Abstract

A pot experiment with five typical landraces (Heshangtou, Hongnong No. 1, Dingxi 24, Damaizi and Jieba), three modern varieties (Qingchun 533, Plateau 602 and Abbondanza) and two water levels was carried out in the present study. The result showed that fertile spike, plant height, grains number of main spike (except Dingxi 24), above ground dry material, grain yield and grain yield water use efficiency of all varieties decreased, but grain weight (except Qingchun 533 and Plateau 602) and harvest index (except Plateau 602) of all varieties increased from 70% to 40% field capacity. The landraces had more fertile spikes, higher plant height, more above ground dry material (except Jieba), higher evaporation transpiration and lower harvest index than modern varieties under both 70% and 40% field capacity. Modern varieties had more grain number of main spike and grain weight than landraces under 70% field capacity on the whole. Although Qingchun 533 and Abbondanza had higher leaf-level water use efficiency than other varieties from heading stage to 30 days after anthesis, still they had lower grain yield water use efficiency than Heshangtou, Dingxi 24 and Damaizi under 40% field capacity. Varieties with higher evaporation transpiration and above ground dry material (higher ability of soil moisture capture) always had higher grain yield, grain yield water use efficiency and drought tolerance under drought stress.

Key words: Landrace, leaf-level water use efficiency, grain yield water use efficiency, drought tolerance.