Response ofPhaseolus vulgaris to inoculation withRhizobium phaseoli under two tillage systems in the dominican republic

Summary Field experiments were established at three locations in the Dominican Republic to evaluate the response of field beans (Phaseolus vulgaris L. cv. Pompadour) to inoculation with selected strains ofRhizobium phaseoli. A comparison of no-tillage and conventional tillage was included to determine whether modification of rhizosphere temperature and moisture would influence the inoculation response. Yields of inoculated treatments were not statistically difference from controls and ranged from 30–80% of those obtained on N-fertilized plots. Neither tillage systems nor P fertilization influence the response to inoculation. Serological investigations indicated that the applied rhizobial strains nodulated successfully. This host/endophyte combination appears to form an ineffective symbiotic association. Inoculation trials employing indigenous and commercial strains compared with N fertilizer in the greenhouse support the conclusion from the field studies that symbiotic N₂ fixation can provide only a fraction of the plant's N requirement.     

The influence of shading on associative N2 fixation

Summary The effect of reduced solar radiation on associative N₂-fixation and plant parameters was studied in three field experiments (1978–80). Gahi-3 pearl millet (Pennisetum americanum (L.) K. Monch.) field plots were shaded with saran shade cloth that reduced solar radiation by 50% and 75%. Acetylene reduction activity (ARA) was reduced by shading in one of the three experiments. The two non-responding experiments were conducted on a wall-drained, low-activity site (ARA means ranging 17–68 n moles ethylene core^–1 h^–1), the responding experiment was conducted on a poorly drained, high-ARA site.Shading affected the plants drastically, reducing fresh weight and dry matter yields up to 46% (50% shade) and 57% (75% shade). Shading also reduced dry matter percentage from 19.6 (no shade) to 15.3 (75% shade) and increased nitrogen content from 0.6% (no shade) to 1.53% (75% shading). However, shading did not affect protein yield. Inoculation withAzospirillum brasilense had no measurable effect on yield or acetylene reduction in the first two experiments.In the third experiment, shading reduced mean ARA of inoculated plots over 100% but had no significant effect on control plots. Inoculation significantly increased ARA in the nonshaded plots but not in shaded plots. Acetylene reduction activity was high, with means ranging between 208 and 465 n moles ethylene evolved core^–1 h^–1. Soil moisture and millet growth stage also affected acetylene reduction activity.     

Nodulation,accumulation and redistribution of nitrogen in soybean (Glycine max (L.) Merrill) as influenced by seed inoculation and scheduling of irrigation

Summary A field experiment was conducted on soybean (Glycine max (L.) Merrill) with a view to find out the effect of seed inoculation and scheduling of irrigation on nodulation, accumulation and re-distribution of nitrogen in plant tops and soil. The eight treatment combinations consists of two seed inoculations,viz. uninoculated and inoculated with rhizobium culture, and four irrigation schedules,viz. irrigation water to the cumulative pan evaporation (IW/CPE) ratio of 0.5, 0.7, 0.9 and a control (rainfed). Seed inoculation by, rhizobium culture increased the number, dry-weight and N content of nodules per plant. Inoculation of seeds also increased the N accumulation rate in plant top and it was 2.48 kg/ha/day during the flower-initiation to the pod-initiation stage (30–60 days interval). At harvest, 32.2, 47.8 and 26.2 kg N/ha was re-distributed from the stems, leaves and pods-wall of inoculated plants to the grains, respectively. A total of 186.5 kg N/ha was harvested and 64.7 kg N/ha, was accumulated in soil under the inoculated condition.Scheduling of irrigation at 0.7 IW/CPE proved better, than other irrigation schedules and helped in increasing the nodulation, nitrogen accumulation and grain yield. As compared to control, 8.4, 17.8 and 18.4 kg more of N/ha was redistributed from the stems, leaves and pods-wall respectively when the irrigations were scheduled at 0.7 IW/CPE ratio. Under this irrigation schedule the total N harvest was 200.1 kg/ha while the total N increased by 55.9 kg over that present in soil at the time of sowing.     

沙棘Frankia的侵染特性

比较了３株沙棘Ｆｒａｎｋｉａ菌感染能力,Ｈｒ１６可与野生菌作用互补．测定了不同接种方式和多种环境因子对回接的影响．土壤表层施菌接种,菌龄８周,苗龄４周,接种量每株０．０１ｍｌＰＣＶ,可产生高效共生效果．     

刺槐接种VA菌根真菌与环境条件的关系

1 引言 国内外众多的试验表明,VA菌根真菌侵染植物根系后,促进植物对养分吸收和物质转化,从而大幅度增加寄主生物量,但也有试验表明,接种VAMF后,寄主生物量并无明显增加,这可能与菌根接种物本身的特点及外界条件有关,其中土壤中磷的含量是重要因素之一。据报道,土壤P过高,对菌根的形成有影响。本文就刺槐接种VAMF,在不同立地环境下寄主生长变化及不同施磷量对VAMF侵染能力、孢子产生量、植株生物量等进行了研究。     

Response of cowpea (Vigna unguiculata) to inoculation with VA-mycorrhizal fungi and to rock phosphate fertilization in some unsterilized Nigerian soils

Summary The effects on cowpea of inoculation with vesicular-arbuscular (VA) mycorrhizal fungi and rock phosphate (RP) fertilization were studied in pots using Alagba and Araromi series soils and in the field on Alagba, Apomu and Egbeda series soils. Inoculation of the plants with VA-mycorrhizal fungi caused very rapid infection of the roots. A higher per cent mycorrhizal infection was maintained during subsequent plant growth in the field. RP application reduced the degree of infection without affecting plant growth in the field and in pot experiments. Nodulation, nitrogen fixation and utilization of RP were increased by inoculation with mycorrhizal fungi in the pot experiments but not in the field experiments. In the pot experiments, inoculated plants supplied with RP flowered earlier, and took up more phosphorus than either inoculated plants without RP or uninoculated plants. The largest response to inoculation in terms of shoot dry matter, nodule yield and nitrogen content of shoots was obtained in Alagba soil under both pot and field conditions.IITA Journal Series Paper No. 136.     

Available phosphate content of an alluvial soil as influenced by inoculation of some isolated phosphate-solubilizing micro-organisms

Summary Among several phosphate-solibilizing micro-organisms isolated from an alluvial soil (Fluvaquent) in sucrose-Ca₃(PO₄)₂ agar plates, two fungal strains, ACF₂ (Aspergillus candidus) and ACF₁ (A. fumigatus) two bacterial strains, ACB₅ (Bacillus firmus B-7650) and ACB₆ (B. firmus B-7651) and one actinomycete strain, ACS₆ (Streptomyces sp.) were efficient solubilizers, solubilizing 297.0, 288.3, 49.0, 45.8 and 29.0 μg of P as free PO₄ ⁻³, respectively, containing 15 mg insoluble P from Ca₃(PO₄)₂ in broth. Solubilization was lesser from AlPO₄ and FePO₄. The isolates producing oxalic and tartaric acids without or with citric acid showed higher ability of solubilizing insoluble inorganic phosphates. All the above isolates possessed the ability of solubilizing rock phosphate in considerable amounts, ACF₁ (A. fumigatus) being the highest (31.5 μg), while ACB₆ (B. firmus B-7651) and both the aspergilli also possessed cellulose-decomposing ability in addition. Inoculation of the isolates, in a flask culture experiment, had no significant effect on the accumulation of available phosphorus in soil even when amended with rock phosphate (RP), farm yard manure (FYM), (FYM+RP), rice straw (RS) and (RS+RP). Nevertheless, the overall performance of ACF₂ (A. candidus) and ACB₆ (B. firmus B-7651) was better than that of the others, in this respect, while ACB₅ (B. firmus B-7650) and ACF₁ (A. fumigatus) intensified the enhancing effect of FYM and RS. Partial sterilization, by autoclaving, of the soil had no significant effect on available phosphorus content of the soil irrespective of any inoculation.     

外生菌根菌接种马尾松和相思树幼苗的研究

以外生菌根菌Ｘｅｒｏｃｏｍｕｓｃｈｒｙｓｅｎｔｅｒｏｎ接种相思树与马尾松幼苗,不灭菌栽培,植株生长指标和生理特性测定,都优于对照．以外生菌根菌Ｃａｌｖａｔｉａｌｉｌａｃｉｎａ加ＶＡ菌根菌Ｇｌｏｍｕｓｓｐｉｇａｎｕｓ双接种于相思树幼苗,灭菌栽培．植株含Ｎ量和脯氨酸等含量优于ＶＡ菌根菌单接种的效果．幼根切片观察到接种的外生菌根菌进入根皮层细胞间隙,原有菌根的发育和结构状况有所改变．     

影响DpCPV杀虫剂高产条件的研究

DpCPV杀虫剂的产量不仅受到气候、环境等因素的影响,而且严重受到生产工艺技术水平的制约。针对DpCPV杀虫剂生产过程中工艺技术问题,我们对马尾松毛虫质型多角体病毒湖南株在室内、室外和林间大量增殖中的集虫虫质、接种浓度、频率、收获时间等及其相互间的关系进行了详细研究,得出在DpCPV杀虫剂生产过程中接种1×10~7CPB/mL病毒浓度为宜,接种虫龄以4～5龄虫为宜,收获病毒时间13～14d为宜。其室外单虫病毒产量平均可达到7.5×10~8CPB,比国内报道要高。研究结果对DpCPV杀虫剂的高产增殖有很强的指导意义。     

Significance of inoculation density control in production of polysaccharide and ganoderic acid by submerged culture of Ganoderma lucidum

Control of inoculation density was significant for cell growth, morphology, and production of polysaccharide and ganoderic acid in submerged culture of the higher fungus Ganoderma lucidum. A maximal cell concentration of 15.7 g dry cell weight (DW)/l was obtained at an inoculation density of 330 mg DW/l. For inoculation density within the range of 70–670 mg DW/l, a large inoculation density led to a small pellet size and high production of extracellular and intracellular polysaccharides, while a relatively big pellet size and high accumulation of ganoderic acid were observed at a low inoculation density. It was also shown that small pellet size resulted in high polysaccharide production, while large pellet size led to high production of ganoderic acid.