EFFECTS OF Zn STRESS ON NPK UPTAKE AND Zn ACCUMULATION IN 4 VARIETIES OF CHINESE CABBAGE

In a pot experiment with 4 Chinese cabbage [Brassica campestris L.ssp pekinensis(Lour) Olsson] cultivars,the root bag method was used to study the influence of Zn stress on their growth,nutrient contents and Zn accumulation.The results showed that plant growth was stimulated when Zn concentration ranged from 0 to 0.5 mmol/kg and depressed with Zn ≥1.0 mmol/kg in soil.N and K contents increased with Zn concentration in all the 4 cultivars studied.P in the roots and shoots climbed with Zn concentration to a certain point and declined thereafter.Zn contents in the shoots and roots of Chinese cabbage increased with Zn concentration.Zn accumulation and transfer were higher in the cultivars Fengkang 78 and Fengyuan Gaokang 2 than in the other two,Zn content in the shoot being(139.1) and 154.7 mg/kg,resopectively,with 2 mmol/kg Zn~(2+).Thus they are recommended for cultivation in regions without Zn application.Fengkang 80 and Fengkang 90,owing to their relatively low Zn accumulation and transfer,are recommended for cultivation in regions with Zn pollution hazard.