Usually, garlic clove keeps itself in dormancy during summer months and tends to break their dormancy as the climate becomes cooler toward autumn. Prolonged storage of garlic clove under relatively high temperature is a good measure taken in practics to retain its dormancy and refrain from sprouting. In fact, if garlic is stored around 30 ℃, its dormancy can be extended to more than six months while its exposure to low temperature (4 ℃) for a short duration will eventualy break its dormancy. The Dormant release can be diagnosed in the upper epidermis by signs of nuclear disintegration and appearance of APase, ATPase and POase activities. The nuclei in dormant epidermal cells keep their characteristic round shape and in the central position of the cells which are devoid of the enzyme activities mentioned. In case the clove is kept in 30℃ over a year, partial disintegration of the cells evacuation of the constituents also take place, as clearly shown by numerous proteinaceous granules suspended in the interior and by “nuclear extrusion” across the intercellular boundary.

The relationship between photosynthesis of soybean and nitrogen fixation of the nodules by symbiotic Rhizobium was studied. The contents of total nitrogen and chlorophyll, the net photosynthetic rate and seed yield of soybean were much higher in either hydroponically cultivated or field-grown plants inoculated with Rhizobium B16–11C (or Clark nodulating strain) than in control without inoculation (or Clark non-nodulating strain). These results show that the symbiotic nitrogen fixation has a beneficial effect on photosynthesis. However, the effect was indirect and slow so that there was no change in the net photosynthetic rate of the soybean leaves until three clays after removing nodules from the soybean roots. On the other hand, decreasing the photosynthate supply to nodule by shade, defoliation or shoot removal of the soybean, the nodule activity declined significantly. It seems that the supply of photosynthate to root nodule is a limiting factor for symbiotic nitrogen fixation. However, the diurnal variation of the nodule activity could not be explained by change neither in the contents of sucrose and starch of the root nodules nor in the ambient temperature. The factor controlling the diurnal variation deserves further study.

The wood structure of Syringa oblata var. giradii Rehd. grown on the north side of Taibai Mountain varied with the increasing altitude: the width of growth ring, the length of vessel member, the vessel diameter, the length and width of fibretracheid and the ray height gradually increased with the altitude; the frequency of vessel, the frequency of ray and the frequency of solitary vessels decreased; the vessel and fibretracheid walls grew thinner. The spiral thickenings of the vessel wall and the fibre-tracheid wall in the lower altitude are more evident and them gradually obscure.

Protoplasts of Brassica carinata Braun. (accession No. 84A165) were enzymatically isolated from hypocotyls and cotyledons of 3–5 day-old test-tube seedlings or first true leaves taken from greenhouse grown plants at a three-leaf stage. The protoplasts were suspended in a P-B liquid medium solidified with 0.15%–0.3% low melting agarose which formed a thin layer floating on the surface of the liquid medium. The optimum protoplast density was ranging from 5× l03 to 1 × 104/ml. As for the hypocotyl protoplasts, the first division was observed after 48 h in the culture. The division frequency reached 21% and 34% at day 3 and 6 respectively. The initiation of cell division in the case of cotyledon and mesophyll protoplast culture was late, usually at day 5, and the division frequency was also somewhat lower. One week after culture, the cultures were transferred to fluorescent light condition with an intensity of about 1000 lx. A dilution medium DPDK3 was then added and the dilution procedure was repeated at one week interval thereafter. One month after culture, microcalli with 300–500 μm in size were formed. It was also found that in some cases globular embryoid structure protruded on the callus surface. Totally, a 2%–3% plating efficiency was achieved. Shoot regeneration occurred when cotyledon and mesophyll protoplast-derived calli were transferred onto a modified MS medium supplemented with NAA 0.1, BA 3 mg/l. Individual shoots were rooted on a rooting medium supplemented with 0.2 mg/l of IAA. Intact plants with normal morphology were eventually produced.

Rice embryo sac consists of an egg cell, two synergids, a central cell with two polar nuclei, and a multicellular antipodal mass. The egg cell bears no wall at its chalazal end. Its nucleus is centrally located. The greater part of its cytoplasm surrounds the nucleus, while vacuoles of various sizes are distributed at the peripheral region. The mature egg cell appears to be an inactive cell in the light of its organelle state. The two synergids show no difference with each other one day before anthesis, but by the time just prior to anthesis, one of them has degenerated. The synergids bear no wall at the chalazal end and have a thick wall at the micropylar end, where a filiform apparatus is formed. The nucleus occupies a mid-lateral position with the majority of organelles distributed at the micropylar part and many vacuoles at the chalazal part. The central cell is occupied by a large vacuole which presses the cytoplasm to a thin peripheral layer. The polar nuclei, partially fused with each other, are located in proximity to the egg apparatus and surrounded by organelles. Long, parallel endoplasmic reticula are seen near the plasma membrane bordering the egg apparatus A thick, multilayered embryo sac wall which bears numerous finger-like ingrowths seperate the central cell from the nucellus. The antipodal cells keep dividing before and even after fertilization, proliferating into a nmlticellular mass. Amitosis accompanied with freely growing walls is a usual phenomenon in this proliferation process. The cells contain abundant, active organelles and have many ingrowths at the wall bordering the nucellus. Six hours after fertilization, double fertilization is finished, resulting in a zygote and several endosperm nuclei. The zygote has now formed a new wall at its chalazal end. Its cytoplasm shows no significant changes except that more polysomes are seen and the vacuoles become smaller in size. In contrast, the cytoplasm of endosperm becomes more abundant and active than before. The degenerated synergid elongates and embraces the chalazal part of the zygote. Besides formerly existing electron-dense materials many starch grains and spherical bodies are seen in the degenerated synergid as a result of pollen tube discharge. After fertilization, both synergids are characterized by newly formed walls at their chalazal part. To our knowledge, the present paper is the first report on ultrastructure of rice embryo sac. Based on the results obtained by this paper and the reports on other graminaceous species, a discussion is made around the following problems as polarity of the egg cell, degeneration of the synergid, changes of the boundary wall between egg apparatus and central cell, and division of antipodal cells.

The Paleogene deposits in the East China Sea Basin may be divided into the Yangzijiang and Lower subformation of the Qiangtajiang Formation in ascending order. The mudstone and shale are rich in sporopollen fossils. They may be divided into two palynological assemblages as follows: 1. Ulmipollenites minor-Ulmoideipites krempii assemblage (In the Yangzijiang Formation). The Sporepollen assemblage is characterized by the absolute predominance of Angiospermous pollen, while Gymnospermous and Pteridophytous are second. The pollen of Angiosperae is dominated by Quercoidites (Q. asper, Q. henrici, Q. microhenrici, Q. minor), Ulmaceae (Ulmipollenites undulosus, U. minor, U. granulatus, Ulmoideipites krempii, U. tricostatus), Rutaceae (Ru- taceoipollis ovatus, R. rotundatus, R. oblongatus), Meliaceae ( Meliaceoidites minor, M. rhomboi- porus and M. rotundiporus) and Hydrocaryaceae (Sporotrapoidites minor and S. medius), with also some Caryapollenites, Juglanspollenites, Plicapollis, Tiliaepollenites, Krutzipites and Trilobapollis. The pollen of Gymnospermae are more aboundant in Pinuspollenites. As to Pterido phyta, the Spores Polypodiaceae, Magnastriatites howardi and Pterisisporites are relatively common. 2. Pinuspotlenites-Trilobapollis assemblage (In the Lower subformation of Qiangtangjiang Formation). The Sporepollen assemblage is also characterized by the absolute predominance of Angiospermous pollen Quercoidites, Ulmaceae, Rutaceae and Hydrocaryaceae, and less in pollen of Gymnospermae and Spores of Pteridophyta, but it is different from that of the Yangzijiang Formation, the major difference lie in acute attenuation of Podocarpidites, Quercoiditcs minor, Rutaceoipolhs ovatus, Ulmipollenites minor and Ulmoideipites krempii, and well development of Pinuspollenites, Ulmipollenites undulosus and Trilobapollis. Based on the fact that spore pollen assemblage of the Eocene-Oligocene in the coastal region of the Bohai Sea, and the provinces of Jiangsu, Anhui, Zhejiang, Jiangxi, Hubei and Guangdong, the South Yellow Sea and northern shelf of the South China Sea are characterized by the great abundance of Ulmaceae, Rutaceae, Meliaceae and Quercoidites. The Yangzijiang Formation can probably be defined as Eocene, the climate was marine, central-south subtropical type. The lower subformation of the Qiangtangjiang formation is identified as Oligocene, dry and cool, central subtropical climate.

Six homoerythrina alkaloids were isolated and identified from the weak base fraction of alkaloids from Cephalotaxus fortunei Hook. f. grown in Anhui Province, China. Five of them were known compounds and identified as cephalofortuneine (2), comosimine (Phelline alkaloid 6) (3), 3-epifortuneine (4), wilsonine (6) and epiwilsonine (7), respectively. One of them is a new alkaloid and proved to be 7-deoxycephalofortuneine (1) on the base of spectral analysis. Its MS shows a molecular ion at m/z 345, 16 mass units less than that of cephalofortuneine (2). Comparison of its 1H-NMR spectrum with that of 2 indicats that 1 lacks 7-hydroxyl group, but it still has 2-hydroxyl group.J3,4ax and J3,4eq are ll.2 Hz and 3.0 Hz, so that 3-Hpresumably is axial. The J1,2 and J2,3 are found to be 4 Hz. These indicat that the 2-H should be equatorial, since J2,3= 4 Hz is small for the trans-axial coupling.

Cytokinln stimulates the induction of nitrate reductase (EC 1.6.6.l, NR) ABT inhibites the induction of NR and counteractes the effect of 6-benzyladenine (6-BA) on the induction of NR. 6-BA alone could not induce NR activity and the effect of 6-BA became stranger when appropriate concentration of NO3- induced higher NR activity. In the dark a little NR activity was induced by NO3- in etiolated leaves and the effect of 6-BA was very weak at the same condition. Cycloheximide depresses the induction of NR by NO3-. These results showed that the accelerative effects of cytokinin on NR induction was a indirect action depending on NR inducing process rather than on the presence of NO3- alone.

The changes of adenine nucleotide and adenylate energy charge (AEC) during the development of mitochondria in imbibed mung bean cotyledons and the relationship between these changes and cellular energy status are studied. After cotyledons were imbibed in water for two hours, mitochondrial cristae were not observed, but for 12 hours, they appeared obviously on the inner membrane. With the structural integrity of the mitochondria, the functional mitochondria were graduately shown. For instance, the activity of H+-ATPase of cotyledons imbibed for 24 hours was about twice higher than that of 2 hours. The ATP content and the AEC value in the cotyledons imbibed for 24 hours increased sharply and the AMP decreased, but these were not observed in the mitochondria of the cotyledons imbibed either for 24 hours or 2 hours. When the cotyledons were imbibed in 1 × 10-4 mol/l or 5 × 10-4 mol/l DNP solution for 24 hours, the ATP and the AEC in the Cells exhibited a rapid decrease, but in the mitochondria they remained canstant. In the same DNP solution with cotyledons for 24 hours, the activity of mitochondrial adenylate kinase (AK) not only was not decreased but also increased by about 50% over the control. This result shows that the energy equilibration in the mitochondria seems likely to be regulated by adenylate kinase locating between inner and out membranes of the mitochondria.

Three crystalline compounds have been isolated from the Desmodium triquetrum (L.) DC. On the basis of their spectroscopic data and chemical correlations, the structures have been identified as friedelin (Ⅰ), epi-friedelinol (Ⅱ), stigmasterol (Ⅲ). They were obtained for the first time from the Desmodium triquetrum (L.) DC.

Four constituents were isolated from the bark of Eucommia ulmoide; Oliv. Based on the physico-chemical constants, spectral analysis and properties of derivatives, they were identified as: liriodendrin (1), geniposidic acid (2), (+)-pinoresinol di-O-β-D-glucopyranoside (3), and daucosterol.