Zhang Xinquan

Cytogenetic and systematic analyses of Kengyilia gobicola, K. zhaosuensis and K. batalinii var. nana (Poaceae)

Kengyilia batalinii var. nana J.L. Yang, Yen et Baum, K. gobicola Yen et J.L. Yang, K. zhaosuensis J.L. Yang, Yen et Baum are short-lived perennial grasses of the family Triticeae distributed throughout the upper and middle mountain ranges of west China. They were cytogenetically studied with testers R. kamoji Ohwi (StStHHYY) and K. hirsuta (Keng) J. L. Yang, Yen et Baum (PPStStYY). Analysis of metaphase I pairing configurations in the F1 indicate that K. batalinii var. nana, K. gobicola, K. zhaosuensis possess the P, St, and Y genomes, with o nly minor structural rearrangements. These results showed that the three target taxa are good species in the genus Kengyilia.Kengyilia batalinii var. nana J.L. Yang, Yen et Baum, K. gobicola Yen et J.L. Yang, K. zhaosuensis J.L. Yang, Yen et Baum are short-lived perennial grasses of the family Triticeae distributed throughout the upper and middle mountain ranges of west China. They were cytogenetically studied with testers R. kamoji Ohwi (StStHHYY) and K. hirsuta (Keng) J. L. Yang, Yen et Baum (PPStStYY). Analysis of metaphase I pairing configurations in the F1 indicate that K. batalinii var. nana, K. gobicola, K. zhaosuensis possess the P, St, and Y genomes, with o nly minor structural rearrangements. These results showed that the three target taxa are good species in the genus Kengyilia.

Genetic variation and relationship in orchardgrass (Dactylis glomerata L.) germplasm detected by SSR markers

Genetic variation and relationship of 53 accessions of D. glomerata collected from 5 continents were analyzed using simple sequence repeat (SSR) molecular markers with 15 SSR primer pairs. The following results were obtained. (1) A total of 127 alleles were detected at 15 loci. The number of alleles per locus ranged from 5 to 12, with an average of 8.5. The rate of polymorphic sites (P) was 95.21%; the polymorphic information content (PIC) ranged from 0.30(A04C24)to 0.44(A01F24) with an average of 0.36. (2) The genetic similarity (GS) among all accessions ranged from 0.43 to 0.94, for all geographical groups GS ranged from 0.73 to 0.91, and high genetic diversity was observed in Asia (P, 90.55%) and Europe (P, 86.61%) groups. These results suggested that there was rich genetic diversity among all orchardgrass accessions tested. (3) Based on the cluster and principal component analyses, 53 accessions could be divided into five groups according to the nearest phylogenetic relationship, and accessions from the same continent were classified into the same group associated with their geographical distributions.

Plant Community Characteristics of Trampling Disturbance Kobresia humilis Community along the Road in Naqu,Tibet

The change of plant community character during recovery succession processes of high mountain meadow in Naqu, Tibet, was investigated. The results show that there are 41 plant species in the inventoried quadrates. The high-plants in four big families plays important roles in natural vegetation recovery, whileKobresia play an important role in climax communities. The plant species components changed with each succession stage. The plant species were mainly annual and biennial during the early succession stage, and perennial during the medium; and dominated byKobresia humilis during the late.Potentilla bi furca andPotentilla tanaletfolia were both found in all stages. The accumulated number of family, genus, and species during the succession process varied quadric with the stages. The main plant community characteristics varied logistically with the succession stages except the height. The community characteristics mainly affected by dominant species which were changed in same rhythm. The biomass under ground was far more than the upground. The plant diversity inflated in the medium stage.

Clonal Structure and Clonal Diversity of Hemarthria compressa Based on SRAP Markers

The clonal diversity and the spatial pattern in a natural population of Hemarthria compressa (L. f.) R. Br. was determined by means of SRAP. The clonal diversity indexes were respectively: number of samples N= 46, number of genotype G= 28, average number of clones Nc= 2.09, proportion distinguishahle PD= 0.48, cloned diversity of genotype Simpson’s index D= 0.957. The relative high clonal diversity of Hemarthria compressa was found in this population. The analysis of clonal structure demonstrated that there were mosaics among Hemarthria compressa clones, probably because of diverse clonal structure. The formations of Hemarthria compressa population included guerilla, phalanx and a transitional type.