福建省16种蔬菜对锌毒害敏感性的研究

The Sensibility to Zinc Toxicity of 16 Vegetables Commonly Cultivated in Fujian Province, China

采用水培试验研究了福建省16种常见蔬菜幼苗对不同浓度锌(0.05、0.5、1、2、4、8、16mg·L-1和32mg·L-1)的敏感性。结果表明,黄瓜和空心菜的锌毒害表观症状最为明显,在添加Zn后第2d表现出严重的毒害症状,快白菜、早熟五号、莴笋、油麦菜、芥菜、胡萝卜症状表现最不明显,添加Zn最高浓度处理32mg·L-111d左右才出现轻微黄化现象。各蔬菜的地上部鲜重和根鲜重随营养液中锌浓度基本呈现先增加后降低的趋势,且与锌浓度呈现显著相关(快白菜的根鲜重除外)。黄瓜和早熟五号地上部鲜重的降低最显著,而茼蒿、胡萝卜、芥菜、快白菜地上部鲜重的降低最不显著。在症状表现和地上部鲜重降低显著的蔬菜种类中,选择地上部鲜重降低最显著(EC20值最小)的蔬菜作为对锌毒害最敏感的蔬菜品种,据此确定黄瓜为对锌毒害最敏感品种。

A series of hydroponics experiments with different zinc concentrations（0.05, 0.5, 1, 2, 4, 8, 16 mg·L-1 and 32 mg·L-1）using the seedlings of 16 vegetable species commonly cultivated in Fujian Province, southeast of China, were conducted in order to compare the sensibility of the vegetable species to zinc toxicity and to select the species with the highest sensibility to zinc-toxicity. The results showed that the zinc-toxic symptoms appeared more obviously on cucumber and water spinach than the others. The symptoms appeared on cucumber and water spinach as early as 2 days after Zn was added. On the contrary, cabbages（Fast cabbage, Prematurity No.5）, asparagus lettuce, lettuce, mustard leaf and carrot did not show apparent zinc-toxic symptoms, suggesting that these vegetables were more tolerant to zinc toxicity. These vegetables cultured in the solutions with 32 Zn mg·L-1 appeared chlorosis phenomenon until 11 days after the zinc was added. The fresh weights of shoot and root of all the vegetables increased in the beginning, and then decreased with increasing zinc concentrations in the solutions and showed significant correlations with the zinc concentrations in the solution, except the fresh weight of Fast cabbage. The shoot fresh weights of cucumber and Prematurity No.5 decreased the most significantly while those of crown daisy, carrot, leaf mustard and Fast No.5 decreased the least. The vegetable that had the most obvious zinc toxic symptoms and the lowest EC20 value（the zinc concentration at which the fresh shoot weight decreased by 20%）was selected as the most zinc-toxic sensible vegetable. Therefore, the most zinc-toxic sensible vegetable species was cucumber because its EC20 was only 3.12 Zn mg·L-1.