Correlation between yield per plant and main phenotypic traits of Paeonia suffruticosa for oil production

Objective To analyze the variation of main phenotypic traits and yield per plant of oil peony (Paeonia suffruticosa), study the correlation between yield per plant and phenotypic traits, and determine the components of yield per plant.

Method Twenty five peony varieties were selected. Correlation analysis, principal component analysis, multiple regression analysis and path analysis were performed on their main phenotypic traits.

Result The variation coefficients of all the investigated phenotypic traits ranged from 11.36% to 82.57%. Yield per plant was significantly(P < 0.01) positively correlated with 10 traits including fruit mass per plant, fruit number per plant, valid fruit number per plant, seed rate, follicle width, crown area, new branch number per plant, two-year-old branch number per plant, flower number per plant and leaflet number. Yield per plant was significantly (P < 0.05) positively correlated with three traits including aggregate follicle diameter, compound leaf width and compound leaf length to petiole length ratio. Yield per plant was significantly(P < 0.05) negatively correlated with three traits including seed moisture content, top leaflet length and top leaflet shape index.The principal component analysis showed that there were five common factors with eigen values above 1, and the accumulative contribution rate was 69%. The multiple linear regression analysis and path analysis showed that yield per plant was significantly correlated with six traits including fruit mass per plant, fruit number per plant, valid fruit number per plant, seed rate, thousand-seed mass and top leaflet shape index.

Conclusion The key traits influencing yield per plant of oil peony in order were fruit mass per plant, valid fruit number per plant and seed rate. The three traits should be paid more attention in oil peony breeding and germplasm innovation.