The effects of nitrogen on grain yield, nutritional quality and processing quality of wheat for different end uses were studied in Yangzhou from 2000 to 2002. Increasing N application amount and/or the ratio of topdressing N after elongation stage could raise grain yield, protein content, wet gluten content, sedimentation, falling number, development time and stability time. To produce strong-gluten and medium-gluten wheat, the suitable ratio of basis : tillering: elongation: booting N fertilizer was 3: 1: 3 : 3 or 5: 1 : 2: 2with 180 - 240 kg N ha-1. To produce weak-gluten wheat, the ratio of basis: tillering: elongation N fertilizer should be 7 : 1: 2 with 180 kg N ha-1 and 240 × 104 ha-1 seedlings.
ZHU Xin-kai, GUO Wen-shan, ZHOU Jun-liang, HU Hong, ZHANG Ying, LI Chun-yan, FENG Chao-nian and PENG Yong-xin(Agricultural College of Yangzhou University , Yangzhou 225009 , P. R. China)
On the basis of the phytotron, the effects of high temperature (daily average temperature 25, 30, 35 and 40°C, respectively) on antioxidant enzymes and lipid peroxidation in flag leaves of wheat at 50% relative air moisture during grain fastest filling stage [19-21 days after anthesis (DAA)] were studied. The wheat cultivars tested were Yangmai 9 with weak-gluten and Yangmai 12 with medium-gluten. Compared with 25°C, the higher the temperature was, the higher was the MDA content in flag leaves, while lower were the SOD, POD, and CAT activities. SOD and CAT activities in Yangmai 12 appeared to be more sensitive to high temperature than that in Yangmai 9. But POD activity in Yangmai 12 was less sensitive to high temperature. MDA content in Yangmai 12 was higher than that in Yangmai 9. The 1 000-grain weight declined with increase in temperature.
LIU Ping GUO Wen-shan PU Han-chun FENG Chao-nian ZHU Xin-kai PENG Yong-xin
