Patterns of genetic and morphometric diversity in baobab (Adansonia digitata) populations across different climatic zones of Benin (West Africa). (1/3)

BACKGROUND AND AIMS: Baobab (Adansonia digitata) is a multi-purpose tree used daily by rural African communities. The present study aimed at investigating the level of morphometric and genetic variation and spatial genetic structure within and between threatened baobab populations from the three climatic zones of Benin. METHODS: A total of 137 individuals from six populations were analysed using morphometric data as well as molecular marker data generated using the AFLP technique. KEY RESULTS: Five primer pairs resulted in a total of 217 scored bands with 78.34 % of them being polymorphic. A two-level AMOVA of 137 individuals from six baobab populations revealed 82.37 % of the total variation within populations and 17.63 % among populations (P < 0.001). Analysis of population structure with allele-frequency based F-statistics revealed a global F(ST) of 0.127 +/- 0.072 (P < 0.001). The mean gene diversity within populations (H(S)) and the average gene diversity between populations (D(ST)) were estimated at 0.309 +/- 0.000 and 0.045 +/- 0.072, respectively. Baobabs in the Sudanian and Sudan-Guinean zones of Benin were short and produced the highest yields of pulp, seeds and kernels, in contrast to the ones in the Guinean zone, which were tall and produced only a small number of fruits with a low pulp, seed and kernel productivity. A statistically significant correlation with the observed patterns of genetic diversity was observed for three morphological characteristics: height of the trees, number of branches and thickness of the capsules. CONCLUSIONS: The results indicate some degree of physical isolation of the populations collected in the different climatic zones and suggest a substantial amount of genetic structuring between the analysed populations of baobab. Sampling options of the natural populations are suggested for in or ex situ conservation.  (+info)

Seven new species of the Botryosphaeriaceae from baobab and other native trees in Western Australia. (2/3)

In this study seven new species of the Botryosphaeriaceae are described from baobab (Adansonia gibbosa) and surrounding endemic tree species growing in the Kimberley region of northwestern Australia. Members of the Botryosphaeriaceae were predominantly endophytes isolated from apparently healthy sapwood and bark of endemic trees; others were isolated from dying branches. Phylogenetic analyses of ITS and EF1-alpha sequence data revealed seven new species: Dothiorella longicollis, Fusicoccum ramosum, Lasiodiplodia margaritacea, Neoscytalidium novaehollandiae, Pseudofusicoccum adansoniae, P. ardesiacum and P. kimberleyense.  (+info)

Larvicidal and repellent properties of Adansonia digitata against medically important human malarial vector mosquito Anopheles stephensi (Diptera: Culicidae). (3/3)

BACKGROUND & OBJECTIVES: Development of plant-based alternative compounds for mosquito control has gained importance now-a-days, in view of increasing resistance in mosquito vectors to existing insecticides. The larvicidal and repellent activities of benzene, chloroform, hexane and methanol leaf extracts of Indian medicinal plant, Adansonia digitata were investigated against malarial vector, Anopheles stephensi. METHODS: In all, 25 III instar larvae of An. stephensi were exposed to various concentrations (30-180 mg/l) in the laboratory by using the standard protocol described by WHO (2005). The larvae were exposed for 24 h and mortalities were subjected to log-probit analysis. Repellent activity of crude leaf extract at the dosages of 2, 4 and 6 mg/cm2 was evaluated in a net cage (45 x 30 x 45 cm) containing 100 blood starved female mosquitoes of An. stephensi using the protocol of WHO (1996). RESULTS: Preliminary phytochemical analysis of A. digitata showed the presence of triterpenoids and saponins. The LC50 and LC90 values of hexane, benzene, chloroform, and methanol extracts of A. digitata against An. stephensi larvae in 24 h were 111.32, 97.13, 88.55, 78.18 and 178.63, 176.19, 168.14, 155.42 mg/l, respectively. The repellent activity of methanol extract was found to be most effective and at higher concentration of 6 mg/cm2 benzene, chloroform hexane and methanol extracts provided 100% protection up to 150, 180, 120 and 210 min against An. stephensi, respectively. CONCLUSION: The preliminary study indicated that A. digitata showed larvicidal and repellent activities against An. stephensi and could be used for controlling mosquitoes. Further studies are indicated to purify the active compounds from these plants for developing larvicide and repellents.  (+info)