Effects of elevated temperature and CO2 concentration on growth and leaf quality of Morus alba seedlings.

Abstract

To estimate the potential effects of climate change on the growth and leaf quality of Morus alba, one-year-old M. alba seedlings were exposed 60 d under four treatments, i.e., elevated temperature (ET, +2 ℃), elevated CO2 concentration (EC, +300 ppm CO2), elevated temperature and CO2 concentration (ETC, +2 ℃ & +300 ppm CO2), and control treatment (CK). The results showed that basal diameter, leaf number, total leaf area, leaf dry mass, leaf dry mass fraction and soluble protein were 9.9%, 17.4%, 23.0%, 9.2%, 10.1% and 23.1% higher under ET than those under CK, respectively. EC significantly increased the stem, root and total dry biomass by 10.7%, 15.9% and 9.2% compared with CK, respectively, whereas leaf quality was similar between EC and CK. Compared with CK, leaf number, height, diameter, total leaf area, the leaf, root and total dry biomass, leaf soluble sugar content and crude protein content increased significantly by 28.8%, 9.1%, 19.4%, 32.6%, 12.4%, 17.2%, 10.1%, 45.8% and 11.9% in ETC while the leaf crude fibre content decreased by 16.8%. Our results indicated that climate change had a positive effect on the growth and leaf quality of M. alba in a short period.