Characterisation Of Local And Exotic Accessions Of Moringa (Moringa Oleifera Lamarck)

Abstract

Knowledge of existing diversity especially at the genotypic level in plant population is crucial for the effective breeding, conservation, management, and efficient utilization of plant genetic resources (PGR) (Mondini et al., 2009). However, Moringa (Moringa oleifera Lamarck), a common and popular plant growing in almost every part of the country with several uses and benefits still remains underutilized tropical crop in Ghana. This is due to the fact that the crop has either received little or no attention with respect to research and breeding programmes. Moringa oleifera seeds were collected from ten provenances with eight from Ghana and one each from United State of America and India. A completely randomised complete block design and modification of AVRDC-GRSU record sheet was used to evaluate morphological characteristics of thirty seven accessions from these provenances. Eight out of twelve traits observed revealed variability among the accessions studied. For quantitative characters studied; tripinnatum leaf length ranged between 25.2cm and 61.6cm, tripinnatum leaf width ranged between 17.8cm and 48.5cm, tripinnatum leaflet length ranged from 10.8cm to 25.9cm and tripinnatum leaflet width was from 5.7cm and 17.6cm. There were also significant differences among the accessions of Moringa oleifera for the vegetative features. Dry leaf samples of Moringa from eight provenances with 40 accessions were used for both biochemical and molecular analysis. The dried leaf samples were found to contain 0.0014 - 0.0736% (Fe), 0.0006 – 0.0097% Mn, and 0.0005 – 0.111% Zn. The accessions also contained 40.3 – 79.3 mg/kg (Ca), 19.23 - 48.13 mg/kg (Mg), 87.5 -253.1 mg/kg (Na), 1549 – 2272 mg/kg (K) and 0.179 – 0.438 mg/kg (P). There were significant differences in the nutritional content of the dried Moringa leaf samples except for potassium (K). The heavy metal Pb ranged from 0.0005 -0.0058%. Percentage dry matter, crude protein and nitrogen ranged from 14.63 – 25.37%, 12.9 – 26.3% and 2.064 – 4.208% respectively. Eleven distinct bands with a monomorphic locus at a distance of 1.2cm for the forty accessions were observed in gel electrophoresis of total protein from the accessions. The bands ranged from a length of 0.1cm to 3.9cm with two accessions, E40 and E41 producing all eleven bands. Forty genotypes from different ecological zones were assayed for polymorphism using twelve decamer RAPD markers. Ten primers amplified and showed distinct DNA fragments. A high polymorphic level was recorded with 95.1% of the fragments produced being polymorphic (4.9% monomorphic). Cluster analysis showed a separation of BNR 4 accession from the rest. Accessions E41 and UE49 could not be resolved by the RAPD marker. Cluster analysis of the combined data of total protein and RAPD produced two major clusters with accession BNR4 separating itself from the rest. In conclusion, enough variation existed among the accessions studied and can be used in the establishment of Moringa breeding programme to produce superior varieties.