The changes in protein patterns were monitored with SDS PAGE and IEF/2D during callus proliferation and adventitious bud differentiation of Populus euphratica. The results showed callus differentiation potential was closely related to its expressed proteins. Callus induced from shoot bases on the medium with the ratio of BA to NAA 1 under light, had a high differentiation capability, and expressed less sorts of proteins than those being subcultured, indicating its differentation degree was lower. Marker proteins for different kinds of calli and different phases of callus differentiation were identified. Two subculture specific markers protein bands, 24.5 kDa and 58.6 kDa, were observed in callus proliferated in dark on the medium with the rate of BA to NAA 0.5. Meanwhile, the 19 kDa and 31 kDa protein bands that expressed during callus differentation were also found in the subcultured callus, suggesting that gradual loss of organogenesis ability of the subcultured callus may be contributed to the increasing of its differentiation. When the callus induced from shoot bases was cultured on the regeneration medium with the ratio of BA to NAA 0.5 under light, it firstly differentiated into a few smaller green meristematic islands in its surface layer, then adventitious shoot primordial from the islands. Two protein bands of 20 kDa and 55?kDa, as distinctive differentiation markers, expressed obviously in the differentiated callus. The 20 kDa protein with pI of 5.5～6.5 was specific to callus differentiation. A 43 kDa protein with pI of 6.5～7.5 generated during the early stage of differentiation. The relation between callus organogenesis potential and its expressed proteins was discussed.

The plasticity of biomass allocation, morphology, light utilization and hydraulic features was compared between the Salix matsudana branches growing under the contrasting light environments. (1) Branch weight ratio(BWR) was higher in the branches growing under unshading condition and connecting to different branches under shading condition(Bhl) than that in the branches of the plants entirely growing under full sunlight(Bhh); BWR was lower in the branches growing under shading condition and connecting to different branches under unshading condition(Blh) than that in the branches of the plants entirely growing in shading condition(Bll), while leaf weight ratio followed the opposite direction.(2) There were no significant differences in morphology between Bhl and Bhh; leaf area ratio, specific branch length and leaves per branch length were higher in Blh than those in Bll. Thus, Blh had higher potential to capture light than Bll.(3) Canopy productivity indices in Bhl and Blh were larger than those in Bhh and Bll, respectively. This implied that light use efficiency of the S. matsudana branches was higher in heterogeneous than homogeneous light conditions.(4) Water saturated deficit and losing water coefficient were smaller in Bhl than those in Bhh, suggesting that Bhl had higher holding water and resistant drought ability than Bhh.

Based on the data collected by located observation, the density, storage and spatial distribution of carbon were studied in Chinese fir plantation at fast growing stage. The results showed that carbon density in different organs of Chinese fir ranged from 0.4558 gC·g^-1 to 0.5003 gC·g^-1,and was in the order as: bark>leaf> trunk>root>cone >branch. The carbon density in the perennial branch and leaf was higher than that of the youngers'. Carbon density in shrub, herb and floor was 0.4344?gC·g^-1, 0.4009 gC·g^-1 and 0.4341 gC·g^-1, respectively. Carbon density of the surface soil was a little lower than that of the second surface soil. Carbon storage in different organs was basically in direct proportion to the biomass of respective organ ,biomass of trunk made up 47 7% of the standing forest biomass, correspondingly its carbon storage amounted for 47.5% of the standing forest carbon storage , the rest in branch, leaf, bark and root, etc., seized 52.5%. The total carbon storage in Chinese fir plantation at fast growing stage was up to 127.88 tC·hm^-2,including 35.883 tC·hm^-2 in the plant, and 91.997 tC·hm^-2 in the soil (including floor). The annual net productivity of Chinese fir plantation at fast growing stage was 7.351 t·hm^-2a^-1, stored carbon up to 3.489 tC·hm^-2a^-1. Forest was an important sink of atmospheric CO₂.

Some important physiological characters of Liriodendron reciprocal hybrids and parents under water stress were studied.The results were as follows:The decrease rate of relative water content, chlorophyll content as well as protein content and increase rate of RNase activity in leaf blades under water stress were L.chinense (Hemsl.) Sarg.> L.tulipifera Linn.>plus crossing F₁>minus crossing F₁.L.chinense was severely damaged by short water stress. Direct evidences from ³H-Gly labeling under water stress proved both that RNase genes of parents and hybrids were expressed in translation level as well as RNase were synthesized de novo and that intensity of RNase gene expression was L.chinense>L.tulipifera>plus crossing F₁>minus crossing F₁. Indirect evidences from protein synthetic inhabitor under water stress indicated that RNase activity increase of parents might be involved in cytoplasmic mRNA translation and RNase release, activation and/or synthesis of chloroplast and/or mitochondria, but RNase activity increase of hybrids might originate mainly from cytoplasmic mRNA translation, not from chloroplast and/or mitochondria. The above-mentioned experimental evidences fully proved both that reciprocal hybrids displayed notable super-parent heterosis of resistance to water stress and that minus crossing F₁ possessed stronger powerful heterosis of resistance to water stress than plus crossing F₁. The researches revealed molecular mechanism of powerful positive heterotic formation of growth, adaptability and resistance on the basis of the resistance to water stress and showed geneticists and breeders of forest-tree who are engaged in fixation and utilization of heterosis of the hybrid tulip tree must lay special stress on clones of minus crossing F₁.

Under the ambient atmospheric CO₂(350±10)μL·L^-1,70%±5% relative humidity and PPFD of 400、800 and 1200μmol·m^-2s^-1,the temperature dependence of net photosynthetic rate (Pn),stomatal conductance (g_s),transpiration rate (E) and dark respiration (Rd) of 3 age classes of 18-year-old Chinese fir shoots were measured in 3 growing seasons of 1998 in Fenyi County of Jiangxi Province, one of the central distribution area of Chinese fir. With the increase of temperature the Pn, g_s and E showed sharp parabolic responses while R d responded exponentially. However the maximum g_s reached at much lower temperature than Pn and E. The optimum temperature of Pn was around 25℃ in fast-growing season (late May) and late season (middle October) while it was around 30℃ in middle season (late July) except for the current shoot in the late May with the optimum temperature between 22℃ and 23℃ because it was not fully developed then.The optimum temperature of Pn for mature shoots was more relevant to the average highest temperature of 5 days before measuring date. The impact of temperature on g_s may result from the changes of saturated vapour pressure deficiency (VPD) and the intercellular CO₂ concentration (Ci). The response of E to temperature may be related to the changes of g_s and VPD. The Rd of old shoot was lower than current shoot due to the lower physiological activity and poor light environment. However the responses of Pn,E and g_s to temperature discussed in this paper are instantaneous and the long-term responses and acclimation need to be studied further.

The leaf transpiration (TR) and stomatal conductance(g_s) of 4-year-old Eucommia ulmoides in the hilly land of Taihang Mountain were measured and analyzed. The results showed that: (1) the diurnal variation of TR was demonstrated double-peak curve in clear day and cloudy to clear day, and single-peak curve in overcast day; (2) the tend of diurnal variation of g_s was almost the same as TR; (3) the values of TR showed good agreement with meteorological elements such as photon flux density(PFD), saturation vapour pressure deficit of air(D) and water surface evaporation (EV); (4) Because there was close relation between EV and TR,and the approach of measuring EV was relative simple,it was feasible that TR was estimated using data on EV.

The endophytohormones in the rhizomal buds of Phyllostachys praecox were tested monthly by ELISA. The results showed that the endophytohormones such as IAA, ZT and iPA in one-year-old rhizomal buds had the similar changes which fluctuated monthly, however the changes of ABA gave the opposite pattern. IAA, ZT and iPA arose one month earlier in spring at the top of the one-year-old rhizomal buds than at the bottom. When the coverage used, the buds at the bottom produced high level of IAA, ZT and iPA one month earlier than those non-coverage used. In July when buds on the top of rhizome developed a new rhizome, the ZT and iPA got lower and IAA kept high; ABA was much high in the buds at the bottom, however it was quite lower at the top. So the formation of the shoots and the rhizome were great relative with the changes of endophytohormones. IAA/ABA was relative with the activity of buds. ZT/ABA and iPA/ABA was relative with the formation of shoots. The biological mechanism of producing shoots earlier by using covering method was also discussed.

The taxonomic disorder in genus of Arundinaria Michaux is the disputing focus in the taxonomic study of leptomorph bamboos.For a long time,there is no suitable strategy to study the genus of Arundinaria and the related genera.In this paper we presented a method of using the SSR primers of rice to settle the problem according to the near phylogenic relationship between bamboo and rice.Differing to the traditional taxonomy,it showed that there was a large differentiation beween genus of Bashania Keng f.et Yi and related genera of Arundinaria Michaux,and proved that Bashania Keng f.was regarded as a distinct and isolated genus.The taxonomic problem of Arundinaria amabilis (McClure) Keng f. was also discussed in this paper.It provided a new result for the relationship of the genus of bamboo related to Arundinaria Michaux from different aspects comparing to the traditional study.It also offered a reference for the phylogenic study of Arundinaria Michaux in a broad sense by modern molecular biotechnique.This study put forth new thought and strategy to carry out molecular biology research in bamboo.

Karyotypes of five species of Cycas were studied.The results showed that the numbers of chromosomes of five Cycas species were 2n=22; C.micholitzii:2n=22=4m+4sm+2st+12T;C.multipinnata:2n=22=4m+4sm+2st+12T;C.revoluta:2n=22=4m+6sm+12T;C.taitungensis:2n=22=4m+6sm+12T;C.taiwaniana:2n=22=4m+4sm+2st+12T.The variation and evolution of karyotypes in Cycas were also discussed in this paper.

The tissue culture of the stem section in Ginkgo biloba carried out in the paper,using MS medium with the addition of different concentrations of activated carbon,6-BA and NAA.The orthogonal table L₉(3⁴)with the compound of three elements with three levels was selected.The various actions on the culture effect were analysed,such as different hormone,including activated carbon or not,and the regeneration ability of stem section in different growth period.The results showed that the MS medium with activated carbon 0.5% +6-BA1.0mg·L^-1+NAA0.1mg·L^-1 +NAA 0.1 mg·L^-1 was the best for the culture of stem section in Ginkgo biloba. In all elements,the positive effect of activated carbon was the most obvious.The proper time of sampling was in the middle and last ten days of April.

Abies georgei var.smithii virgin forest was main distribution type in southeastern area of Tibet. By adopting the posting and typical-plot method, the physical properties of the soils inside and outside the forest was studied, through two year observation (1999～2000) in Sejila Mountain Research Station of Forest Ecosystem. The bulk densities of layer A, layer B, and layer C soils was 0.74, 0.94, and 1.34 respectively inside forest and was 0.92, 0.99, and 1.22 respectively outside forest, which indicated that the bulk density for layer A inside forest was less than that of outside forest, while for B and C layers there existed no significant difference between inside and outside forest. By comparison of the saturated moisture capacity, capillary moisture capacity, field moisture capacity, non capillary porosity, capillary porosity, and the total porosity of soil, all values of these factors for layer A soil inside forest were higher than that of outside forest, but those for layer B had no marked difference between inside and outside forest. With depth increasing, the soil water content decreased. It was the highest in surface layer (0～10 cm), with a maximum value of 75% inside forest and 63% outside forest, and tended to be stable below 50 cm (30%～40%). Based on change law of soil water and water absorption and utilization of plant root, the soil water utilization of Abies georgei var.smithii forest was first divided into three levels: weak utilization layer (0～10cm), utilization layer (10～50 cm), and regulating layer (below 50 cm). The soil water content of the forest was the highest in January and February in winter and had little change in growing season. The dynamic of soil water content was divided into consumptive, accumulative, receded, and stable periods. The permeability of both layer A and layer B soils in forest were better than those of outside forest. The time for reaching the stable permeation in layer A was 10 min and 45 min respectively for inside and outside forest.The results showed that the soil physical properties inside forest were superior to that of outside forest. It also indicated that the soil physical properties would be changed obviously and evolved towards adverse directions after forest interfered or destroyed.

A mathematical model and a computer simulation of succession process of Leymus chinensis microcommunities in abandoned field were presented. The results accord with data very well. The mathematical model isY(t)=1-e -πV 2N3t 3 Where Y(t) is area occupied by microcommunities of Leymus chinensis, V the expansion speed of Leymus chinensis microcommunities, N the number of seed which invade the abandoned field in unit time and unit area.

This paper started from normal forest equation model,based on the 40 years'observation data of natural even-age stable sub-compartment,dealt with forest age class transfer,and constructed natural forest age class transfer sustainable model:P′S′=λS′,where characteristic root (λ) was 1.By analysing the structure of stable state S’,the natural forest age retard was discovered and natural even-age forest sustainable age vector was equidifferently ascending.According to the amount of retard,the natural forest resource transfer sustainable models were divided into three types.It also pointed out that the forestry mechanism of phenomena above-mentioned was the probability of forest tree withering and damage increasing with its age increase.

Based on a lot of field investigation of stumps in Tilia broadleaf Korean pine forest,the results showed that Korean pine forest was composed of grouped patched trees with different ages.The dominated generations had not showed strict difference.The community age structure always appeared two or more peaks.The distribution of broadleaf tree species in Korean pine forest was grouped or scattered.Age distribution of broadleaf trees was uneven-aged.There existed apparent species number increase and decrease relation between broadleaf species and Korean pine.So,it shaped multi-storied and mixed forest.The model of age structure and growth showed their positive correlation trend,but growth began to lessen when woods had grown into old age.

The approach installment calculation and comprehensive balance for deciding optimal annual forest felling volume overcame the disadvantages of current methods when forest age grades do not distribute evenly.Annual felling volume in every period of time can be adjusted.The approach provides scientific basis for revising short\|term annual felling volume and deciding middle-term and long-term forestry development planning.

The cytology of interactions between poplar cultivars and leaf rust (Melampsora larici-populina Kleb.)with different compatibilities were observed using electron microscopy at various times after inoculation. The results are as follows:(1) In non-compatible combination, the infection structure of the hypha was restrained in different ways. In medium resistant species or hybrids with the hypha were slightly restrained, and the extending area was relatively large. As compared with susceptible species, there were more vacuoles and lipid body in the hypha, and the hypha became more the electron dense. Species or hybrids with a high ability of resistant were similar to the medium resistant ones, but the number of hypha was smaller with more hypha deformity, darker in electron dense. Compare with resistant species, hypha deformity in near immune species or hybrids was more serious, and the cell wall of hypha were thicker, hypha became darker, the vacuole was larger, some of the organelles disintegrated, and hypha cells were dead or near dead.(2) The restrain and death of haustorium in all incompatible combination were similar. All the haustoria showed deformity and darken, with irregular form and with more black grains on the plasmallemma. (3) The reaction of host cells to pathogen was different in different compatible combinations. When rust hypha grew in the intercellular spalls between cells or along the cell wall, the cells of mesophyll maintained in normal state within the susceptible species. In the resistant combination, the cell wall became thicker when contacted with hypha, and papilla formed to restrain the infection. There were some black deposit between cell wall and membrane. Nucleus, mitochondria, and golgiosome gathered around the haustorium. Chloroplast deformed, starch grain became smaller and disappeared. The tonoplast membrane broke and some dark grains deposited on it, and all other organelles disintegrated, granulated or vacuolized, and then died. Cells adjacent to the infected cells were normal in medium resistant species, cell disintegration and death were common in resistant and immune species, and cells adjacent to the infected cells disintegrated or died to different level. (4) The death of haustorium was earlier than the death of host cell. When haustorium deforming or in necrosis, organelles in the host cell were still normal. With the developing of infection, the necrosis occurred to haustorium and host cells. The host hypersensitive necrotic reaction was similar to other rust fungi.

The diversity and insect community in different intercropping and managing jujube yard ecosystems in Taigu were studied. The results showed that there were 209 species of insect that belong to 13 order and 80 families in different jujube yard ecosystems in Taigu (including harmful mites). The number of order and species and individual were not the same in different jujube yard ecosystems. In different ecosystems, proportion of principal groups in insect community was different,so that diversity and evenness and dominant concentration index were not the same. Annual dominant species in each jujube yard was insect scales, and sometimes was Scythropus yasumatsui Kono et Morimoto and Sucra jujuba Chu and Tetranychus cinnabarinus (Boisduval). The dominant concentration index of insect community and its principal groups was not the same in different month and jujube yards.

Based on the method of PCR-RFLP and SDS-PAGE,cry genes and their expression products of 72 isolates of Bacillus thuringiensis from different forestry site zones in China were analyzed. Result showed that twenty one strains contained three cry type genes: cry1,cry2 and cry1I, six strains contained both cry1 and cry2 genes, four strains contained both cry1 and cry1I type genes, one strain contained cry1 type gene, four strains contained cry2 type gene. 36 strains did not contain ten cry type genes. Most cry1 genes encoded 130 kDa protein toxic to Lepidopteran pest, and most cry2 genes encoded 60 kDa protein.The isolates containing cry1Aa,cry1Ac and cry2 type genes were highly toxic to Helicoverpa armigera larvae, isolates containing one or no cry gene had low or no toxicity activity to pests.

Based on the results of observations and analyses for successive three years ,the relationships between Apriona swainsoni and its host trees were reported in this paper. The results were as follows:(1) According to the feeding and oviposting behaviour ,the survival time of the adult and the inoculating egg situation on different trees , the host trees reported in other papers could be divided into four types—highly sensitive tree (Sophora japonica); lowly sensitive tree (including Dalbergia hupehana,Caesalpinia decapetala);resistant tree (Robinia pseudoacacia)and immune tree (Salix matsudana). (2) Phenotic compound content in S.matudana (3.03～9.73 mg·(100g)^-1)was much higher than that in other host trees,which may be the reason why A swainsoni refused to eat, ovipsit and bore on this tree .The higher content of amino acid with the most types and higher C/N ratio was notable characteristic of nutrient material in S.japonica. Maybe this nutrient characteristic offers many attractions for A swainsoni. On the contrary, perhaps the lowest C/N ratio of R.pseudoacacia results in slight harm to it .The wood of D.hupehana with 0.837 mm in average fibre length,18.90 μm in average fibre width and 50.96 in the ratio of length to width,indicated that its tenacity and bending strength were the highest in that of all experiment host trees. In addition, the C/N ratio in the wood of this tree was also lower (0.36).These factors might make it difficult for the larvae to nibble and live on it .C.decapetala has thin and smooth trunk bark ,so it is hard for the adult to oviposit on this type of tree.

In the history of our earth,forest-fires have destroyed large areas of woodlands,doing great damages to environment,natural resources,other properties,and even human life,therefore,theories and practice in forest-fire prevention have always been the center of people's attention.This paper,in light of the author's perennial scientific research,introduced to the application of forest-fire prevention technology,espeically the extensive research on the supporting system for forest-fire prevention decision through technological problems solved during 3 stages within the recent decade.Examples were as follows:the establishment of large-area system,the operation of self-adapting display resolution,basic graphic processing techniques,Web-based bulletins,and applications of 3S(GIS,RS,GPS) and DSS.With the continuous development and extending application of high tech in networks and 3S,the research methodology for forest-fire prevention has changed a lot,thus the technical application will gradually be consolidated.

According to the statistic data of serious forest fire disaster in the year of 1951 to 1990 in Heilongjiang Province's forest area and the actual 286 data detected monthly from 1951 to 1991 in the North Pacific area,the basic laws and the time and phase characters of abnormal change,which were about monthly mean temperature of the North Pacific in the year when the forest fire disaster was serious in the Heilongjiang Province,were studied with the technology of analysis to abnormal degree.At the same time,the basic rules and the time and phase characters of abnormal change were also researched with the same technology in three years ahead of the serious year and three years after the serious year.It was concluded from the study that the years when the forest fire disaster was serious were positively related to the periods when the average distance of the sea surface temperature near the equator of the Pacific Ocean and they were synchronous.What's more,they were based on the prophase background that the sea surface temperature was abnormally low in the two years before the serious year came.It had important referenced value to scientifically predict the intending and quarter forest fire disaster activities and the lead-to-disaster potential of the forest area.

In order to supply necessary scientific bases and reference for breeding, genetic variation regularities in growth and wood properties of eucalyptus during hybrid breeding process were investigated. Variation and genetic parameters of major growth and wood properties were studied with F₁ of E. urophylla×E. grandis as materials. The results are as follows. (1) Tree height, DBH and dry timber yield of F₁ are mainly genetically controlled by father trees. (2) Wood basic density is controlled genetically by both father and mother, and their interaction too. (3) Fiber length and microfibril angle are mainly controlled genetically by mother trees; whereas tangential diameter of pores, cell-wall percentage of wood, wood fiber percentage and 1%NaOH extractives are mainly controlled by father trees genetically, and the ratio of fiber length to width too, but to a lesser extent; Percentage of vessel is controlled genetically by both father and mother trees; (4) Phenotypic variation in the ratio of cell wall thickness to fiber lumen diameter is mainly affected by environmental factors, father and mother and their interaction all show no significant genetic control on it.

Research was carried on the wood properties of 18 provenances of Pinus elliottii in Changle Forest Farm, Zhejiang province. The results showed that there existed significant differences among these provenances in wood air dry density, bending strength, modulus of elasticity (MOE), and compressive strength as well as toughness, tracheid length and width. In tracheid wall thickness and cell walls percentage, there were not significant differences. Meanwhile, there were not significant differences in wood air-dry density, mechanical strength and cell wall percentage of intra provenance. However, the differences in tracheid length and width, and wall thickness of intra provenance were markedly higher than those of inter provenance. As a result, it was probably effective in inter provenance selection according to wood air-dry density, mechanical strength and tracheid morphology, and in intra provenance selection based on the inter provenance selection with reference to tracheid morphology (tracheid length and width, and wall thickness). The broad sense heritabilities for wood tracheid length (0.3615), width (0.5993), wall thickness (0.7473), cell walls percentage (0.1698), wood air-dry density (0.4142), bending strength (0.2646), MOE (0.1082), compressive strength (0.2977), toughness (0.1246), tree height (0.4057) and DBH (0.4747) of 18 provenances were calculated. These results indicated that wood tracheid, wood density and tree growth (except cell wall percentage) were under moderate or low moderate genetic control. So high genetic gains could be gained by inter provenance selection of suitable intension. In addition, this study could provide a base for the selection of pulpwood and building timber after combination evaluation of tree growth, tracheid morphology and mechanical strength.

For veneer peeling, the most crux technique of the peeling is how to fix the optimum centering point. In this paper based on the three points centering and four points centering theory, peeling log six points centering theory is pointed out. Arbitrarily six points of the log cross section are taken out by this theory and with these six points the optimum circle centering axis of the log internal envelope cylinder is regressed. Then the log centering precise is raised up and the veneer out put rate of end product veneer qualified rate is increased. This makes the theory of log centering up to a higher level.

Biodiversity conservation has become one of the important goals of sustainable forest management. Biodiversity indicators can be of three principal types: species and communities, structures, and processes. Species can only serve as an incomplete, surrogate measure. The progress in indicators of structural diversity within stand is reviewed in the paper. It can be included as distance independent indicators and distance-dependent indicators, which describe tree size diversity, horizontal pattern of trees, intermingling of two tree species, and spatial structure complexity. The study trends are discussed.

The pathway and genes of anthocyanin biosynthesis in ornamental plants were discussed in this paper. Factors affecting pigmentation included anthocyanin structures ,pH value in cell sap of petals, co-pigmentation, metal chelates, the shape of epidermal cells, and so on. Modification of flower color using genetic engineering was also summarized. It was suggested that new flower color could be created by regulating those factors that affected pigment and probing anthocyanin biosynthetic genes.

In the paper, the area of the Conversion of Cropland to Forest and Grassland Project was divided into two main regions and nine types of subregions. On the basis of subregion,the basic technical thinking and the model for the conversion of cropland to forest and grassland in each type of subregion were studied including the following contents: the geographical scope,the characteristics of natural resources,the social-economic features, the main limiting factors,the basic technical thinking,the structure of forest and grass types,the ways of vegetation recovering, the techniques for vegetation recovering,the main tree and grass species, the protection and management patterns,etc.

Based on many facts of experiments, this paper demonstrated and filtered all factors affected the thickness swelling of particleboard after considered them in care, and founded the equation model for thickness swelling of particleboard, that's TS(t)=F(t)+f(M .C ,t)+V(t) It means that the thickness swelling comes mainly from the recovery of visco-elastical deformation of wood in particleboard, hygroscopical swelling of wood in particleboard and deformation caused by destroyed glue lines between particles. When the change of moisture content in the board is rather great or obvious, the mechano-sorption creep item A(M .C ,t), shall add to the model.

The contents of endogenous hormones and nutrients were determined for the ovary of normal chestnut and empty-shell chestnut.the results showed that,the contents of endogenous GA₁₊₃,iPA_S and the ratio of (GA₁₊₃+iPA_S)/ABA in normal chestnut ovary showed as a “Double peaks” pattern,while the content of endogenous ABA in ovary tended to reversely change by a small range.In contrast,the endogenous hormone contents and their ratio in empty-shell chestnut ovary showed no obvious peak,the contents of endogenous GA₁₊₃iPA_s and the ratio of (GA₁₊₃+iPA_S)/ABA appeared a descending trend while the endogenous ABA content appeared an ascending trend during whole embryo developmental period.The contents of reducing sugar,starch,protein,amino acids,phosphorus and potassium in empty-shell chestnut ovary started to decline or maintained in a declining state on the 45th day after bloom(early-July),meanwhile,those in normal chestnut ovary tended to rise up or remained high level.It is suggested that the declines of endogenous GA₁₊₃,iPA_S contents and the ascending of endogenous ABA content lead to the low levels of reducing sugar,starch,protein,amino acids,phosphorus and potassium in ovary,which consequently cause an empty-shell formation.

The main economic characters of 45 walnut species from Jianshi County, Hubei, which include fruit weight, per fruit weight, per kernel weight, kernel rate, index of kernel catching, kernel weight, content of crude lipids, content of crude proteins, and content of soluble sugars, were analysed by principal component analysiss according to the correlation matrix of samples. According to more than 91% of the cumulativee variance proportion, six principal components and their function equations of the main economic characters of walnut from Jianshi, Hubei, were proposed. The relevant combinations of the principal components were proposed according to the trendency of market requirement after the important values of the principal components were computed, and the synthetical evaluating indexes were built according to the arrangement of the excellent trees for different market aims. The results are similar to the actual phenotypes of excellent trees, suggesting synthetical index analysis is more scientific and simple than the tranditional giving marks and single-charactered selection in evaluation of the main economic characters of walnut. The results provided theoretical basis for the selection and usage of walnut.