Studies on seed germination and storage of the invasive harmful species Chenopodium ambrosioides

The effects of temperature and illumination on seed germination of Chenopodium ambrosioides,an invasive alien harmful weed,and changes of germination capacity during its storage under different temperature were studied.The results showed that illumination was necessary for its seed germination.The germination percentage was only 9.7% under the dark condition.It was over 80% from 15 ℃ to 20 ℃,but under constant 25 ℃ or 0 ℃,it was greatly restrained to a very low level.The difference of germination percentage between fresh seeds(89.3%) and seeds stored at-20 ℃ and 4 ℃ for three months(86.3% and 84.7% respectively) was not significant.As for the seeds stored at room temperature for three months,the germination rate decreased gradually to 14.3% after three months.