Abstract:A genomic cosmid library of the wide-compatibility-variety rice (Oryza sativa L.Cpslo17) had been generated using vector SuperCos1. The library containing more than 1.0×10⁵ recombinants with an average insert size of approximately 40 kb represented more than 9 times haploid genomic equivalents, but 5% clones did not carry any insert. Using RFLP marker 23D12R linked tightly to S₅ as probeto screenlibrary, a new clone R2I19 was isolated and determined.

Abstract:Bulked segregant analysis was used to identify RAPD markers linked to the hermaphrodite gene (M₂) in papaya (Carica papaya L.). DNA bands amplified from 205 random 10-mer primers were screened. Two polymorphic bands, OPQ-07₁₈₀₀ and OPE-06₁₀₅₀, were found, which were present in the hermaphrodite bulked DNA sand absent in the female bulked DNAs. 210 individual papaya plants were then tested with these two primers. The results indicated that the RAPD markers, OPQ-07₁₈₀₀ and OPE-06₁₀₅₀, were tightly linked to M₂, which located at both sides of M₂, and have a map distance of 4.5 cM and 1.9 cM, respectively.

Abstract:With the help of LM and SEM, leaf epidermal structure was studied in l0 species of Annonaceae．Epidermal cells of them are polygonal and nearly isodiametric or irregular in outline with straight, arched，sinuolate， undulate or sinuate anticlinal walls．In Fissistigma oldhami and F. uonicum，the outer periclinal walls of abaxial epidermal cells are papillate．Druses or prismatic crystals are found in some epidermal cells of some species． The stomata in 9 species are restricted to abaxial surface, only stomata in Artabotrys hexapetalus are distributed on both adaxial and abaxia1 sides．The mature stomata of 10 species are paracytic with 2-6 subsidiary cells． Contiguous and abortive stomata are also observed in some species．Simple unicellular ，umseriate of biserlate multicellular ，clavate and stellate (tufted) trichomes are present on different surfaces in 9 species except Annona glabra，the surfaces of which are glabrous． All characters of the leaf epiderm al structure as mentioned above are of significance in the identification of some taxa at specific or generic level， and in probing their systematic relationship．

Abstract:Pollen morphology of 9 species in genus Paspalum was observed from sample scollected from Guangdong Province. The pollen grains are usually spheriodal with mean diameters ranged from 34 to 50 μm. Pollen ornamentation is commonly verrucate or rugulate. Unusual polyporate pollens were found in tetraploid P.formosanum, P.paspaloides, P.thunbergii, P.conjugatum, P.orbiculare, P.longifolium and a decaploid P.commersonii.

Abstract:In order to make sure whether Cycas miquelii and C．ferruginea are of the same species，the authors have observed an atomically the two species．The results show that the leaf surface of C. miquelii covered with thick cuticle． Wall of epidermal cell is thick and arranged regularly in one layer．Hypodermal sclerenchyma cells exist in the raised midrib region and pinna margins．Mesophyll consists of patisade and spongy tissues．Palisade tissue is composed of cylindrical cells being regularly arranged，beneath adaxial hypodermis and present above the midrib． The cells of spongy tissue are distributed at the two sides of the accessory transfusion tissue．Crystal cells are few．The phloem locates on abaxial side and is arranged in arch shape，while the xylem on adaxial side．Tracheids are scattered．Cucas miquelii is obviously different from C. ferruginea in structure in transverse section, such as the shapes of pinna margin，raised midrib region and hypodermal sclerenchyma cells． Based on such difference between C. miquelii and C. ferruginea，the authors consider that they are separate species．

Abstract:The fruits of Litchi chinensis Sonn.cv．Huaizhi at maturity of 85％ were used in the experiment．7.5 kg of fruits were packed by 0.05mm plastic film and stored in sealed foam boxes，in which different weights of ice were added surrounding the fruit package．After 72 hours of storage，the fluits were taken out and placedfor 24 hours at ambient temperature．Pericarp of the fruits was observed by SEM．The results showed that ice addition could effectively maintain the integrity of pericarp and poapone the break down of pericarp tissue．The surface of small emergences on pericarp of less mature fruits was smooth, while that of more mature fruits was rugate. Rugate honeycomb-like concavity appeared on peficarp of collapsing fruits after the small emergences being destroyed. The effects of ice-addition percentages and storage duration on the changes in fruit temperature were analyzed． The relationship between pericarp structure and preservation of litchi fruits is discussed．

Abstract:Root-tip metaphase chromosome numbers of 6 taxa of Hibiscus were investigated by wall degradation hypotonic staining method. Chromosome numbers for H. schizopetalus (Masters) Hook.f.(2n=42), H. mutabilis L.(2n=92), H. rosa-sinensis L.(2n=84), H. rosa-sinensis cv. Double Rainbow (2n=105), H. rosa-sinensis cv. Flavo-plenus (2n=138) and H. rosa-sinensis cv. Carminatus (2n=147) arereported. It is shown that the ploidy relationship exists among them except cv. Flavo-plenus, the basic chromosome number being x=21. From the observation on chromosome numbers and morphological characters， H H. rosa-sinensis L. is thought to be a hybrid which arose from cv．Carminatus and H. schizopetalus．

Abstract:

Abstract:As oneofthelargest andpantropical generainthefamily Rubiaceae，the genus Heddyotis L．sensu lato， including subgenera Hedyotis，Oldenlandia and Houstonla，is applied in this paper．They characterized by having tetramerous flowers with valvate corollas and equal calyx lobes，expanded，fleshy，peltate placentae and moderately flattened capsular with selerified endocarps． Basing on the extant literatures，699 species are included in this genus．Tropical Africa and Asia are two modern distribution centers．Endemic species are distributed in all tropical continents．About 68 species(including varieties) growing in S．and SW China．The modern distribution pattern and cytogeography data reveal that：(1)Hedyotis was originated in the Gondwana land before late Jurassic，and might be originated on the amplearea of NE Gondwana land during Jurassic，even in early Triassic;(2) They dispersed in four ways from the original center：eastward，to SE Asin via Turkey，Iran and S．China，where was the southern areas of the Laurasia land; southeastward，to India and Australia via paleo-antaletie land：northward，to North America via cent1al paleo-pacifie; southwestward，to S．America，which was united with Africa at that time and was also one main part of the Gondwana land．The continantal drift，especially the breakup of Gondwana， slowed down the speed of such dispersal in Jurassic time．Subsequently， the species developed in these separated continents．The global glacier had also ptayed an important role in the present distribution pattern．

Abstract:Based on the survey of 3 to 5 sampling plots with areas of 1 300-3 000 m² in communities at four sites of tropical montane rain forest at 700-1 300 m altitude On Hainan Island， the spatial feature ofspecies diversity in each layer of the community was studied．The species diversity of tree and herb layers decreased in communities located from east to west, i.e. from Diaoluo Mountain to Wuzhi Mountain，Bawangling，and Jian fengling,while that of shrub layer and extrastratum plants increased．Spatial fluctuation of species diversity in extrastratum plants and tree layer were more stable than in shrub and herb layers．species diversity in tree，shrub，extrastratum and herb layers of the montane rain forest communities had various trends at altitudinal gradient．The species diversity in tree，shrub, extrastratum and herb layers within a community showed different features according to slope aspect．

Abstract:Species relative abundanee distribution in Tsoongiodendro odorum community in Wanmulin Nature Reserve，Fujian Province, was studied by using patterns of geometric series distribution，log series distribution, log normal distribution，broken stick modeI and W eibul1 distribution to evaluate the simulation of such methods．Twenty-two species in tree layer were randomly investigated，and 33 species in shrub layer were surveyed in a quadrat of 5 m × 10 m．The simulation results show that the species relative abundance of tree layer in the community can be well described by all the models mentioned above，while that of shrub layer can be well described by log series distribution, log normal distribution and Weibull distribution．It is suggested that these methods might be useful for the protection of biodiversity of the community dominated by endangered Tsoongiodendron oderum．

Abstract:Based on the data on Castanopsis carlesii population in Wuyishan Nature Reserve, Fujian, the curves of loserate, survival, mortality rate, and survival function of the population were made for static life table to analyse the population dynamics. The population had a peak of mortality atⅡage class, and survival curve of the population belongs to the type Ⅲ of Deevey, representing that the mortality rate of young individuals was highand was followed by a low and stable mortality. The functions used in staticlifetable could well explain th estructure and dynamics of Castanopsis carlesii population.

Abstract:Photosynthesis and fluorescence parameters involving photosynthetic process in the leaves of 2-year-old subtropical tree species Castanopsis fissa and understory shrub Psychotria rubra were determined by using gas exchange and fluorescence techniques，which were transplanted in 25 plots for 6 months under flIl sunlight and shade (17％ of full sunlight)for each treatment The daily course variation of net photosynthesis rate (Pn)，stomatal conductance (g_s) ratio of intercellular to ambient CO₂ concentration (Ci/Ca)，ratio of carotenoid to chlorophyll content (Car/Chl)，and the efficiency of photochemical reaction (Fv/Fm) for both plants under shade were relatively stable and less difference between species．However，in full sunlight，the Pn，g_s and Ci/Ca for the two species generally declined with time, consistently with the decrease of the q_P and Ф_PSII．q_N and Car/Chl for Castanopsis fissa increased with time， but decreased for Psychotria rubra． The decrease of q_P and Ф_PSII in leaves of Castanopsis fissa under full sunlight around the noon time indicated that the numbers of tlle open PSII reaction center were possibly reduced，but its photochem ical efficiency still maintained at a relativdly stable level indicated by Fv/Fm．Meanwhile，the increase in Car/Chl and q_N suggested that the excessive activated energy could be safely dissipated．While for Psychotria rubra, the g_s q_N and Fv/Fm decreased and were significantly lower, but Ф_PSII and q_P maintained relatively stable and were higher as compared to Castanopsis fissa, implying that its PSII reaction center may change a little， but CO₂ exchange， photochemical efficiency, and heat dissipation capacny had been weakened to acertain degree．In general，Psychotria rubra showed more sensitivi to strong light intensity than Castanopsis fissa.

Abstract:The seedlings of two tree species (Schima superba and Castanopsis fissa )and two shrub species (Psychotrla rubra and A rdisia quinquegona) from a subtropical natural forest were grown in pots under 100％，36％ and 16％ natural light． The difference in activities of lipoxygenase (LOX)， xanthine oxidase (XOD) and monoamine oxidase (MAO) in leaves and the production rates of three active oxygen species (O₂^-., OH·, H₂O₂) in chloroplasts were c0mpared．Leaves grown under 100％ sun light showed highest activities of LOX and XOD．The changing trends ofO₂^-., OH· and H₂O₂ in chloroplasts responding to light intensity were significant and similar to that of LOX and XOD activities．High activities of LOX and XOD might be one of the causes of high active oxygen level in leaves that were adapted to high light intensity．The tested understory shrub plants showed lower LOX and XOD activities than the canopy tree species， but the response of enzyme activity and active oxygen production to the change of light intensity was more sensitive than tree species.

Abstract:In this paper the theory of developmental phases in trees, the studies on its molecular biology and the heredity of traits during phase change,and the application of theory of developmental phasesin the breeding of Hevea brasiliensis are presented. The distinction of features between juvenile and adult phases, and the phase change in relation to rubber production are discussed.

Abstract:The application of remote sensing (RS) and geographical information system (GIS) technologies in the study of the effects of climatic change on vegetation is reviewed. Literatures and the brief contents of ecological studies using RS and GIS is presented. More attention to the study of south subtropical vegetation in China is recommended.