Eco-Geographic Patterns of Morphological Traits and in-vivo Conservation of Murraya paniculata

Abstract

Murraya paniculata L., a widely grown ornamental species, exhibits notable phenotypic variation across diverse agro-ecological regions. This study investigated morphological diversity in leaves, flowers, and fruits across Sri Lanka and established a field gene bank for long-term conservation. Surveys were conducted in 13 districts representing varied climatic conditions, and accessions were collected using multi-stage sampling. Twenty-four qualitative and quantitative traits were assessed over two years through field and laboratory characterization. Geographical distribution was mapped using GIS, and ten-year climatic data were incorporated into correlation analysis and Principal Component Analysis (PCA). Morphological traits showed significant associations with precipitation, temperature, and latitude. PCA identified key traits such as petal length, petal width, leaf length and width, petiole length, and internode length that explained 84.75% of the total variation. Accessions from cooler, high-rainfall regions tended to have larger vegetative and floral structures, whereas more compact morphologies dominated in warmer, drier areas. All accessions were successfully established in a field gene bank. Overall, the study demonstrates that climatic, and geographic factors strongly shape morphological variation in M. paniculata, underscoring its high phenotypic plasticity and providing valuable insights for breeding, horticulture, and conservation.