钾肥类型对菜心(菜薹)生长、细胞保护酶和内源激素的影响

Effect of different types of potassium fertilizer on growth, cell protective enzymes and endogenous hormones of Flowering Chinese Cabbage

摘要:

为探讨钾肥类型对菜心(Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee)的作用效应，研究了不同钾肥类型和水平对菜心生长、细胞保护酶和内源激素的影响。结果表明，氯化钾或硫酸钾处理可提高菜心叶片的POD和CAT活性、IAA和GA3含量，降低MDA含量，提高菜薹产量。随着钾水平的提高，叶片IAA和GA3含量、POD和CAT活性以及菜薹质量明显提高，MDA含量降低。当施钾90 kg hm–2时，叶片的GA3和IAA含量显著下降，而POD活性和菜薹产量没有显著变化。在相同水平下，氯化钾与硫酸钾对植株生长、菜薹产量、叶片GA3含量的影响不显著。当施钾0~90 kg hm–2时，氯化钾处理的叶片POD活性显著高于硫酸钾处理的；而施钾135~180 kg hm–2时，氯化钾处理的叶片POD活性则显著低于硫酸钾处理的。除了90 kg hm–2氯化钾处理的CAT活性和45 kg hm–2 氯化钾处理的MDA含量低于硫酸钾处理的，90 kg hm–2和180 kg hm–2氯化钾处理的IAA含量高于硫酸钾处理的外，相同水平氯化钾和硫酸钾处理的CAT活性、MDA含量和IAA含量没有显著差异。可见，钾肥类型对菜心的活性氧代谢系统及内源激素含量有一定的影响，但氯化钾与硫酸钾对菜心的施用效果相当，生产上可采用氯化钾代替硫酸钾以节约肥料成本，K2O施用量以90 kg hm–2为宜。

Abstract:

The experiment was conducted to investigate the effects of different types and levels of potassium fertilizer on plant growth, cell protective enzymes and endogenous hormones in flowering Chinese cabbage. Both of two types of potassium fertilizer (KCl, K2SO4) included 5 K2O levels respectively and in total of 9 treatments. The K2O levels was as follows: 0, 3, 6, 9 and 12 kg.(666.7m2)-1. The results showed that both KCl and K2SO4 fertilizer could increase the activities of POD and CAT, and the contents of IAA and GA3, but decreased MDA content, and thus increased the yield of flowering Chinese cabbage. With the increasing of potassium levels from 0 to 6 kg.( 666.7m2 )-1, the contents of IAA and GA3, the activities of POD and CAT and flower stalk yield increased significantly, however, when the potassium levels increased for further, the contents of IAA and GA3 decreased quickly, and POD activities and flower stalk yield kept stable. At the same potassium levels, two types of potassium fertilizer had no effect on plant growth, flower stalk yield and GA3 contents of leaves. At 0～6 kg.(666.7m2)-1 of potassium fertilizer, the POD activities in leaves fertilized by KCl were higher than those fertilized by K2SO4, but at levels of 9～12 6kg.(666.7m2)-1, K2SO4 fertilizer exerted higher promotion on POD activity. CAT activities in leaves fertilized by 6kg.(666.7m2)-1 of KCl and MDA contents in leaves fertilized by 3 kg.(666.7m2)-1 of KCl were lower than those fertilized by same levels of K2SO4. In contrary, treatment with 6kg.(666.7m2)-1 and 12kg.(666.7m2)-1 of KCl exerted higher promotion on IAA contents than K2SO4 fertilizer. At other fertilizer levels, two types of potassium fertilizer had no effects on CAT activity, MDA and IAA contents. In concluded, although two potassium types exerted different influence on the reactive oxygen species metabolic system and endogenous hormones in plants, they had no effects on the plant growth and flower stalk yield of flowering Chinese cabbage at the same levels of potassium fertilizer. Thus, in the field production, KCl fertilizer can be used to save the cost instead of K2SO4 fertilizer, and the effect of 6 kg.(666.7m2)-1 of KCl fertilizer showed the best.