Euphytica: International Journal of Plant Breeding, 2016, Vol.211(2), p.255(21)
To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1007/s10681-016-1751-x Byline: Philipp Braun (1), Traud Winkelmann (1) Keywords: Albinism; Delosperma; Embryogenesis; Lampranthus; Pollen tube guidance; Reproductive isolation Abstract: The large succulent plant family Aizoaceae offers an enormous diversity of growth forms and flower pigmentations as well as prevalent tolerance to drought. Although many family members have potential for a wider use as ornamental plants, directed breeding of midday flowers is still in its infancy and only few cultivars have been launched onto the market so far. Most probably, this fact can be ascribed to the presence of cross-incompatibilities. The present study aimed at localization of intra- and intergeneric hybridization barriers between different genotypes of the genera Delosperma and Lampranthus by pollen germination tests, fluorescence and DIC microscopy, in vitro culture of seeds and ovules, and AFLP analysis. Aside from distinct self-incompatibility, the analyses revealed that pollen tube growth towards the ovules was not inhibited, even after intergeneric pollinations. Cross-combinations within Delosperma seemed to be compatible to a high extent, while hybridizations of the investigated Lampranthus genotypes and intergeneric combinations were largely unsuccessful. Investigations of embryo sacs following wide crosses using ovule clearing and differential interference contrast microscopy revealed fertilization failures as well as abnormal early embryogenesis. Seedlings obtained after wide crossings, mostly exhibited partial or complete loss of chlorophyll causing frequent hybrid breakdown. We therefore conclude that hybridization barriers between the investigated midday flowers occur both pre- and postzygotically. Author Affiliation: (1) Institute of Horticultural Production Systems, Leibniz Universitat Hannover, Herrenhauser Str. 2, 30419, Hannover, Germany Article History: Registration Date: 12/07/2016 Received Date: 18/03/2016 Accepted Date: 11/07/2016 Online Date: 11/08/2016 Article note: Electronic supplementary material The online version of this article (doi: 10.1007/s10681-016-1751-x) contains supplementary material, which is available to authorized users.
Fluorescence Microscopy – Analysis ; Chlorophyll – Analysis ; Flowers – Analysis ; Fluorescence – Analysis ; Horticultural Industry – Analysis