Leaf anatomical structures of Paphiopedilum and Cypripedium and their adaptive significance

Abstract

Paphiopedilum and Cypripedium are closely related in phylogeny, but have contrasting leaf traits and habitats. To understand the divergence in leaf traits of Paphiopedilum and Cypripedium and their adaptive significance, we analyzed the leaf anatomical structures, leaf dry mass per area (LMA), leaf lifespan (LL), leaf nitrogen concentration (N mass ), leaf phosphorus concentration (P mass ), mass-based light-saturated photosynthetic rate (A mass ), water use efficiency (WUE), photosynthetic nitrogen use efficiency (PNUE) and leaf construction cost (CC) for six species. Compared with Cypripedium, Paphiopedilum was characterized by drought tolerance derived from its leaf anatomical structures, including fleshy leaves, thick surface cuticles, huge adaxial epidermis cells, lower total stoma area, and sunken stomata. The special leaf structures of Paphiopedilum were accompanied by longer LL; higher LMA, WUE, and CC; and lower N mass , P mass , A mass , and PNUE compared with Cypripedium. Leaf traits in Paphiopedilum helped it adapt to arid and nutrientpoor karst habitats. However, the leaf traits of Cypripedium reflect adaptations to an environment characterized by rich soil, abundant soil water, and significant seasonal fluctuations in temperature and precipitation. The present results contribute to our understanding of the divergent adaptation of leaf traits in slipper orchids, which is beneficial for the conservation of endangered orchids.

Effects of different light quality on growth, photosynthetic characteristic and chloroplast ultrastructure of upland cotton (Gossypium hirsutum L.) seedlings

“…Plants were able to respond to changes in irradiance environment by modifying structural and physiological traits of their leaves (Wyka et al, 2008;Dunbar-Co et al, 2009;Guan et al, 2011). The structure and function of chloroplasts were important for the growth of plants and influence their physiological responses (Peng and Zhou, 2009).…”

De novo assembly and characterization of the root transcriptome and development of simple sequence repeat markers in Paphiopedilum concolor

“…As well-known horticultural plants, Paphiopedilum plants have attracted much attention from botanists and horticulturists (Williams et al, 1983;Assmann and Zeiger, 1985;Cribb, 1998;Guan et al, 2011;Zhang et al, 2011). Botanists and horticulturists mainly focus their attention on peculiar leaves and beautiful flowers.…”

Physico-Chemical Evaluation for <em>Allium hookeri</em> Thw. Enum Leaves

“…Thin cross sections from the middle portion of matured portion of matured leaf of Allium hookeri are obtain by sharp razor blade and stained with safranine [5].The sections were examined under light microscope (OlympusBX41) under different magnifications. The adaxial and abaxial epedermis of matured leaves was peeled for observation of stomatal type.…”

“…The adaxial and abaxial epedermis of matured leaves was peeled for observation of stomatal type. The area of stomatal apparatus is calculated by using the formula ¼ × ‫ח‬ × l × w [5]. and the stomatal index is calculated by following formula [6].…”