Definition of a growth medium to evaluate pollen viability in Hemerocallis cultivars

Abstract

Hemerocallis is a floriferous species, which presents numerous genotypes that are constantly crossed, generating new cultivars. The germination and viability of pollen are influenced both by factors that are intrinsic and extrinsic to the pollen. In view of the above, the purpose of this study was to establish a growth medium for the germination of pollen grains. Cultivar Morgana was used in the experiments performed to establish the growth medium, in which four pH ranges were tested alongside four agar concentrations. For the next test, five sucrose concentrations were tested. Afterwards, four boric acid concentrations were added to the medium, finally followed by four calcium nitrate concentrations. After the definition of the growth medium, the incubation time for pollen grains germination of the species was evaluated. The results were then applied to four cultivars in order to verify the respective germination percentages. It was noted that the highest percentage of in vitro germination occurred with the concentrations of 4 g L−1 agar, 74.6 g L−1 sucrose, 800 mg L−1 boric acid and 590 mg L−1 calcium nitrate, with a pH of 5.74 and ideal incubation time of 3 h. Regina being to cultivar with the highest germination percentage.