HUMIDITY STRESS RESPONSES IN POLLEN OF ANEMOPHILOUS AND ENTOMOPHILOUSSPECIES

Pollen grains of 10 anemophilous and entomophilous species of angiospe rms were kept at 4 relative humidities (RH) (15, 51, 79 and 98%) and t heir viability tested by fluorochromatic reaction after time lapses ra nging from 6 to 144 h. Pollen viability in the anemophilous species de creased more rapidly than in the entomophilous ones with the exception of the dioecious palm Chamaerops humilis. The modes of anther and flo wer opening, times of anther exposure etc. were recorded. Cytological data are discussed and compared with these aspects of reproductive eco logy.