A new species of the genus Armeniaca, Rosaceae-A. xianjuxing J.Y.Zhang et Z.X.Wu was found. The distinction between A. xianjuxing J.Y.Zhang et Z.X.Wu and Armeniaca vulgaris Lam are both sides of leaves with sophie short hair, the length of pedicel or stalk is 1-1.2 cm，the petal margin is crenation or lobule, and the edge of calyx with small blunt sawtooth.

Based on examinations of specimens housed at HNNU, IBSC, KUN and PE, Ophiorrhiza aureolina Lo f. aureolina and O. luchunensis Lo are treated as new synonyms of O. subrubescens Drake.

The perichaetium structure and origin of component of perichaetium of Hepaticae was studied through morphology comparing and anatomy research. We divided perichaetium of Hepaticae into Calyptra type, Perianth type, Coelocaule-perianth type, Coelocaule type, Perigynium type, Involucre type and Carpocephalum involucre type for the first time, among them, the Calyptra type was the most simple one and was the original group in evolution, the Carpocephalum involucre type was the most complex type and was the top class of evolution. We also presented diagrammatic sketch of perichaetium evolution and Diagramm perichaetia for expressing the structure and component of perichaetium.

The chromosomes from root tips of Lilium leucanthum(Baker) Baker were analyzed by Giemsa C-banding. The result showed that, the karyotype is 2n=2x＝24, the banding number of one genome was 21.The C-banding karyotype would be: 2n＝24＝6C+2CI+2I+2CI⁺+2CI⁺+4I⁺+2I⁺+2T⁺+2I+S. Significantly different C-banding points were shown on each chromosome. Most of the strong bands of L. leucanthum were distributed on the centromeric regions of the chromosomes. Each chromosome of L. leucanthum(Baker) Baker can be distinguished by Giemsa C-banding.

Cyclorhiza peucedanifolia(Franch.) Constance （Apiaceae） endemic to China was karyo-morphologically studied.The result shows that its chromosome number is 22 and karyotype formula is 2n=22=10m+12sm. According to comparison this result with other cytological data of Apiaceae, it could be considered the classification of this species and C. waltonii in the same genus be reasonable and the genus Cyclorhiza be close to Vicatia DC in phylogeny.

The chromosome number of 10 species and karyotypes of 9 species of them in the genus Caragana from China were analyzed in this paper, and the results are as follows: C. roborovskyi, 2n＝16＝10m(2SAT)+6sm; C. erinacea, 2n=16=10m+6sm; C. densa, 2n=16=10m（2SAT）+6sm; C. acanthophylla, 2n=16=12m+4sm; C. stipitata, 2n=16=10m+6sm; C. opulens, 2n=16=12m(2SAT)+4sm; C. leucophloea, 2n=32=22m(4SAT)+10sm; C. camilli-schneideri, 2n=32=20m(4SAT)+12sm, C. tragacanthoides, 2n=32=20m(2SAT)+10sm+2st+2B. For two populations of C. licentiana, only chromosome numbers are reported here, both with 2n=4x=32, being tetraploid. From the results we inclined to suppose that the karyotype of chromosomes in Caragana is not so much differentiated, and if differentiated it always follows by some morphological characters. The diploid and tetraploid are the main ploidy level of this genus, with 2n=16 (diploid) or 2n=32(tetraploid). Triploid was found only in C. sinica, and hexaploid was seen only in C. ussuriensis. Those species with diploid chromosomes mostly are pinnate-leaved, and are mainly distributed in Estern Asia where probably is the genus’ ancestral areal, but those species with tetraploid chromosomes are majorly with digitate leaflets, and incline to adapt to desert areas in Northwestern China.

The leaf epidermis of 16 species and 1 variety of Astragalus subgenus Pogonophace was investigated by the light microscopy (LM) and partially by the scanning electron microscopy (SEM). The result shows that the stomatal apparatus of these species are present in both abaxial and adaxial epidermis. It is shown that the leaf epidermal cells are polygonal or irregular in shape. The patterns of anticlinal walls are straight, sinuous or sinuate. Based on the shape and the anticlinal wall patterns of the epidermis cells, there are four types of epidermis can be recognized. The four epidermis types are consistent with the sections of Pogonophace to some extent but not all. Under SEM observation, because of the cuticular layer of the leaf epidermis, the stomatal appatatus is at a lower place. The outer stomatal rim and its inner margin of these species are almost the same. In a few species, the cuticular layer of the leaf epidermis has a special appearance. Therefore, this character can be used as a criterion to identify these species in Pogonophace.

The epidermal structures of the six species of Coniogramme in Hemionitidaceae were investigated under light and scanning electron microscopes.The results indicate that: There are no trichome on both upper and lower epidermis of leaves in the six species; There are 7 types of stomatal apparatus(Polocytictype, Axillocytictype, Aisocytictype, Anomotetracytictype, Copolocytictype, Coaxillocytictype and Anomocytictype), the components of stomatal apparatus are polymorphic, all the stomatal apparatuses only occur in the lower epidermis, no caved in; Their epidermal cells are irregular, anticlinal walls undulate or sinuate. The six species of Coniogramme are different in the size of cell of leaf epidermis, the size of stomatal, Stomatao density and Stomatal index.These provide evidences for systematics of Coniogramme.

The ethylene mutants of Arabidopsis thaliana, including ein2-5, ein3-1, EIN3ox, EIL1ox and wild type Col-0 were conducted to investigate the morphological difference in control and drought stress. It is demonstrated that the rosette leaf diameter, leaf area, inflorescence, water potential of four ethylene mutants and A. thaliana wild type were significantly different under the conditions of drought stress, so were the morphology adaptation features of the mutants. These results indicate that ethylene is actively involved in shaping the plant morphology, and has a close correlation with plant drought-resistance.

Light responsive curve models have been widely used in plant physiological studies. However, most of the researchers emphasize their study aims, ignoring the practicability of the used models to their special plant materials. In this paper, 7 different light responsive curve models were compared to investigate the fitted effects using birch(Betula platyphylla Suk.) and larch(Larix gemelinii(Rupr.)Rupr.). The fitted results using the different models for the same species were different. Furthermore, the fitted results using the same model for the leaves of different parts of the same species were different also. These results indicated that it is necessary to consider the practicability when a model is used to a selected plant species and the optimal model is essential to ensure the accuracy of the estimated physiological parameters.

The Iris deal with NaHCO₃ of different concentrations solution, In order to study Iris leaf membrane permeability, soluble protein and lipid peroxide content changes. In this experiment, 1-year-old Iris seedlings is the study object. According to the measurement of cell membrane permeability, MDA, SOD, POD, the soluble protein and other indicators, the response and adapt ability of Iris deal with NaHCO₃. The result shows that: with more NaHCO₃ concentration and increasing stress time stress, the content of Iris leaves soluble protein influenced by NaHCO₃ salt stress tends to totally decline after the first prompt; on the 30^th day, the content of Iris soluble protein with the stress of 0.4% and 0.6% concentration increases by 21.7%, 38.6%, respectively more than those of contrast; membrane permeability of Iris leaves slightly declines in the condition of NaHCO₃ salt stress; during the 10^th day and the 20^th day, membrane permeability has a rapid increase. on the 20^th day under NaHCO₃ press, the POD activity has reached the maximum, by 32.1%,13.8% and 29.5% respectively, compared to control; with the same salt stress and time extension of salt press, SOD activity first increases and then decreases; on the 30^th day, as the product of membrane lipid peroxidation, the content of MDA in Iris leaves at 0.6% concentration accumulates dramatically, along with the increase in salt concentration and salt stress time. Based on the above analysis, there is salt(NaHCO₃)-stress resistance ability in Iris which is the important saline-alkali plant. Therefore, the study provides powerful evidence of salt-stress resistance in Iris, which strengthen the theoretical basis that Iris should be applied to the saline-alkali field control.

For a deep study on the characters of starch phosphorylase(SP) as well as its physiological effects during starch metabolism, the optimum extractive techniques and measurement conditions of SP in the bulb of Lilium davidii var. unicolor were ascertained, furthermore, some biochemical nature of this enzyme were preliminarily studied in this experiment. The results indicated that the best extractive buffer was succinic acid solution with pH 5.8. The optimal reaction system comprised 25 mmol·L^-1 Glc-1-P as substrate, and incubating for 10 min at 30℃. Within the pH scale from 5 to 6, SP presented higher activity. However, SP in lily bulb couldn’t be reserved for a long time and couldn’t sustain higher temperature. Stored for 12 hours at 4℃, SP activity only remained 50%, and almost lost completely after incubating for 30 min at 40℃.

Using scanning electron microscopy techniques to observe the leaves surface of Alnus mandshurica and find it far axial epidermis with peltate glandular hairs. It made up of two-cells,four stem cells and 20～25 head-cells,with the accumulation of secretion material,cells rupture,finally disappear. Theree is no peltate glandular hairs far axial epidermis, in young leawes only has stoma distribution. The cross section of A. mandshurica leaves showed it belongs to bifacial leaf, cells of far axial epidermis with peltate glandular hairs connect with leaf vein vascular tissue, the author consider this peltate glandular hairs shoule belong to “Peltate glandular hairs”, and suggest that the nouns of “Glandular scales”,“Peltate gland”,“Peltate scale”,“Peltate glandular hairs” should be normalized.The process of shields-glandular in A. mandshurica leaf epidermis and the component of secretion material need to be further studied.

We assessed how Neotyphodium infection influenced the photosynthetic characteristics of three natural populations of Achnatherum sibiricum, one of the main resources of forage in Inner Mongolia Steppe. We used the Licor6400 apparatus to measure the parameters including photosynthetic rate (P_n), transpiration rate (T_r), stomatal conductance (G_s) and intercellular CO₂ concentration (C_i). Some environmental parameters such as photosynthetic available radiation (PAR) and air temperature (T_a) were automatically recorded. We also obtained the light response curve under a gradient of controlled PARs. The results showed that in Leymus chinensis plot of the IMGERS-CAS population and Xi Ujimqin Qi population, the diurnal average photosynthetic of E+ plants were significantly higher than those of E- plants, but in Hulingol population the difference was not significant. The effect of Neotyphodium on photosynthetic might have some correlation ship with the water condition of the local habitat. In lower water availability habitats, the endophytes tended to increase the photosynthetic ability of the host plants, while in higher water availability habitats, the endophytes had no significant contribution. In each population, the T_r, G_s, C_i, LUE(light use efficiency) and WUE(water use efficiency) were not significantly different between E+ and E- plants. The decrease of mid-day P_n was caused by non-somatal factors, and has nothing to do with the endophytic infection.

Culture conditions for embryogenic callus induction from immature zygotic embryos of Picea koraiensis were studied. The effect of basal medium, light conditions, collection period of immature seeds on induction rate of embryogenic callus were compared through L₁₆(4²×2) mixed level orthogonal experiment, subsequently culture temperature optimization experiment were also performed. The results were as follows: the optimal basal medium and culture conditions were improved RJW medium, dark culture, zygotic embryo collection date of July 20, culture temperature of 22 ℃。The highest embryogenic callus induction rate(81.3%) was achieved on the improved RJW medium supplemented with 1.0 mg·L^-1 BA, 5.0 mg·L^-1 NAA, 20 g·L^-1 sucrose, 450 mg·L^-1 L-glutamine, 750 mg·L^-1 casein hydrolysate, 2.0 g·L^-1 gelrite, dark culture under 22℃, the average induction frequency was 81.3%.

Soybean PM2 protein belongs to the family of group 3 LEA (late embryogenesis abundant) proteins. In the present paper, yeast expression vectors encoding full-length PM2 protein and deleted polypeptides containing 22-mer motif were constructed. The yeast recombinants were obtained after transformation. Expression of PM2 and the deleted polypeptides of PM2A, PM2B and PM2C were identified in yeast lysis by SDS-PAGE and ESI-MS/MS or MALAI-TOF/TOF analysis. The growth performances of yeast recombinants and their control with empty vector were tested under normal, high salinity（1.5 mol·L^-1 NaCl）or high osmotic（2 mol·L^-1 sorbitol）conditions. The results showed that: 1) the expressions of PM2 protein and its 22-mer motif are not deleterious to the growth behavior of yeast recombinants under normal condition; 2) the recoveries of 4 recombinants are better than that of control with the empty vector under high salinity conditions, indicating that PM2 protein and its 22-mer motif could improve salt tolerance of yeast directly. The high salt tolerance of yeast conferred by 4 polypeptides are PM2C>PM2B≈PM2A≈PM2; 3) no growth difference was observed between the 4 recombinants and the control under high sorbitol stress. These results showed that 22-mer motif is a functional domain in PM2 protein and it is consist with the results described as in E. coli. All these results provide directly experimental support for the hypothesis that “LEA proteins may represent analogous protection to the high salinity stress in prokaryotes and eukaryotes” for the first time.

The orthogonal design was used to optimize RAPD amplification system of Larix gmelnii(Rupr.) Rupr with five factors (Taq polymerase, Mg²⁺, dNTP, primer, DNA templet) at four levels, respectively. Through the deep analysis, a suitable RAPD-PCR reaction system was established, namely 20 μL reaction system containing 1.0 U Taq DNA polymerase, 2.5 mmol·L^-1 Mg²⁺，0.25 mmol·L^-1 dNTP, 0.5 μmol·L^-1 primer, 1×PCR buffer, 90 ng DNA template. 20 primers with stable amplification and rich polymorphism for RAPD were screened. The optimal annealing temperature for RAPD-PCR reaction was proposed by gradient PCR. The result provided a standardizing RAPD-PCR program for the analysis of genetic diversity of L. gmelnii(Rupr.) Rupr.

In order to creat wheat-rye translocations which have very important value in wheat breeding and production, we selected the lines with common wheat rye’s characters in the crossing between wheat-rye substitution line 5R/5A and 6R/6A. Now we have obtained 9 lines of F6, 6-26，06-60-11，06-6-24，06-6-15，06-6-35，6-34，6-28，06-6-17，06-6-14. These lines are useful for the genetic stability and fertility and dry and disease resistance and they have multispikelets with more number of grains per ear, higher grain weight, more ears per plant as well as other good characters. Twenty primer pairs located on chromosomes 5R and 6R were used for SSR amplification in these lines and their parents.The results showed that the molecular marker SCM268 was singled out from 20 primers，which could amplify the specific molecular marker SCM268₁₅₀ of rye in 8 of 9 lines,6-26,06-60-11，06-6-15，06-6-35，6-34，6-28，06-6-17 and 06-6-14.It can be deduced from the result that the 8 lines are wheat-rye translocation lines which have very important value in production and wheat breeding.

To establish a rapid assay for heat-tolerance of Celosia cristata, seeds and ten-leaf stage seedlings of six cultivars of C. cristata were studied under high temperature stress which increased 5℃ every four hour from 30 to 50℃, respectively. Wilting index, seed germination rate, percentage of seedling establishment, relative electrolyte leakage, malondialdehyde(MDA) content and the activities of superoxide dismutase(SOD) were measured. The results showed that seed germination and percentage of seedling establishment were significantly reduced under high temperature stress, and the most sensitive organ to high temperature stress is terminal bud. Seedlings can be recovered normally in the recovery solution if wilting index is below 4. Under the high temperature stress, both leaf relative electrolyte leakage and MDA increased, while the activities of SOD increased initially but decreased later. Leaf relative electrolyte leakage and MDA increased dramatically after reaching 45℃, and the activities of SOD reached its peak at 45℃. The heat tolerance among 6 C. cristata cultivars was ranked in the order from most tolerant to least tolerant as follows: variety-Centrury Green，Dollbaby, Newlook，Plumosa-Castle，Kimono and Variety-Century Copper. All the physiological indexes measured can be used to assess heat tolerance for C. cristata.

There are 1 471 species (including infraspecific taxon) of the seed plants belonging to 140 families and 720 genera in Tianjin. Among them, they include 16 species of gymnosperm belonging to 10 genera and 7 families and 1 455 species of angiosperm belonging to 710 genera and 133 families. In addition, there are 11 Chinese endemic genera to China. Based on the analysis of compositions and the geographical elements and characteristics of the flora, the paper has discussed the major characteristics of the flora as follows: the flora contain abundant plant species; the flora is ancient origin, but also has younger elements; the geographical elements of the flora are comparatively complex, and the genera of north temperate are the dominant areal types, but there are so large proportional genera and species of tropic, subtropic in the region of temperate show that the flora of temperate relates to the flora of tropic, presenting transitional features from the subtropical zone to the temperate zone; the flora is crisscrossing and assembling of diversified geographical elements, and widely relate to their surrounding flora; the geographical elements of the flora is mainly made up of the North China components.

Genus size analysis is an important component in floristic research. The distribution pattern of genus size can reflect taxonomic diversity and phylogenetic diversity of a certain flora to some extent. In floristic studies, we cannot perform meta-analysis with mean genus size for its dependence on flora size. We applied logseries model to fit genus size distribution patterns of 8 spermatophyte floras in China, and achieved good fitting result. The goodness of fit R²＞0.99, indicating similar patterns between genus size distribution and species abundance distribution. Rarefaction analysis and correlation analysis showed that, mean genus size is not significantly correlated with its original values before rarefaction when the sampling size is small, while α index from the logseries model is stably correlated with its original values. Moreover, α index is significantly correlated with mean genus size for all sampling size, thus it could be taken as a stable index to describe the flora richness.

The allelopathic effect of the aqueous extraction of Polytrichum commune Hedw. and Conocephalum japonicum(Thunb.) Grolle.on the seed gerimination and seedling growth was determined. The seeds of Vigna radiate, Raphanus sativus and Brassica campestris were used as bioassay materials, and the indices including the germinating rate, germinating index, germination energy, seed vitality, weight of seedling and radicle, as well as root length were determined. The experiments show that Vigna radiate is an ideal bioassay material, and the seed vitality index, seedling root weight, and root length are perfect bioassay indices for the two bryophytes. Besides, the effects of the aqueous extractions of the two bryophytes on the seed germination and seedling growth are somewhat similar to those of phytohormones, the aqueous extraction at low concentration is able to promote the seed germination and seedling growth, while inhibit at higher concentration.

The leaf epidermises of the major species of Psathyrostachys, Critesion and Hordelymus in Poaceae were examined, their similarities and differences on the leaf epidermis were summarized, and the taxonomic significance of leaf epidermal features among them also were discussed. Furthermore, according to the evolutionary trends of leaf epidermal characters of the three genera, their evolutionary positions and relationships were inferred as well. The results show that the genus Psathyrostachys is the most primitive one among the three genera, the genus Critesion is slightly more advanced than the former, and the genus Hordelymus is the most advanced of them; the genus Psathyrostachys might produce immediately the genus Critesion, whereas the genus Hordelymus might derive immediately from the genus Critesion. The biosystematic relationships of the three genera are corroborated by the evolutionary trend of trispikelet in the external morphology.

Liparis kumokiri F. Maek is distributed over Japan,Korea and Russian Far East, it had been reported existent in the northeast of China. But it is doubt whether exists in the northeast of China by S C.Chen in Flora Reipublicae Popularis Sinicae. This study proves that L. kumokiri F. Maek does exist in the northeast of China.

Ten secondary metabolites in phloem of different strains of poplars were extracted by different chemical methods and their contents were determined. The effect of different treatment process for samples on the extraction efficiency of tannin, phenols and phenolic acids was studied in detail. The results showed that the contents of phenol and pyrocatechol in Populus alba×P.berolinensis were maximum, while these values were minimum in P. nigra. The temperature of sample preparation had influence on the extraction efficiency of tannin. It was found that the sample treated at 75℃ had the optimal extraction result for tannin, phenol and phenolic acid constituents. In addition, the experimental results also indicated that there were no alkaloids in poplar phloem or their contents were too low to be detected within the detection limit of instrument.

The optimum macroporous resin and process were optimized for the purification of total flavonoids from Euonymus alatus，orthogonal-test method was adopted to study the effects of several factors including the kinds of resins, the concentration of eluent, the pH, etc., on the purification. The concentration of flavonoids in E. alatus was determined by ultraviolet spectrophotometry,the adsorption capacity, the rate of desorption and the content of total flavonoids in the extract were calculated to determine the suitable conditions. AB-8 resin is suitable for enriching and purifying total flavonoids of E. alatus, the optimum adsorption capacity and the rate of desorption are 7.32 mg·g^-1 and 90.98% respectively. The content of total in the extract was increased from 764% to 52.12%. This resin can be used to enrich and purify the total flavonoids of E. alatus, which can increase the content of total flavonoids in the extract.

A new species of Abelia R.Br.(Caprifoliaceae)from Guizhou，China are reported，i.e. Abelia lipoensis M. T. An et G. Q. GOU. The new species is nearly related to A. chinensis R. Br.，but the differences are in its glabrous branches and leaves，spacious and loose inflorescences，wide cone-shaped，nearly hairless calyx lobes，small white corolla with 6-9 mm long, subequal to the calyx lobe or longer.

The new species Sorbus tiantangensis X. M. Liu et C. L.Wang is closely related to the species S. amabilis Cheng ex Yü,but the former differs in its pinnate leaflets 6-7 pairs,margin crenato-serrate,stipule broad lanceolate,stamina in a flower 20,10 of them longer and the other 10 shorter.The ripening fruits in complex corymb are densely aggregated,the total numbers reaching up to 160-195.

Polystichum jiucaipingense P. S. Wang et Q. Luo, a new species of Dryopteridaceae from Guizhou, China, is described. It is similar to P. castaneum(Clarke) Nayar et Kaur, but smaller, with light brown scales on its petiole and rachis, and sori bearing on all the pinnae abaxially.

The process of sex differentiation of Acer truncatum, an andromonoecious woody plant, was morphologically and cytologically observed. Results showed that at early phase of sex differentiation, both pistil and stamen primordia could be found in male and bisexual flower buds, but selective abortion occurred in the pistil primordia of male flowers when macrosporocytes developed to megaspore tetrads. Pistils of bisexual flowers could develop and set fruits normally, and the stamens could produce mature two-celled pollen but the pollen could not dehisce. It is suggested that the failure of anthers of bisexual flowers to dehisce might be caused by the low lignification in fibrous layer.

The morphological features and anatomical structures of Tugarinovia mongolica were studied by means of traditional paraffin wax sections. The result showed: The leaf belongs to equilateral leaf. Each epidermis consists of a row of epidermis cells, which are arranged closely. There are many irregular stomata which exist in both higher and lower epidermis. Its palisade tissue is composed of 1 layer cells and the spongy tissue consists of 2~3 layers cells which arranged loosely. The primary structure of stem consists of epidermis, cortex and vascular cylinder. The developed pith is in the center of stem. But the root does not have this structure, which contains periderm, cortex and vascular cylinder. Many secretory structures exist in parenchyma of the root and stem. It was found that the vegetative organs of T. mongolica contain proteins by the reaction of coomassie brilliant blue. In addition, it was discussed that these structures were in conformity with the ecological environment it was located.

The leaf epidermis of 108 samples belonging to Kadsura Kaempf. ex. Juss. (eleven species) and Illicium Linn. (two species) are described using light and scanning electron microscopy. Several characters, such as pattern of epidermal cells, shape of stomatal apparatus, cuticular ornamentations, shape of cuticular intrusions at the polar region of guard cell, hair on epidermis, etc., are constant in some species and variable in others, and thus of considerable taxonomic value for studying the phylogenetic relationships within Kadsura and among Kadsura, Schisandra Michaux and Illicium Linn. A new character, cuticular reticulations that has not been reported previously in the order Illiciales is revealed in the study, which is congruent with the taxonomic assignment of two distinct subgenera (Subg. Cosbaea and Subg. Kadsura) in Kadsura. These characters of leaf epidermis sustain the subdivision of Subg. Kadsura into Sect. Kadsura and Sect. Sarcocarpon, and also support the combinations of some species by R. M. K. Saunders and Q. Lin. Moreover, stomata and other epidermal characters suggest close phylogenetic affinities of Kadsura, Schisandra and Illicium, whereas Kadsura seems more complex than Schisandra and Illicium on the basis of the characters of leaf epidermis. Evidence from leaf epidermis serves as a criterion for negating the separation of Schisandraceae from Illiciales as Schisandrales.

The floral traits and pollination system of Impatiens chinensis were studied. Individual flowers bloom for 2.3 days and the male phase was 6.8 times as long as female phase. The nectar quantity and sugar concentration is 0.56 μL and 28.2%, respectively. Stigma is receptive on the day of anthesis. Pollen viability is highest on the moment of corolla displaying（95%）, thereafter decreases gradually and maintains a considerable level until the flower drops（55%）. The results of P/O detection (5 730.3±2 941.1) and bagging treatments suggest that I. chinensis is self-compatible with facultative xenogamy breeding system, its outcross-pollination require pollinators. I. chinensis is mainly visited by honey-bees, butterflies, bumble-bees and several species in ceratina(Apidae). Bombus trifasciatus is the dominant pollinator. The nectar robber Amegilla caldwelli may be the most important biological factor which influences the sexual reproduction of I. chinensis except for the legitimate visitors.

We investigated the reproductive ecology of Chirita gueilinensis in different habitats populations (YZ population,semi-wild,at the sunny cracks and crevices of calcareous rocks with little soil; DB population,at the rupicolous in a cave). Our results indicated that: (1)Flowering took place from late February to middle April,and anthesis of a single flower lasted 10~17 days in YZ population and 16~24 days in DB population depending on environmental conditions. (2)The pollen-ovule ratio(P/O) is different in the two populations,and we noted larger variation in pollen than ovule production,which may be related to habitats. (3)Breeding experiments showed that C. gueilinensis is facultative xenogamy by insects and no agamospermy. (4)There were limitations both in pollination and ripening of seeds,which resulted in a low seed-setting ratio(<45%) for all artificial treatments and natural pollination. (5)Chalcididae sp.and Amegilla albigena(Lepeletier) （DB population） or Apis cerana Fabricius (YZ population) were main pollinators of C. gueilinensis. (6)The reproductive investment per plant increased but the reproductive allocation decreased with increased individual size. （7）Plants in YZ population obtained more available resources from environment and greater reproductive investment than plants in DB population,this indicated that reproductive investment was relatively favored by plants from YZ population, whereas vegetative propagation was favored by plants from DB population to obtain more resources from the environment.

Based on the surveyed data of Helianthemum ordosicum population in different slope positions, the age structure, the static life table, survival curve and mortality curve and vanish rate curve ware analyzed. Additionally, the survival functions were also analyzed. The results indicated that age structure of H. ordosicum in different slope positions exists the trend of decline. The number of young-age individuals accounts a small proportion of total population, that of the middle-age occupies big proportion. The H. ordosicum population density differ in different slope positions, with the characteristics of the biggest population density in upper slope position, less in middle slope position and least in lower slope position. The expectant life span of the first-age H. ordosicum population in different slope positions is maximum, and the fluctuation of expectant life span exists in fifth-age or sixth-age population. The survivorship curves of the H. ordosicum population in different slope positions belong to Deevy Ⅱ～Ⅲ type as a whole. One peak of the mortality rate exists from sixth-age to eighth-age, that on the middle and lower slope position is one age class later than that on the upper slope position. These four function values from the survival analysis could be well used to analyze the structure and dynamic change of H. ordosicum population in different slope positions.

The photosynthetic characteristics of Caragana davazamcii plants of different ages were investigated. The net Photosynthetic rate(P_n) and transpiration rate(T_r) of mid-aged plants(5 years old) were higher than those of senile plants(24 years old). The decrease of P_n in senile plants between 12:00-14:00 was caused by non-stomatal factors that impaired photosystem Ⅱand photosynthetic capacity of the leaves, while that in mid-aged plants was a consequence of both stomatal and non-stomatal inhibition. The determination of photosynthetic pigment contents showed that the contents of chlorophyll and carotenoid in mid-aged plants were significantly higher than those in senile plants, so that the mid-aged plants had higher P_n, LUE and capcity of intensive radiation adaptation. In addition, the mid-aged plants had higher WUE, which made them more tolerant to drought, so the mid-aged plants were able to adapt to the local envioronments with high temperature and severe drought.

Using winter bud of Davidia involucrate as explant, we studied its tissue culture and plant regeneration. The results indicated: the best medium for the clump shoot induction directly from D. involucrata winter bud was WPM+NAA 0.2 mg·L^-1+6-BA 3.0 mg·L^-1+AC 2.0 g·L^-1; the appropriate medium for shoot segment multiplying of D. involucrate bud was WPM+NAA 0.05 mg·L^-1+6-BA 1.0 mg·L^-1+GA₃ 2.0 mg·L^-1+AC 2.0 g·L^-1; the medium for rooting culture was White+IBA3.0 mg·L^-1+6-BA 1.0 mg·L^-1+AC 2.0 g·L^-1, under these conditions, the roots were well developed and the plants were healthy; finally, about 80% of these seedlings could survival after transplantation.

Iris lactea Pall. var. chinensis(Fisch.) Kordz. is a kind of water-saving, ornamental, medicinal and fodder plants with excellent characteristics. In this paper, the mature seeds were used as the explants, and the combining medium schemes for inducing callus, differentiation and rooting, etc. were designed with different concentration of 2,4-D, NAA, BA, KT based on the MS culture medium, and the system of tissue culture and rapid propagation of I. lactea was studied. The results showed that the variable ratio of hormones had the great effects on the rates of callus, and the mediums of MS+2,4-D 4 mg·L^-1+BA2 mg·L^-1、MS+2,4-D 4 mg·L^-1+BA5 mg·L^-1 and MS+2,4-D 2 mg·L^-1+KT1.5 mg·L^-1 could give higher rates of callus (more than 58%) than others, so they were thought as the greatest combining schemes. MS+BA4 mg·L^-1 and MS+BA1 mg·L^-1+NAA0.15 mg·L^-1 were the optimal schemes for the differentiation of callus. The optimal regeneration and enrichment culture mediums were MS+BA2 mg·L^-1+NAA0.1 mg·L^-1 and MS+BA1 mg·L^-1+NAA0.2 mg·L^-1. The best medium for rooting was 1/2MS, and the schemes of 1/2MS+IBA0.5 mg·L^-1, 1/2MS+IBA 0.5 mg·L^-1+NAA0.5 mg·L^-1 could also have good effects on the rootgrowth. The rooting plantlets were easily planted on the mixed medium of V_soil∶V_sand=2∶1 without any training. Therefore, the available system of tissue culture and rapid propagation for I. lactea was established including the mature embryo-inducing of callus-differentiation and regeneration of plantlets-propagation-rootingtransplanting.

The tender buds of Rhododendron schlippenbachii Maxim. were used as explants in the experiment. Uniform Design was used-for screening the most suitable culture medium for shoots regeneration immediately at base of tender buds, rooting and in vitro germplasm preservation. The results showed that DR+2-ip3.00 mg·L^-1 was the most suitable for shoots regeneration, the rate of regeneration was more than 95.5%; MS(modified)+IAA0.50 mg·L^-1+IBA0.10 mg·L^-1+KT0.10 mg·L^-1 for rooting, the rate of rooting was more than 99%; N-68+B₉ 2.30 mg·L^-1+phloridzin 1.50 mg·L^-1 for germplasm preservation in vitro for 30 months. Stems each with one node were cut from regenerated shoots and cultured for propagation, and a 65-fold proliferation rate was achieved within 28 days. The method of “defering growth with dwarfing” was utilized for in vitro germplasm peservation at normal temperature. In vitro culture and in vitro germplasm peservation system of R. schlippenbachii Maxim. has been successfully established.

The seedling of wheat (jinmai8) were exposed to He-Ne laser (5 mW·mm^-2), enhanced UV-B radiation (10.08 kJ·m^-2·d^-1) and the combined treatment of He-Ne laser irradiation and enhanced UV-B radiation. The measurement permeability of chloroplast membrane，chloroplast protein content，Hill reaction activity and ATPase activity of wheat seedlings. Result enunciation: the chloroplast membrane permeability has increased after UV-B radiated wheat seedlings，chloroplast protein content went down, Hill reaction activity and ATPase activity were restrained. The He-Ne laser can make chloroplast membrane permeability fall，chloroplast protein content go up certainly. Hill reaction activity and ATPase activity were also partially activated.These variety explain enhanced UV-B radiation cause damage chloroplast of wheat seedling, but certain the He-Ne laser partially repair UV-B damage the system of photosynthesis on wheat seedling.