نتایج جستجو برای: immature pollen
تعداد نتایج: 47880 فیلتر نتایج به سال:
BACKGROUND Allergies to grass pollen are the number one cause of outdoor hay fever. The human immune system reacts with symptoms to allergen from pollen. OBJECTIVE We investigated the natural variability in release of the major group 5 allergen from grass pollen across Europe. METHODS Airborne pollen and allergens were simultaneously collected daily with a volumetric spore trap and a high-v...
Global synthesis indicates that limitation of plant fecundity by pollen receipt (pollen limitation) is positively related to regional plant diversity and is higher for self-incompatible than self-compatible species. While self-incompatible species are always dependent on pollinating agents, self-compatible species may be pollinator-dependent or autofertile. This should cause variation in pollen...
The forests of north-eastern Croatia, as well as various plants and trees in the parks and streets of the Osijek-Baranja County, produce large amounts of pollen during the pollen season, which can cause allergy symptoms in pollen sensitive individuals. The aim of this study was to determine the most frequent types of pollen in this area and estimate possible health risks, especially the risk of...
Here we describe a new phenomenon, entombed pollen, which is highly associated with increased colony mortality. Entombed pollen is sunken, capped cells amidst "normal", uncapped cells of stored pollen, and some of the pollen contained within these cells is brick red in color. There appears to be a lack of microbial agents in the pollen, and larvae and adult bees do not have an increased rate of...
The most abundant biological particles in the atmosphere are pollen grains and spores. Self protection of pollen allergy is possible through the information of future pollen contents in the air. In spite of the importance of airborne pollen concentration forecasting, it has not been possible to predict the pollen concentrations with great accuracy, and about 25% of the daily pollen forecasts ha...
Pollen forecasting is of increasing interest as a way to help the general public avoid contact with allergy-inducing pollen. It was recently reported that the dynamics underlying pollen concentration series is very similar to that of low-dimensional deterministic chaos, thus opening up new avenues of development in local pollen forecasting. Our analysis of hourly cedar pollen series for two sea...
The cell wall is important for pollen tube growth, but little is known about the molecular mechanism that controls cell wall deposition in pollen tubes. Here, the functional characterization of the pollen-expressed Arabidopsis cellulose synthase-like D genes CSLD1 and CSLD4 that are required for pollen tube growth is reported. Both CSLD1 and CSLD4 are highly expressed in mature pollen grains an...
BACKGROUND The route by which pollen enters dwellings has not been clarified. OBJECTIVE To evaluate the amount of pollen entering dwellings by ventilation and adhesion to textile products. METHODS The amount of pollen clinging to fabrics (clothes, laundry, and futon bedding) out of doors was measured by quantification of Japanese cedar pollen antigen Cry j 1. The effect of air ventilation o...
Purpose. Investigation of cytogenetic aspects embryological processes in the culture immature apomictic embryos, breeding genotypes sugar beet with cytoplasmic sterility for differentiation and selection by gametophyte reduced parthenogenesis.
 Methods. Cytological, biotechnological, fluorescent cytophotometry, field, laboratory.
 Results. The features genesis embryos cells induced vi...
Pollen, an extremely reduced bicellular or tricellular male reproductive structure of flowering plants, serves as a model for numerous studies covering wide range of developmental and physiological processes. The pollen development represents a fragile and vital phase of plant ontogenesis and pollen was among the first singular plant tissues thoroughly characterized at the transcriptomic level ...
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