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921.
Our study aimed to assess the effect of dual inoculation with the selected Rhizobium strain KWN35 and the arbuscular mycorrhizal isolate BEG 176 (Glomus etunicatum) on the growth of Calliandra
calothyrsus cultivated under irrigation in the field in Senegal (Dakar) over a period of 24 months. Although plants inoculated with both
microsymbionts grew better (height and root collar diameter) than plants from three other inoculation treatments (control,
single inoculation with KWN35 or BEG 176), these results were not statistically different except at 1 and 5 months after field
transplantation. KWN35 was present in a relatively high percentage of nodules harvested from plants inoculated with this rhizobial
strain either alone or with mycorrhiza (approximately 60% and 40% 1 and 2 years after field transplantation respectively).
The percentage of mycorrhizal root infections was around 60% in the inoculated plants after 12 months with significantly higher
N, P and K foliar contents of trees compared with the non-inoculated controls. However, as for nodulation, by 24 months after
transplantation, there were no significant differences between treatments. We conclude that field inoculation of C. calothyrsus with Rhizobium strain KWN35 and arbuscular mycorrhizal isolate BEG 176 did not have a long-lasting effect on the growth of trees, even when
a majority of nodules were occupied by the inoculated rhizobia and the roots infected by the mycorrhiza. Several reasons can
be postulated for these results, such as a possible effect of soil fertility on the efficiency of the nodules. 相似文献
922.
Menandro N. Acda 《Journal of pest science》2008,81(2):109-113
Thiamethoxam (ACTARA® 25WG) was evaluated for its insecticidal activities against the bamboo powder post beetle Dinoderus minutus Fabricius (Coleoptera: Bostrichidae). The study showed that thiamethoxam had contact toxicity against D. minutus. Based on dose-mortality responses, LC50 values for thiamethoxam against D. minutus ranged from 1.74 to 7.94 μg ml?1. Laboratory and field exposure tests showed that thiamethoxam at concentration of atleast 10 μg ml?1 may have anti-oviposition or anti-feeding effects on D. minutus and can protect post harvest Bambusa vulgaris Schrad. culms against the infestation of this bamboo boring beetle. 相似文献
923.
Jörg Prietzel Karl Eugen Rehfuess Ulrich Stetter Hans Pretzsch 《European Journal of Forest Research》2008,127(1):43-61
Long-term (40 years) effects of two soil amelioration techniques [NPKMgCa fertilization + liming; combination of PKMgCa fertilization,
liming, tillage, and introduction of lupine (Lupinus polyphyllus L.)] on chemical topsoil properties, stand nutrition, and stand growth at two sites in Germany (Pfaffenwinkel, Pustert) with
mature Scots pine (Pinus sylvestris L.) forest were investigated. Both sites are characterized by base-poor parent material, historic N and P depletion by intense
litter-raking, and recent high atmospheric N input. Such sites contribute significantly to the forested area in Central Europe.
Amelioration resulted in a long-term increase of pH, base saturation, and exchangeable Ca and Mg stocks in the topsoil. Moreover,
significant losses of the forest floor in organic carbon (OC) and nitrogen stocks, and a decrease of the C/N ratio in the
topsoil were noticed. The concentrations and stocks of OC and N in the mineral topsoil increased; however, the increases compensated
only the N, but not the OC losses of the forest floor. During the recent 40 years, the N nutrition of the stands at the control
plots improved considerably, whereas the foliar P, K, and Ca concentrations decreased. The 100-fascicle weights and foliar
concentrations of N, P, Mg, and Ca were increased after both amelioration procedures throughout the entire 40-year period
of investigation. For both stands, considerable growth acceleration during the recent 40 years was noticed on the control
plots; the amelioration resulted in an additional significant long-term growth enhancement, with the NPKMgCa fertilization
liming + being more effective than the combination of PKMgCa fertilization, liming, tillage, and introduction of lupine. The
comprehensive evaluation of soil, foliage, and growth data revealed a key relevance of the N and P nutrition of the stands
for their growth, and a change from initial N limitation to a limitation of other growth factors (P, Mg, Ca, and water). 相似文献
924.
The hyphal sheath is a morphological feature of many kinds of fungi. Although the fine structures of the sheath have been
studied in detail by a number of electron microscopy techniques, the function and physiology of the hyphal sheath are not
yet clarified. One reason for this is that the hyphal sheath is a colorless, mucilaginous, and delicate material so that it
is not easily identified. We developed a simple method to visualize and identify the hyphal sheath of the white-rot fungus
Phanerochaete crassa WD1694. The small mycelial pellets in shaken liquid cultures of P. crassa WD1694 were stained directly with phloxine B. Both the hyphae and the hyphal sheath that filled the gaps between each of
the hyphae were visualized and observed by light microscopy. The stained hyphae were further studied by transmission electron
microscopy, atomic force microscopy, and fl uorescence microscopy. Based on these observations, we confirmed that the staining
of the hyphae was also due to the presence of the hyphal sheath that closely covered the fungal cell wall. These results clearly
showed that the hyphal sheath was selectively stained with phloxine B and could be observed and identified by conventional
light microscopy.
Part of this report was presented at the 50th Lignin Symposium, Nagoya, October 2005 相似文献
925.
The spotted stem borer, Chilo
partellus (Swinhoe) (Lepidoptera: Crambidae) is being successfully reared on artificial diets for screening programmes. Besides quality
characteristics of the diet, rearing density and adult nutrition have significant implications on the successful mass multiplication
of lepidopterans. The performance of C. partellus moths was assessed on different adult diets (water and sugar solution) and compared with unfed adults. Further, three pairing
densities, viz. 2, 5 and 8 pairs/oviposition jar (1177.5 cm3) were compared for their effect on C. partellus longevity and fecundity. In another experiment, different larval densities (100, 150 and 200 neonate larvae/diet jar) were
evaluated for their effect on the larval survival. Water-fed moths (both males and females) lived longer (7.32 and 7.26 days,
respectively) and showed higher fecundity (307.17 eggs) than the sugar-fed or unfed moths. The latter, however, showed better
egg hatchability (76.55%) than the water- or sugar-fed moths (60.45 and 50.59%, respectively). The longevity (5.67 days) and
fecundity (258.46 eggs) were significantly greater at pairing density of 2 pairs/jar. The larval survival was higher (58.50%)
at rearing density of 100 larvae/jar. The neonate larval release into diet jars was compared with conventional egg release
and both modes were no different with respect to larval survival. 相似文献
926.
Variable adventitious rhizogenesis of juvenile shoot cuttings was observed in seven half-sib families (TP-1, BAN-1, AN-3,
JR-3, SL-16, UM-3, and UM-5) of Albizia procera Benth. Treatment with IBA invariably promoted sprouting by 8%, adventitious rooting by 218%, root number by 869%, and root
length by 36.4% compared with the control. Interaction between families and IBA treatment significantly enhanced sprouting
and root length in BAN-1, JR-3, UM-3, and UM-5, and root number in all families, but had a significant suppressive effect
on sprouting in AN-3. Treatment with IBA increased family heritability (h
f
2) 1.38-fold for sprouting, 2.86-fold for adventitious rooting, and 10.86-fold for root number, but reduced family heritability
by a factor of 8.25 for root length. Thus, direct genetic effects seem to have strongly affected sprouting and adventitious
rooting, with IBA playing an auxiliary role, but had little effect on root number and length, for which IBA had a dominant
regulatory role. 相似文献
927.
Narcisa Urgiles Paúl Loján Nikolay Aguirre Helmut Blaschke Sven Günter Bernd Stimm Ingrid Kottke 《New Forests》2009,38(3):229-239
Most tree species in tropical mountain rain forests are naturally associated with arbuscular mycorrhizal fungi. Previous studies
in southern Ecuador of 115 tree species revealed that only three species were not associated with arbuscular mycorrhizal fungi.
Seedlings of tropical tree species raised in the nursery may need to be associated with arbuscular mycorrhizal fungi to survive
transplantation shock in higher numbers. Methods for establishing plantations with native tree species are not yet established
for Ecuador. Thus, we investigated the feasibility of using mycorrhizal roots of seedlings of Inga acreana, Tabebuia chrysantha, Cedrela montana and Heliocarpus americanus that had trapped mycorrhizal fungi from forest humus in the nursery to inoculate C. montana and H. americanus with native arbuscular mycorrhizal fungi. Inoculation with either a mixture of mycorrhizal roots from the four species or
only with mycorrhizal roots from the same tree species were compared with effects of moderate fertilization. Assessment of
plant growth and mycorrhizal status of 6-months-old Cedrela montana and Heliocarpus americanus revealed an improvement in growth and diverse associated fungi through mycorrhizal root inoculation in comparison with moderate
fertilization. Moderate fertilization did not suppress mycorrhization. 相似文献
928.
In Seong Choi Seung Gon Wi Se Ra Jung Darshan H. Patel Hyeun-Jong Bae 《Journal of Wood Science》2009,55(5):329-334
β-Glucosidase (β-1,4-D-glucoside glucohydrolase: EC.3.2.1.21) catalyzes the hydrolysis of β-glucosidic bonds between saccharides
and aryl or alkyl groups. A gene encoding β-glucosidase from Bacillus licheniformis KCTC 1918, an anaerobic spore-forming soil bacterium, was cloned and characterized. The structural gene for the β-glucosidase
consists of 1410 bp encoding 469 amino acid residues, and has a molecular weight of 53.4 kDa as estimated by sodium dodecyl
sulfate polyacrylamide gel electrophoresis with 12% separating gel. The enzyme activity was determined against pNPG as a substrate. The enzyme was optimally active at pH 6.0 (citrate-phosphate buffer) and 47°C. β-Glucosidase retained
100% of its original activity for 24 h. The activity of the enzyme was stimulated by glycerol and urea and was decreased by
Ca2+, Cu2+, Hg2+, Mg2+, and Mn2+. In particular, Cu2+ had the strongest negative effect on β-glucosidase activity. The purified β-glucosidase was active against pNPG and cellobiose. When the β-glucosidase was tested for cellulose hydrolysis, the supplement of β-glucosidase with cellulose
increased the glucose yield from pine wood powder by 139.8%. 相似文献
929.
930.
孟加拉无机肥料对几种农林作物生物固氮和种苗生长的影响(英文) 总被引:1,自引:0,他引:1
Mohammad Belal Uddin Mohammed Abu Sayed Arfin Khan Sharif Ahmed Mukul Mohammed Kamal Hossain 《林业研究》2008,19(4):303-306
比较了不同浓度无机肥料(尿素和重过磷酸钙)对四种农林作物(楹树、雨豆树、相思树和印度田菁)生物固氮和种苗生长的影响。种子萌发一个月后利用不同浓度肥料(尿素:40kg·hm-2,80kg·hm-2;重过磷酸钙:40kg·hm-2,80kg·hm-2;(尿素 重过磷酸钙)40kg·hm-2和(尿素 重过磷酸钙)80kg·hm-2)处理种苗。结果表明:中等浓度无机肥料促进了种苗的生长,但较高浓度无机肥料也不利于种苗的生长。当施加尿素时根瘤菌的数量大小明显受抑制,但随着增加磷肥(重过磷酸钙)根瘤菌的数量大小增加。本研究有助于农业人员利用无机肥料改善土壤提高农林作物的生物固氮和种苗生长。图2表6参33。 相似文献