Photosynthetic performances of five Cypripedium species after transplanting

Abstract

Photosynthesis and leaf traits of five species in genus Cypripedium were compared in natural habitats and transplant nursery to develop effective strategy for cultivation and conservation. Among five species, C. guttatum had the highest photosynthetic capacity (P Nmax ) in the natural habitat and nursery, while C. lichiangense the lowest. The differences in P Nmax among species were correlated with leaf N content (LNC) and leaf dry mass per unit area (LMA). After transplanting from natural habitats to nursery, the P Nmax of C. lichiangense and C. yunnanense decreased, that of C. guttatum increased, while those of C. flavum and C. tibeticum remained relatively constant. The variations in LNC and biochemical efficiency would be responsible for the differences in P Nmax between plants in natural habitats and in the nursery, but not the relative stomatal limitation. After transplanting, the F v /F m of C. lichiangense and C. yunnanense were declined. Meanwhile, the temperature ranges maintaining 90 % P Nmax of C. lichiangense and C. yunnanense were narrower than those of the other three species. Thus the biochemical process in five species played a major role in the differences of P Nmax after transplanting, and the widespread species had higher photosynthetic adaptability than the narrow-spread species.

Leaf anatomical structures of Paphiopedilum and Cypripedium and their adaptive significance

“…Previous studies indicate that leaf physiological functions in the same genera of Paphiopedilum and Cypripedium showed many interspecific similarities (Donovan and Arditti 1984;Johnson 1992;Zhang et al 2006). Thus, only P. armeniacum and C. flavum were selected to investigate the physiological functions because of the limited experimental materials.…”

Changes in anatomy and chlorophyll synthesis in orchids propagated in vitro in the presence of urea

“…In one study, a reduction of the "a/b" ratio was reported in shaded plants (ZHANG et al, 2006(ZHANG et al, , 2008 due to an increase in the production of accessory pigment "b", which is important for optimizing the efficiency of photosystem II under conditions of shade or stress (KOIKE et al, 2001).…”

“…The extracts were filtered, diluted to 50 mL and evaluated in a spectrophotometer at wavelengths λ= 645 and 663 nm. Chlorophyll contents "a" and "b" and the total chlorophyll were calculated based on the following equations: chlorophyll "a" (μg mL (KOIKE et al, 2001;ZHANG et al, 2006ZHANG et al, , 2008. The treatments were established by providing nitrogen substitution in the proportions presented in Table 1.…”

“…Environmental conditions and nutrient availability can also influence the "a" and "b" chlorophyll content, altering the a/b ratio and influencing the photosynthetic efficiency (ZHANG et al, 2006(ZHANG et al, , 2008.…”

Comparative Chemical Characterisation of Soils at Cypripedium Calceolus Sites in Latvia

“…The N concentrations in orchid leaves varied around 2.00% and corresponded with a low to sufficient level reported for orchids (Jones et al, 1991;Arditti, 1992). It is well established that nitrogen concentration in leaves has positive correlation with photosynthesis capacity (Zhang et al, 2006) and some Cypripedium species have a greater photosynthesis adaptation ability than narrowly specific species (Zhang et al, 2006a).…”