Determination of pollen quantity, pollen viability and pollen germination in some dogrose species (Rosa section Caninae)

Pollen quantity, viability and germination capability was investigated for one genotype each from four different dogrose (Rosa section Caninae) species. Pollen quantity was determined by the hemacytometric method. Pollen viability was tested by incubating pollen grains in 2,3,5-triphenyl tetrazolium chloride. In vitro pollen germination was assessed in petri dishes at 22 +/- 2 degrees C on saturated media with 1% agar and 15% sucrose. The following treatments were applied to the media: boric acid (BA) 50, 100 and 200 ppm, and gibberellic acid (GA(3)) 100, 200 and 400 ppm. Pollen quantity varied from 17708 to 53125 pollen grains/flower depending on genotype, and pollen viability from 66.2% to 87.9% when based on well-shaped normal-looking pollen grains only. Adding of low doses of BA did not increase germination except in one genotype, whereas 200 ppm BA reduced germination in two genotypes. All GA(3) concentrations reduced germination, and the addition of 200 ppm inhibited all germination.