Genetic tracking of the brown bear in northern Pakistan and implications for conservation     

Eva Bellemain  Muhammad Ali Nawaz  Alice Valentini  Jon E. Swenson  Pierre Taberlet 《Biological conservation》2007,134(4):537-547

Asian bears face major threats due to the impact of human activities as well as a critical lack of knowledge about their status, distribution and needs for survival. Once abundant in northern Pakistan, the Himalayan brown bear (Ursus arctos isabellinus) has been exterminated in most of its former distribution range. It presently occurs sparsely, in small populations, the Deosai National Park supporting the largest isolate. This decline might imply a reduction in genetic diversity, compromising the survival of the population. Using a combination of fecal DNA analysis and field data, our study aimed at assessing the size and genetic status of the Deosai population and give guidelines for its conservation and management. Using fecal genetic analysis, we estimated the population to be 40-50 bears, which compares well with the field census of 38 bears. The northern Pakistani brown bear population may have undergone an approximate 200-300-fold decrease during the last thousand years, probably due to glaciations and the influence of growing human population. However, in spite of the presence of a bottleneck genetic signature, the Deosai population has a moderate level of genetic diversity and is not at immediate risk of inbreeding depression. Gene flow might exist with adjacent populations. We recommend careful monitoring of this population in the future both with field observations and genetic analyses, including sampling of adjacent populations to assess incoming gene flow. The connectivity with adjacent populations in Pakistan and India will be of prime importance for the long-term survival of Deosai bears.  相似文献   

Toxic Effect of Certain Metals Mixture on Some Physiological and Morphological Characteristics of Freshwater Algae     

Shehata  Salwa A.  Lasheen  Mohamed R.  Ali  Gamila H.  Kobbia  Imam A. 《Water, air, and soil pollution》1999,110(1-2):119-135

The toxic effect of multi metals mixture which exist simultaneously in aquatic ecosystem on natural phytoplankton assemblages (green algae, blue-green algae and diatoms) was studied. For this purpose a laboratory scale unit was designed to evaluate the effect of continuous flow metals mixture in forms if triple and penta metals in Nile water algae. Clear changes in algal biomass in terms of chlorophyll a (chl a) took place when subjected to metals combination. The rise or decline in chl a was in relation with other algal pigments (chl b, chl c, carotenoides and phenophytin), protein and carbohydrate content of algal cells. Substantial changes in phytoplankton community structure was detected and the most tolerant group was blue-green algae followed by green algae while diatoms was the most sensitive group. The most dominant species in all cases were blue-green alga Oscillatoria mougeotii and green alga Scenedesmus quadricauda. In addition clear changes in morphological shape was observed for tolerant species belonging to the three algal groups. Nile water algae has ability to remove and accumulate metals in the following order therefore Zn > Cd > Ni > Cu > Cr. In addition, phytoplankton has ability to recovered from the stress of metals when eliminated from the media and the recovered biomass was nearly equivalent to that before exposing to metals stress. The overall effect of metals mixture depending on the type and number of metals, the algal community structure and ratio between different morphological forms of algae (unicellular, colonial and filamentous).  相似文献   

Inheritance and fitness costs of sulfoxaflor resistance in Nilaparvata lugens (Stål)     

Xun Liao  Kaikai Mao  Ehsan Ali  Ruoheng Jin  Zhao Li  Wenhao Li  Jianhong Li  Hu Wan 《Pest management science》2019,75(11):2981-2988

  相似文献   

Effect of elevated carbon dioxide concentration on growth,productivity and glyphosate response of parthenium weed (Parthenium hysterophorus L.)     

Ali A Bajwa  Haochen Wang  Bhagirath S Chauhan  Steve W Adkins 《Pest management science》2019,75(11):2934-2941

  相似文献   

Correction to: Impact of leaf infestation by herbivorous insects on the elemental uptake of citrus trees     

Semhi  Khadija  Clauer  Norbert  Al-Raeesi  Ali Ahmed 《植物病害和植物保护杂志》2019,126(1):77-77

Journal of Plant Diseases and Protection - In the original publication, the article title was incorrectly published as ‘Impact of leave infestation by herbivorous insects on the elemental...  相似文献   

Characterization of sulfoxaflor resistance in the brown planthopper,Nilaparvata lugens (Stål)     

Xun Liao  Ruoheng Jin  Xiaolei Zhang  Ehsan Ali  Kaikai Mao  Pengfei Xu  Jianhong Li  Hu Wan 《Pest management science》2019,75(6):1646-1654

  相似文献   

球孢白僵菌不同施用方式对玉米促生作用的研究     

崔雨虹  白云  曹娜  刘亦豪  Ghulam Ali Bugti  王滨 《热带作物学报》2017,(2):206-212

采用土壤施用和叶面喷施2种方式将球孢白僵菌(Beauveria bassiana)菌株Bb202接种至玉米,研究不同接种方式及处理浓度对玉米生长的影响。结果表明,2种喷施方式对玉米苗均存在促生作用,且这种促生作用与孢子接种浓度密切相关。在叶面喷施处理中,白僵菌仅对玉米地上部分生长指标有促进作用,而对玉米苗的根长无显著影响;其中1.0×10~4孢子/m L处理组对玉米苗的促生效果最佳,其株高、叶长、叶宽、鲜重指标比蒸馏水对照组分别高出7.47%、15.42%、25.70%和16.85%。在土壤喷施处理中,白僵菌对玉米苗地上与地下部分均有显著促生作用;其中1.0×106孢子/m L和1.0×10~8孢子/m L处理组,玉米株高、叶长、根长、生物量指标较蒸馏水对照组分别提高了28.66%和29.59%、30.66%和37.85%、43.08%和33.60%、28.35%和32.55%。从对玉米苗的促生作用来看,用1.0×106孢子/m L的白僵菌悬浮液处理土壤,可以取得最经济、最显著的促生效果。  相似文献   

Nano-calcium carbonate reinforced polypropylene and propylene-ethylene copolymer nanocomposites: Tensile vs. impact behavior     

Mangala Joshi  Satyajit Brahma  Anasuya Roy  S. Wazed Ali 《Fibers and Polymers》2017,18(11):2161-2169

Improvement of both the tensile and impact strength of the same polymeric material has always been a great challenge for the plastic industry. The study focuses on the effect of incorporation of calcium carbonate nanoparticles (0.3 wt% to 15 wt%) into three polypropylene (PP) based matrices viz. PP homopolymer, propylene-ethylene (PP-PE) copolymer and the blend of PP:PP-PE (30:70) to improve their impact behavior without hampering the tensile strength much. A loss in both the tensile and impact properties was observed in PP based nanocomposite. However, PP-PE based nanocomposites showed a significant improvement in impact strength (47 %) at 10 wt% loading with a loss of tensile strength by 22 %. To minimize this loss a blend of PP:PP-PE (30:70) was explored as a matrix. At 10 wt% loading, this matrix showed an improvement of 30 % in impact strength whereas the tensile loss was minimized to 10 %. Further, silane coupling agent which promoted good interfacial adhesion was used for best compositions. The variation of crystalline morphology of the nanocomposites with various formulations was analyzed using differential scanning calorimetry and X-ray diffraction.  相似文献   

Nitrogen and Phosphorus Use Efficiency in Improved Potato (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.) Cultivars in Southern Ethiopia     

Gebru Hailu  Dechassa Nigussie  Mohammed Ali  Belew Derbew 《American Journal of Potato Research》2017,94(6):617-631

Use of nutrient efficient crop species or cultivars within species in combination with improved crop production practices offer the best option for meeting the future food requirements of growing world populations. Efficiency improvement has a key role for nutrient use and it improves both productivity of yield and minimizes risks of losses that potentially harm the environment. To improve nutrient use efficiency (NUE), one strategy is to select cultivars of crops with high NUE. Both nitrogen (N) and phosphorus (P) are among essential macronutrients commonly applied to agricultural crops to optimize yields. Evaluation of potato cultivars with high N and P efficiency is essential for sustainable production of the crop. In Ethiopia, however, little research has been done to elucidate better NUE of potato crop until recently. This study was, thus, designed to evaluate selected potato cultivars (Belete, Gudene, Jalene, Marachere and one local check) for NP use efficiency under low levels of the nutrients in Wolaita Sodo University, Ethiopia during 2014 and 2015. Factorial combination of 3 levels of each N (0, 55.5 and 111 kg N ha^?1 ) and P (0, 19.5 and 39 kg P ha^?1 ) were assigned to the main plots and the 5 cultivars to subplots of split-plot design in three replications. Efficiency indices such as agronomic efficiency, physiological efficiency and recovery efficiency were computed for combined NP nutrients. Results showed that agronomic nitrogen use efficiency, apparent phosphorus use efficiency and phosphorus use efficiencies were significantly influenced by the interaction effect of rates of NP nutrition and variety. Application of NP more than 55.5:19.5 kg ha^?1 will not beneficial due to their less or equal use and recovery efficiencies to 55.5:19.5 kg NP ha^?1. Belete was the most NP efficient variety followed by Jalene and Gudene in all efficiency indices. Therefore, Belete, Jalene and Gudene return better for NP at 55.5:19.5 kg ha^?1 for economical use of fertilizes while obtaining satisfactory yield. It can be concluded that yield response variation of the varieties was related to their differences in NP uptake and use efficiencies; and the improved potato varieties were superior to local check in using NP nutrients efficiently.  相似文献   

Diversity of root-knot nematodes in Moroccan olive nurseries and orchards: does <Emphasis Type="Italic">Meloidogyne javanica</Emphasis> disperse according to invasion processes?     

Mohamed Aït Hamza  Nadine Ali  Johannes Tavoillot  Odile Fossati-Gaschignard  Hassan Boubaker  Abdelhamid El Mousadik  Thierry Mateille 《BMC ecology》2017,17(1):41

  相似文献