砷胁迫对三七生长及生物量的影响

Effects of Arsenic on the Growth and Biomass of Panax notoginseng

通过田间试验,研究了不同砷浓度对三七生长株型、叶型特征指标和生物量的影响。结果表明:低浓度砷处理(≤80mg/kg)对三七株型特征指标无明显影响,随着砷浓度的增加,高浓度砷处理(≥140mg/kg)明显减少了三七的株高、茎基直径的增长,根冠比逐渐减小。在营养生长期和开花期,砷与三七的株高、根冠比、茎基直径具有显著负相关;砷≤80mg/kg三七叶片数、叶中长、叶中宽、叶面积指数均无明显变化;砷≥140mg/kg处理各叶型指标减小。在营养生长期和开花期,砷与三七叶片数、叶中长、叶中宽和叶面积指数均呈极显著负相关;三七相对生长速率在砷≥140mg/kg时逐渐降低,并与之呈极显著负相关;三七花、茎叶、根系的生物量及总生物量在砷≤80mg/kg无显著影响,砷≥140mg/kg生物量减小,与三七总生物量均呈极显著负相关;三七对砷的最大忍耐浓度为140mg/kg,土壤砷含量过高对三七生长具有毒害作用,砷对根系的毒害作用大于地上部分。

A field experiment was carried out to study the effects of arsenic on the plant growth,and leaf type characteristic index and biomass of panax notoginseng. The results showed that： no significant effects were observed under the treatment of low soil arsenic concentration（ ≤80mg/kg）, while the plant height and stem base diameter decreased under high soil arsenic concentration（≥ 140mg/kg）. The ratio of root to shoot decreased with increases in arsenic concentration. The correlation analysis indicated that significantly negative relationships between plant height,ratio of mot to shoot, stem base diameter and As were observed in vegetative growth period and the flowering period; The number of blades, leaf length, leaf width, leaf area index had no change with soil As concentration（ ≤ 80mg/kg）, then decreased with increase in soil As concentration（ ≥ 140mg/kg）. Significantly negative relationships between number of blades, leaf length, leaf width, leaf area index and soil As concentration were observed in vegetative growth period and the flowering period;Relative growth rate decreased with increase in soil As con- centration（ ≥140mg/kg）. Significantly negative relation between soil As concentration and relative growth rate was observed. Biomass of flowers,stem leaf, root system and total biomass had no change with soil As concentration（ ≤ 80mg/kg） ,then decreased with increase in soil As concentration（ ≥ 140mg/kg） ,Significantly negative relationships between total biomass and soil As concentration was observed in the two growth periods;In conclusion, growth and biomass of P. notoginseng should be inhibited with high soil arsenic concentration and the toxicity of arsenic in root system is greater than aboveground part. The maximum tolerant AS concentration for growth of P. notog/nseng is 140mg/kg.