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981.
Sublethally infected adults ofChilo partellus Swinhoe were allowed to mate in experimental cages. The mated gravid females were dissected and specific tissues including eggs were removed and examined under both light and electron microscopes. Males were similarly dissected and examined under a ligh microscope only. Results showed that infected males did not transmitNosema marucae Odindo and Jura venereally. Microscopic studies revealed thatN. marucae was transmitted through contamination of the egg chorion. No spores were seen in the yolk neither were spores seen in the spermathecae. The significance of these studies is discussed. 相似文献
982.
Lignin distribution in spruce (Picea abies) determined by mercurization with SEM-EDXA technique 总被引:1,自引:0,他引:1
Summary The lignin distribution between the middle lamella and the cell wall of spruce fibers has been determined by a new technique based on a mercurization of the lignin and a concomitant determination of mercury by the SEM-EDXA technique. The ratio of lignin in the middle lamella at the cell corners to the lignin in the secondary wall was 2.5±0.6 for latewood and 2.4±0.6 for earlywood. This gives a lignin content of 55–58% in the true middle lamella in the cell corners. The reactivity to mercuric acetate of different wood elements was determined in separate experiments. Fractions enriched in ray cells, middle lamella, and compression wood all reacted at the same rate as the whole wood; about one mole of mercury was incorporated per mole of lignin (C9-unit). 相似文献
983.
The flight activity of the larch case-bearer mothColeophora laricella can be succesfully determined under natural conditions by pheromone traps baited with (Z)-5-Decen-l-ol. The activity starts in the middle of Bohemia (Czechoslovakia) at the beginning of June and ends at the end of June, with a short peak between the 2nd and 8th June. 相似文献
984.
985.
986.
The Conductivity of Bark-Extracts from Spruce, a Sensitive Indicator for Air Poilution . Bark of spruce is a useful and sensitive indicator for air pollution. The latter may be determined more precisely by electrolytic conductivity of bark extracts than by pH-value or sulphate level of foliage. By an additional simple sulphate analysis of bark extracts the effects of SO2 may be distinguished from those of certain components in dust. 相似文献
987.
Pinguinain is the name given to a proteolytic enzyme preparation obtained from Bromelia pinguin fruits that has been scarcely studied. The present paper deals on the reexamination of the proteases present in fruits of B. pinguin grown in Cienfuegos, Cuba. The preparation (partially purified pinguinain, PPP) showed the main characteristics of the cysteine proteases, i.e., optimum pH within alkaline range (pH 7.2-8.8), inhibition of proteolytic activity by thiol blocking reagents, which is usually reverted by addition of cysteine, a remarkable thermal stability and notable stability at high ionic strength values. Isoelectric focusing and zymogram of PPP revealed the presence of several proteolytic components between pI 4.6 and 8.1. Preliminary peptidase purification by cationic exchange chromatography showed the presence of two main proteolytic fractions with molecular masses of approximately 20.0 kDa, according to SDS-PAGE. 相似文献
988.
The methanol extract of the Careya arborea Roxb. bark significantly reduced castor oil-induced diarrhoea in mice. This effect supports the local traditional use of the plant against diarrhoea. 相似文献
989.
990.
F. M. Amoah B. N. Nuertey K. Baidoo-Addo F. K. Oppong K. Osei-Bonsu T. E. O. Asamoah 《Agroforestry Systems》1995,30(3):289-299
Mature oil palms at the Oil Palm Research Institute at Kusi, Ghana were underplanted with cocoa to study the feasibility of mixed cropping of the two crops under West African conditions. The oil palm trees used in this trial were planted in 1970 and had achieved maximum canopy formation. Three triangular spacings of the oil palms used were 8.7, 9.9 and 10.5 m. The cocoa was underplanted in June 1988 at a spacing of 2.4 m triangular using mixed hybrids. There were no significant differences in oil palm yield between plots with cocoa and the controls. There was no appreciable damage to the cocoa trees from falling palm fronds and fruits during harvesting or pruning. Cocoa seedling growth and yield were significantly better under the oil palm spaced at 9.9 or 10.5 m triangular than under oil palm space at 8.7 m triangular. 相似文献