Natural hybridization between Salix matsudana and Salix cavaleriei was investigated based on populations from Yunnan, China. Field observations revealed that the putative hybrid, S× heteromera had intermediate morpho
logies between Smatsudana and S. cavaleriei. This was further confirmed by principal component analysis. Sequence data of nuclear rDNA internal transcribed spacer region showed both intraspecific and intragenomic polymorphisms in all the three species, and S× heteromera showed a strong additive pattern between its suspected progenitors at all nucleotide sites of the genotypes identified. Therefore, S× heteromera was confirmed to be a natural hybrid between Scavaleriei and Smatsudana. Flow cytometry analysis indicated that all the three species are tetraploid, and the hybridization was homoploid. Sequence data from four chloroplast datasets indicated that the hybridization was asymmetric, with Scavaleriei as the maternal parent. The hybridization between the exotic common species Smatsudana and native rare species Scavaleriei might increase the risk of endangerment and even extinction, indicating that the introduction of Salix species should be made very cautiously.

Despite the general rarity of femalesterile reproductive systems, male flowers are widespread in Liliaceae. Nomocharis (Liliaceae) consists of ca. seven species which have been traditionally classified as hermaphrodite. However, our preliminary investigation suggested that male flowers may occur frequently in this genus. We got data of the flower sex phenotypes, flower size, plant height and altitude by observing and measuring specimens of Nomocharis from several herbaria (PE, KUN, HITBC CDBI) in China, and then used them to determine the sex distribution and to analyze the relationships between plant size and flower size, sex expression. We found that male flowers occurred in all six studied Nomocharis species and different combinations of hermaphroditic and male flowers at plant level resulted in complex sex expression. Of four further studied species, male plants were significantly smaller than plants with hermaphroditic flowers in three species. Plant height, which was not related to altitude, but not sex phenotype has significant effects on flower size. The number of total flowers and hermaphroditic flowers per plant increased with plant size. However, the number of male flowers was independently of size. Our study suggested resources availability (ie. plant size) determined the sex phenotypes of individuals. We highlighted the occurrence of male flowers in genus Nomocharis and suggested further field studies are absolutely necessary. Furthermore, this study provides a case study to better use herbarium specimens as prerequisites for field researches of floral sexual diversity.

 Rhododendron cyanocarpum is a narrow endemic species with pink and white floral color. In the present study, to investigate the significance of petal color morphs, we examined color morph frequencies, petal color reflectance and other associated floral characters, effective pollinators, visitation frequencies, and fruit production in the field. In all surveyed known populations, plants with pink color morph dominanted and comprised 77%-100% of individuals. Two peaks at 430 nm and 650 nm were found in the petal color reflectance of pink flowers, and only one peak at 430 nm was found in the reflectance spectrum of white flowers. In addition, color morphs were also associated with colors of style and stigma, lengths of corolla, calyx and pedicel, the closest distance between stigma and stamen, but not with style length and nectar production. Moreover, higher visitation frequency of their shared pollinators (bumblebees) and fruit production were observed of pink flowers than white flowers. Despite a briefly temporal and spacial study, we suggest that color morph frequencies, visit frequencies of bumblebees and fruit production, all favor to be stablilizing selection for the pink color morph.

The levels of genetic diversity and population structure were assessed for 104 ancient tea plants from three Camellia taliensis populations, three Csinensis var. assamica populations and two transitional populations of Ctaliensis based on data from 11 nuclear microsatellite loci. In this study, a relative low genetic diversity was revealed for all three population groups. The average number of alleles (Na) was 485, the average Shannon’s diversity index (I) was 117, the average expected heterozygosity (He) and observed heterozygosity (Ho) was 059 and 052 respectively, for the studied populations. The level of genetic diversity of Ctaliensis was lower than for Csinensis var. assamica and the transitional Ctaliensis. An AMOVA analysis indicated a significant genetic differentiation (FST=0305) between populations of Csinensis var. assamica and Ctaliensis. Most of the genetic variation was partitioned within population of Csinensis var. assamica (9351%) and Ctaliensis (8941%), and a low partition among populations (649% and 1059%, respectively). Populations of Csinensis var. assamica and Ctaliensis (including the transitional populations of Ctaliensis) formed two distinct genetic clusters in a principal component analysis (PCoA) and in STRUCTURE clustering, which suggests that the transitional populations of Ctaliensis originated mainly from Ctaliensis, and then followed somewhat genetic differentiation during the process of domestication. Gene introgression was detected in the cultivated Csinensis var. assamica and Ctaliensis from the same tea garden, and genetic material of Ctaliensis apparently infiltrated into Csinensis var. assamica. This study demonstrated that Ctaliensis was genetically involved in the domestication of Csinensis var. assamica. Finally, suggestions on how to protect the genetic resources of ancient tea plants are discussed on the findings in this study.

After analysis, statistics and conclude 1175 species (variety) of plants,1370 Dai names and 1691 meanings were obtained to elucidate how the Dai people recognize and define the plant. They used ‘hongebin’, which means‘the things with life come out from the ground’ to define the plant. This is similar to the modern science which defined the plant as ‘anything that grows from the ground’. This is a highly synthesized scientific term that seldom seen in many other ethnics in the world. In their method of naming plants, they used the types of plant lifeform and economic type for ‘generic’ names, and used the meanings of plant morphogenesis and characters, economic uses, ecological distribution, and stories and legends etc. for ‘specific’ names. Among the 1691 meanings, they are occupied 60%, 30%, 8% and 2% respectively. This reflected that the naming method of Dai for plant ‘Just see what′s looking alike on naming them’ is similar to Linnaeus′ binomenclature of the modern botanical taxonomy. Moreover, the folk plant classification system based on the structure of Dai names is then established, including 5 categories as plant kingdom, tow ‘families’ of wild or cultivated plant, about 20 ‘genera’ of lifeforms and economic types, and more than 3000 species and over 1000 varieties, by the ‘two names’ in the paper as well.

The heat stress associated with extremely and moderately high temperatures affects a series of physiological activities in plants especially photosynthesis. However, it is proposed that the plants use different photosynthetic strategy to deal with extreme and moderate heat stresses. Most reports focus on the cold tolerant ability but thermotolerance of alpine plants. In the present study, we used the alpine plant Arabis paniculata as a model alpine plant to examine whether its capacity for heat tolerance is exhibited under moderate heat stress and, if so, how this capacity is related to differences in its photosynthesis compared with that of its close relative Arabidopsis thaliana. We found that Apaniculata had high photochemical efficiency at a moderately high temperature and a rapid reversible recovery process, which reflected substantial heat tolerance. Despite no obvious difference in F0 between the two species, the higher Fm values after heat treatment and recovery in Apaniculata than in Athaliana facilitated the rapid photochemical recovery. A rapid and transient increase in nonphotochemical quenching after moderate heat stress provided timely protection for PSII against the damage caused by heat and light. The rapid accumulation of heat shock protein 101 upon exposure to moderately high temperatures might initiate photochemical repair. Finally, the high rate of survival of Apaniculata after severe heat treatment attested to the substantial heat tolerance of its photosynthetic machinery under moderate stress. Our results indicated that a highly heattolerant photosystem and effective photochemical repair mechanism contribute to the capacity of Apaniculata to tolerate moderate heat stress.

The members of the genus Cymbidium are important ornamental flowers. Most species of this genus prefer to grow on the shady places of the forest floor, while epiphytic Ctracyanum can grow well in the presence of direct sunlight. To explore the physiological mechanism underlying the adaptation of Ctracyanum to high light, we used terrestrial Csinense as the control, and measured the chlorophyll fluorescence and P700 redox state in those two species grown at two different light regimes. Our results showed that the activities of photosystem I and II in Csinense under high light decreased more strongly than those in Ctracyanum. The activation of cyclic electron flow (CEF) in Ctracyanum under high light could serve as a main mechanism of photoprotection. However, the weak of CEF in Csinense limited its adaptation to high light. Since epiphytic habitats may suffer more intermittent direct sunlight than understory, the strong adaptability of Ctracyanum to high light may contribute to its utilization of light energy in epiphytic habitats.

 This paper studied desiccation tolerance and optimal storage methods of Podocarpus nagi seeds and achieved the following results: Podocarpus nagi seeds were desiccation sensitive and recalcitrant, with an initial moisture content of (35 ± 07)% and a critical moisture content of (1686 ± 073)%; both moist storage and partiallydried storage can be applied to shortterm conservation of Podocarpus nagi seeds in practice, and storage at 4℃ produced better results than that at 15℃, but storage at subzero temperature was lethal no matter what seed moisture content was; In the partiallydried seed storage experiment, the undried seeds (the control) had no obvious viability decrease during 6months’ storage duration at 4℃ but seeds at critical moisture content had higher viability than those at other moisture contents after 9months storage; no matter what media moisture content was used, and whether stored at 4℃ or 15℃, 9months’ moist storage did not reduce Podocarpus nagi seed viability while seeds stored at 15℃ had significantly higher viability than those at 4℃ when storage expanded to 12 months, but some of these seeds were found germinating during 15℃ storage at the third month, and more and more germinated seeds there were as media moisture content and storage duration increasing; 2h flash drying to moisture content 7% let more than 90% excised embryos survive freezingthaw treatment and oneyear’s cryostorage made no difference to their post thaw survival, indicating that it is feasible to cryopreserve Podocarpus nagi. These findings can be referred to short and longterm conservation of recalcitrant seeds.

Arbutin was widely used in cosmetics as a whitening agent because of blocking the synthesis of melanin as the inhibitor of tyrosinase. Arbutin synthase (AS) as one member of UDP glycosyltransferases (UGTs) which belongs to the glycosyltransferase (GTs) family is a ratelimiting enzyme in arbutin synthesis from hydroquinone. To reveal the biological function and provide scientific basis of application on plant genetic engineering for Vaccinium dunalianum arbutin synthase (VdAS), a gene VdAS1 encoding VdAS1 was isolated by RTPCR combined with RACEPCR from Vdunalianum. The fulllength cDNA clone comprised 1577 nucleotides consisting of a 17nucleotide 5′untranslated region, an open reading frame of 1428 nucleotides, and a 132nucleotide 3′untranslated region. The open reading frame encoded a putative VdAS1 comprising 475 amino acid residues with molecular weight of 5222kD. and isoelectric point of 574. The total numbers of negative charged residues (Asp+Glu) and positive charged residues (Arg+Lys) in VdAS1 were 53 and 45, respectively. VdAS1 shares 74% similarity with UGT in wolfberry (Lycium barbarum). It was predictive VdAS1 had no signal peptide and transmembrane structure. The main parts of predicted secondary structures of VdAS1 were ahelices and random coils. The study results established the foundation for the heterologous expression and functional analysis of VdAS1.

Used the random sampling and recommendation, 30 households of Mongolian in Horqin Juun Garon Country were selected to compare with 10 households of Han nationality which lives in the region of nearby. Forty sampling plots of homegardens were investigated. The results indicates that the perpendicular structure of homegarden plants in Mongolian and Han nationality can be classified to 0-1m, 1-2m, 2-5m, 5-10m, and higher than 10m. The perpendicular structure lower than 5m is predominance in both large and small homegardens. Comparing the cultivation pattern in two nationality, Mongolia still stay in the level of vegetable cultivation which  relaled to the daily life, the plants for view and admire are very few at present. But Han nationality have started attaching importance to the view and admire homegarden plants. Besides, this research applied the software MVSP to analyze the type of homegardens and indacates that the homegarden of Mongolian in Horqin Juun Garon Country have four categories, and Han nationality have three categories. The results indicate that  there are many differences between Mongolian and Han nationality. This is caused by the differences between the two nationalities in traditional farming culture, animal husbandry culture, the area of homegarden, the history of homegarden, the management of homegarden, and the traditional botanical knowledge on plant species utilization.

Forest transition is a process of overall forest cover from net loss to net gain over time. Forest transition especially the process after turning point from deforestation to reforestation has inspired lots of researches for its potential to improve environmental services. China has undergone forest transition since the 1980s. However, in tropical China, deforestation was still existed, while the overall forest cover increased greatly. To investigate this issue, we conducted this research by classifying overall forest into natural forest and plantation in Xishuangbanna, which has  undergone forest transition and deforestation and overall forest cover increasing. We found that natural forest continues decreasing while overall forest cover increasing and plantation expansion in forest transition. The forest transition in Xishuangbanna was found to be a tree cover transition, which was mainly contributed by large plantation expansion. In Xishuangbanna, deforestation is still undergoing after its overall forest cover transition occurred in 1988. The general overall forest definition used by forest transition will not be able to recognize deforestation when natural forests are displaced by plantations because the overall forest cover remains unchanged or even increasing. We therefore recommended to classify forest types in forest transition researches.

Atmospheric nitrogen deposition and human activities may enhance the nitrogen input into ecosystems, increase content of nitrogen in soil and reduce biodiversity due to promoting the growth of dominant species and decreasing spatial heterogeneity of environment. To study the relationship between the content of nitrogen in soil and tree diversity in Xishuangbanna tropical seasonal rainforest, we randomly setted 14 plots with each of 1ha, investigated the tree species richness, total soil nitrogen (TN), biomass of the foundation species (Parashorea chinensis) and the whole trees of each plot. Our study showed increasing content of total soil nitrogen will promote growth of dominant species, decrease niches for species coexistence and reduce tree diversity due to competitive exclusion. The study indicated that reducing anthropogenic nitrogen supply to ecosystems would play a vital role for protecting tree diversity in Xishuangbanna tropical seasonal rainforest.

Gentiana rigescens and Swertia mileensis belonged to Gentianaceae are endemic plants in China. Four iridoids (loganic acid, swertiamarin, gentiopicroside and sweroside) in Grigescens and Smileensis were determined by HPLCDAD. Their chemometrics characterizations were analyzed with multiple statistical analyses. The results showed that there were differences of chemometrics characterization of the iridoids between the two species. All the samples of Grigescens could be classified into four groups based on contents and percentage contents of the four iridoids. Content of loganic acid had significant negative correlation with longitude (R=-0348，P<005) and had significant positive correlation with altitude (R=0307, P<001). Longitude had significant negative correlation with content of swertiamarin (R=-0592, P<001) and had significant positive correlation with percentage content of sweroside (R=0245, P<005). However, content of gentiopicroside hadn’t correlation with geographical factors (P>005) in the study.