Morpho-Histological Analysis of Direct Shoot Organogenesis Induced in Flower Buds Cultures of <i>Allium altissimum</i>

Abstract

The present work gives a detailed study of in vitro shoot organogenesis of the ornamental onion A. altissimum Regel from the buds of the middle layer of the inflorescences. The course of morphogenesis was examined by light and scanning electron microscopy. Histological observation revealed that during 3-5 days of culture on the BDS medium supplemented with 2.0 mg•L −1 of BA and 2.0 mg•L − 1 of NAA the epidermal cells of the stamen filament in the area of its fusion with the tepal became competent and dedifferentiated. Originally the organogenesis involved several initial epidermal cells. The formation of meristematic centers was observed from day 3 to day 14. The apical shoot meristems and leaf primordia in a roller shape formed from day 14 to day 28 of culture on the same media. The further development of vegetative shoots and formation of the bulblets were observed when the explants were stimulated by triapenthenol (2.0 mg•L −1).

A novel approach for begonias micropropagation by inflorescence explants

“…A similar differentiation pathway of receptacle epidermis played a crucial role in initial stages of Allium altissimum Regel shoot development in vitro culture from the immature inflorescences covered with the spathe (Poluboyarova et al, 2014). The ability to regenerate buds and shoots from subepidermal or epidermal layers was observed earlier in histological Begonia studies (Lai et al, 2018).…”

Flower Power: Floral reversion as a viable alternative to nodal micropropagation inCannabis sativa

“…Inclusion of TDZ, which has both auxin and cytokinin-like activity (Guo et al 2011), promoted callus induction in C. sativa inflorescences, but yielded low frequency of floral regeneration (Piunno et al 2019). As a result, the current study focused on the proliferation of shoots using the cytokinins mT and BAP, rather than the induction of callus Floral reversion has also been reported to occur via direct organogenesis through the formation of adventitious shoots and meristemoids from the base of the floral organs (Punyarani et al 2013;Poluboyarova et al 2014;Asker 2016). Histological sampling by Punyarani et al (Fig.…”

“…Floral reversion has also been reported to occur via direct organogenesis through the formation of adventitious shoots and meristemoids from the base of the floral organs (Punyarani et al 2013; Poluboyarova et al 2014; Asker 2016). Histological sampling by Punyarani et al .…”

“…(2013) revealed that shoot primordia with apical meristems, leaf primordia and procambium strands developing directly from the base of the floral explant in Musa ssp . Histological studies in Allium altissimum L. have also shown proliferation of shoots from the base of inflorescences with development of meristem centers occurring at the junction between the filament and tepal (Poluboyarova et al 2014). Additional studies have suggested direct regeneration based on growth of shoots from the base of floral organs in vitro , but lack histological data validating these claims (Appleton et al 2012; Asker 2016) and it is possible that reversion could be occurring from existing meristems in these cases.…”

Flower power: floral reversion as a viable alternative to nodal micropropagation in Cannabis sativa.

“…The cellular development which characterizes floral reversion have been differentially described depending on the species studied (Zayed et al 2016). In some species floral reversion occurs from existing meristems (Sen et al 2013) while from others reversion is a result of de novo regeneration (Poluboyarova et al 2014;Zayed et al 2016). The mode of floral reversion has implications in plant biotechnology where early transient gene expression studies have shown the potential to express transgenes in floral tissues (Deguchi et al 2020).…”