نتایج جستجو برای: Pollen grains

تعداد نتایج: 46074  

Asthma and allergic diseases cases have risen in recent decades. Plant pollen is considered as the main aeroallergen causing allergic reactions. According to available data, urban residents experience more respiratory allergies than rural residents mainly due to the interaction between chemical air pollutants and pollen grains. This interaction can occur through several mechanisms; chemical pol...

ژورنال: :مجله گیاهشناسی ایران 2011
زهرا احمد خان بیگی مسعود شیدایی فریده عطار

مورفومتری و بررسی ویژگیهای گرده در 16 جمعیت از 6 گونه cousinia با استفاده از روشهای آماری یک و چند متغیره انجام گرفت. آزمون anova اختلاف معنی دار گونه های مطالعه شده را در اکثر صفات کمی نشان داد که بیانگر کارایی این دسته از صفات در تفکیک گونه ها از یکدیگر می باشد. دندروگرام های بدست آمده از آنالیز صفات ریختی، جدایی جمعیت هایc. microcephalaرا ازدیگر گونه ها نشان می دهند. همچنین نزدیکی گونه های c...

Journal: :crop breeding journal 2012
f. ghanavati h. amirabadizadeh

pollen grain morphology of 15 taxa of the hedysareae tribe distributed throughout iran was studied using light and electron microscopy to identify major taxonomical characteristics of pollen grains. the pollen grains were tricolpate and tricolporate, prolate and perprolate. the ectocolpi were elongated, shallow or deep, narrowing at the poles. the colpus membrane was covered by large granules. ...

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...

Journal: :iranian journal of allergy, asthma and immunology 0
maryam sharif shoushtari immunology, asthma and allergy research institute, tehran university of medical sciences, tehran, iran and department of biology, faculty of biology science, islamic azad university, north tehran branch, iran ahmad majd department of biology, faculty of biology science, islamic azad university, north tehran branch, iran zahra pourpak immunology, asthma and allergy research institute, tehran university of medical sciences, tehran, iran and department of immunology and allergy, children medical center, tehran university of medical sciences, tehran, iran youcef shahali laboratoire “sciences analytiques, bioanalytiques et miniaturisation”, espci paristech, umr 7195 cnrs, 75231 paris cedex 05, france mostafa moin immunology, asthma and allergy research institute, tehran university of medical sciences, tehran, iran and department of immunology and allergy, children medical center, tehran university of medical sciences, tehran, iran mohammad bagger eslami department of pathobiology, immunology division, school of public health, tehran university of medical sciences, tehran, iran

weed pollen grains belonging to  the  asteraceae  family contain  a variety of  allergens inducing type i  and iv allergies in susceptible people. the  aim of this research was to compare  the  allergenic properties  of  immature  and  mature  shasta  daisy pollen  grains (chrysanthemum maximum ramond) to define the potential role of the maturation process on the allergenicity of asteraceae pol...

Journal: :Annals of agricultural and environmental medicine : AAEM 2003
Adem Bicakci Sevcan Tatlidil Nihat Sapan Hulusi Malyer Yakup Canitez

In this study, pollen grains were sampled by using a Lanzoni trap (Lanzoni VPPS 2000) in atmosphere of Bursa in 1999 and 2000. During two years. a total of 13,991 pollen grains/m3 which belonged to 59 taxa and unidentified pollen grains were recorded. A total of 7.768 pollen grains were identified in 1999 and a total of 6.223 in 2000. From these taxa, 36 belong to arboreal and 23 taxa to non-ar...

Journal: :American journal of botany 2016
Charlotte Prieu Alexis Matamoro-Vidal Christian Raquin Anna Dobritsa Raphaël Mercier Pierre-Henri Gouyon Béatrice Albert

PREMISE OF THE STUDY Pollen grains are subject to intense dehydration before dispersal. They rehydrate after landing on a stigma or when placed in humid environment by absorbing water from the stigma or surroundings. Resulting fluctuations in water content cause pollen grains to undergo significant changes in volume. Thus, morphological or structural adaptations might exist to help pollen adjus...

ژورنال: :مجله گیاهشناسی ایران 2014
منا کاوه اختر توسلی رحمان آزادی فرشید معماریانی

.fraxinus l یا جنس ون یکی از 24 جنس از خانواده oleaceae است که با 43 گونه که در نیمکره شمالی انتشار دارند. دو گونه .f. excelsior l   و.f. angustifolia vahl از این جنس در ایران انتشار دارند. از آنجایی که این دو گونه بسیار به یکدیگر شباهت دارند، برای رفع ابهام در تشخیص این دو گونه،  صفات ریخت شناسی، ریز ریخت شناسی 55 جمعیت آن مورد بررسی قرار گرفت. برای بررسی ویژگی های مورد نظر، از آنالیز فنتیک اس...

Atieh Nejhad falatoury Fariba Sharifinia Manijeh Pakravan

Nonea Medik. is a genus of the Boraginaceae tribe Boragineae, with approximately 35 species worldwide. Examination of their palynological characters supported the separation of taxa, which is usually based on morphological and micromorphological reproductive features. Pollen grains of 10 taxa representing three groups of taxa in Iran, the N. caspica group, the N. persica group and the N. lutea ...

2012
Nurit Firon Etan Pressman Shimon Meir Reham Khoury Leviah Altahan

BACKGROUND AND AIMS Exposure to higher-than-optimal temperatures reduces crop yield and quality, mainly due to sensitivity of developing pollen grains. The mechanisms maintaining high pollen quality under heat-stress conditions are poorly understood. Our recently published data indicate high heat-stress-induced expression of ethylene-responsive genes in tomato pollen, indicating ethylene involv...

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