Influence of the sex of flowers on androgenesis in Aesculus hippocastanum L. anther culture

Summary Flowers of Aesculus hippocastanum L. are bisexual and zygomorphic, and are positioned on a 20–30 cm long inflorescence. Those located in the basal part of the panicle are female and fertile (segment A), flowers in the middle are bisexual (segment B), and those on top of the panicle are male (segment C). Androgenesis was achieved in anther culture which originated from three types of flowers cultured on modified Murashige and Skoog medium containing 2,4-dichlorophenoxyacetic acid (4.5 μM) and kinetin (4.6 μM). Differences in viability of uninuclear microspores were found between female (90.0%) and other flowers (bisexual 61.1%; male 72.7%.). Both the percentage of embryogenic anthers and the number of androgenic embryos formed per inflorescence differed according to the segment of origin. The highest embryogenic response was obtained in segment A (47.3%) and the lowest in segment C (24.1%). A significant difference was found between the number of androgenic embryos formed per inflorescence in segments A (921.0) and C (286.7). The highest germination percentage (21.3%) and plantelet formation (41.0%) were obtained on woody plant WPM liquid medium supplemented with 1% activated charcoal. Acclimation and regeneration were best from plantelets originating from female flowers (62.5%). Plantlets originating from bisexual and male flowers have much poorer survival (29.3 and 22.2%, respectively).