１８种蔬菜品种对硼毒害敏感性的研究

通过对不同浓度硼胁迫下豇豆、菜心、黄瓜等18种常见蔬菜幼苗水培试验,筛选对硼毒害敏感性较高的蔬菜种类.结果表明,黄瓜、豇豆、红豇豆的硼毒害症状表现最明显,在高硼处理后第2 d即出现明显的毒害症状,而空心菜和甘蓝的硼毒害症状表现最不明显.各种蔬菜的株高和地上部鲜重都随培养液中硼浓度的升高而降低,除个别蔬菜种类外,株高和地上部鲜重与培养液中硼浓度之间均呈显著相关.红豇豆和豇豆地上部鲜重的降低最显著,而红萝卜、金峰大白菜、松花菜、新冠和甘蓝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(EC_(20)值最小)的蔬菜作为对硼毒害最敏感的蔬菜品种,据此确定红豇豆为对硼毒害最敏感品种.

The Sensibility of 18 Vegetable Species to Boron Toxicity

It is necessary to study the threshold of the soils of boron toxicity to crops in order to establish boron criteria in the soils for evaluat-ing soil boron pollution and better managing boron polluted soils. Selection of the most boron-toxic vegetable is important for the above ob-jective. A series of water-culture experiments with different boron concentrations in the culture solutions and the seedlings of 18 vegetable species commonly cultivated in Fujian Province, southeast of China, were conducted in order to compare the sensibility to boron toxicity of the vegetables and select the most boron-toxic sensible vegetable species. The results showed that the boron-toxic symptoms appeared more ob-viously on cucumber, cowpea and red cowpea than on the others. The symptoms appeared on the sensible vegetables as early as 2 days after the water culture with higher boron concentrations. On the contrary, water spinach and cabbage did not show apparent boron-toxic symptoms suggesting that the two vegetables were more tolerant to boron toxicity. The plant heights and the shoot fresh weights of all the vegetables de-creased with the increase of boron concentrations in the culture solutions and showed significant correlations with each other with only few exceptions. The shoot fresh weights of red cowpea and cowpea decreased more dramatically than the other vegetable species whereas those of carrot, Jinfeng cabbage, egg dishes, pakchoi (new crown)and cabbage decreased the least. The vegetable that had the most obvious boron-toxic symptoms and the lowest EC_(20) value (the boron concentration at which the fresh shoot weight decreased by 20%) was selected as the most boron-toxic sensible vegetable. Therefore, the most boron-toxic sensible vegetable species was red cowpea of which the EC_(20) was only 3.36 mg·L~(-1) boron.