The infrageneric phylogeny of Metagentiana, a newly erected genus in the Gentianaceae, was constructed based on the analysis of the nucleotide sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA of 10 representative species of this genus and 22 species of Gentiana, Tripterospermum and Crawfurdia. The analysis indicates that the genus Metagentiana is polyphyletic, because all sampled species of Tripterospermum and Crawfurdia are clearly embedded within Metagentiana. The species of Tripterospermum and Crawfurdia also did not cluster respectively as two monophyletic clades. These results do not merit status of three separate genera. However, these three genera clustered together as a monophyletic clade sister to Gentiana, which is in agreement with the previous conclusions on the separation of Metagentiana from Gentiana and its closer relationship to Tripterospermum and Crawfurdia based on studies of gross morphology, floral anatomy, chromosomes, palynology and embryology. The ITS sequences do not provide sufficient information to make a robust estimation of the phylogenetic relationships among dysploid cytotypes of x=17, 21 and 23, within the Metagentiana, Tripterospermum and Crawfurdia complex, but the preliminary results seem to indicate their reticulate and paralleling evolution.

The topological effect of the Qinghai-Tibet Plateau during the Quaternary climatic oscillation must have important effects on the patterns of spatial distribution and genetic structure of organisms distributed there. To obtain a better understanding of the historical dynamics of present-day species in this region, we examined the population structure of chloroplast trnT-trnF sequence variation in Juniperus przewalskii, an endemic tree species mainly distributed in the northeast plateau. Data were obtained for 392 trees from 20 populations covering the total distributional range of the species. Three cpDNA haplotypes were recorded and were structured into two geographical areas: haplotype A was present on the plateau platform, while all three haplotypes occurred along the plateau edge. Total genetic diversity, HT, was 0.511, with most variation distributed among rather than within populations (GST=0.847). Along the low altitudinal plateau edge, haplotypes A, B and C tended to be fixed or nearly fixed in different populations, indicating that the species may have survived the last glacial period in different refugia within this area, and the bottlenecks due to the repeated reduction and expansion of the population size resulted in the reduction of biodiversity. However, in one population both haplotypes occurred at intermediate frequencies, indicating the possibility of a contact zone or less strong bottleneck effect. On the eastern plateau platform, haplotype A was commonly fixed in the current disjunct populations, suggesting a common postglacial recolonization and a following founder effect. Our results indicate that there might exist in multi-glacial refugia in the plateau edge and both bottleneck and founder effects resulting from the repeated climatic oscillation combined had played important roles in shaping the current haplotype distribution pattern of this tree species.

The developmental pattern of stigma in flowering plants has been little studied though it plays an important role in pollen capture. An unusual developmental pattern of stigma was observed in three Aquilegia species (Aquilegia yabeana Kitagawa, A. ecalcarata Maxim. and A. incurvata P. K. Hsiao) with scanning electron microscopy and fluorescence microscopy. The stigmas of Aquilegia flowers were on the ventral sides of the styles, and developed into stigmatic papillae by cells along the ventral slits. During anthesis the receptive surfaces matured in a sequence from the apical towards the basal ends of the styles, and posed for pollinators gradually through the style movement of recurving. Such a developmental pattern may enhance reproductive success by the prolongation of stigma receptivity under the unpredictable pollination environments.

The linear leaves of three species in the genus Taxodium Rich., T. distichum (L.) Rich., T. ascendens Brongn., and T. mucronatum Tenore., are amphistomatic or hypostomatic. Stomatal band comprises 4-8 lines of stomata on each side of the midvein on the abaxial surfaces of the leaves. The numbers of stomata are stable on the middle parts of the abaxial surfaces of the leaves, and decrease toward both tip and base of the leaves. On the adaxial surfaces the stomatal band comprises only 1-4 lines of stomata and sometimes no stomata were observed. In the non-stomata areas the epidermal cells are oblong and parallel to the long axis of leaves, and the anticlinal walls of epidermal cells are mostly straight or sometimes undulate. Epidermal cells on areas with stomata are polygonous. Stomatal apparatuses are oval, and the long axes of stomata are mostly perpendicular or oblique to the midvein. Guard cells have thickened walls, forming polar lamellae at the polar end. The stomatal density and index of T. distichum, T. ascendens and T. mucronatum exhibits significant differences. The stomatal density and index of T. distichum from different localities show no statistically significant differences. The coefficient of variability of the stomatal index is smaller than that of the stomatal density, suggesting that the stomatal index is more reliable than stomatal density when it is utilized to study the correlation between stomatal parameter and atmospheric CO2 concentration.

A comparative study of meiosis of pollen mother cells in Manglietia patungensis Hu and its closely related species M. yuyuanensis Law was carried out. These two species had the same chromosome number of 2n=38 and the same karyotype, but their chromosomal behaviors in meiosis were different. In M. patungensis, the typical chromosome configurations observed at metaphase were 2n=0.30IV+18.33II+0.15I, whereas those in M. yuyuanensis were 2n=19II, indicating that some chromosomes in M. patungensis might have undergone inversion and that some chromosome components were possibly paracentric inversion heterozygotes. The abnormal rate of chromosomal behaviors at anaphase I and II was different in the two species. At anaphase II, 8.8% cells were observed with lagging chromosomes which in each cell did not exceed two in M. yuyuanensis, but in M. patungensis, 29.2% cells were observed with lagging chromosomes which could reach 11 in each cell. Additionally, broken chromosomes were observed in M. patungensis. The above results indicate that the abnormal rate of chromosomal behaviors in the meiosis of M. patungensis was higher than that in M. yuyuanensis. The abnormal behaviors of the chromosomes in meiosis observed in M. patungensis may have affected the development of pollen grains in this species.

Four populations of Streptopus simplex (Liliaceae) from western and northwestern Yunnan Province, China, were investigated cytologically. The chromosome count of the two populations growing in spruce forests from Bitahai and Xiaozhongdian, Shangri-La County (formerly Zhongdian County), northwestern Yunnan, was 2n=16 with x=8, confirming the previous counts for this species, but the count of the two populations growing in alpine scrubs, one from Pianma, Fugong County, and the other from Gongshan County, both of western Yunnan, was 2n=14 with x=7, which represents a new count for the species and a new basic number for the genus. The karyotypes of the two populations from Shangri-La were formulated as 2n=4m+8sm+4st and 2n=8m+2sm+6st, respectively, with the chromosomes changing in size gradually from the largest to the smallest one, and those of the other two populations were formulated as 2n=14=4m+10sm, and 2n=14=7m+7sm, respectively, with the first pair of chromosomes being median-centromeric (m) and markedly larger than the remaining ones. As the basic chromosome number of x=8 is the commonest one in the genus Streptopus, this might be considered as the original number whereas the number of x=7 the advanced one. The presence of one pair of much larger chromosomes yet one less pair of smaller subterminal-centromeric (st) ones in the chromosome complement of the x=7 populations suggest that this number may have been derived from x=8 through the Robertsonian fusion of centromeres.

Chromosome numbers and ploidy levels of 14 Chinese Populus species (Populus alba L., P. hopeiensis Hu & Chow, P. tomentosa Carr., P. tremula L., P. simonii Carr., P. maximowiczii Henry, P. ussuriensis Kom., P. cathayana Rehd., P. pseudo-simonii Kitag., P. koreana Rehd., P. trichocarpa Torr. & Grog., P. lasiocarpa Oliv., P. nigra L., P. euphratica Oliv.), three varieties (P. alba L. var. pyramidalis Bge., P. nigra L. var. thevestina Bean., P. nigra L. var. italica (moench.) Koehne) and three hybrid species (P. ×xiaozhuanica W. Y. Hsu & Liang, P. ×beijingensis W. Y. Hsu, P. ×canadensis Moench, P. ×canadensis Moench cv. “serotina”, P. ×canadensis Moench cv. “Sacrau 79”, P. ×canadensis Moench cv. “I-214”) are reported. These taxa represent five sections of the genus. P. tomentosa of section Populus and P. ×canadensis Moench cv. “Sacrau 79”, P. × canadensis Moench cv. “I-214” of section Aigeiros were triploid (2n=2x=38), while the remaining taxa were diploid (2n=2x=38).

Chromosome numbers of 13 taxa and 12 crossing combinations in the Magnoliaceae are reported. The counts of 12 taxa are reported for the first time. The intergeneric crossing combination between Magnolia×soulangeana “Hongyuanbao” (♀), a tetraploid with 2n=4x=76, and Michelia yunnanensis (♂), a diploid with 2n=2x=38, had the number of 2n=3x=57, a half of the total chromosome number of its parents. Similarly, the intergeneric crossing combination between Magnolia×soulangeana “Hongyuanbao” (♀) and Michelia foveolata (♂), a diploid with 2n=2x=38, also had the number of 2n=3x=57. These indicate that the offspring of the two crossing combinations are true hybrids.

Meeboldia (Umbelliferae) is treated as a genus including only two species, i.e. M. yunnanensis and M. achilleifolia.

Desmodium diffusum DC. has usually been included in D. laxiflorum DC., but they are two distinct species. The former is widely distributed in China, while the latter is found only in southern China, i.e., Guangdong, Guangxi, south Yunnan, and rarely in Taiwan. D. unibotryosum C. Chen & X. J. Cui was once applied to the former as a new name, but this name is illegitimate. The taxonomic history of Desmodium diffusum and D. laxiflorum, key to these species, their bibliographies, synonyms and distributions are clarified. The lectotype of D. diffusum is designated.

Sinojackia oblongicarpa C. T. Chen & T. R. Cao is reduced to the synonymy of S. sarcocarpa L. Q. Luo.

The publication date of four names of Lauraceae including Machilus polyneura Chang, Machilus shiwandashanica Chang, Machilus cathayensis Chun ex Chang, and Beilschmiedia furfuracea Chun ex Chang is discussed. These four names were validly published in 1963 but not in 1960.

Kadsura coccinea (Lem.) A. C. Smith is reported as new record to Indonesia, K. induta A. C. Smith as new record to Guizhou of China and K.oblongifolia Merrill as new record to Vietnam, and Fujian and Taiwan of China. The description on carpels and fruit of K. induta is amended. As the holotype of K. hainanensis Merrill and that of K. oblongifolia have been found to be well preserved at PNH, their lectotypes should be superseded.

Prenanthes henryi Dunn (=Notoseris henryi (Dunn) Shih), described from mixed specimens, is lectotypified.

In this paper we presented a review of the advances in the studies of breeding system and pollination biology of gingers. The Zingiberaceae is a large family of animal-pollinated pantropical monocotyledons with more than 1500 species in ca. 50 genera. There are many kinds of sexual variations occurring in the ginger family, such as gynodioecy, andromonoecy, flexistyly, protandry and self-incompatibility. Major pollinators include bees, hawkmoth, butterfly and birds, and different pollinators correspond with different morphological characteristics of flowers. Among the relatively few studies on the pollination biology, members of this family display some unique pollination mechanisms and breeding systems. Flexistyly, found in the genera of Amomum and Alpinia, is regarded as a unique behaviour mechanism that encourages outcrossing; a new self-pollination mechanism has been discovered in Caulokaempferia coenobialis, in which a film of pollen is transported from the anther by an oily emulsion that slides sideways along the flower’s style and into the individual’s own stigma. These studies and discoveries give us a better understanding on the diversity of pollination and breeding systems of gingers. For future research, we suggested that more studies should be carried out on the pollination and breeding systems of gingers in a wider range, and phylogenetic research should be conducted to understand the evolution of pollination and breeding system in Zingiberaceae, and for the flexistyly, more detailed studies should be done about this unique sexual polymorphism.