24m, the karyotype of Baitielan and P. wilsonii was 1B, the karyotype of Mayisong and P. crassifolia was 1A.(7) Numerical taxonomy: According to the tree of Q analysis, there were two branches of four types: one was P. wilsonii and Baitielan, the other was Mayisong and P. crassifolia. P. wilsonii and Baitielan are very similar. The distance of Mayisong and P. crassifolia was farther than that of P. wilsonii and Baitielan in the tree. The relationships of the characters were discussed by the tree of R analysis and principal component analysis, the results indicated that dimorphism and polymorphism characters were interspecific characters of Picea which included whether branchlets had hairs, the color of branches, whether branchlets had powder, the shape of winter buds, whether buds scale had ridge and hairs, whether buds scale were coiling, the shape of bracts scale and so on. The length of cones and width of cones were intraspecific characters.(8) Variation of characters: Through the analysis of characters' variation, we could classify the four types using the 24 characters of the width of cone, pollen, needle and tracheid. The poly-angle figures of four types of Picea were pretty similar except the needle width, cone width and pollen width of Mayisong. In general, the poly-angle figures of P. wilsonii and Matielan were similar. The similarity between Mayisong and P.cressifolai was very high except the width of cone and pollen. The std. dev and CV showed that the discrete degree of needle, cone, bark were smaller than tracheid, pollen and wood ray. 23 CV of Baitielan and 27 ones of P. wilsonii were bigger than Mayisong and P. crassifolia. It was suggested that the variation of characters from Baitielan and P. wilsonii were rich and unstable. Most of characters about Mayisong and P. crassifolia especially cone (including seed, seed wing, seminiferous scale, bract scale) were very stableand they were fit for classifying characters.From all of above we concluded that the dimorphism and polymorphism characters such as whether branchlets had hairs, the color of branches, whether branchlets had powder, the shape of winter buds could be used to classify the interspecies plants in Picea, numerical characters such as cone width, bark longitudinal dehiscence could be used to classify the intraspecies plants. From all experiments we could draw a conclusion that Baitielan and P. wilsonii were very similar, although they had difference in the bark, they were interlacing on the character and the variation was big, so bark in P. wilsonii was an unstable character. The similarity of Mayisong with Baitielan and P. wilsonii was very low, but it had many similarities with P. crassifolia. Although Mayisong was similar to P. crassifolia, there were also evident differences among them, mainly in the cone and bark. Besides, according to anatomy, protein electrophoresis, chemotaxonomy, karyotype analysis we knew that Mayisong and P. wilsonii had similarities and differences. Therefore, Mayisong was not the hybrid species of P. wilsonii and P. crassifolia, but the infraspecific patterns of P.crassifolia. According to the differences of Mayisong and P. crassifolia and distributed area of Mayisong, we assumed that Mayisong was the variety of P.crassifolia.