Changes in Frost Resistance of Wheat Young Ears with Development During Jointing Stage

Abstract

AbstractDuring the jointing stage, the frost resistance of young ears (FRYE) was tested each day for the main stem, and also for the first, second and third tillers of the wheat cultivars Jinmai 47 and Jing 411. At the same time, the developmental progression of young ears (DPYE) of the same four shoots was also recorded each day. In the shoots of both cultivars, FRYE decreased as development advanced through the jointing stage. FRYE dropped off particularly sharply at the point when the anther connective tissue formation phase (ACFP) started. Shoots developing later, though with lower levels of soluble sugar, tended to suffer less from frost injury than those developing earlier. Frost resistance of 12 cultivars (six early‐ and six late‐maturing) was evaluated at ACFP. The results indicate that only one cultivar (Xin 11) is frost resistant, with no significant differences appearing among the other 11 cultivars. The results suggest that DPYE is an important factor affecting FRYE. Evaluation of frost resistance of wheat cultivars should thus be performed at the same phase to obtain a true measure of frost resistance. The early ACFP phase is suggested as being the most appropriate one for frost resistance evaluation.