Abstract:

The objective of this study was to measure leaf water potential, photosynthesis, transpiration, stomatal conductance, inter-cellular CO₂ concentration, transpiration effeciency, water-saving irrigation effects on physiological traits and grain yield using SX733, a new high-yielding and good-quality winter wheat (Triticum aestivum L.) cultivar and HM9, SM9, and H7228 in the field experiments irrigated with differrent times during 2003–2004 and 2004–2005. The results indicated that the leaf osmotic adjustment capability of SX733 was 0.11 MPa, which was higher than the average (0.065 MPa) of other 3 cultivars by 71.6%. Leaf water potential of SX733 was higher than that of H7228 by about 0.1 MPa, and the excised-leaf water loss rate of SX733 was higher than that of other cultivars when it was well-irrigated. Transpiration rate, photosynthetic rate and stomatal conductance of SX733 were similar to those of SM9 and HM9, but higher than those of H7228. There was no remarkable difference among cultivars in inter-cellular CO₂ concentration and transpiration efficiency. The 2 times irrigation treatment maintained almost the same level of leaf water potential and leaf gas exchange parameters as the 5 times irrigation treatment with improved photosynthesis and transpiration efficiency during grain-filling period. Compared with other 3 cultivars, the yield of SX733 was increased by 11.3% and 7.0% in non-irrigation and 2 times irrigation treatments, respectively. The yield of 2 times irrigation treatment at stem elongation and heading for SX733 was 5.6% higher than that of 4 times irrigation treatment. It is concluded that water-saving irrigation management can be well implemented in SX733 production.

Key words: Wheat, Water physiology, Water-saving irrigation