The number size and morphology of resin canals in secondary xylem of three species of normal and dwarf pines, i. e. Pinus thunbergii, P. tabulaeformis and P. densiflora, were comparatively studied. It was found that the number of resin canals in dwarf pines was significantly greater than in normal pines, while the size of resin canals in dwarf pines was invariably smaller than in normal pines. In addition, the epithelial cells around the canals of dwarf pines extended laterally, which made the outline of resin canals aliform-like. These findings might indicate that the raviations of resin canals representing a special adaptation to the unfavourable growth conditions were also correlated with the trend of shortening and narrowing of dwarf pines.

Three new monotetrahydrofuran annonaceous acetogenins, namely; howiicin A ( Ⅰ ), howiicin B ( Ⅱ ) and howiicin C ( Ⅲ ), were isolated from the seeds of Goniothalamus howii. Merr. Et Chun. Their structures were elucidated on the basis of IR, MS, 1H-NMR and 13C-NMR and their acetate derivatives, respectively. The known compound, goniothalamin, was also obtained.

A new diterpenoid lactone,named isotritetraolide, was isolated from Tripterygium wilfordii Hook. f. The structure of isotriptetraolide was elucidated on the basis of UV, IR, MS, 1H-NMR, 3C-NMR , 1H-1Hcosy, 1H-13Ccosy, DIFNOE, NOESY and X-ray diffraction methods.

The earliest undoubted fossils of Quercus L. are not found until Eocene, although the oaks may have originated prior to the late Cretaceous. Most oak species from the old Tertiary rocks, which are assumed to be evergreen and ranged the montane tropics and montane subtropics near the sea ,can scarcely be referred to modern species. Both diversity of oaks and their dominance in flora increased in Oligocene and gradually reached their prosperous stage. In Miocene,there many existed extinct species groups and many essentially modern species were present. The oak distribuiion pattern in Pliocene was similar to modern one. The first deciduous oak species appeared in the middle Oligocene in Northeast China when the oaks in high latitude retreated southward caused by the spreading of colder and drier climate. In early Neogene oaks disappeared in Northwest China because of the occurrence of the Middle Asian Desert. Meanwhile, the species of Sects. Suber and Englerianae evolved in Southwest China as a result of orogenesis of the Mountain Himalaya. The fossil records indicated that the interchange of oaks between North America and China was not ended until the middle Miocene,while the linkage between Europe and China was not ended until the early Pliocene.

Somatic embryos of Coptis chinensis F. were dehydrated with 3 different methods; viz. low temperature (4 ℃ )refrigeration; room temperature in either a conventional oven (oven dried 23 ±1 ℃ ) or a vacuum oven (vaccum dried, 4 to 8 ℃ ). During desiccation, somatic embryos decreased in size and became dark yeUow and brittle. Embryos were tested for their germination potential by placing them on 1/2 strength MS medium supplemented with 6-BA(0.5mg/L),GA(0.5mg/L), IBA(0.5mg/L)and 3%maltose. No germination of embryo was observed if the water content of the embryo was less than 12.5%. Somatic embryos germinated best (86 % )when the relative humidity(RH) was 70% to 90% and germination ceased at 30% RH. After 42 days of storage,a germination rate of 75% of the non-encapsulated somatic embryos were obtained by slow desiccation at 4 ℃ a refrigeration,while the germination rate of somatic embryos desiccated at 23±1 ℃ was zero. On the other hand,germination rates of 82.5% and 30.8% of the encapsulated and non-encapsulated somatic embryos desiccated at 4 ℃ were gained after 42 days of storage respectively. These results indicated that the encapsulated somatic embryos have higher desiccation tolerance and longer storage time than the non-encapsulated somatic embryos. The relationship between water loss velocity and the vigor of desiccated somatic embryos were also discussed.

Calli were induced from plumular axis of Melilotus albus . Calli of differentiated buds were inoculated in liquid Ax media containing 2,4-D(1--4mg/L)and 6BA(0.2—8 mg/L)for vibrating culture. 9 cell lines were obtained among which 4 were cultured in Ay2 media containing 2, 4-D (0. 5—2 mg/L)and 6BA (0. 1—2 mg/L)and only cell line, L5 formed calli. The calli were transferred onto Afl medium containing 0.2 mg/L 2,4-D, where many young buds were differentiated,the buds were then transferred onto Af2 medium (Af1 – 2,4-D + l mg/L GA3), where they developed into young seedlings continuously. High regeneration frequency (793. 3%–1127%) of calli were obtained from isolated cells cultured in 0. 5—1 mg/L 2, 4-D, 0. 7mg/L 6BA. Differentiation frequency of calli from isolated culture cells was increased on the medium containing lower concentration of 2,4-D.

The absorption transportation and distribution of exogenous cholesterol in rice(Oryza sativa L. )seedlings were studied by means of 3H-labelled autoradiographic technique. The results showed that exogenous cholesterol was soon absorbed and transported by the root system, the accumulated radioactivity of the aerial leavesand membrane lipid almost sharply increased during the three-day experimental period with the distribution among the leaves in the order of the second leaf> the third leaf>the fourth leaf. Test of spreading the second leaves with aH-cholesterol proved that aside from a large ainount of radioactivity accumulation in the spread leaves themselves,aH-choles-terol was also distributed in other parts in the order of the first leaf>root>the third leaf>the fourth leaf. Radioautography showed that the silver grains were localized at vacuole and protoplasm as well as plasma membrane and other sub-cell organs. The above results indicate that rice root system and leaves not only absorb exogenous cholesterol quickly but also transport it between roots and leaves and between leaves, where it finally combines with the membrane system in cell to affect the structure and function of the membrane.

The cytochemical localization of ATPase in differentiating and mature phloem cells of broad bean (Vicia faba L. )has been studied using a lead precipitation technique. The phloem of the recurrent vascular bundle of broad bean seed coat contains a considerable number of plasmodesmata, which is benefit for symplastic unloading, and also exhibits ATPase activity in the plasma membrane of sieve elements and companion cells,through which photoassimilates unload apoplastically. The phloem of the complete chalazal vascular bundle persistently exhibits high ATPase activity in the plasma membranes of sieve elements and companion cells and in the plasma membrane of developed transfer cells. It shows that apoplastic unloading is the main pathway of unloading. The epidemic cells of cotyledon transform to typical transfer cells exhibitting strong ATPase activity in the plasma membrane. The photoassimilates actively are transported into the cotyledon passing through the membrane apoplastically.

The results of studies on the photosynthetic characteristics of chloroplast from lotus (Nelumbo nucifera Gaertn. ) during germination in light are as follows: 1. Absorption spectrum of chloroplast from lotus germinated for 2--4 days was different from that of fully developed and incompletely developed chloroplast. Its absorption peaks at 480 nm and 650 nm were very high. They gradually decreased as the time of germination increased. The absorption peak of chlorophyll b at 640 nm almost disappeared on the 4th derivative spectrum. The chlorophyll a/b ratio increased from 0. 7–0.9 on the first several days of germination to the normal value on the tenth day of germination. 2. Low temperature (77K) fluorescence emission spectrum of chloroplast from lotus germinated for 2–4 days was different from that of fully developed and incompletely developed chloroplast. It only had one emission peak at 681 nm. The fluorescence emission peak at 730 nm appeared on the eighth day of germination. The value of this peak increased with germination. 3. The fluorescence induction kinetics at room temperature showed that the only component of fluorescence emitted from lotus cotyledon germinated for 4 days was constant fluorescence (Fo), whereas the variable fluorecence(Fv) did not appear until the 6 day of gemination and its PSII activity and efficiency of primary conversion of light energy at that stage were very low. The P peak appeared at the 13th day of germination and M peak developed even later. It was firstly demonstrated that the pathway of chloroplast development in lotus in light seemed to be different from that of other higher plants.

A strain of Bacillus spp. has been screened from paddy field. It can secrete large amount of antagonistic proteins and has a strong inhibiting activity against several pathogens of rice. The authors studied the inhibiting spectrum and the characterization with antagonistic protein of T3. Total proteins were precipitated with ammonium sulfate at 70 % saturation from cell-free culture. One of the proteins was purified from the crude extract with Sephadex G-100,DEAE52 and FPLC superose 12 columns. This protein (Tzl) was subjected to the 15 % SDS-PAGE and only single band with 6.9 kD was observed. The protein on IEF showed single band with pH7.8. The amino acid composition of the protein was analyzed and sequenced. Work is in progress to clone the gene encoding this protein.

An electron microscopic study on the plasmalemma glycoproteins in the young leaf cells of winter wheat Triticum aestivum. L. seedlings during cold acclimation was carried out using Concanavalin A-conjugated peroxidase for cytochemical observation. Membrane lipids have been observed following glutaraldehyde-osmium tetroxide fixation. The results are summarized as follows: During cold acclimation of winter wheat,partial lipid molecules were released from plasmalemma following cell dehydration and plasmalemma shrinking,and so osmiophilic bodies have been observed underlying the plasmalemma. At the same time ,the glycoproteins which were particulately distributed in plasma membrane before cold acclimation became dispersedly distributed in plasmalemma. When temperature raised and after deacclimation of seedlings,the distribution of lipids and proteins in plasmalemma all resumed to the original state before cold acclimation. These results suggest that the interrelationship between the lipids and proteins in plasma membrane may be altered during cold acclimation. Noticeably, the changes only appeared in cold hardy wheat varieties, and not in cold tender varieties. So they are closely associated with the cold hardiness of plants.

The ultracytochemical localization of ATPase activity was carried out employing the method of lead precipitation in the ovules of wheat(Triticum aestivum)before and during fertilization. Only very little ATPase activity was observed on the plasma membrane of the egg cell in the mature embryo sac before fertilization. At this stage, reaction product was localized primarily on the plasma membranes of two synergids, on the chalazal plasma membrane ,ER and tonoplast of the central cell, on the plasma membranes of the antipodal cells,some nucellar cells surrounding the embryo sac and the inner and outer integument cells. During fertilization, ATPase activity was found in the following places:the plasma membrane, nucleus and nucleolus of the egg cell;the plasma membrane and nucleolus of the persistent synergid and the plasma membrane of the degenerated synergid; the cytoplasm, nucleus and nucleolus of the central cell ; the sperm nucleus within the egg and central cells and the sperm nucleolus appeared in the fusion of the male and female nuclei; the submicropylar embryo sac wall. At the same time, reaction product deposited on the plasma membranes of the antipodal cells and inner and outer integument cells was significantly decreased. In zygote stage, heavy reaction product was localized in the nucleolus of the zygote and the chromatin and nucleolus of the free nuclei of the endosperm. A little enzyme activity was observed on the plasma membrane and ER of the zygote and in the mitochondria of the zygote and central cell. We suggest that the ATPase distribution pattern and its change in different developing stages was associated with the activation of the egg cell ,the movement of the sperm nucleus,the physiological state of the egg, zygote and sperm nucleus,and the nutritional pathway of the embryo sac.