Replacement Control Of Invasive Weeds In Degraded Grassland In Horqin

Horqin grassland have degraded more and more serious because of human unreasonable management activities.The alien invasive plants,Solanum rostratum and Cenchrus spinifex,had caused serious damage in the Horqin Grassland and posed a serious threat to the local agricultural and ecological security.Iris lactea can be used as a replaceive plant for the control of invasive plant in degraded and desertified grassland of Horqin.However,it can not be established population because of low seed germination rate to limits its application.In view of this,the seed germination and seedling breeding matrix formula of I.lactea were studied and the drought tolerance characteristics by transcriptome technology was analyzed.In addition,the control effect of S.rostratum in Horqin grassland with Legumes and Gramineae forages were evaluated.The main conclusions of this paper were as follows:After imbibition,the I.lactea seeds were cultured at 30±2? for 2-4 weeks,then transferred to 30±2? for 16h,20±2? for 8h,which could effectively shorten the germination time and increase the germination rate of I.lactea seeds.d The competitive replacement study showed that the competitive ability of I.lactea was higher than that of Cenchrus spinifex and it could be used for restoration of C.spinifex and S.rostratum.Transcriptome results showed that 1187 differentially expressed genes(DEGs)were identified from the comparison of drought treatment with the control(T/CK),According to GO annotation and Kyoto KEGG pathway analysis,the plant drought tolerance of I.lactea depends on proline metabolism,the action of transcription factors and transporters,and a strong ROS scavenging system.In the second year of the controlled replacement,the coverage of forage gradually increased,the resources and niches were seized by the forage,and the growth of S.rostratum significantly inhibited.The density,biomass and soil seed reserve of S.rostratumwere controlled at a low level,significantly lower than CK(P<0.05).Astragalus adsurgens,Festuca arundinacea,Agropyron cristatum,combined with Leymus chinensis.had the best control effect on S.rostratum.The diversity and abundance of rhizosphere bacterial community in S.rostratum decreased significantly after vegetation restoration,and the soil organic matter(OM),total nitrogen(TN),total phosphorus(TP),total potassium(TK)and available potassium(AK)were important factors affecting the composition of bacterial community.This study provided theoretical and technical basis for replacement control of invasive weeds in degraded grassland of Horqin.