Growth pattern of Bidens cernua L.: relationships between relative growth rate and its physiological and morphological components

• Published in: Photosynthetica Vol. 46; no. 2; pp. 179 - 184
• Main Authors: Gratani, L, Crescente, M. F, Fabrini, G, Varone, L
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.06.2008; Springer Netherlands
• Subjects: Biomedical and Life Sciences; chlorophyll content; dry mass; growth analysis; leaf area ratio; Life Sciences; net assimilation rate; net photosynthetic rate; Original Papers; plant biomass; plant height; Plant Physiology; stomatal conductance; growth analysis; stomatal conductance; net photosynthetic rate; net assimilation rate; dry mass; plant biomass; chlorophyll content; plant height; leaf area ratio
• ISSN: 0300-3604; 1573-9058
• DOI: 10.1007/s11099-008-0029-5

Seedlings of Bidens cernua L. emerged when mean air temperature was 17.0±1.3 °C. The highest net photosynthetic rate (P N), 13.8±0.8 μmol(CO₂) m⁻² s⁻¹, was monitored during the vegetative period (May-August), decreasing on an average by 50 % during flowering (August-September) and during fruiting (September-November) phases. The senescence phase (October-November) was characterised by 79, 58, and 18 % decrease of P N, chlorophyll content, and leaf area (LA), respectively, from the maximum values. The time span from seedling emergence to the end of fruiting phase was 202 d. The total plant biomass was 1.58±0.05 g of which 81 % was aboveground plant portion. The total dry mass relative growth rate averaged over the assimilation period was 0.0804±0.0002 kg kg⁻¹ d⁻¹, and it was correlated to both the net assimilation rate (NAR) and the leaf area ratio (LAR).