Research trends of Melia in tropical plantation forestry

Abstract

The genus Melia is known for its secondary metabolite utility but there are vast differences among its species. One species of this genus, Melia azedarach is reported to be invasive and while another species, M. dubia, has diverse utility with complex germination and regeneration characteristics. Researchers are working on the different aspects of this genus, with an increasing number of scientific publications. We attempted to understand facets of the scientific literature on this genus using the topic modelling and science mapping approach. The literature corpus of the Web of Science database was explored using a single keyword – “Melia” which yielded 1523 publications (1946–2022) and after scrutiny 1263 publications were used in the study. Although nine species were mentioned in the publications, only three species are accepted: M. dubia, M. azedarach, and M. volkensii. This implies taxonomic uncertainty, with potential confusion in assigning scientific findings to particular species. This needs to be sorted out for a better assessment of the economic utility of the genus in many countries. More importantly, our results indicate that the research interests have shifted from the secondary metabolite constituents towards growth, biomass, wood properties, germination, plantation, and green synthesis. The shift in research focus toward wood properties of Melia sp. can impact the wood demand-supply at a global scale owing to its fast growth and the possibility of cultivation over a wider geographical range.