Vegetative Propagation of Bombax costatum Pellegr. & Vuillet (Malvaceae) by Root Segments Cuttings: Effects of Mother Tree Diameter and Origin of Cuttings

Abstract

B. costatum is a local species of great socio-economique importance whose flowers are consummed and commercialized in local and regional market. Despite its economical and social value in local communities, it is still in the wild stand in the Guinean Savannah Highlands of Cameroon. The objective of the study is to contribute to its domestication by root segments cuttings. Root system of the mother trees was carefully excavated and the root samples (0.5−1kg) for the carbohydrate analysis were collected monthly throughout the year. In addition, a total of 180 root segments cuttings (RSC) were collected from 20 parent trees of different diameters at breast height (dbh) (15 - 30 cm; 30.1 - 45 cm and > 45 cm) in «Gamba» and «Karna manga». The experimental design explorated was a split - plot with 03 replicates. The trial was conducted in a non mist polypropagator. The results reveal that among the carbohydrates evaluated, fructose decreased from the dry to the rainy seasons while soluble and total sugars move in inverse order. The first buds appear 08 weeks after planting. At the end of the essay, the highest budding rate (81.11±19.65%) was obtained in root segments cuttings from Karna manga against 68.33±34.88% in RSC from mother trees of dbh 30.1-45 cm. Regarding the origin of root segments cuttings by dbh of parent trees interaction, the budding rate varied significantly from 36.66±5.77% in RSC from mother trees of dbh 15.1-30 cm originated from Gamba to 100±0% in those from parent trees of the same dbh in Karna manga (0.0046 45 cm originated respectively from Gamba and Karna manga to 50±26.45% in those from parent trees of dbh 15 - 30 cm from Karna manga. These results will help to elaborate appropriate domestication and conservation strategies of the species.