Pollen viability and in vitro pollen germination in chrysanthemum (<i>Dendranthema </i>x <i>grandiflora </i>Tzvelv.)

Abstract

Chrysanthemum (Dendranthema x grandiflora Tzvelv.), is one of the commercially grown flower crops worldwide, valued for its cut flower, loose flower, pot mums, bedding etc. To overcome the challenges for cross breeding in chrysanthemum, the access to viable pollen, cultivar distant in location and difference in flowering, are required. Low pollen viability along with self-incompatibility are mainly responsible for low seed set in modern chrysanthemum cultivars. In the present study, pollen viability was tested by staining pollen with Alexander staining solution and examined under light microscope (20X). In vitro pollen germination was investigated in 10 chrysanthemum genotypes with different concentrations of sucrose (0, 5%, 10%, and 15%), PEG4000 (0, 10%, 20% and 30%) and their combination, as basal medium. Significant differences were observed among genotypes with respect to pollen viability, which was recorded highest in Red Stone (95.02%) followed by IIHR6-26 (88.20%), IIHR9-3 (87.44%), Sweta Singar (85.59%), Kalpana (79.97%), IIHR2-7 (73.50%), and White Andaman (64.14%), while, lowest pollen viability was recorded in IIHR6-29 (49.55%). Negligible in vitro pollen germination was observed among the genotypes when sucrose was used as pollen germination medium. However, highest germinability of pollen was recorded at 20% PEG4000 in IIHR9-3 (43.57%) followed by Kalpana (19.43%) and IIHR6-29 (19.34%). The best media for in vitro pollen germination was 15% sucrose + 30% PEG. Irrespective of different media combination, the genotypes namely, IIHR9-3, IIHR2-7 and IIHR6-26 showed better in vitro pollen germination. These results provide a valuable background to theconventional breeding to create hybrids through cross-pollination.