肋果沙棘(Hippophae neurocarpa S.W.Liu et T.N.He)自然种群的风媒传粉特征

野外调查了青藏高原特有植物肋果沙棘的花期物候、开花式样以及风媒传粉特征,对其花粉生活力、柱头可授性及单花花粉量进行了检测.结果表明,肋果沙棘有许多适应风媒传粉的特征:雌雄异株,花小,无花冠,先叶开放,雄花萼片纵裂形成对流的"风洞",花粉近球形,单花花粉量大;雌花柱头细长捻状,伸出萼筒,授粉面大,密布乳突.花粉生活力可以持续16.5 d,柱头可授性为10～20d.肋果沙棘传粉多发生在昼夜温差大的5月中下旬,在多变的气候条件下,种群花期可持续约12～25d,但在晴朗的天气条件下具有爆发性的集中开花机制,是对恶劣条件的适应.重力玻片法检测表明,离花粉源15m左右远的地点花粉密度最大,135m仍能接收到花粉,夜间接收到的花粉数量也很可观,这些研究结果表明,该植物集中在有利的晴朗天气昼夜进行长距离的风媒散粉,能较好地适应青藏高原的复杂环境.     

Aerobiological survey of Alnus pollen in Ourense (N.W. Iberian Peninsula), 1993–2000

Alnus pollen is one of the major components of the aeropalynological spectra during winters in Ourense, with maximum values registered in January and February. This work analyses the intra- and interannual variations within the period 1993–2000, when a volumetric Hirst spore-trap (LANZONI VPPS 2000) was in continuous operation. Statistically significant differences between periods 1996/97 (with a few rainy days), 1998/99, and all the others were observed. The relationships between atmosphere pollen content and the most important meteorological parameters within the same period were studied by means of correlation analysis. Temperature was the most important factor explaining the presence of Alnus pollen in the air. A Scheffe's test was carried out before the correlation analysis to establish years corresponding to the same statistical population. The results obtained from both tests were used for a regression analysis to establish the prediction patterns for this taxon. Even when a negative correlation coefficient was presented, the influence of this parameter did not decline. Previous temperatures in the main pollination period, however, were a determinant factor predicting the onset and intensity of Alnus flowering.     

I. THE EXPRESSION OF INSTABILITY IN N. TABACUM × N. PLUMBAGINIFOLIA

Moav , Rom (Hebrew U., Jerusalem), and D. R. Cameron . Genetic instability in Nicotiana hybrids. I. The expression of instability in N. tabacum × N. plumbaginifolia. Amer. Jour. Bot. 47(2): 87—93. 1960.—N. tabacum (n = 24) and N. plumbaginifolia (n=10) are distantly related species both from morphological and cytological points of view. Hybrids of these species with various genome dosages have exhibited somatic variegation when plumbaginifolia dominant characters were superimposed on an appropriate tabacum genetic background. Five loci were studied in this respect: Wh and Tg—for flower coloration; Ws—for chlorophyll production; Kl—for pollen abortion and Bs—for black shank resistance. All 5 were found to be unstable. Backcross progenies of the sesquidiploid hybrid (tbc-tbc-pbg) to tabacum showed a marked increase in intensity of variegation. This has been attributed to the breaking up of the plumbaginifolia genome into individual chromosomes. The evidence indicates that variegation was due to somatic chromosomal aberrations which probably characterized all the plumbaginifolia chromosomes. An hypothesis regarding the heterogeneity of F₁ hybrids of distantly related homozygous species is outlined and the occurrence of instability due to hybridization in other Nicotiana hybrids is discussed.     

Prof. Dr. H. C. Władysław Węgorek 16 February 1918-16 July 2001

Abstract

In 2004, two field trials with cotton were conducted at two locations in Tajikistan to estimate the effectiveness of FZB 24® Bacillus subtilis (ABiTEP GmbH Berlin) as a biofertilizer for increasing the cotton yield in comparison to the utilization of the conventional fertilizer containing nitrogen (N), phosphorus (P) and potassium (K), with an application rate per ha 180 kg N, 120 kg P, 60 kg K. The following treatments of cotton cultivated as test variants each on 1 ha field under the same conditions were carried out and the effect on the plant growth, the development of number of bolls/plant and mainly the cotton fibre yield were calculated: (i) Seed treatment with water and only crop application of the NPK fertilizer; (ii) Only seed treatment with spore suspension of FZB 24 WG Bacillus subtilis, without application of the NPK fertilizer; (iii) Seed treatment with spore suspension of FZB 24 WG Bacillus subtilis plus crop application of the NPK fertilizer; and (iv) Only seed treatment with the comparable plant-growth-promoting rhizobacteria product Extrasol 55 (ARRIAM St Petersburg), without application of the fertilizer. Comparing cotton growth and yield of the variants in both field tests, there appeared a remarkable yield and growth increase (up to 30%) by the use of FZB 24 alone compared to the application of the NPK fertilizer. The additional application of the NPK fertilizer (Variant: FZB 24 + NPK) could not enlarge this plant productivity-promoting effect. Apparently under the test conditions the increase of the root system in size and capacity as well as the additional enzymatic mobilizing of organic bound phosphorus for the plant as activities from the Bacillus subtilis introduction was more important for the plant system than the limited direct input with N, P and K. The plant treatment alone with Extrasol 55 resulted in similar promotion of cotton growth and yield as FZB 24 when compared with the NPK plant fertilizing, showing that the activity of FZB 24 was not very specific. However the cotton field tests generally demonstrate for FZB 24 Bacillus subtilis a high ability to improve plant growth and yield based on increasing the capacity of roots to mobilize and take up nutrients and substances for overall reproductive plant fitness. The use and value for part-substitutions of some environmentally problematical mineral fertilizers in other and intensive plant production systems is discussed.     

Are differences in productivity between native and exotic trees in N.W. Patagonia related to differences in hydraulic conductance?

Afforestation with the exotic Pinus ponderosa is currently taking place within the natural distributional area of Austrocedrus chilensis, a native conifer of N.W. Patagonia. Annual productivity of the exotic species is double the productivity of the native one. In order to test the hypothesis that these differences in productivity are, at least in part, due to differences in hydraulic characteristics of both species, we measured or estimated several ecophysiological variables in A. chilensis and P. ponderosa trees growing in the same place. Water use (WU) and diameter growth were lower in A. chilensis than in P. ponderosa. Although predawn water potential was relatively constant during the whole growing season, A. chilensis trees showed lower values of this variable than P. ponderosa in a very dry period, suggesting different water sources. Under field conditions, canopy-stomatal (gs) and whole hydraulic conductances, specific hydraulic conductivity and photosynthetic rate (A) were lower in A. chilensis than P. ponderosa. In contrast, instantaneous WU efficiency was higher in A. chilensis than in P. ponderosa. However, gs and A in A. chilensis significantly increased in cut branches of this species suggesting hydraulic limitations on photosynthesis. We hypothesize that hydraulic characteristics of P. ponderosa permit high stomatal conductance for more hours a day than A. chilensis trees, without reaching threshold values of water potential. This can explain, at least in part, differences in C fixation and thus, in productivity between species. In addition, our results suggested a secondary limitation to C fixation in A. chilensis at the photosynthetic apparatus.     

苏联N. P. Korableva教授访沪

苏联巴赫生物化学研究所N.P.Korableva教授于1999年10月18～27日来沪访问。10月23日在中国科学院上海植物生理研究所作了《马铃薯块根的休眠和抗性》的学术报告,并与该所环境生理组和发育生理组座谈及商讨合作问题。     

N.R.S.CWS对小鼠腹腔细胞的激活

日本学者山村一雄.东市郎等人认为红色诺卡氏菌细胞壁骨架(Nocardia-Rubra-Cell Wall skeleton:N.R.CWS)的抗瘤效应极为明显,并认为其抗瘤效应均与巨噬细胞的激活密切相关。自1981年以来,我室观察到珊瑚色诺卡氏菌细胞壁、红色诺卡氏菌细胞壁骨架对小鼠移植瘤具有较强的抗瘤作用。为进一步探讨其抗瘤机制,对N.R.CWS活化的小鼠腹腔细胞(PEC)的吞噬、杀菌作用及细胞毒效应进行了探讨,现将实验结果总结如下。     

Microbial metabolism of aromatic nitriles. Enzymology of C–N cleavage by Nocardia sp. (Rhodochrous group) N.C.I.B. 11216

1. An organism utilizing benzonitrile as sole carbon and nitrogen source was isolated by the enrichment-culture technique and identified as a Nocardia sp. of the rhodochrous group. 2. Respiration studies indicate that nitrile degradation proceeds through benzoic acid and catechol. 3. Cell-free extracts of benzonitrile-grown cells contain an enzyme that catalyses the conversion of benzonitrile directly into benzoic acid without intermediate formation of benzamide. 4. This nitrilase enzyme was purified by DEAE-cellulose chromatography and gel filtration on Sephadex G-100 in the presence and absence of substrate. The purity of the enzyme was confirmed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and isoelectric focusing on polyacrylamide gel. 5. The enzyme shows a time-dependent substrate-activation process in which the substrate catalyses the association of inactive subunits of mol.wt. 45000 to form the polymeric 12-unit active enzyme of mol.wt. 560000. The time required for complete association is highly dependent on the concentration of the enzyme, temperature and pH. 6. The associated enzyme has a pH optimum of 8.0 and K(m) with benzonitrile as substrate of 4mm. The activation energy of the reaction as deduced from the Arrhenius plot is 51.8kJ/mol. 7. Enzyme activity is inhibited by thiol-specific reagents and several metal ions. 8. Studies with different substrates indicate that the nitrilase is specific for nitrile groups directly attached to the benzene ring. Various substituents in the ring are compatible with activity, though ortho-substitution, except by fluorine, renders the nitrile invulnerable to attack. 9. The environmental implications of these findings and the possible significance of the enzyme in the regulation of metabolism are discussed.