Germination ability and airborne counts of Scots pine (Pinus sylvestris L.) pollen were studied during the spring of 1993 at Turku in southern Finland (60 degrees 32' N, 22 degrees 28' E) and at Utsjoki in northern Finland (69 degrees 45' N, 27 degrees 01' E). Pollen waas trapped from the beginning of May to the end of June in a high-volume air sampler. Germination tests were performed to deter...

Background: Alongside hazel, alder and birch pollen allergies, ash pollen allergy is a relevant cause of hay fever during spring in the European region. For some considerable time, ash pollen allergy was not routinely investigated and its clinical relevance may well have been underestimated, particularly since ash and birch tree pollination times are largely the same. Ash pollen extracts are no...

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...

The effect of Persian bee propolis and pollen extracts on innate immune response of rainbow trout (Onchorhynchus mykiss) was investigated. Fish were fed diets containing 1% Pollen, 1% propolis and combination of the two immune-stimulants (0.5% Pollen and 0.5% propolis) as treatment groups and fed without the two immune-stimulants as positive and negative control groups for 4 weeks. The effects ...

In spite of the low atmospheric pollen levels, Artemisia sensitisation and allergy has been reported widely. The aim of the study was to determine the length of pollen season, intradiurnal, daily and monthly pollen variation, and the effect of some meteorological parameters on atmospheric pollen concentrations in Central Croatia. Seven-day Hirst volumetric pollen and spore traps were used for p...

We conducted an atmospheric pollen survey using a Durham sampler from 1983 through 1998 in Toyama City, Japan. We investigated yearly changes in the pollen season of Japanese cedar Cryptomeria japonica and analyzed the relationships between climatic factors and changes in the pollen counts. The results were as follows: (1) The first day of the Japanese cedar pollen season advanced from mid-Marc...

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...

PREMISE OF THE STUDY Pollen size varies greatly among flowering plant species and has been shown to influence the delivery of sperm cells to the eggs. Relatively little is known, however, about the functional significance of within-species genetic variation in pollen size. This study tests whether pollen size influences the relative siring success of a pollen donor during in vivo pollen competi...

Hypothesis: Sex allocation theory predicts that the pollen–ovule ratio should decrease linearly with increasing pollen size among seed plants (Charnov, 1982). Data examined: We retrieved data for pollen–ovule ratio, pollen size, pollen grain number, and mating system from published literature for 311 angiosperm plant species. Methods: We used model II regressions on cross-species data as well a...

In order to evaluate eight different protein sources in honey bee nutrition, some experiments were conducted as a completely randomized designs with four replicates and three steps incubator, field and overwintering in Isfahan region. Protein sources were lentil flour, soybean flour, soybean meal, bread yeast, wheat gluten, skim milk powder, fish meal and Pollen. Results showed that the longevi...