Phenological growth stages of Magnolia ×soulangeana according to the extended BBCH scale

Abstract

Magnolia  soulangeana, one of the most famous ornamental trees of Magnoliaceae, is widely cultivated around the world. However, its phenological characteristics at lifecycle scale have never been detailedly reported so far. In this article, the extended BBCH (Biologische Bundesanstalt, Bundessortenamt, und Chemische Industrie) scale was applied to divide the growth and development cycle of M.  soulangeana in both juvenile phase and adult phase, and describe the characteristics of phenological development stage, so as to provide theoretical guidance for its cultivation measures implementation. Based on the BBCH phenological scale, the processes of germination (0), leaf development (1), main stem elongation (3) and dormancy (9) were observed in the juvenile phase. Likewise, the morphological changes of organs in adult phase were abundant, and eight principal growth stages were described: vegetative bud development (0), leaf development (1), shoot development (3), reproductive development (5), flowering (6), fruit development (7), maturity of fruit (8) and dormancy (9). Our newly developed scale provides a unified standard for describing and identifying the phenological period of M. soulangeana. In addition, it is of great significance to understand the phenological characteristics of M.  soulangeana for its breeding and cultivation management.

Phenological growth stages of Gleditsia sinensis Lam. (Fabaceae) using the extended BBCH scale

“…With reference to the BBCH model of woody plants (Finn et al, 2007) and the BBCH model of mono-and dicotyledonous plants (Meier, 2018), the growth and development stages of G. sinensis were divided into eight major stages, beginning with the stage 0 (bud devel- The vegetative and reproductive growth phases of G. sinensis observed with respect to meteorological conditions throughout the study period have been documented at different stages with their specific codes (Table 1, Figures 1-6). Eight principal stages were used to describe the phenology of G. sinensis except stage 2 and stage 4, which were inappropriate for this species, just as the phenological period described in other woody plants, like Sapindus mukorossi (Zhao et al, 2019), Magnolia  soulangeana (Li et al, 2022), Corylus avellana (Paradinas et al, 2022), Actinidia deliciosa 'Hayward' (Salinero et al, 2009) and so on. In addition, a total of 64 secondary developmental stages was described here.…”