Fig. 1.

(A) Rate of leaf elongation at warm temperature and (B) chilling temperature, and (C) percentage of leaf elongation retained in chilling temperature relative to warm temperature for 51 Miscanthus accessions and four control sugarcane and maize lines. In chilling, developing leaves were measured during 14 d every other day, while for warm conditions data were collected during 7 d every day. The growing conditions were 10 °C/5 °C (chilling) or 25 °C/25 °C (warm) day/night and a 12h day/12h night cycle under 1000 μmol photons m^–2 s^–1. In all panels, accessions are ordered according to percentage of leaf elongation retained in chilling temperature relative to warm temperature (from the highest to the lowest, C). For each treatment stage, open symbols indicate no significant differences and filled symbols indicate significantly faster (black) or slower (red) elongation in comparison with M. ×giganteus (Mxg) (3x) ‘Illinois’ (yellow frame) based on Dunnett’s test (P≤0.1). Rates of leaf elongation for Mxg (3x) ‘Illinois’ were: (A) 22.87 (mm d^–1); (B) 2.53 (mm d^–1); (C) 11.08 (%). Data are mean ±SE (n=3). Grey- and yellow-highlighted genotypes were selected for a subsequent experiment to study chilling-tolerant photosynthesis. F1, the first generation of Msa×Msi hybrids; Mol, M. oligostachyus; Msa, M. sacchariflorus; Msi, M. sinensis; Mxg, M. ×giganteus; con., condensatus; P1 (high), parent 1 of interspecific Msa×Msi hybrids (Msa with high chilling tolerance); P2 (low), parent 2 of interspecific Msa×Msi hybrids (Msi with low chilling tolerance).