ABSTRACT
In some cases, depending on the season of the pollen load collection we can determine what pollen is included in pollen load. For instance, maximum 520-530 nm is peculiar to Trifolium repens, T. pratense and Salix caprea. Maximum 550 nm is seen in the fluorescence spectra of Taraxacum officinale, Medicago falcata and Cerasus vulgaris (Fig. 6.3). The plants, from which bees collect pollen and nectar for honey, includes meadow species such as clovers, dandelion or willows flowering in early spring. Some of them are similar in their fluorescence spectra with pollen loads collected by bees (Fig. 6.2). As it is demonstrated in Fig. 6.2, pollen loads from 7 samples were multicomponent, although there are no prevailing components among the fluorescence spectra. In pollen loads 1 and 4 one maximum is seen, mainly, in green-yellowish (520-530 nm), while in pollen loads 2 and 6 the same maximum was characteristic only for small amount of pollen grains. This peak is usually correlated with the increased content of carotenoids (Roshchina et al., 1997c). Comparing the fluorescence spectra of pollen received from clovers, both Trifolium pratense and T. arvense, we should mark the same maximum 520-530 nm that are characteristic for the meadow plants (Fig. 6.3 ), as well as for pollen from dandelion Taraxacum officinale and other species. Non-matured pollen of clovers also have maximum at 680 nm, peculiar to chlorophyll whereas in pollen loads studied - they do not. In the blue region of the spectra pollen grains from samples of pollen loads 2, 4 and 6 fluoresce with maximum 460480 nm and the same peak is characteristic for willow Salix caprea. Depending of the time when the pollen load was collected and from analysis of the fluorescence spectra or a colour of fluorescence under a luminescence microscope, one can establish, which pollen is present in the bee collection. Moreover, maxima of prevailing pollen grains indicate which
