Role of abscisic acid(ABA) in the induction of freezing tolerance in Acacia mearnsii suspension-cultured cells was studied, which mainly concerned the concentration of exogenous ABA added into medium, the time course for the induction of freezing tolerance,induction of increase in soluble proteins and inhibitory effects of cycloheximide on development of freezing tolerance.The results indicated that Acacia mearnsii suspension-cultured cells could be hardened for 8 days at 25℃ by adding ABA into MS medium. Cells treated with ABA (10mg/L) attained a survival of 83.6% at-6℃, while the survival of the nonhardened(control) was 0.In comparision,the cells treated with ABA increased 5.5 fold more soluble proteins.The biosynthesis of soluble proteins was inhibited by cyclohexomide,and the development of freezing tolerance induced by cold acclimation and ABA was simultaneously prevented.

In the area (24°39′-30°08′N, 108°47′-114°15′E),the root systems of 68 trees belonging to 12 tree species were investigated to furnish the scientific basis of tree species selection for planting in the water-eroded lands.By the combiming method of qualitative and quantitative,the ecological adaptability of common tree species to the water-eroded lands in the subtropical zone were evaluated.The conclusions were:1.The limit of ecological adaptation for 20 tree species to soil layer depth were worked out.The limit of 0-5cm was for Pinus massoniana,P.taeda,P.elliotii,Liqiuidambar formosana,Robinia pseudoacacia,Pistacia chinensis,Quercus fabri,Q.acutissima,Q.chenii,Castanea henuyi,Cyclobalanopsis glauca,6-20cm for Q. rariabilis,Dalbergia hupeana,Schima superba,Nyssa sinensis, Cupressus funebris,Ziziphus juiuna,Myrica rubra;and 21-30cm for Cunninghamia lanceolata, Sassafras tzumu.The root traits of the tree species which have the minimum limit of the ecological adaptation are as follows:The larger area,the deeper distribution and creeping on the shallow layer of soil and developing along the crevice of rock in soil.2.Using Quantification theory (I)the relationship between 11 tree species and ecological factors,and the adaptability of plants to the ecological factors were found out.According to their contribution to the plant growth,the order of the ecological factors were arranged.In addition,we found that the soil layer,soil layer plus parent material and slope were the most important factors to the growth of plants in water-eroded land.

The accumulation,distribution and bioligical cycling of 11 nutrient elements in the three plantation ecosystems of 12-year-old Eucommia,Chinese Corktree,Twolobed Official Magnolia are studied.The results show that among the various organs of above ground,the nutrient elements contents are different,that the changing rules of the nutrient element contents in plant and soil system are identical,that the orders of the average rates of nutrient elements in the biollogical cycling of these three medicine plantations are,Twolobed Officinal Magnolia>Eucommia>Chinese Corktree,and that the utilization efficiency of the nutrient elements in stand systems is in order of Eucommia>Chinese Corktree>Twolobed Officinal Magnolia.

By the methods of fluorochroma(FDA),in vitro,in vivo and nursery stock growing,the pollen quality of the two woody plants, Liridendron chinense and L. tulipifera is examined,and the change in pollen quality was observed during the flowering period.Meanwhile,the pollen germination on the stigma and the growth of pollen tube in the style were investigated under the natural or artificial pollination condition.The results indicate that in vitro condition the pollen germination and pollen tube growth are promoted by the style and ovary tissue obviously.The pollens are affinity,and germinate well on oneself or alien stigma and ovule,however the rate of the pollen tube passing the style is low,only 24%,which is in accordance with our previous study.The results prove again that the developmental phase of the male gametophytes is one of the important factors which influence the seed setting rate,and the style is the region where the inaffinity reaction occurs.

Cell suspension cultures are successfully established from the friable calli which are produced mainly on a medium(M4:Ms + 0.45mg/L 2,4-D +0.3mg/L NAA + 0.1mg/L Kinetin). The best suspension medium is:Ms + 2,4D(0.5mg/L) + sucrose (30g/L). Addition of glutamic acid, aspartic acid and arginine into the liquid medium was beneficial for the growth of the suspension cell. In a culture cycle, there is a direct relationship between the growth rate of suspension cell and the change of the medium pH.Several NaCl-tolerant (3.0-4.5‰ NaCl) cell lines were obtained by direct selection and the adventitious buds had grown out from these NaCl-tolerant cell lines.

Based on the Cunninghamia lanceolata zone and region,which are divided in 14 southern provinces(regions)accordiog to the Chinese fir research coordinated groups,in 1981 the experimental plantations of Cunninghamia lanceolata were established in Guangxi,Jiangxi,Fujian, Sichuan and Henan Provinces,which consisted of 5 different densities.The measurements of 10 years showed that densities influenced the main growth parameters of trees and wood quality. According to the analysis of timber yield and economic benefit,the optimum initial planting densities for various index classes are determined,i.e.5000 trees per hectare are optimum for the index class of 14-16 in the south and middle zone, and for the index classes of 12-14 in the north zone, 3333 trees for those over 18 classes in the mid zone.

Brown spot needle disease is one of important diseases on Pinus elliottii and P.taeda in south China.On the basis of resistance selection,the glucose-6-phosphate dehydrogenase and phenylalanine ammonia lyase activities in needles of 9 resistant clones and 4 susceptible individuals of slash pine were studied and analyzed.The results showed that there were close relations between the activity levels of glucose-6-phosphate dehydrogenase and disease resistance in two-year-old needles of slash pine.The enzyme activity levels of 9 resistant clones were mostly higher than those of 4 susceptible individuals.Phenylalanine ammonia lyase activities of the resistant clone needles,in general,were also a bit higher than those of susceptible individuals.After resistant and susceptible needles were treated by primary toxin of brown spot fungus,their glucose-6-phosphate dehydrogenase activities all increased,and the increment extents were all about 0.5-1 times,but their phenylalanine ammonia lyase activities didn't evidently change.

After investigating the ectomycorrhiza of 35 species poplars in Shoaanxi Province,9 species of ectomycorrhizal fung were identified. Experimental results proved that a species of ectomycorrhizal fungus can infect differentspecies of poplars,and that a species of poplar can be infected by different species of fungi.It was also dicovered that in the same small root mantle was formed on the top,and vesicular-arbuscular was formed on the middle and lower parts.This is a special form of mix-mycorrhiza.

In this paper a new species of the genus Hoplocampa──H. danfengensis is described, which is a serious pest of cherry in Shaanxi Province, china.Male:Body black,shining;antenna, palpi brownish black; apex of mandible reddish yellow; wings hyaline, barely tinged with brown; veins, margin of stigma pale yellow,center of stigma light yellow; legs with coxae,trochanters, base of femora black; tibiae,tarsi 1 and 2 yellowish brown; genitalia, apex of hypopygium reddish yellow. Clypeus convex, with anterior margin emarginate; fovea round, small and shallow;frontal carina distinct;antennal furrows deep; transverse suture distinct; lateral and coronal sutures obsolete; relative length of postocellar area to its width= 1:4.8;OOL:POL:OCL== 2.5: 2. 5: 1; hind tarsus about as long as hind tibia; penis valve see fig.1. Head, mesonotum, mesepisternum with fine, dense puncturest showingrugose surface;abdominal terga, sterna, Lypopygium with minute, dense punctures and fine sculptures. Body length 4-4. 5mm; antenna 9-segmented,length of segment 3: length of segments 4+5 = 1:1.3 pubescence on head and thorax short, golden yellow.Female: Body color as in male; antenna dorsally black, ventrally brownish black; veins, margin of stigma black; center of stigma greyish black;hind leg black; relative length of postocellar area to its width= 1:7.8;OOL: POL: OCL= 1: 5: 1; lancet see fig. 2; other characters as for male. Body length 4. 5-5mm; antenna 9-segmented, length of segment 3:length of segments 4 + 5 = 1 : 1. 4.Variability: In a few male specimens antenna dorsally dark yellow,ventrally yellow; 6th and 7th sterna reddish yellow; legs with femora except apices, tibiae, tarsi deep yellow. In the female, in a few cases, apex of abdomen and sterna deep yellow.Holotype , Danfeng County, Shaanxi Province, 22. -Ⅲ. 1991, Sun Yizhi leg. Allotype ♀, same as for holotype. Paratypes 14 , 2 ♀♀, same as for Holotype.Host:Prunus pseudocerasus Lindl.The new species resembles Hoplocampa rutilicornis (Klng),but differs from the latter in penis valve and lancet.The type specimens are kept in the insect collection of the Forest Research institute, the Chinese Academy of Forestry.

Hindolodes sporsuta Jacodi was first collected at Shaowu, Fujan Province in 1944 and the host plant was not recorded.The author discovered a large number of this insect in 1990 on the twigs of Celtis sinensis Pers. At Taigu,Shanxi Province.There is one generation per year. Winter is passed as the full-grown nymphs in the tubes constructed on the twigs of the host.In early April to May.The sex ratio is about 1:1.08. Females lay eggs on the surface of the fruits arranging in single line of 2 to 14 eggs. Generally each female lays about 80 eggs. The egg stage is a month and the hatching rate may reach 82.8% There are 5 instars in the nymphal stage, the stadia are 18, 20, 30, 230 days, respectively.In June and July,the young nymphs construct calcareous helical tubes densely fixed on the petiole of fruit This tube is called "summer tube", In August, the 3rd instar nymph comes out of the summer tube and crawls the twigs, oil which they construct pale and hard tubes with the glue fluid from the anus The principal composion of the tube is calcium carbonate The nymphs develop in tube untill mature and emergece.The morphological characteristics of the pest are also describes.

Based on the results from the studies on wood cutting resistance of 11 coniferous woods and 15 hardwoods,a model was developed, with which the law of the variation of wood cutting resistance for various wood species under various conditions involving different chip thickness,knife rake angle,and wood moisture content in diffrernt cutting directions can be quantitatively described,and the prediction of such variation can be made.The model consists of three parts:(1) average levels of the cutting resistance under various conditions,(2)effects of chip thickness, koife rake angle,and wood moisture content for various species,(3)correlation between wood density and cutting resistance under various conditions.

This paper gives a review of techniques used previously in inside country and abroad to measure wood surface roughness,and establishes a statistic model of wood surface. By means of random process theory,the theoretical model of optical Fourier transform spectrum intensity distribution(OFTSID)of the 1-D Gaussian distribution wood surface is established. And the numerical expression of the theoretical model that can calculate root-mean-square height Rq and autocorrelation function of wood surface is got by numerical calculation.This paper mentioned a new type of measurement system that can measure the two parameters above.This system has the advantages of noncontact,high measurement speed,unaffected by the inspected wood material and giving more abundant information about inspected surface This method can be used in classification and in-time measurement of wood surface roughness after improved.

In order to evaluate technich condition of bridges in forest regions properly,the difference between theory and test value of deflection on reinforced concrete and prestressed concrete beams bridges which are simply supported in forest regions is analysed by authors in this paper.According to test date and the regulation on railway bridges; the limiting values of test deflection are given which are 1/3000 of beam span simply supported to R.C.beams bridge and 1/1600 to P.C.beams bridge.The limiting value can be rigidity standard when supporting test evaluate bridges.

Following the theories of ecological comparative and plant community succession,this paper describes the population dynamics and establishment of mathematical models of growth of arrow bamboow stands on subalpine in Sichuan Province, based in observations of the number of new bamboos,ground diameter,age,density and biomass etc.The posibitity was discussed to provide giant pandas with imitated habitats through establishing plantations of arrow bamboo.The result also suggested that forest environments were not only critical for the survival of giant pandas but also for the establishment of arrow bamboo plantations.

The habits of Hololrichia trichophora Fairmaire,Adoretus sinicus Burmeister and Anomala antiqua Gyllenhal were observed The first and the second kinds of scarabs each has one generation per year, the first overwinters as adult or a few larvae and pupas under the soil surface at a depth of 60-90cm,its adult is very active during the early Spring, the female lays eggs under the soil surface at a depth of 15cm,the egg stage lasts 5-10 days,the average number of eggs laid by a female is 15.9;The second overwinters as larvae in the soil at a depth of 5-10cm, it has two damage peak periods,one is from mid-May to early June,and the other is from mid-August to late august,each female has 35-63 eggs which was laid under the soil surface ata depth of 5-10cml The third has two generations each year and overwinters as larvae under the soil at a depth of 15-30cm,its eggs usually lay in the moist and loose soil,the average number of eggs laid by a female is 16.9.The three kinds of scarabs have aggregation character,the second kind has stronger phototaxis than the other two kinds.