[en] Order this fact sheet now to learn how replacing the ''closed drum'' debarking technology method used in the forest industry with the ''open drum'' method saves time and production costs, and increases the economic value of wood products by inflicting less damage on logs so that they can be used for high-value economic products

[en] To find the biological effect of space mutagenesis on P. chlamydosporia. Totally 29 strains isolated from the colonies of survival space-induced strains were tested not only for their biological characteristics, such as morphology, colony growing rate, dry weight of mycelium, spore production, and the parasitism to the eggs of Meloidogyne incognita, but also for salt tolerance and benomyl resistance. The results showed that the biological characteristics of space-induced strains of P.chlamydosporia were significantly different from the original strain. For space-induced strains, the colony growing rate and dry weight of mycelium showed higher negative mutation rates, the spore production showed greater positive mutation rates, and the pathogenicity against the eggs of M. incognita was more great, for instance, the improved parasitic rates of Pc-m-4, Pc-m-6, Pc-m-10, Pc-m-15 and Pc-m-123 were 92.33%, 93.67%, 91.67%, 90.67% and 90.33%, respectively, higher than the parasitic rate of original strain (81.00%), besides, Pc-m-6 had a good resistance to the benomyl and Pc-m-10 was able to survive in the high salinity condition. The influence of space mutagenesis on P. chlamydosporia was significant, and the superior strains obtained showed potential in biological control of M. incognita. (authors)

No abstract available

[en] The structure of the fruit, seed and seedling of Hydrocharis dubia in Hydrocharitaceae were studied with light microscope. The results show that the fruit has incompletely six locules with superficial placentation. The seed has anchor-like trichomes occur on the surface and with no endosperm. The seed embryo develops on the water. The hypocotyl hairs appear earlier than the primary root which develops weakly. The adventitious roots are formed with the leaf development. The paracytic stomata are present in the upper epidermis of the young leaf and the air canals are present in the mesophyll. The petiole has a sheath-like base. The seedlings usually die and only a few could develop into mature plants and the development of the species is similar to those of the other taxa in Alismatales. The study provides the morphological evidence for the placement of the Hydrocharitaceae in the order Alismatales. (author)

[en] Ascospores of Sordaria macrospora germinated and produced hyphae exhibiting normal growth and differentiation after examination by scanning electron microscopy and following numerous, different preparative protocols. Seventy-nine to ninety-nine percent of the ascospores retained normal viability after being observed in the fully frozen-hydrated, partially freeze-dried, and vacuum-dried states at accelerating voltages of 5 and 40 keV. Hyphae did not survive these treatments. From these observations it is concluded that ascospores of S. macrospora can remain in a state of suspended animation while being observed in the scanning electron microscope. The ascospores also survived, but with reduced viability: 6 h in glutaraldehyde and formaldehyde, 6 h in OsO4, or 2 h in glutaraldehyde and formaldehyde followed by 2 h in OsO₄. However, the ascospores did not germinate after dehydration in ethanol. (author)

[en] Nearly one quarter of the world's land surface is occupied by permanent grassland, and possible ways of increasing the productivity of grassland deserve attention. Since permanent grasslands rarely receive phosphorus fertilizer, mycorrhizas could be important. Research in Britain has shown that mycorrhizal abundance is related to grazing intensity and to the percentage of ground area covered by vegetation. Infection levels in a plant are also influenced by what other species are growing nearby. Knowledge of factors affecting mycorrhizal abundance could allow grasslands to be managed for greater abundance of indigenous mycorrhizas. (author)

[en] The goal of field studies with vesicular-arbuscular mycorrhiza (VAM) is to improve crop yield by establishing vigorous VAM infections that will substantially enhance the uptake of phosphate. This objective is usually approached by introducing efficient inoculum into a field crop early enough and at a high enough rate to affect plant growth. Some consideration should also be given to ways of manipulating the native mycorrhizas because satisfactory field inoculation procedures for large-scale application are not yet well developed and the indigenous soil populations of VAM fungi are sometimes symbiotically efficient but too sparse to be effective. Thus mixed cropping systems and crop rotations that include strongly mycorrhizal plant species may well prove to be useful for building up the native VAM population. However, in this article, we are concerned primarily with the methodology of field inoculation, using VAM endophytes that have already been cultured on stock plants and tested for their symbiotic potential and soil/plant preferences

[en] A more efficient methodology for mycorrhizal studies under field conditions needs to be developed if the benefit of mycorrhizal symbiosis is to be utilised in large-scale crop production. Furthermore, no mycorrhizal programme can function effectively if the basic methods are not properly carried out. Research objective was to obtain the best possible strains of VA mycorrhizal fungi and develop practical inoculation methods to achieve benefits from mycorrhiza in various cropping systems

No abstract available

[en] Studies on the induction of mutation in Dendrobium orchid at MINT has produced a number of new orchid mutant cultivars. Tissue culture techniques on orchid seeds and meristem cloning are employed in preparing the samples for the mutation induction. Solid medium based on the Murashige and Skoog (1962) and liquid medium based on Vacin and Went (1949) were found to be suitable in producing protocorm like bodies (PLBs) that are required for the irradiation treatment. (Author)