Provenance Variation in Seed Morphometric Traits and Growth Performance of Senna siamea (Lam.) Erwin et Barneby at Lad Krating Plantation, Chachoengsao Province, Thailand

Abstract

Genetic variation patterns of Khilek (Senna siamea (Lam.) Erwin et Barneby) an indigenous species with potential as a source of wood energy, were evaluated at the population level. Seed samples were collected from nine provenances throughout Thailand and examined for variations in seed morphometric traits and growth performance in provenance trials in the Lad Krating plantation. Analysis of variance revealed signifi cant differences among provenances in all the study traits except the relative growth rate in some stages of development. The provenance effect as determined by broad sense heritability was 50–83% for seed morphometric traits, 53–85% for height, 33–62% for diameter at ground level, 14–67% for the height relative growth rate and 11–50% for the diameter at ground level relative growth rate. Signifi cant correlations were found within seed mophometric traits and growth characters while the inter-character correlations between seed and growth characters were very weak. At this early stage, it is recommended that the top three most suitable provenances for planting are Potaram (Ratchaburi-seed lot 2002), Muang (Kanchanaburi), and Muaklek (Saraburi). The observed patterns of variation will have important implications for gene conservation and the tree improvement program of the species.