نتایج جستجو برای: pollen grain

تعداد نتایج: 81981  

2006
George E. Bowker Hugh C. Crenshaw

During fair-weather conditions, a 100Vm 1 electric field exists between positive charge suspended in the air and negative charge distributed on the surfaces of plants and on the ground. The fields surrounding plants are highly complex reaching magnitudes up to 3 10Vm . These fields possibly influence the capture of charged wind-dispersed pollen grains. In this article, we model the electric fie...

Journal: :دانش گیاه پزشکی ایران 0
سمانه یاری دانشجوی کارشناسی ارشد دانشکده علوم کشاورزی دانشگاه گیلان جلیل حاجی زاده دانشیار دانشکده علوم کشاورزی دانشگاه گیلان رضا حسینی استادیار دانشکده علوم کشاورزی دانشگاه گیلان اصغر حسینی نیا مربی پژوهشی، ایستگاه ملی تحقیقات گل و گیاهان زینتی، محلات، استان مرکزی، ایران

the developmental period, prey consumption of different nymph instars, survival, reproduction and longevity of orius albidipennis were studied on three different diets including the two-spotted spider mite, tetranychus urticae plus corn pollen; two-spotted spider mite; and eggs of sitotroga cerealella plus corn pollen under laboratory conditions. leaves of pelargonium hortom served as ovipositi...

ژورنال: :مجله گیاهشناسی ایران 2012
نرگس فاطمی فریده عطار محمد حسن عصاره بهنام حمزه

در این مطالعه دانه گرده 13 گونه از جنس rosa متعلق به دو زیر جنس rosa و hulthemia و یک دورگه با استفاده از میکروسکوپ نوری و الکترونی مورد مطالعه قرار گرفت. بر اساس شکل دانه گرده، در 11 تاکسون شکل subprolate و به ندرت prolate, prolate- spheroidal مشاهده شد. دانه­های گرده سه شیار منفذی و ساختار دریچه شامل 3 ectocolpi و3 endopores است. endopores معمولا در بخش میانی ectocolpi  قرار گرفته اند. مشابه ...

2001
Arnaldo de Albuquerque Araújo Leonardo Max Batista Claudino Ricardo Augusto Rabelo Oliveira

The purpose of this work is to identify pollen grains from its sample images. Pollen grain recognition is used for the classification of the apiaria samples. In this paper we present an image retrieval technique that is being applied to pollen grain identification, based on querying a database of reference neural networks.

2007
Thomas BjOrkman

Flowers of cultivated buckwheat (Fagopyrum esculentum Moench) often receive natural pollen loads of fewer than 10 pollen grains. The cultivated varieties also have high genetic variability. These observations raise the question of whether seed production in buckwheat is often limited by pollen delivery, and whether small increases in pollen load could result in gametophytic selection through po...

2002
Alain Boucher Pablo J. Hidalgo Monique Thonnat Jordina Belmonte Carmen Galan Pierre Bonton Régis Tomczak

A semi-automatic system for pollen recognition is studied for the european project ASTHMA. The goal of such a system is to provide accurate pollen concentration measurements. This information can be used as well by the palynologists, the clinicians or a forecast system to predict pollen dispersion. At first, our emphasis has been put on Cupressaceae, Olea, Poaceae and Urticaceae pollen types. T...

2015
Murat Bağcıoğlu Boris Zimmermann Achim Kohler Jonathan A Coles

BACKGROUND Analysis of pollen grains reveals valuable information on biology, ecology, forensics, climate change, insect migration, food sources and aeroallergens. Vibrational (infrared and Raman) spectroscopies offer chemical characterization of pollen via identifiable spectral features without any sample pretreatment. We have compared the level of chemical information that can be obtained by ...

2017
Flavio Padilla Norman Soria Abrahan Oleas Darwin Rueda Bangeppagari Manjunatha Rajesh R. Kundapur Naga Raju Maddela Bugude Rajeswari

The objective of this study was to determine the effect of application of pesticides on morphology, viability, and germination of pollen grains of Blackberry (Rubus glaucus Benth.) and Tree tomato (Solanum betaceum Cav.). The study was performed at Patate, Tungurahua province, Ecuador and was divided into two phases. Phase one dedicated to the study of morphology, viability, and identification ...

ژورنال: :مجله گیاهشناسی ایران 2007
احمد قهرمان سید نصر نوربخش کاظم مهدی قلی فریده عطار

ریخت شناسی دانه گرده 26 گونه از جنس .artemisia l (درمنه) از 33 گونه درمنه ای که در ایران می رویند با استفاده از میکروسکوپ نوری(lm) و میکروسکوپ الکترونی (sem) بررسی شد. بر اساس مطالعات تزئینات اگزین بوسیله میکروسکوپ الکترونی اسکنینگ، دو تیپ دانه گرده تشخیص داده می شود: در نوع i سطح اگزین دارای خارچه های نوک تیز ومتراکم است و در نوع ii سطح اگزین دارای تراکم کمی از خارچه ها می باشد. تصاویر تمام گو...

2017
John J. Skvarla John R. Rowley William F. Chissoe

We have explored methods to achieve excellent results in study of the pollen grain wall by using only one electron microscope, the scanning electron microscope (SEM). While the secondary electron imaging mode , the most common in use, has great value in characterizing the exine surface it is possible to obtain a more comprehensive representation of pollen grain walls by expanding the capability...

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