Allelopathy of Eupatorium adenophorum on Seed Germination of Rice

Purpose To explore the allelopathy of Eupatorium adenophorum on rice seed germination and seedling growth.

Methods Two varieties of Yunlu142 and Daijia rice were treated by different mass concentrations of water extracts from roots, stems and leaves of E. adenophorum. The germination rate, seedling growth and malondialdehyde (MDA) content of rice were determined.

Results Treated with 0.02 g/mL leaf extract of E. adenophorum, the germination rate of Yunlu142 and Daijia rice were 86.00% and 65.00%, respectively, significantly lower than CK (92.00% and 74.00%, respectively), and the germination rate decreased with the increase of extraction mass concentration of E. adenophorum. The allelopathic effect of leaf extract was stronger than root and stem. The inhibition rates of rice root length and seedling height reached 100% and about 40%, respectively; also the MDA content were increased.

Conclusion E. adenophorum contains allelochemicals that inhibit rice seed germination and growth; the leaf extract is stronger than stem and root, and the inhibition of rice root elongation is stronger than the aboveground part. The response of Yunlu142 to the allelopathy of E. adenophorum is higher than that of Daijia rice. The results provide useful information for revealing the harm of E. adenophorum, selecting rice varieties with weak allelopathy and reducing yield loss in E. adenophorum.