Identifying dormancy class and storage behaviour of champak (Magnolia champaca) seeds, an important tropical timber tree

Abstract

Abstract:Magnolia champaca is a culturally important tree in the tropics with a high commercial value. Its natural regeneration is rare. Hence, the species is usually propagated from seeds but with great difficulties. The class of dormancy in M. champaca seeds has been reported to be physical, physiological, and morphological. Their storage behaviour as orthodox, intermediate, and recalcitrant has been reported by various authors. During the present research, seeds of this species in Sri Lanka were collected to determine their dormancy class and storage behaviour. Both scarified and non-scarified seeds imbibed water; however, high germination occurred only on gibberellic acid (GA 3 ) showing the presence of physiological dormancy. Embryos elongated inside of seeds at warm temperatures before radicle emergence indicating morphological dormancy. Thus, seeds have morphophysiological dormancy (MPD) and probably the nondeep simple level. The moisture content of fresh mature seeds was 25 %. Low germination occurred on GA 3 for seeds dried to 10 % moisture content, and the seeds stored dry at 4 and -1 ºC for 1 month did not germinate. Thus, the storage behaviour may be best classified as intermediate. Knowing that the seeds of this species have MPD allows future studies to partition the factors driving embryo growth, unblocking physiological dormancy, and stimulating germination in nature and in propagation. But the storage behaviour may limit seed usage in propagation programmes relying on stored seeds.

An efficient micropropagation protocol for an endangered ornamental tree species (Magnolia sirindhorniae Noot. & Chalermglin) and assessment of genetic uniformity through DNA markers

“…It was found that a high level of GA 3 effectively increased shoot length, whereas a lower concentration of GA 3 inhibited shoot growth in in vitro culture of potato 45 . GA 3 has been used to break dormancy and stimulate shoot elongation in different species of magnolias for a long time [46][47][48] . In the present study, GA 3 was found to be important for bud induction, effectively shortening the time of initiation and inducing stronger buds, which is consistent with previous reports 49,50 .…”

Germinación de semillas de Magnolia pugana (Magnoliaceae), especie endémica y en peligro de extinción del occidente de México

“…En este estudio se encontró que las semillas de M. pugana no tienen latencia física debido a que tienen la capacidad de absorber agua. En otras investigaciones se ha sugerido la existencia de latencia mecánica, como en M. acuminata (Smith, 1990) y M. iltisiana (Saldaña-Acosta et al, 2001); o bien, morfo-fisiológica, como en M. globosa (Baskin y Baskin, 1998), M. ingrata (Han y Long, 2010a), M. biloba (Hu et al, 2011), M. officinalis (Shu et al, 2012) y M. champaca (Fernando et al, 2013), pero para M. pugana no se encontraron estos tipos de latencia.…”

How to Save Endangered Magnolias? From Population Biology to Conservation Action: The Case of Allopatric Radiation in Western Mexico

“…Different studies have shown a low percentage of germination because they can present different types of dormancy (including physical, chemical, mechanical, physiological and morphological) [76]. To eliminate dormancy and increase the percentage of germination and produce the greatest number of Magnolia seedlings, different pre-germination procedures have been applied [77][78][79][80]. This section will present the research carried out in Magnolia iltisiana, M. pacifica, M. pugana and M. vallartensis, to know the viability percentages and the different most successful pregermination treatments, to break the lethargy and increase germination.…”