Study On Insect Resistance Of Three Species Of Meliaceae

This paper investigates the resistance of 3 species of Toona ciliata Roem,Toona ciliata and Chukrasia tabularis var.Velutina species,and analyses the appearance of the branches,the anatomical structure of the branches,the nutrients and secondary metabolites of the branches of the 3 three species of Meliaceae.The combination of the resistance to insect resistance of the 3 plants was used to compare and analyze the factors affecting the resistance of the 3 plants,and to explore the reasons for the influence of Toona ciliata Roem for resistant and Toona ciliata for susceptible,and to provide scientific basis for the study of Toona ciliata Roem,Toona ciliata and Chukrasia tabularis var.Velutina species.The main results are as follows:Through field investigation,the results showed that 3 species of Meliaceae were attacked by the Hypsipyla robusta Moore,the Toona ciliata Roem was a pest resistant plant,the Chukrasia tabularis var.Velutina was a medium degree plant,and the Toona ciliata was a highly susceptible plant.The thickness,color,tightness and roughness of the branches of plants are compared in the morphological structure of plants.The thickness and tightness of the outer skin are related to the plant's insect resistance,that is,the thicker and looser the branches,the lower the insect resistance,and the other factors are not related.In the cross section of plant branches,the number of catheters in the Toona ciliata Roem and the wall thickness of the stone cells are related to the size of the insect resistance,that is,the number of catheters in the Toona ciliata Roem is less,and the thickness of the stone cells is the reason of the Toona ciliata Roem is a resistant plant.The width of the rays of Toona ciliata is greater than that of the Chukrasia tabularis var.Velutina,and the radius of the lignification cells is smaller than the Chukrasia tabularis var.Velutina.The width of the rays and the radius of the lignification cells are related to the strength of the insect resistance,and the width of the rays and the radius of the lignification cells are the reasons for the high sensitivity of the Toona ciliata.The moisture content of phloem and xylem of Toona ciliata is higher than that of Toona ciliata Roem and Chukrasia tabularis var.Velutina,the high water content is one of the reasons of the high susceptible of Toona ciliata.The contents of nutrients and the secondary metabolites of 3 species of Meliaceae were compared.There was no significant difference in the reducing sugar content of the phloem and xylem of Toona ciliata Roem,Toona ciliata and Chukrasia tabularis var.Velutina,and the reducing sugar content in the xylem of Toona ciliata Roem was higher than that of Toona ciliata and Chukrasia tabularis var.Velutina.The results showed that the content of reducing sugar in plants was not the main factor affecting Toona ciliata Roem's insect resistance.The difference of protein content in the xylem of the three plants was not obvious,and the difference of phloem was obvious.The protein content of the tender branches of Toona ciliata Roem was lower than that of the Chukrasia tabularis var,but it was higher than the high susceptible Toona ciliata,and the protein content of the three xylem was not distinct,so the content of protein in twigs is not the main factor that affects the insect resistance of Toona ciliata Roem.The content of total phenol in the three plants was different,the total phenol content between the three is not correlated with insect resistance,indicating that the content of total phenol was not an important factor affecting the non feeling of Toona ciliata Roem.The cellulose content of the three plants was different,and the content of cellulose was not related to the strength of the resistance.The results showed that the cellulose content in the shoots was not a factor affecting the insect resistance of the three species of Meliaceae.The content of flavonoids in the three plants was different.The results showed that the content of flavonoids in the branches of the three plants was not related to the resistance to insect,so the content of flavonoids in the branches was not the factor affecting the non feeling of Toona ciliata Roem.The tannin content of the three plants was significantly different,and the tannin content in the xylem of three plants was positively correlated with the resistance to insect resistance.The higher the tannin content,the stronger the resistance to insect.The results showed that tannin was an important factor affecting the insect resistance of Toona ciliata Roem.