Net photosynthetic rate (P_n) (a), stomatal conductance (G_s) (b) and intercellular CO₂ concentration (C_i) (c).

<p>The values represented mean ± SE, and different letters mark significant differences among shade treatments on the same day (P<0.05).</p

Curves of diurnal variation of photosynthetically active radiation (PAR) under 50%, 30%, 20% and 5% light irradiances during one day in June 2012 in Lin’an, China.

<p>Curves of diurnal variation of photosynthetically active radiation (PAR) under 50%, 30%, 20% and 5% light irradiances during one day in June 2012 in Lin’an, China.</p

The Chl a content (a), Chl b content (b), Chl a+b content (c) and Chl a/b (d).

<p>The values represented mean ± SE, and different letters mark significant differences among shade treatments on the same day (P<0.05).</p

Protein content (a), POD activity (b), SOD activity (c), CAT activity (d), Soluble sugar content (e) and MDA content (f).

<p>Protein content (a), POD activity (b), SOD activity (c), CAT activity (d), Soluble sugar content (e) and MDA content (f).</p

The chloroplast ultrastructure observed in the leaves of Anoectochilus roxburghii at 40 DOT.

<p>(a), (b), (c) the plants under 50% irradiance treatment; (d), (e), (f) the plants under 30% irradiance treatment; (g), (h), (i) the plants under 20% irradiance treatment; (j), (k), (l) the plants under 5% irradiance treatment. Notice the differences of the number of SG (indicated by arrow heads) and the number of grana lamella (indicated by arrows) between different irradiances. Abbreviation: Ch, chloroplast; CW, cell wall; OG, osmiophilic globules.</p

The appearance of whole plants (a) and leaves (b) exposed to 40 d of various levels of shading.

<p>The appearance of whole plants (a) and leaves (b) exposed to 40 d of various levels of shading.</p

Electron transport rate (ETR) (a), photochemical quenching (qP) (b) and nonphotochemical quenching (NPQ) (c).

<p>The values represented mean ± SE, and different letters mark significant differences among shade treatments on the same day (P<0.05).</p