Exploration of method of Inducing pycnidia of dieback of Pinus sylvestris var.mongolica

MA Teng; FU Sina; Aierpani Abulimiti; HE Aaomen; GUO Jing; ZHOU Boru

doi:10.3969/j.issn.1002-2724.2025.02.012

Abstract：Pinus sylvestris var.mongolica dieback is one of the main diseases that harm the growth of P.sylvestris var.mongolica.The pathogen of this disease is a weak parasitic fungi and is not easy to produce spores,which poses difficulties in studying the biological characteristics of the pathogen and conducting indoor fungicide screening.In order to provide experimental materials for the research on the dieback pathogen of P.sylvestris var.mongolica.,this experiment explored the induction method for inducing pycnidia of the pathogen of P.sylvestris var.mongolica.The experiment used 1-4 year old detached needles of P.sylvestris var.mongolica,as well as 1-year-old detached needles of P.tabulaeformis,P.koraiensis,and Picea asperata as materials to explore the optimal conidia induction method of P.sylvestris var.mongolica dieback pathogen and potential host disease threats,aiming to provide a basis for the prevention and control of P.sylvestris var.mongolica dieback disease.The results showed that the conidiophores induced by 1-year-old needles of P.sylvestris var.mongolica are the largest,with an average of only about 0.181 mm,which was smaller than other tree species.The size and quantity of conidia induced by 2-year-old,3-year-old,and 4-year-old detached needles of P.sylvestris var.mongolica decreased with increasing leaf age.Compared to the other three tree species,the annual coniferous leaves of P.sylvestris var.camphora produced 1.722 more conidia per mm,followed by P.tabulaeformis with 0.798 conidia per mm.P.koraiensis and P.asperata had the least and no significant difference,with 0.073 conidia per mm and 0.120 conidia per mm,respectively;After mechanical damage treatment,regardless of whether it has been disinfected or not,the maximum number of conidia was 3.578/mm and 2.873/mm,respectively.