نتایج جستجو برای: plant diversity

تعداد نتایج: 563074  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده کشاورزی 1391

بررسی تنوع ژنتیکی ژنوتیپ‏های بومی پیاز ایرانی در مقایسه با انواع خارجی چکیده: برنامه های اصلاحی گیاهان بر اساس تنوع و انتخاب صفات برتر کمی و کیفی صورت می گیرد. لذا، ارزیابی تنوع ژنتیکی، اولین مرحله در برنامه های اصلاحی است. در این راستا، استفاده از روش های جدید مطالعه‏ی تنوع ژنتیکی ضروری به نظر می رسد. در این بررسی تعیین تنوع ژنتیکی سیزده ژنوتیپ پیاز ایرانی در مقایسه با دو ژنوتیپ خارجی با است...

Journal: :Molecular ecology 2013
Cheng Gao Nan-Nan Shi Yue-Xing Liu Kabir G Peay Yong Zheng Qiong Ding Xiang-Cheng Mi Ke-Ping Ma Tesfaye Wubet François Buscot Liang-Dong Guo

Microbial diversity is generally far higher than plant diversity, but the relationship between microbial diversity and plant diversity remains enigmatic. To shed light on this problem, we examined the diversity of a key guild of root-associated microbes,that is, ectomycorrhizal (EM) fungi along a plant diversity gradient in a Chinese subtropical forest. The results indicated that EM fungal dive...

Journal: :international journal of advanced biological and biomedical research 2013
alireza ekrami

gonabad located at khorasan razavi and coordinates 580 30’ n 34o 35’ e. the highest point of the zone belongs to peak of siah mountain (height of 2,863 meters above sea level) and the lowest place has height of 810 meters above sea level, which is located in north west in salt desert. the mean temperature of the warmest and coldest of year is 29.3 and 3.9 respectively. moreover, mean of rainfal...

2014
Xoaquín Moreira Luis Abdala-Roberts Víctor Parra-Tabla Kailen A. Mooney

Despite increasing evidence that plant intra- and inter-specific diversity increases primary productivity, and that such effect may in turn cascade up to influence herbivores, there is little information about plant diversity effects on plant anti-herbivore defenses, the relative importance of different sources of plant diversity, and the mechanisms for such effects. For example, increased plan...

Adel Sepehry Hossein Barani Mohsen Sharafatmandrad,

In arid and semi-arid rangelands, grazing as one of the natural or human induced processes has direct and indirect effects on structure and dynamics of plant community and ecosystems. A study was done to analyze the effects of grazing on plant species diversity and Plant Functional Types‘ (PFTs) diversity of arid and semi-arid rangelands. We analyzed plant richness and diversity data from 75 sa...

Journal: رستنیها 2008

Mouteh Refuge covers an area of 200,000 hectars situated in the northwest of Meymeh and southwest of Delijan. Minimum and maximum of altitude are 1800 and 3000 m, respectively. The Refuge presents a variety of habitats, including stony slopes, pedimont plains, alluvial plains, salt marshes, saline rivers and springs.A total of 580 species and subspecific taxa were identified based on plant samp...

Journal: :Plant Physiology 2001

Journal: :Ecology letters 2011
John L Maron Marilyn Marler John N Klironomos Cory C Cleveland

One robust result from many small-scale experiments has been that plant community productivity often increases with increasing plant diversity. Most frequently, resource-based or competitive interactions are thought to drive this positive diversity-productivity relationship. Here, we ask whether suppression of plant productivity by soil fungal pathogens might also drive a positive diversity-pro...

Journal: :Ecology 2014
Tanja Rottstock Jasmin Joshi Volker Kummer Markus Fischer

Fungal plant pathogens are common in natural communities where they affect plant physiology, plant survival, and biomass production. Conversely, pathogen transmission and infection may be regulated by plant community characteristics such as plant species diversity and functional composition that favor pathogen diversity through increases in host diversity while simultaneously reducing pathogen ...

2015
Erika C. Brandt John E. Petersen Jake J. Grossman George A. Allen David H. Benzing Jian Liu

The diversity of plant species and their distribution in space are both thought to have important effects on the function of wetland ecosystems. However, knowledge of the relationships between plant species and spatial diversity remains incomplete. In this study, we investigated relationships between spatial pattern and plant species diversity over a five year period following the initial resto...

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