Morphological characterization of cashew (Anacardium occidentale L.) in four populations in Malawi

An assessment of the genetic diversity in cashew (Anacardium occidentale L.) would assist in planning for future selection of good high yield germplasm that will produce nuts of high quality and fetch highprices on the market. The genetic diversity and relationship among 40 accessions of cashew collected from 4 populations (Liwonde, Nkope, Kaputu and Chikwawa) was characterized using quantitative andqualitative traits. The study results have revealed similarity values between 35 to 66%. Analyses of genetic similarity based on unweighted pair group method of arithmetic averages (UPGMA) grouped the 40 accessions into 4 clusters with 14 sub-clusters and the principal component analysis revealed that apple length, apple nut ratio, nut weight, kernel weight, out turn percent and flower sex ratio accounted for most of the variation. The variation could be attributed to genetic history, ecogeographic origin andselection for desired agronomic traits by farmers. Accessions LW41, NE2, NE4, CH18 and PAL26 showed potential for selection in nut and kernel weight and out turn percent suggesting that this could be a valuable source of variation for tree improvement programme in cashew nuts. The findingssuggest availability of broad genetic base that could be exploited for future cashew selection and breeding in Malawi

Minituber production potential of selected Potato (Solanum tuberosum L.) genotypes in different propagation media

Potato farmers in Malawi and other developing countries lack healthy and quality potato seed. This is mainly due to limited seed multiplication programmes to provide farmers with clean potato seed. A study to evaluate minituber production potential for selected genotypes in different media types would assist in planning for future selection of good high yielding varieties. It will also assist in planning for rapid seed multiplication programme of pathogen free planting materials to increase production of potato in the country. Three different propagation media (vermiculite, sand and sawdust) and seven different genotypes (two local genotypes- Magalabada and Rosita, five introduced genotypes-Up to date, Buffelspoort, Van der plank, Lady Rosetta and Bp 1 2007) were investigated. Plantlets grown on vermiculite performed better with higher mini tuber yield of 1740 g/m2 for all genotypes while 850 and 292 g/m2 in sand and sawdust, respectively. Among the genotypes ‘Up to date’ and Lady Rosetta produced more tubers of between 12 tubers/plant and 10 tubers/plant. Thus, vermiculite increases the number and size of Minitubers which is a very important step for rapid multiplication of potato seed. The study findings provide valuable information for potential genotypes and propagation media to assist in scaling up seed multiplication programmes for pathogen free planting materials. Keywords: Propagation media, genotype, potato, minituber.African Journal of Biotechnology, Vol 13(48) 4430-443