| Kengyilia is a genus in the tribe Triticeae (Poaceae) with Kengyilia gobicola Yen et J.L. Yang as the typical species. Species of Kengyilia can be utilized as the potentialcontributor to genes of cold hardiness, drought resistance, and resistance to head scab forcereal crops in Triticeae. Twenty-six species and six varieties were involved in this genus.They are mainly distributed from the Pamir and Qinghai-Tibet plateau to the Karkorum,Altai, Tianshan, and Qilian mountain ranges at altitudes of about 1100～5100 m. However,the taxonomic treatments of Kengyilia species have been unstable from time to time.Nevski and Tzvelev combined a number of these species into Elytrigia sect. Hyalolepis.Keng and Chen classified them as Roegneria sect. Paragropyron. Love combined thespecies into Elymus sect. Goulardia. Chen et al. and Yang et al. transferred the species ofRoegneria sect. Paragropyron to Kengyilia. Since then, the new species of Kengyilia willbe constantly discovered and new combinations will be combined to this genus. Cai andZhi treated morphologically K. melanthera and K. melanthera var. tahopaica as K.thoroldiana var. melanthera and K. hirsuta var. tahopaica, respectively. Subsequently theysystematically coordinated the species of Kengyilia and carried out the phylogeneticanalysis according to the morphological characters. However, the treatment of somespecies and the circumscription of the genus were different from previous scholar'sopinions. Some grass researchers still included these species in Elymus L.. Therefore, thetaxonomic status, circumscription and the interspecific relationships of the Kengyiliaspecies are still under discussion.In order to inspect the genetic diversity and to investigate the interspecific relationshipin Kengyilia, Giemsa-C banding, gliadin analysis, esterase isozyme analysis and ITSsequences analysis were carried out. The main results showed as follows:(1) 5 accessions of Kengyilia were analyzed by Giemsa-C banding technique.Results indicated that the species of Kengyilia had different C-banding patterns. K. gobicola had distinct centromeric bands and no banded chromosomes. While K. hirsuta, K.longiglumis, K. rigidula and K. thoroldiana hand more abundant and disgnostic C-bandswith interstitial and terminal bands, which indicated they had close affinities.(2) The gliadin pattern of 35 accessions of Kengyilia was analyzed by using acidpolyacrylamide gel electrophoresis. The follows results are obtained. A total of 59 bandsare detected in all accessions, the bands ranged from 7 to 34 in each accession, 100% arepolymorphic bands. The Nei's genetic similarity coefficient of the tested accessions rangedfrom 0.537 to 0.905, and the average Nei's coefficient was 0.368. 35 accessions ofKengyilia can be clustered into three groups at GS=0.721 level on dendrogram. The firstgroup comprised of K. longiglumis, K. thoroldiana, K. kokonorica, K. stenachyra, K.grandiglumis, K. rigidula, K. mutica, K. melanthera, K. melanthera var. tahopaica and K.hirsute and the second group comprised of K. nana, K. alatavica, K. batalinii and K.kaschgarica. The third group included three accessions of K. gobicola. The principalcoordinates reflectes almost the same relationships among the studied materials as shownin cluster analysis. Morver, the speices from the same origin frequently or neighboringgeographical regions cluster together. Distinct genetic differences and extensive geneticdiversity were present among the population, the genetic variation among the differentspecies were more abundant than that of the different accessions. The tidings implied acorrelation betwwen gliadin pattems and geographical distribution.(3) The esterase isozyme of 28 accessions of Kengyilia was analyzed by usingpolyacrylamide gel electrophoresis. There are 19 bands with different migration rate, eachaccession with 2～8 bands. The Nei's genetic similarity coefficient of the tested accessionsranged from 0.427 to 0.805, and the average Nei's coefficient is 0.616. The cluster analysisand principal coordinates analysis showed that: there existed extensive genetic diversityamong the 28 species. These species can be clusterd into four groups, and the first groupcomprised of K. mutica, K. stenachyra, K. longiglumis, K. grandiglumis, K. kokonorica, K.rigidula. The second group comprised of K. hirsuta, K. melanthera and K. melanthera var.tahopaica, the third group included only one species K. alatavica. And the forth groupcomprised of K. batalinii, K. tahelacana, K. gobicola, K. nana and K. kaschgarica. Thespecies from the same origin or similar and the species with similar morphological chararcters frequently clustered together, which suggested that they had close relationships.The results were consistent with the conclusion from gliadin patterns.(4) The results of direct sequencing of PCR products and sequencing by cloning PCRproducts of the internal transcribed spacers and the 5.8S coding reions of nuclear ribosomalDNA in Kengyilia were compared and phylogenetically analyzed. The results show thatITS sequences are of existed differences between the direct sequencing of PCR productsand sequencing by cloning PCR prdoducts. The phylogenetic relationship in Kengyiliaspecies based on sequences by cloning PCR products was consistent with the analysis ofmorphology, geographical distribution, cytology and molecular markers. K. tahelacana, K.batalinii and K. goicola species clustered into one group, which suggested a closerelationship. While K. kokonorica, K. hirsuta, K. grandiglumis, K. zhaosuensis, K. mutica,K. rigidula and K. melanthera species clustered another group, inferring a closerelationship among them. The results manifested geographical polarization in Kengyiliaspecies. Therefore, phylogenetic analysis carried out by sequencing of cloning PCRproducts is more credible than that inferred from direct sequencing of PCR products.
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