Evaluation of the possibility of obtaining viable seeds from the cross-breeding Hippeastrum × chmielii Chm. with selected cultivars of Hippeastrum hybridum Hort.

Abstract Hippeastrum sp. is a popular cut flower and a popular potted plant, currently occupying the 11th position among cut flowers sold on the Dutch flower auctions. Hippeastrum × chmielii was bred by Henryk Chmiel at the Warsaw University of Life Sciences (WULS), Poland. The aim of this study was designed to test the ability of two clones of H. × chmielii to reproduce generatively by pollinating by three cultivars of Hippeastrum hybridum – ‘Gervase’, ‘Rio Negro’ and ‘Royal Velvet’. Pollen viability was tested by germination on the medium and by acetocarmine staining. The receptiveness of the stigmas and ovules of H. × chmielii and thus their ability to possibly accept compatible pollen were checked by staining with red alizarin. The viability of pollen grains of tested cultivars was estimated at 66.4–83.0% and their high ability to develop pollen tube was found. It was determined that the embryos of both H. × chmielii clones were fully receptive. A total of 72 crossings were performed in 6 combinations. Seeds collected about 1 month after pollination were germinated immediately after harvest either on moist tissue paper on Petri dishes or in jars with distilled water. After 28 days the percentage of germinated seeds ranged between 48.3% and 77.9%, for different crosses. In the case of seeds obtained from crossing H. × chmielii clone 18 × H. hybridum ‘Gervase’ a higher average percentage of germinated seeds was obtained in jars while no differences were noted between the germination methods in other cases.