Diurnal changes in gas exchange and chlorophyll fluorescence parameters of Fritillaria cirrhosa and F. delavayi under field conditions

Abstract

To determine what factors limit the growth of wild Fritillaria cirrhosa and Fritillaria delavayi in field conditions, we investigated diurnal changes of the net photosynthetic rate (P N ) and the correlation between P N and various environmental factors. Parameters of chlorophyll (Chl) fluorescence were evaluated to test whether ecological fragility caused the extinction of wild F. cirrhosa and F. delavayi. Our study reveals for the first time that F. cirrhosa and F. delavayi did not encounter significant stress under field conditions. A small reduction in maximum photochemical efficiency was observed under high irradiance. The maximum P N of F. cirrhosa was 30 % higher than F. delavayi (p<0.05), and a similar difference was observed for apparent quantum yield (27.3 %, p<0.01). F. delavayi was better adapted to a wide range of irradiances and high environmental temperature. Correlation between P N and environmental factors (without considering the effects of interactions among environmental factors on P N ) using leaves of F. cirrhosa revealed that the three primary influencing factors were air pressure (p<0.01), relative humidity (p<0.01), and soil temperature (p<0.05). In F. delavayi, the influencing factors were relative humidity (p<0.01), soil temperature (p<0.05), CO 2 concentration (p<0.05), and air pressure (p<0.05). Path analysis (considering effects among environmental factors on P N ) showed that air temperature (negative correlation), photosynthetic photon flux density (PPFD) and relative humidity were the three primary limiting factors influencing the growth of F. cirrhosa. For this species, relative humidity reacted indirectly with air pressure, which was reported singularly in other species. Limiting growth factors for F. delavayi were PPFD, air pressure (negative correlation), soil temperature (negative correlation) and air temperature (negative correlation).

Composition of photosynthetic organisms and diurnal changes of photosynthetic efficiency in algae and moss crusts

“…Through downregulation of photosynthetic efficiency, BSCs achieve self-protection. This adaptation strategy is also observed in higher vascular plant (Sobrado 2008;Li and Chen 2009). In higher vascular plants, the midday depression of photosynthetic efficiency is a common phenomenon, and many studies have verified the stomatal closure is responsible or at least partially responsible for this phenomenon (Hirasawa et al 1989;Hirasawa and Hsiao 1999;Quick et al 1992).…”

Microstructures and photosynthetic diurnal changes in the different types of lichen soil crusts

“…Through down regulation of photosynthetic efficiency, BSCs achieve selfprotection. This adaptation strategy is also observed in other crust types and also higher vascular plants [22,39,40].…”

Metabolomics Study of Cultivated Bulbus Fritillariae Cirrhosae at Different Growth Stages using UHPLC‐QTOF‐MS Coupled with Multivariate Data Analysis

“…For the past 20 years, commercially available BFC has been mainly obtained from wild plants, which only grow at high altitudes in the Qinghai–Tibet Plateau. Because this plant grows slowly, it is very difficult to collect enough material to meet market demands and this scarcity has led to a price increase (Chen, Jia, Wang, Xue, & Xiao, ; Li & Chen, ). Furthermore, it would not be sustainable to exploit all wild habitats of the plant.…”