新疆巴音布鲁克高山草地物种丰富度与生产力的关系

利用野外调查的物种丰富度和生物量资料,对位于新疆天山中段巴音布鲁克草地的20个样地进行群落数量分类,揭示每种群落类型的物种丰富度和生产力特征,在此基础上,考察了群落内和群落间物种丰富度与生产力的关系,并探讨其形成机制.结果表明:利用TWINSPAN将20个样地划分为6个群落类型(亚高山草原、亚高山草甸化草原、亚高山草原化草甸、亚高山草甸、高山草甸和高山沼泽草甸).6个草地群落类型地上生物量、物种丰富度差异明显:就地上生物量而言,亚高山草原和亚高山草甸较低,高山沼泽草甸和高山草甸较高,而亚高山草甸化草原和亚高山草原化草甸处于两者之间;就物种丰富度而言,亚高山草甸和高山草甸较高,亚高山草原和高山沼泽草甸较低,而亚高山草甸化草原和亚高山草原化草甸处于两者之间.群落内物种丰富度与生产力的关系表现出多种形式:亚高山草原、亚高山草甸和高山草甸的物种丰富度与生产力呈正相关,亚高山草甸化草原的物种丰富度与生产力呈负相关,而亚高山草原化草甸和高山沼泽草甸的物种丰富度与生产力没有表现出显著的相关关系.群落间物种丰富度与生产力呈现"单峰"关系.群落内生产力范围不够大,可能是群落内未能观察到"单峰"关系的原因;环境异质性是导致群落间出现"单峰"关系的关键因素.     

Immunostimulatory and protective effects of Aloe vera against coccidiosis in industrial broiler chickens

This paper reports the immunostimulatory and protective effects of Aloe vera extracts (aqueous and ethanolic) against coccidiosis in industrial broiler chickens. The study was divided into two experiments. Experiment-I was conducted for the evaluation of immunostimulatory activity of A. vera and experiment-II demonstrated the protective efficacy of A. vera extracts against coccidiosis in chickens. Results of the experiment-I revealed significantly higher (p<0.05) lymphoproliferative responses in chickens administered with ethanolic extract of A. vera as compared to those administered with aqueous extract and control group. Microplate haemagglutination assay for humoral response on day 7th and 14th post primary and secondary injections of sheep red blood cells (SRBCs) revealed significantly higher (p<0.05) anti SRBC antibody (total Igs, IgG and IgM) titers in chickens of experimental groups as compared to the control group. None of the extracts, however, demonstrated significant effects on the development of lymphoid organs. Results of experiment-II revealed maximum protection (60%) in chickens administered with aqueous Aloe extract as compared to the ethanolic extract administered chickens (45%). Mean oocysts per gram of droppings in the control group was significantly higher (p<0.05) as compared to the chickens in both the experimental groups. Chickens administered with aqueous Aloe extract showed a minimal mean lesion score (2.3) followed by those administered with ethanolic Aloe extract (2.6) and control chickens (3.05) for caeca, and a similar pattern was observed for intestinal lesion scoring. Further, significantly higher weight gains and antibody titers (p<0.05) were observed in chickens administered with A. vera extracts as compared to those in the control group. It was concluded that A. vera may be a potential and valuable candidate to stimulate the immune responses and can be used successfully as an immunotherapeutic agent against coccidiosis in industrial broiler chickens.     

Anti-inflammatory and analgesic potential of a novel steroidal derivative from Bryophyllum pinnatum

A new steroidal derivative, urs Stigmast-4, 20 (21), 23-trien-3-one and other four compounds were isolated from the leaves of Bryophyllum pinnatum. The structure of this new steroid was elucidated and established by standard spectroscopic methods. Carrageenan induced paw edema model was used for anti-inflammatory and acetic acid induced model used for analgesic activity. This new steroidal compound was found to be active in reducing inflammation (% inhibition 87.29 and 84.45 respectively) when compared with diclofenac. Further, it showed 75.72% protection in analgesic activity in acetic acid induced writhing test in mice. In conclusion the % inhibition against carrageenan induced rat paw edema and % protection against acetic acid induced writhings showed by new compound revealed that the anti-inflammatory and analgesic activity of aqueous extract B. pinnatum are mainly due to the presence of this steroidal compound.     

新疆库车县耕地人口承载能力研究

库车县地处南疆腹地。由于库车县人口增长过快 ,造成耕地资源的过度利用 ,导致土地退化、环境恶化。因此 ,确定适当人口规模 ,对库车县耕地资源和干旱区绿洲生态环境保护至关重要。本文根据库车县光、温、水、土生产潜力 ,折算库车县耕地人口承载能力 ,试图确定在不同生活水平要求下库车县适当的人口规模 ,为库车县农业资源的合理开发利用提供参考依据     

Morphology and ontogeny of directly differentiating shoot buds and somatic embryos in Santalum album L.

Santalum album L.is a commercially important tree that yields essential oil of high medicinal value.Regeneration research through organogenesis and embryogenesis has been documented but no report depicts comparative ontogeny of directly differentiating shoot buds(SB)and somatic embryos(SE).In the present study aseptic seedling derived hypocotyl segments(HC)and hypocotyl+root junction(HC+R)were used to induce SBs and SEs,respectively.Ontogenic differences between the structures were confirmed using scanning electron microscopy and histological analysis.MS medium containing 6-benzyladenine or BA(2.5μM)produced highest number of direct SB,while MS+BA(7.5μM)proved suitable for higher frequency of SE differentiation.The differentiating structures attained growth when transferred to MS medium containing a combination of BA and anaphthalene acetic acid or silver nitrate(AgNO3).A combination of indole-3-butyric acid and silver nitrate(AgNO3)in half-strength woody plant medium and lesser osmotic concentration(2%sucrose),induced rhizogenesis.     

Coordinate induction of antioxidant defense and glyoxalase system by exogenous proline and glycinebetaine is correlated with salt tolerance in mung bean

The purpose of this study was to assess the synergistic effects of exogenously applied proline and glycinebetaine (betaine) in antioxidant defense and methylglyoxal (MG) detoxification system in mung bean seedlings subjected to salt stress (200 mmol·L⁻¹ NaCl, 48 h). Seven-day-old mung bean seedlings were exposed to salt stress after pre-treatment with proline or betaine. Salt stress caused a sharp increase in reduced glutathione (GSH) and oxidized glutathione (GSSG) content in leaves, while the GSH/GSSG ratio and ascorbate (AsA) content decreased significantly. The glutathione reductase (GR), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glyoxalase II (Gly II) activities were increased in response to salt stress, while the monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT) and glyoxalase I (Gly I) activities sharply decreased with an associated increase in hydrogen peroxide (H₂O₂) and lipid peroxidation level (MDA). Proline or betaine pre-treatment had little influence on nonenzymatic and enzymatic components as compared to those of the untreated control. However, proline or betaine pre-treated salt-stressed seedlings showed an increase in AsA, GSH content, GSH/GSSG ratio and maintained higher activities of APX, DHAR, GR, GST, GPX, CAT, Gly I and Gly II involved in ROS and MG detoxification system as compared to those of the untreated control and mostly also salt-stressed plants with a simultaneous decrease in GSSG content, H₂O₂ and MDA level. These results together with our previous results suggest that coordinate induction of antioxidant defense and glyoxalase system by proline and betaine rendered the plants tolerant to salinity-induced oxidative stress in a synergistic fashion.     

乌鲁木齐市四个不同点地衣形态结构及重金属含量的比较研究

[目的]探讨地衣形态结构特征、地衣体重金属含量和大气重金属污染三者之间的关系.[方法]采自乌鲁木齐市近郊区花儿沟、仓房沟、西山农场和南山小渠子的丽石黄衣(Xanthoria elegans(Link)Th.Fr)和碎茶渍(Lecanora argopholis (Ach) Ach.)作为实验材料进行形态结构和重金属含量比较并分析与大气污染之间的关系.[结果]4个区域地衣样品形态结构有差异.长势变化程度依次为仓房沟＞西山农场＞花儿沟＞南山小渠子.各采样点丽石黄衣地衣体内重金属含量之间有显著性差异.4个样点重金属综合污染程度依次为仓房沟＞西山农场＞花儿沟＞南山小渠子.[结论]仓房沟是Fe、Mn、Zn和Pb污染区,西山农场是Cr、Mn和Pb污染区,花儿沟是Cr污染区.地衣形态结构特征、地衣体重金属含量和大气重金属污染之间具有显著的相关性,即大气重金属含污量是地衣体重金属含量增减的直接原因,地衣体重金属含量的增加导致地衣形态变化的主要因素之一.大气重金属污染是导致地衣形态变异以及地衣消亡的致命性因素之一.     

The impact of forest service litigation success on administrative appeals of proposed fuels reduction actions

In this paper, we explore empirically whether the USDA Forest Service's litigation success rate in each Forest Service region helps explain the persistent regional effects noted by Laband et al. (Laband, D.N., González-Cabán, A., and Hussain, A. (2006). “Factors That Influence Administrative Appeals of Proposed USDA Forest Service Fuels Reduction Actions,” Forest Science, 52(5): 477–488.) with respect to the pattern of administrative appeals of proposed fuels reduction actions. We find strong evidence of an inverse relationship between the Forest Service's litigation success rate and the likelihood of administrative appeal of proposed fuels reduction actions on public lands. However, inclusion of this variable explains only about 20% of the region-specific impact noted in Laband et al. (Laband, D.N., González-Cabán, A., and Hussain, A. (2006). “Factors That Influence Administrative Appeals of Proposed USDA Forest Service Fuels Reduction Actions,” Forest Science, 52(5): 477–488.), which continues to command additional investigation.