Background: Due to its nutrient content, a variety of spoilage microorganisms can grow in bee pollen, especially when handling practices are not appropriate. So, this survey was designed to assess the physicochemical and microbiological properties of bee pollen collected from Bulgaria. Methods: In June 2014, 13 fresh and 19 dried bee pollen samples were collected from Bulgaria. Water activity ...

Potassium antimonite was used to locate calcium in the anthers of Torenia fournieri (Linderniaceae). Abundant calcium precipitates accumulate in the microsporocyte cytoplasm. After meiosis, calcium precipitates are abundant on the microspore wall, as well as the callosic wall of each tetraspore. A large number of calcium precipitates also occur on the outer membranes of the tapetal cells, and i...

Butterflies of the neotropical Genus Heliconius feed on pollen. This is the first known instance in butterflies of a habit that is well known for other insects. The butterflies remove amino acids and proteins from pollen; this feeding innovation plays a role in the reproductive and population biology of these insects. It is suggested that other animals may use pollen in a similar fashion.

In flowering plants, pollen grains germinate to form pollen tubes that transport male gametes (sperm cells) to the egg cell in the embryo sac during sexual reproduction. Pollen tube biology is complex, presenting parallels with axon guidance and moving cell systems in animals. Pollen tube cells elongate on an active extracellular matrix in the style, ultimately guided by stylar and embryo sac s...

BACKGROUND Pollen forecasts are highly valuable for allergen avoidance and thus raising the quality of life of persons concerned by pollen allergies. They are considered as valuable free services for the public. Careful scientific evaluation of pollen forecasts in terms of accurateness and reliability has not been available till date. OBJECTIVE The aim of this study was to analyze 9 mobile ap...

Greenhouses are a well-accepted containment strategy to grow and study genetically modified plants (GM) before release into the environment. Various containment levels are requested by national regulations to minimize GM pollen escape. We tested the amount of pollen escaping from a standard greenhouse, which can be used for EU containment classes 1 and 2. More specifically, we investigated the ...

The stingless bee Trigona carbonaria is a small, shiny black bee native to Australia. These bees collect pollen and nectar in much the same way as the well-known honey bee Apis mellifera, but can be more effective at pollination because as well as crawling over the anthers, they crawl over the style of the flower, delivering pollen to the stigma. The main scanning electron micrograph above show...

Pollen morphology of three parental Quercus species (Q. robur L., Q. petraea (Matt) Liebl, Q. pubescens Willd.) and two spontaneous hybrids of these species (Q. ×calvescens Vuk. = Q. petraea × Q. pubescens and Q. ×rosacea Bechst. = Q. robur × Q. petraea) was investigated in this study. The pollen originated from 18 natural oak sites and 67 individuals (oak trees). Each individual was represente...

The pollen diet of Africanized honeybees Apis mellifera L. was studied during seven months (October 2006 to April 2007) in a natural forest fragment in the southern Pantanal, sub-region of Abobral, Mato Grosso do Sul. The analysis of the pollen diet was based on direct observations of the bees visiting flowers as well as through the use of a pollen trap installed in a wild colony in a tree hole...

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...