地肤对硼的耐受及富集能力研究

为了考察地肤对硼的耐受及富集能力,开展了溶液培养试验。将溶液硼浓度设置为0(对照)、10、20、30、40、80、120 mg·L~(-1),考察了硼胁迫对地肤植株生长、硼积累和细胞酶活性的影响。结果表明:地肤在溶液硼浓度为30 mg·L~(-1)以下能够正常生长。溶液硼浓度超过30 mg·L~(-1)后,随着溶液硼浓度的增加、地肤的生物量显著降低。当硼浓度达到120 mg·L~(-1)时,根、茎、叶生物量分别比对照降低了56.0%、72.2%和71.4%。随着溶液硼浓度的增加,地肤根、茎、叶中的硼浓度均显著增加,在120 mg·L~(-1)时,地肤体内硼浓度可达4000 mg·kg~(-1)。经计算,地肤地上部和根部的BCF和TF值均大于1,地上部的BCF甚至大于20,表现出较强的硼富集能力。随着硼浓度的增加,地肤体内SOD和POD的浓度呈现先增加后降低的趋势,CAT的浓度呈现增加的趋势,表现出较好的抗氧化防御机制。综上所述,地肤在硼胁迫下有较好的抗氧化防御机制,其对高浓度硼具有较强的耐受和富集能力,可以作为高硼土壤植物修复的候选物种。

Boron tolerance and accumulation in Kochia scoparia

To evaluate the capacity of boron (B) tolerance and accumulation in Kochia scoparia, hydroponic studies were conducted. Seedlings of K. scoparia were cultivated in solutions with B concentrations of 0 (control), 10, 20, 30, 40, 80 mg·L^-1 and 120 mg·L^-1, respectively. The biomass, B accumulation and enzymatic activity were determined after 15-d cultivation. The results show that K. scoparia was able to grow normally at B supply concentrations ranging from 0 to 30 mg·L^-1. The biomass of K. scoparia decreased significantly with increasing B supply concentrations at B supply concentrations greater than 30 mg·L^-1. At B concentration of 120 mg·L^-1, the biomass of root, stem and leaf of K. scoparia decreased by 56.0%, 72.2% and 71.4%, respectively, compared to the control. Moreover, with increasing B supply concentrations, plant B concentrations increased gradually. At B supply concentration of 120 mg·L^-1, the plant B concentration in K. scoparia was 4000 mg·kg^-1. The BCF and TF values of K. scoparia were all greater than 1, and even greater than 20 for shoot BCF values, indicating a outstanding capacity of accumulating B for K. scoparia. With increasing B supply concentrations, the POD and SOD activities in K. scoparia increased firstly and then decreased and the CAT activity increased all the time, indicating that the defense system of active oxygen of K. scoparia was well-organised under B stress. Our results suggest that, K. scoparia has a considerable tolerance to B and is able to accumulate high level of B, due to the defense system of active oxygen of it. Therefore, K. scoparia is considered as a potential candidate for the phytoremediation of high-B soil.