Genetic variation among and within provenances of Adansonia digitata L. (Baobab) in seed germination and seedling growth from selected natural populations in Malawi

Abstract

Baobab (Adansonia digitata L) trees have a wide variety of subsistence and economic values across sub-Saharan Africa. Knowledge of the genetic variation within and between the species is essential for management and designing domestication, improvement and conservation strategies.Fifty-nine half-sib families were evaluated in the nursery to determine the genetic variation and control within and between the populations from four silvicultural zones. Seed germination and seven seedling growth parameters were assessed. Total phenotypic variance, family variance, within family variance, individual narrow sense heritability, and additive genetic coefficient of variation (AGCV) were derived from observed and expected mean squares. There were highly significant differences in seed germination, plant height, root collar diameter, number of leaves, shoot height and diameter, tuber diameter and weight. Provenance variation in germination ranged from 46.7 ±3.3% to 68.7±3.3% while tree -to-tree variation ranged from 6.3±8.6% to 95.5±8.6%. Coefficient of variation in seedling growth variables ranged from 18.6% to 43.6%.Individual narrow sense heritabilities (h 2 ) ranged from 0.07 to 0.71. AGCV ranged from 3.21% to 14.67%. Morphological traits showed that mainland populations were genetically distant from the island one. High and moderate additive genetic control of traits and AGCV show the potential that Baobab can also respond well to tree improvement. High phenotypic variation found in the study offers an opportunity to effect selection of superior attributes at both provenance and individual tree-to-tree level.

Mineral and phytochemical composition of baobab (Adansonia digitata L.) root tubers from selected natural populations of Malawi

“…The seeds were pretreated through nicking to allow water penetration. Mzuzu University lies in silvicultural zone M and falls at an altitude of 1270m above sea level with mean annual temperature range of 13.5°C to 24°C and mean annual rainfall of 1150mm12.…”

“…The use of baobab tree parts has been reported to vary from place to place3. In Malawi, a study revealed that people in Chikhwawa (56.3%) and Karonga (46.4%) utilize baobab root for medicinal purposes12. In southern Malawi, an infusion of baobab root has for a long time been used to treat sore throats13.…”

“…In southern Malawi, an infusion of baobab root has for a long time been used to treat sore throats13. The wide ecological adaption of baobab tree suggests the species has evolved a wide genetic diversity across its geographical range12. In this regard, it is possible that variations in mineral and phytochemical composition of baobab root tubers are influenced by geographical or genetic differences, hence their use cannot be generalized.…”

Comparison of genetic parameters between optimal and marginal populations of oriental sweet gum on adaptive traits

“…Knowledge on the existing genetic variation within and between populations is essential for the species management, its domestication and the application of breeding and conservation strategies , Munthali et al 2012. The molecular markers and the common garden tests are two powerful tools applied for the characterization of genetic variation in forest tree populations.…”

An optimized method for in vitro propagation of African baobab (Adansonia digitata L.) using two-node segments

“…However, natural reproduction and regeneration cycles of baobab are threatened due to damage caused by domestic animals and seedlings clearance for other land use (Assogbadjo et al 2009). Furthermore, the increased harvesting of fruits from wild or semidomesticated individuals for commercial purposes is suspected of potentially reducing seeds available for the spontaneous generation of new plants (Munthali et al 2012). Domestication and cultivation programmes are thus urgently needed to preserve genetic diversity, maintain multiple specimens and promote the cultivation of varieties suitable for commercial cultivation (Assogbadjo et al 2011;Cuni Sanchez et al 2011).…”