应用水培方法筛选砷低吸收生菜的比较研究

为准确、快速比较作物对砷吸收能力的差异,建立适合砷低吸收作物筛选的方法,以5个生菜品种为对象,以土培法为基准,对旺盛生长期水培、全生育期水培和短期胁迫培养等方法下生菜砷吸收能力等进行了比较。结果表明:旺盛生长期水培、全生育期水培所得出的不同品种生菜对砷吸收能力与土培法基本一致,各品种间差异显著,且旺盛生长期以后生菜地上部砷含量不再随时间和生物量的变化而出现显著变化;短期胁迫培养下各品种生菜地上部砷含量尽管有一定差异,且其获得的不同品种生菜对砷吸收能力的顺序与其他方法基本一致,但相互间差异不显著。5个生菜品种中紫罗马生菜对砷吸收的能力最弱,在轻微和中度砷污染土壤中地上部砷含量分别为0.42 mg·kg-1和0.77 mg·kg-1,仅为其他品种生菜的49.8%~72.4%,各品种生菜砷吸收能力的大小排列顺序为耐抽薹生菜绿萝美国大速生罗沙绿紫罗马。综合本研究结果,旺盛生长期水培可以作为砷低吸收生菜筛选的优选方法。

Comparison of three types of hydroponics methods in screening for low arsenic uptake lettuces

In order to accurately and efficiently compare the low arsenic uptake capabilities of vegetables and to build up appropriate screening methods, the As uptake capabilities of five lettuce(var. ramosa Hort.) varieties were studied by using three hydroponics methods:vigorous growth period, whole growth period, and short-term stress uptake. Pot experiments were conducted as the reference method to verify the feasibility of the tested hydroponics methods. The results indicated that the As uptake capacities of the five lettuce varieties via the vigorous growth and whole growth period methods were basically identical with the results of the pot experiments. The variation of As content in the aboveground biomass of the five lettuce varieties between the vigorous growth period and the whole growth period methods showed no difference. However, no significant differences in arsenic content between lettuce varieties were observed in the short-term stress absorption method. The As concentration in the aboveground biomass of the Ziluoma lettuce was the lowest among all varieties, at 0.42 mg·kg^-1 and 0.77 mg·kg^-1 in the slight and middle As-contaminated soils, respectively. The capacities of As uptake from high to low were in the order:Naichoutai, Lvluo, Meiguodasusheng, Luoshalv, and Ziluoma. The hydroponics method of vigorous growth can be used to screen low As uptake vegetables.