نتایج جستجو برای: pollen
تعداد نتایج: 20847 فیلتر نتایج به سال:
BACKGROUND AND AIMS The integrity of actin filaments (F-actin) is essential for pollen-tube growth. In S-RNase-based self-incompatibility (SI), incompatible pollen tubes are inhibited in the style. Consequently, research efforts have focused on the alterations of pollen F-actin cytoskeleton during the SI response. However, so far, these studies were carried out in in vitro-grown pollen tubes. T...
Successive stamen movement directly controls pollen presentation schedules through sequential stamen maturation and changes the extent of herkogamy by altering the positions of sexual organs. However, the implications of such movements in terms of pollination are not well understood. Pollen presentation theory predicts that staggered pollen presentation should be favoured when plants are subjec...
We present for the first time continuous hourly measurements of pollen near-surface concentration and lidarderived profiles of particle backscatter coefficients and of volume and particle depolarization ratios during a 5-day pollination event observed in Barcelona, Spain, between 27 and 31 March 2015. Daily average concentrations ranged from 1082 to 2830 pollen m−3. Platanus and Pinus pollen ty...
in this study, we examined the chromosome number, detailed male meiosis, microsporogenesis, pollen fertility and distribution of cytotypes of diplotaxis harra (forssk.) boiss. this is the first cytogenetic report of the taxon. the two of the populations scored now from regions of the central showed aneuploid (x = 14) meiotic chromosome count and one of the populations studied from the existed a...
background: allergy is a clinical disorder affecting the human population with wide geographical distribution. platanus orientalis (p. orientalis) trees are planted in many countries and their pollen causes allergic reactions. cyclophilin has recently been identified as one of the most important allergens of p. orientalis pollen. we aimed to clone and purify this allergen in escherichia coli fo...
self-incompatibility is one of the most important difficulties in almond production which reduce fruit set dramatically.therefore, breeding almond to produce self-compatible genotypes is very important. in this research, pollen tube growth was studied in 28 genotypes obtained from crossing between touno (male parent) and shahrood 12 (female parent) after self pollination by fluorescent microsco...
Double fertilization in flowering plants requires the delivery of two immotile sperm cells to the female gametes by a pollen tube, which perceives guidance cues, modifies its tip growth direction, and eventually enters the micropyle of the ovule. In spite of the recent progress, so far, little is known about the signaling events in pollen tubes in response to the guidance cues. Here, we show th...
Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using an in vitro medium containing...
PURPOSE The occurrence of pollen allergy is subject to exposure to pollen, which shows regional and temporal variations. We evaluated the changes in pollen counts and skin positivity rates for 6 years, and explored the correlation between their annual rates of change. MATERIALS AND METHODS We assessed the number of pollen grains collected in Seoul, and retrospectively reviewed the results of ...
Pollen monitoring is an important and widely used tool in allergy research and creation of awareness in pollen-allergic patients. Current pollen monitoring methods are microscope-based, labour intensive and cannot identify pollen to the genus level in some relevant allergenic plant groups. Therefore, a more efficient, cost-effective and sensitive method is needed. Here, we present a method for ...
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