نتایج جستجو برای: pollen
تعداد نتایج: 20847 فیلتر نتایج به سال:
BACKGROUND AND AIMS Pollen grains of 37 species from 11 genera in the family Zingiberaceae were examined to assess qualitatively starch or lipid contents; the pollen grain and ovule numbers per flower and pollen : ovule ratios were also counted and calculated. Pollen : ovule ratios were studied to reveal patterns of variation in the Zingiberaceae. METHODS Freshly open flowers with dehiscing a...
In parts of the world where teosinte and maize are grown in close proximity, there is concern about gene flow between them. Pollen is the primary vehicle for gene flow. Quantifying the biophysical properties of pollen, such as its settling speed and dehydration rate, is important for evaluating outcrossing potential. These properties were measured for teosinte (Zea mays subsp. parviglumis) poll...
Reproduction of flowering plants requires the growth of pollen tubes to deliver immotile sperm for fertilization. Pollen tube growth resembles that of polarized metazoan cells, in that some molecular mechanisms underlying cell polarization and growth are evolutionarily conserved, including the functions of Rho GTPases and the dynamics of the actin cytoskeleton. However, a role for AGC kinases, ...
For sexual selection to be important in plants, it must occur at pollen load sizes typical of field populations. However, studies of the impact of pollen load size on pollen competition have given mixed results, perhaps because so few of these studies directly examined the outcome of mating when pollen load size was varied. We asked whether seed paternity after mixed pollination of wild radish ...
AtAMT1;4, a Pollen-Specific High-Affinity Ammonium Transporter of the Plasma Membrane in Arabidopsis
Pollen represents an important nitrogen sink in flowers to ensure pollen viability. Since pollen cells are symplasmically isolated during maturation and germination, membrane transporters are required for nitrogen import across the pollen plasma membrane. This study describes the characterization of the ammonium transporter AtAMT1;4, a so far uncharacterized member of the Arabidopsis AMT1 famil...
Self-incompatibility is one of the most prominent inhibiting factors in almond production which reduces fruit set, making orchard management difficult. Therefore, breeding of almond to produce self-compatible genotypes is indispensably important. In this research work, pollen tube growth rate was studied in 38 genotypes obtained from crossing between Touno (male parent) and Shahrood 12 (female ...
The present research was conducted with the purpose of studying self and cross-compatibility in some commercial cultivars of peach through field and microscopic studies in order to increase the quantity and quality traits of the product. The study was carried out in years 2010 and 2011. In a first experiment, the pollen germination of 10 cultivars of peach was studied in culture medium. The res...
Here we present the amount of pollen of eucalypt and pollen of other types for birds captured in two bird ringing stations for 14 months (March 2014 to April 2015) in NW Spain. Common and latin names of all birds species captured, together with the number of captured individuals (N), prevalence of eucalypt pollen (percentage of individuals with eucalypt pollen) and of pollen of other types and ...
The study of pollen morphology has historically allowed evolutionary biologists to assess phylogenetic relationships among Angiosperms, as well as to better understand the fossil record. During this process, pollen has mainly been studied by discretizing some of its main characteristics such as size, shape, and exine ornamentation. One large plant clade in which pollen has been used this way fo...
High quality of bee pollen for commercial purpose is required. In order to attend the consumer with the best identification of the botanical and floral origin of the product, 25 bee pollen batches were investigated using two techniques of pollen grain preparation. The first started to identify pollen loads of different colors in two grams of each well mixed batch, and the second to identify pol...
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