关键词: 生物量分配, 出苗推迟, 植物结构, 繁殖生长, 营养生长, 垂直分层

Abstract: Architectural plasticity in traits should be useful for understanding morphological and allocation plasticity at the whole-plant level and associated growth strategies of plants in dealing with variation in emergence time. To investigate how plants respond to emergence timing via dynamic architectural plasticity, we conducted a field experiment by sowing plants of Abutilon theophrasti on different dates to make them emerge in spring, late spring, summer and late summer, as four treatments of emergence time (ET1-ET4), and measured a series of mass and morphological traits in different vertical layers (with an inter-distance of 10 or 20 cm per layer) of plants at three stages. The ‘vertical arch' and ‘inverted-cone' shapes displayed at reproductive stage by plants emerged between spring and summer (ET1-ET3) and in late summer (ET4), respectively, revealed that they had contrasting timing schemes for vegetative and reproductive growth. Plants emerged earlier had relatively isolated vegetative and reproductive stages, while late-summer emerged plants had overlapped vegetative and reproductive stages due to accelerated leaf and reproductive growth simultaneously, as a result of shortened lifetime. In spite of this, plants emerged earlier were still able to adopt different optimal strategies in dealing with their corresponding circumstances. Architectural analysis should be a useful approach to better understanding diverse plant strategies in the context of varying environmental conditions.

Key words: biomass allocation, delayed emergence, plant architecture, reproductive growth, vegetative growth, vertical layer