Effects of Zinc on Growth and Physiological Characters of Flag Leaf and Grains of Winter Wheat after Anthesis

Abstract

The study explored the effects of supplementing 0, 200, 400 and 800 mg/kg Zn in cultivating soils on the growth and yield characters of winter wheat Zhoumai 18 and Aikang 58, the two popular wheat varieties currently in Henan, China, planted in pots in a screen house after anthesis during 2009-2010. The results indicated that the differences in activities of Peroxidase (POD), Superoxide Dismutase (SOD) and Catalase (CAT) in flag leaf and grains at 5 and 25 days after anthesis mainly came from differences in Zn concentration, not varieties. In addition, the Photosynthetic rates (Pn) of flag leaf in the two varieties were the same. Zn treatment significantly influenced CAT activity and Pn of flag leaf at 5 days after anthesis, SOD activity in flag leaf at 25 days after anthesis, SOD activity in grains at 5 days after anthesis, as well as POD and CAT activities in grains at 25 days after anthesis (p<0.01). Adequate Zn enhanced SOD, POD and CAT activities and Pn of flag leaf after anthesis, SOD and POD activities in grains at 5 days after anthesis and POD activity in grains at 25 days after anthesis, but reduced CAT activity in grains after anthesis. Pn of flag leaf was higher at 200 mg/kg Zn content. Moreover, the yield characters such as grains per spike, grain weight per spike and 1000-grain weight tended to be the highest at 200 mg/kg Zn content and lowest at 800 mg/kg Zn content. The correlation analysis showed that 1) Pn of flag leaf at 25 days after anthesis was positively correlated with grain number per spike, grain weight per spike and 1000-grain weight (p<0.05); 2) the activities of SOD, POD and CAT in grains at 25 days after anthesis were positively correlated with grain yield characters. In conclusion, appropriate Zn amount could promote the growth of flag leaf and grains after anthesis and improve yield characters.