In flowering plants, pollen deposited upon the stigma of a flower germinates to produce a pollen tube that must grow through the maternal transmitting tract and into the micropyle of an ovule in order to release its two sperm cells for double fertilization with the egg and central cell. In addition to pollen tubes being useful for studying polar cell growth, the myriad interactions between the ...

the present research was conducted to determine the percent self-incompatibility in some asian pear (pyrus serotina rehd.) as well in european pear (pyrus communis l.) cultivars. the experiment was carried out during 2006 and 2007 growing seasons. pollen grains were collected and tested for viability using in-vitro pollen culture. for microscopic examination of pollen tube growth in the style, ...

pollen grains as well as whole plants of four olive (olea europaea l.) cultivars were screened for nacl salinity stress. different vegetative and physiological indexes of the cultivars were analyzed. leaf and root na/k ratio as well as stomatal resistance of plants exposed to salinity proved to be appropriate indexes of whole plant response to salt stress. whereas, in vitro pollen germination p...

Wk are quite sure that we approve of Dr. Jacobson's most interesting and exceptionally well written book, but we are far from sure that we approve of his main thesis, which is that genius is inseparable from degeneracy. " Ironically enough," he writes, " it is_ in the outcast, disinherited, vagabond, criminal, defective, insane and generally abnormal elements of humankind that genius germinates...

The successful establishment of angiosperms on land is in part determined by their floral design. Because plants cannotmove to find the idealmate, they have developed agreat variety of flowers to provide different mechanisms of pollen release, pollen transfer, and deposition of the pollen from the male to the female sexual organs, the anther and the pistil, respectively. Pollination ensures the...

New approaches for treatment of infectious diseases in aquatic animals have important roles in aquaculture technology progress. In the present study, In vitro effects of different extracts of propolis, royal jelly and pollen obtained from beehives have been investigated on aquatic pathogenic bacterial isolates. The isolated bacteria identified on the basis of their biochemical properties and se...

the developmental period, prey consumption of different nymph instars, survival, reproduction and longevity of orius albidipennis were studied on three different diets including the two-spotted spider mite, tetranychus urticae plus corn pollen; two-spotted spider mite; and eggs of sitotroga cerealella plus corn pollen under laboratory conditions. leaves of pelargonium hortom served as ovipositi...

new approaches for treatment of infectious diseases in aquatic animals have important roles in aquaculture technology progress. in the present study, in vitro effects of different extracts of propolis, royal jelly and pollen obtained from beehives have been investigated on aquatic pathogenic bacterial isolates. the isolated bacteria identified on the basis of their biochemical properties and se...

the study aimed to investigate the microsporogenesis, tapetum and pollen development in petunia hybrida juss.under control and air pollution condition. the connective shows a well-developed placentoid, giving thesporogenous tissue a crescent-shape. the sporogenous tissue of each of the four anther locules is surrounded bydimorphic tapetum. the outer (towards the epidermis) and inner (towards th...

Pollen analysis and AMS radiocarbon dating of a short sediment core from a mire in Veisar (Mazandaran province, N Iran) reveals the late-Holocene vegetation history of the area. High pollen values suggest that Caucasian alder (Alnus subcordata) has been present in the vicinity of the mire throughout the record. Wingnut (Pterocarya fraxinifolia), which was previously abundantly present, shows a ...