The RNA genome was purified from tobacco mosaic virus (TMV) infecting Chinese tobacco plants. The cDNA of the gene encoding 54 kD protein of TMV was synthesized using the RNA genome as template, and a piece of artificial oligonucleotide as primer. The eDNA was cloned into pBluescript, generating pRC19, and identified by restriction endonuclease digestion. Determination of the nucleotlde sequence of the eDNA fragment shows that the gene is 1422 bp in length and encodes a protein of 474 amino acids. The gene is highly homologous in DNA sequence to that of TMV U1 strain. The deduced amino acid sequence of the 54 kD proteins of both strains are identical. The 54 kD gene was transformed to tobacco plants and the transgenic calli growing on selective medium were obtained.

The intergeneric cross between wheat and maize are characterized by a high frequency of formation of hybrid embryos, but maize chromosomes are rapidly eliminated in the first few cell division cycles to produce haploid wheat embryos. If left the embryos on the plants they will soon abort, as a result of the absence or poor development of the endosperm. Embryo rescue techniques should not enable these embryos to grow to plants because of the embryos were extremely young for embryo culture. Viable embryos were obtained at much higher frequenc, if spikes containing cross-pollinated florets were dipped in 100 ppm 2,4-D solution 4 hours after pollination. Of the 382 florets treated, 64(16.8%) embryos were obtained 10 days after treatment, and 47 plants recovered on the culture medium. In control (2,4-D not applied) only 1 (0.96%) embryo and 1 plant was obtained from 104 florets. This simplified technique should enable haploid wheat plants production through wheat - maize to apply to practical breeding.

This is a highly condensed summary of the author’s life-long undertaking in the field of cellular respiration, photosynthesis and bioenergetics in the green plants.

The emission of nitrous oxide is not only a way of nitrogen loss in ecological system of agriculture, it is also a contamination source of increasing nitrogen oxide concentration in the atmosphere. This paper reports the analysis of gas chromatographic determination of N2O on the soybean plant and its different four organs-root, stem, leaf and cotyledon under strict aseptic condition. The results showed ,hat they all are able to emit nitrous oxide.

Protoplasts were isolated from leaf, petiole and stem segment-derived calli induced from one pistillate plant of Actinidia deliciosa line No. 26. Regenerated plantlets were obtained from protoplasts of leaf-derived and stem segment-derived calli, while only calli regenerated from protoplasts of petiole-derived calli. Seventy-six plants from protoplasts of leaf-derived calli and 21 plants from that of stem segment-derived calli survived after transplanting or grafting during 1987–1989. One staminate plant and two pistillate plants bloomed in May, 1991 and fruited soon afterwards. In all of those three plants regenerated from protoplasts of leafderived calli, sex differentiation occurred from somatic cells of Actinidia was verified. Somaclonal variation on leaf shape and plant morphology was obviously appeared. Chromosome number identified from 16 plants varied from 116 to 180.

In this paper, a new species of the genus Phyllocladoxylon on the basis of fossil woods from the Fuxin Formation in Western Liaoning province, Phyllocladoxylon xinqiuensis sp. nov., is reported and its anatomic structures are described.

Six compounds were isolated from the tuber of Xylanche himalaica (Hook. f. et Thorns.) G. Beck Based on the physico-chemical constants, spectral analysis (IR, MS, 1H-NMR, 13C-NMR)and preparation of the derivative, they were identified as 3-epi-acetoxyurs-12-en-28-al (Ⅰ), ursolic acid (Ⅱ), 3-epi-ursolic acid (Ⅲ), (+)-pinoresinol (Ⅳ), (+)-pinoresinol monoglucoside (Ⅴ) and daucosterol (Ⅵ). Ⅰis a new compound.

Cells were isolated after enzyme treatment from the thalli of Porphyra yezoensis Ueda and cultured in enriched seawater media (MES). Cultures were put in an incubator with light intensity of 2000--2500 lx from cool-white flurescent lights and were maintained on a 12:12 LD cycle. The temperature was 20±2℃ and the media were changed weekly. Two main types of differentiation and development ways in cultured cells under light microscope: 1. Cells directly formed the single cell seedlings Eke monospores; 2. Cells first divided into cell aggregates, then released lots of spores that could germinate into sporelings. Both single cell seedlings and sporelings were called cell seedlings. So it is possibole to breed from the ceils isolated directly from the thalli in Porphyra yezoensis.

The seeds of Aconitum kusnezoffii Reichb. take three months to germinate after shedding. This is due to the fact that the embryo of A. kusnezoffii is not fully developed at the time of shedding, remaining in the stage of heart-shaped or early torpedo-shaped embryo. The germination of seed is epigeal, but in the first year the shoot apex remains in the soil and the short subterraneous stem hibernates with the thickened root-hypocotyl. In the following spring, the stem sprouts out and the axillary bud of the first year's radical leaf develops into a monkshood-tuber. The individual monkshood-tuber is monocarpic, each sprouts out one flowering stem and, at the same time, gives rise to one or sometimes more monkshood-tubers from the underground basal buds, thus, A. kusnezoffii may actually be considered as a “replaced biannial plant”.

Studies of ultrastructure and ATPase localization of the mature embryo sac in Vicia faba L. show that the egg cell has no cell wall at thechalazal end, it has a chalazally located nucleus and a large micropylar vacuole. There are many nuclear pores in the nuclear membrane. The cytoplasm is restricted around the nucleus. Dictyosome and mitochondria are few. There are some starch grains and lipid grains in the egg cytoplasm. There are no obvious differences between two synergids. No cell wall is seen at the chalazal end either, but there are some vesicles which project to vacuole of the central cell and fuse with its vacuolar membrane. Plasmodesmata connections occur within the synergid wall where it is adjacent to the central cell. The synergid has a micropylarly located nucleus and a chalazal vacuole, the nucleus is irregularly shaped. The synergid cytoplasm is rich in organelles. The filiform aparatus is of relatively heterogeneous structure. The central cell is occupied by a large vacuole and its cytoplasm is confined to a thin layer along the empryo sac wall, but is rich in various organelles, starch grains and lipid bodies. Nucleolar vacuoles are often present two polar nuclei. The nuclear membranes of two polar nuclei have partly fused. ATPase reactive product was located obviously at the endoplasmic reticulum in cytoplasm of the egg cell and central cell. The embryo sac wall consists of different density of osmiophilic layer. There are some wall ingrowths in chalazal region of the embryo sac. The long-shaped and cuneate cells of chalazal region are peculiar. Special tracks of ATPase reactive products are visible at their intercellular space which may be related to transportation of nutrients.

Relevant effects of ethylene and Ca2+ on germination of lettuce (lactuce sative L.) seeds were investigated. It was shown previously that lettuce seeds were highly sensitive ro temperatures. More than 70% of seeds germinated at 22℃, but they ceased to germinate at 25℃. 40%–50% of seeds could be induced to germinate after imbibition with 400 ppm exogenous ethylene for 3 days at 25℃. The amounts of endogenous ethylene liberated at 22℃ were much greater than those at 25℃. Ethyleneglycol bis NN tetraacetic acid(EGTA, Ca2+ specified chelating regent) La3+, Co2+ and chlorpromazin(CPZ, calmodulin antagonist) could be used ant only to inhibit germination at 22℃, but also to inhibit germination induced by ethylene at 25℃. Although La3+ and CPZ inhibited seed germination, they could not repress the production of ethylene at 22℃. It was suggested that Ca2+ and CaM affected the induction response of ethylene to lettuce seed germination, but had no effect on ethylene liberation. Co2+ could be applied to inhibit the action as well as its production of ethylene.

The embryo culture in vitro response was examined among ten rice (Oryza sativa L.) cultivars and 26 cross combinations to evaluate the correlation between callus induction rate and differentiation rate with plantlet regeneration rate, the influence of parents to hybrid Fl embryo culture in vitro as well as the cytoplasmic effects. Plantlet regeneration rate was used as the product of callus production and regeneration capacity. The ten pure-lines, the five F1s and their reciprocal hybrid as well as the ten F1s among the ten lines were evaluated for callus production and regeneration capaticy. Significant variation was observed among the 36 genotypes in callus induction rate, callus differentiation rate and plantlet regeneration rate on embryo culture in vitro. The positive correlation between general callus induction rate and differentiation rate with plantlet regeneration rate was significant. There was a similar trend for callus induction rate between maternal parents and Fis during mature embryo culture in vitro. However, parent-offspring correlation for callus differentiation rate and plantlet regeneration rate were nonsignificant. Whether cytoplasmic effects for embryo culture response exist among the six pure-lines was examined py the differences between reciprocal F1 hybrids. The extent of cytoplasmic effects depended on cross combination.

Gliadin and glutenin of seeds of a pollen-derived pure line “H-33” and its 9 stable somaclones of wheat (Triticum aestivurn L.) from inflorescence callus were investigated using SDSPAGE. Among the 9 somaclones 6 were identical to the “H-33” in SDS-PAGE patterns of of gliadin and glutenin. The other 3 somaclones were identical with each other, but different from “H-33”. The varied electrophoretic bands of seed protein showed that somaclonal variation had occured at gene level during tissue culture in which the somaclones were produced.

Comparative studies on localization and distribution of cyclic adenosine monophosphate phosphodiesterase (cAMP-PDEase) activity in the young leaf cells of two different cold resistant wheat (Triticum aestivurn L.) varieties during cold acclimation were carried out by means of ultracytochemical method. The results indicated that the reaction products of cAMP- PDEase activity in two varieties of the seedlings grown at optimum temperature (20–25℃) were mainly localized at plasmalemma, nucleoli and chromatin. When the wheat seedlings were subjected to low temperature acclimation, cAM P-PDEase activity in the strong cold resistant variety Yanda 1817 seedlings was markedly decreased; however, little alteration of this enzyme activity was observed in the weak cold resistant variety Zhengzhou 39-1. cAMP-PDEase activity was recovered after deacclimation. The results suggested that changes in cAMP-PDEase activity during cold acclimation were closely related to the development of plant cold hardiness.

Thidiazuron (TDZ) was ussed as a cvtokinin in micropropagation of two Ficus species for comparison of its activity was compared with BAP, a purinetype cytokinin. In the cultures of F. lyrata, TDZ in concentrations ranged from 0.01 to 0.02 mg/L could stimulate micropropagation. When the concentration of TDZ exceeded 0.2 ml/L, the shoots became somewhat malformed and vitrified in both species. Our result revealed that the cytokinin activity of TI)Z in stimulation of shoot proliferation was higher than that of BAP in the cultures of F. benjamina, but not in F. lyrata.

Swertia erythrosticta Maxim. (Gentianaceae) is a herb used for curing some diseases in Tibetan traditional medicine system. Eight xanthones were isolated from this species. Their structures were identified as 1,8-dihydroxy-3,7-dimethoxyxanthone(Ⅰ), 1,5,8-trihydroxy-3-methoxyxanthone (Ⅱ), 1,3,8-trihydroxy-5-methoxyxanthone (Ⅲ), 1,7,8-trihydroxy-3-methoxyxanthone (Ⅳ), 1,3,5,8-tetrahydroxyxanthone (Ⅴ), 1,3,7,8-tetrahydroxyxanthone(Ⅵ), as well as 8-O-β-D-glucopyranosyl-1, 5-dihydroxy-3 -metho xy xanthone(Ⅶ), 8-O-β-D-gl ucopyr anosyl- 1,3,5- trihydroxyxanthone(Ⅷ) by means of chemical methodes and spectral analyses.