新疆山地针叶林植物物种组成与丰富度研究

通过对新疆阿尔泰山、天山北坡、天山南坡和昆仑山西部11个地点122个样方的调查,发现阿尔泰山针叶林植物(包括乔木、灌木和草本)丰富度显著高于天山南坡和昆仑山;天山南坡和昆仑山物种组成相似,阿尔泰山和天山北坡物种组成相似.全疆针叶林物种丰富度随年平均气温和海拔的增加显著下降,随纬度的升高显著升高.在不同区域,物种丰富度随...     

Gastrointestinal parasites of dogs in Iran

Summary The results are described of a survey on the incidence of intestinal helminths and protozoa in house-dogs in Teheran, Iran. Eleven species of adult helminths, six species of eggs and two species of protozoa were recovered.Toxocara canis, Taenia multiceps andSpirocerca lupi were the most common helminths in dogs.Toxascaris leonina, Physaloptera preputialis, Trichuris vulpis, Isospora bigemina andI. rivolta are reported for the first time from Iran.

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Sumario Se describen los resultados de una encuesta sobre la incidencia de helmintos intestinales y protozoarios en perros “caseros” en Teherán, Iran. Se recuperaron once especies de helmintos adultos, seis especies de huevos y dos especies de protozoarios. Los helmintos mas comunes en los perros fueron encontrados serToxocara canis, Taenia multiceps ySpirocerca lupi. Por primera vez se reportan en IranToxascaris leonina, Physaloptera preputialis Trichuris vulpis, Isospora bigemina eIsospora virolta.

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Résumé Cet article donne les résultats d'une étude sur l'incidence des helminthes et des protozoaires intestinaux chez les chiens de particuliers à Téhéran. Onze espèces de vers adultes, six espèces d'oeufs et deaux espèces de protozoaires furent recensés.Toxocara canis, Taenia multiceps etSpirocera lupi étaient les helminthes les plus courants chez les chiens.Toxascaris leonina, Physaloptera preputialis, Trichuris vulpis, Isospora bigemina etI. rivolta sont cités pour la première fois en Iran.

     

天山南北坡植物种-面积关系

通过对天山南北坡25个样地的物种-面积关系的研究,结果发现:①所有样地种-面积关系斜率的平均值为0.21±0.02,低于全球平均水平;②草甸、草原和荒漠的种-面积关系的斜率分别为0.14±0.02,0.13±0.01和0.28±0.02.草甸和草原的种-面积关系斜率无显著差别,但两者显著低于荒漠的种-面积关系斜率;③天...     

喀喇昆仑山-西昆仑山苔藓植物区系及物种多样性1）

对喀喇昆仑山—西昆仑山苔藓植物区系成分进行了划分,并对该区系与邻近9个地区的地理成分进行了聚类分析。经查阅有关资料和标本鉴定,确定新疆喀喇昆仑山共有苔藓植物32科、76属、178种（含5变种）,其中苔类为7科、8属、11种,藓类25科6、8属、167种。喀喇昆仑山—西昆仑山苔藓植物区系成分可划分为10种类型,其中北温带成分居主导地位,占该地区苔藓植物总种数的71．81％,东亚成分次之,占8．85％,热带成分甚微。地理成分区系谱及聚类分析结果表明,新疆喀喇昆仑山—西昆仑山与东部天山苔藓植物区系关系最为接近,与贺兰山密切相关。对喀喇昆仑山—西昆仑山10个样点中苔藓植物多样性指数的分析结果表明,西合休和果萨斯苔藓植物分布较丰富。     

The nature of organic matter in soil organo-mineral complexes

“The union of mineral and organic matter to form the organo-mineral complex is a synthesis as vital to the continuance of life as, and less understood than, photosynthesis.”(JACKS) (1).     

Evaluation of nitrogen status of agricultural soils in Java,Indonesia

Abstract

To evaluate the content of nitrogen (N) fractions of agricultural soils in Java, Indonesia, in relation to soil type and land use, 46 surface soil samples, 23 from paddy and 23 from upland, were collected throughout Java to include various types of soils. Soil N was separated into four fractions according to form and availability: inorganic extractable nitrogen (Iex-N), fixed ammonium nitrogen (Ifix-N), organic mineralizable nitrogen (Omin-N) and organic stable nitrogen (Osta-N). The total-N content was determined by the dry combustion method. The Iex-N content was determined by extraction with a 2 mol L^?1 potassium chloride (KCl) solution and the Ifix-N content by extraction with an hydrofluoric and hydrochloric acid (HF-HCl) solution after removal of organic-N. The Omin-N content was evaluated as the potentially mineralizable N based on a long-term incubation method. The Osta-N content was calculated as the difference between the contents of total-N and the three other fractions. The total-N content was 2.06 g kg^?1 on average. The contents of Iex-N, Ifix-N, Omin-N and Osta-N were 25.8, 99.1, 103 and 1,832 mg kg^?1, respectively, and corresponded to 1.3, 4.8, 5.0 and 88.9% of the total-N. Hence, available (Iex-N and Omin-N) and stable (Ifix-N and Osta-N) fractions accounted for 6.3% and 93.7% of the total-N, respectively. Correlation analysis indicated that the contents of total-N and Osta-N had positive correlation with (Alo + 1/2Feo) as an index of amorphous minerals (p < 0.01), suggesting strong influence of volcanic materials for the accumulation of organic matter in Java soils. The content of Ifix-N had a positive correlation with nonexchangeable potassium (K) content (p < 0.01), suggesting the contribution of 2:1 clay minerals which can fix both ammonium (NH₄⁺) and K⁺ in their interlayer sites. On the contrary, Omin-N did not have any significant correlation with soil properties, implying the importance of management for the improvement of the available N level in soils, rather than intrinsic soil properties. Soil N status further showed strong topographical trends depending on the elevation where soil developed. The contents of total N, Iex-N, Ifix-N, Omin-N and Osta-N in Java soils were on average 80, 69, 90, 65 and 80% of those in Japanese soils, respectively, suggesting that the soil N level in Java was lower than that in Japan, probably due to accelerated decomposition of organic matter, especially degradable fractions, reflecting high temperature, but that the level was relatively high for tropical soils due to the effect of volcanic materials. In conclusion, these results should be taken into account for the sustainable management of soil N in agricultural fields in Java, Indonesia.     

Evaluation of elite bread wheat lines for resistance to blast disease in Bangladesh

Euphytica - Genetic approaches often lead to the most cost-effective and efficient means to improve crops, especially those grown widely. But for most crops, cotton included, genetic improvement...     

Persistence and residual activity of an organophosphate, pirimiphos-methyl, and three IGRs, hexaflumuron, teflubenzuron and pyriproxyfen, against the cowpea weevil, Callosobruchus maculatus (Coleoptera: Bruchidae)

Three insect growth regulators (IGR), the chitin synthesis inhibitors (CSI) teflubenzuron and hexaflumuron and the juvenile hormone mimic (JHM) pyriproxyfen, as well as the organophosphate (OP) pirimiphos-methyl, were evaluated for their activity against the cowpea weevil, Callosobruchus maculatus (F), in cowpea seeds stored for up to 8 months post-treatment. The initial activity data showed that, based on LC50 level, teflubenzuron had strong ovicidal activity (LC50 = 0.056 mg kg(-1)) followed by pirimiphos-methyl (1.82 mg kg(-1)) and pyriproxyfen (91.9 mg kg(-1)). The residual activity data showed that none of the IGRs tested had strong activity when applied at 200 mg kg(-1) in reducing the oviposition rates of C maculatus at various storage intervals up to 8 months post-treatment. However, teflubenzuron reduced adult emergence (F1 progeny), achieving control ranging from 96.2% at 1 month to 94.3% at 8 months. Hexaflumuron showed a similar trend in its residual activity, ranging between 93.8% control at 1 month to 88.2% control at 8 months post-treatment. However, pyriproxyfen was more active than the CSIs tested and caused complete suppression (100% control) of adult emergence at all storage intervals. Unlike the IGRs tested, pirimiphos-methyl applied at 25 mg kg(-1) was more effective in reducing oviposition rates of C maculatus up to 8 months post-treatment. A strong reduction of adult emergence was also observed at various bimonthly intervals (98.6% control at 1 month to 91.6% control at 8 months post-treatment). The persistence of hexaflumuron and pirimiphos-methyl in cowpea seeds was also studied over a period of 8 months. The loss of hexaflumuron residue in treated cowpeas (200 mg kg(-1)) was very slow during the first month post-treatment (4.43%). At the end of 8 months, the residue level had declined significantly to 46.4% of the initial applied rate. The loss of pirimiphos-methyl residue in treated cowpeas (25 mg kg(-1)) was relatively high during the first month post-treatment (36.7%) and increased to 81.6% after 8 months.     

Effects of increasing dietary protein supplies on milk yield,milk composition,and nitrogen use efficiency in lactating buffalo

Nitrogen efficiency of lactating buffalo can be increased by providing dietary crude protein (CP) precisely to the requirement. Twelve lactating Nili-Ravi buffaloes (6 primiparous and 6 multiparous) at 76?±?37.5 days in milk (DIM) were used in this study. The treatments were diets providing three levels of CP (% DM basis): (1) low-protein?=?11%; (2) medium-protein?=?13.1%; (3) high-protein?=?14.2% according to a 3?×?3 Latin square design. The period length of each treatment was 21 days and the total duration of experiment was 63 days. The diets were designed to provide similar energy. The nitrogen intake of buffalo increased linearly by increasing CP levels. Dry matter intake showed a tendency toward decrease in quadratic fashion, whereas milk yield decreased linearly in high-protein diet. No effect was observed on milk protein yield and content. Increasing the dietary CP levels increased plasma urea nitrogen, whereas glucose and triacylglycerol levels remain unaffected. Efficiency of dietary nitrogen utilization to milk averaged 21% and showed both linear and quadratic decreases by increasing the protein supply levels. In conclusion, low CP level showed higher milk production with low plasma urea nitrogen and high nitrogen efficiency in this experiment.