砷对绿豆和黑豆种子萌发的影响

为了认识砷污染与种子萌发的关系,进行绿豆和黑豆加砷砂培种子萌发实验.结果表明：低浓度的砷（1mgkg-1）对绿豆和黑豆种子萌发有促进作用,对萌发质量的促进作用可达12%以上,当砷水平超过一定浓度（5mg kg-1）则表现出明显的抑制作用,且随砷水平增加,抑制作用增强.砷处理第6天绿豆的发芽率和萌发质量的最大抑制率分别为88.2%和56.2%,黑豆发芽率和萌发质量的最大抑制率分别为57.9%和43.6%.同一砷水平下,砷对绿豆和黑豆萌发的抑制作用均随萌发时间的延长而减弱.在高砷水平15和20mg kg-1砂下,黑豆发芽率高于绿豆,砷对黑豆发芽率的抑制率小于绿豆.无论是发芽率还是萌发质量,黑豆的半抑制浓度均大于绿豆.总之,低剂量的砷可以促进绿豆和黑豆种子萌发,大于5mg kg-1的砷则抑制种子萌发,砷毒害导致种子发芽率和萌发质量降低,萌发延迟,豆芽变短;黑豆种子的耐高水平砷毒害的能力比绿豆种子强.

Effects of arsenic on seed germination of mung bean and black soybean

Arsenic is a toxic element both to animals and plants,and arsenic pollution may reduce the crop yields and threat to food safety.An experiment germinating mung bean and black soybean seeds by arsenic addition in sands was conducted to understand the effect of arsenic on seed germination,in which the situation of seed germination was observed and the percentage of seed germination and germination weight was determined.The results showed that 1 mg kg-1 arsenic addition stimulated the mung bean and black soybean seed germination and increased about 12% of the germination weight,but the seed germination was significantly suppressed when the arsenic addition was over 5 mg kg-1,and thereafter the suppression to seed germination was increased with the increasing of arsenic concentrations.The highest decreasing rate of percentage of seed germination and the germination weight at 6 days after incubation was 88.2% and 56.2% for mung bean and 57.9% and 43.6% for black soybean,respectively.The suppression of arsenic to seed germination of mung bean and black soybean in the same arsenic level decreased with incubation time.Under the same high arsenic concentration,such as 15 and 20 mg kg-1,the seed germination percentage of black soybean was higher than that of mung bean,while the suppression rate to the percentage of seed germination of black soybean was lower than that of mung bean.Both germination rate and germination weight,the half maximal inhibitory concentration of black soybean seeds was higher than that of mung bean seeds.It was concluded that the seed germination of mung bean and black soybean was promoted by low arsenic addition and suppressed by over 5 mg kg-1 arsenic addition and the arsenic toxicity to seed germination was the declination of percentage of seed germination and germination weight,germination retardation and the short buds,but the arsenic tolerance of black soybean seeds was stronger than that of mung bean seeds.