Growth and Photosynthesis Adaptation of Dwarf-Type Chinese Cherry (Prunus pseudocerasus L. cv. Laiyang) Leaves to Weak Light Stress

Adaptation of leaf morphology and structure, photosynthesis, the Chl content, and the soluble protein content of one-year-old dwarf-type Chinese cherry (Prunus pseudocerasus L. cv. Laiyang) in greenhouse to weak light stress (100%, 70%, 48%, 30% and 11%) were studied by whole-tree shading. The results showed that increasing shading markedly reduced specific leaf weight and leaf thickness. The decrease of spongy tissue thickness was greater than that of palisade tissue thickness, so the ratio between palisade tissue and spongy tissue increased. Compared with the unshaded control, the net photosynthetic rate, light compensation point and light saturation point of the Chinese cherry leaves under weak light stress were remarkably lower. In contrast, there was an increase of the content of Chl a, Chl b and Chl (a+b) and the content of soluble protein of Chinese cherry leaves. The increase Chl b exceeded that of Chl a and consequently decreased the ratio between Chla and Chl b.