Variation in reproductive and developmental parameters of Callosobruchus maculatus (F) reared on ten Botswana cowpea landraces

A study was conducted on ten Botswana cowpea landraces to evaluate their resistance to the cowpea weevil (Callosobruchus maculatus (F) (Coleoptera: Bruchidae). The variations in reproductive and developmental parameters were used to evaluate the landraces for resistance against C. maculatus under laboratory conditions. The landraces B339, B383, B013-F and B261-B had significant lower percentage adult emergence and oviposition than the landraces B001-B, B055, B109-C and B154. The landraces B339, B383, B013-F and B261-B also significantly prolonged developmental period of beetles. The reduction in oviposition, beetle emergence and prolonged developmental period by these landraces indicate inherent level of resistance against C. maculatus.Key words: Landrace, Callosobruchus maculatus, resistance, developmental period, Botswana

Genetic diversity in terapy bean (Phaseolus acutifolius) landraces grown in Botswana

A field experiment was conducted at Department of Agricultural Research in Sebele in the 2012 to 2013 season using nine accessions that were sourced from the National Plant Genetic Resource Centre (NPGRC), Gaborone, Botswana. Multivariate statistical procedures such as clusters and principal component analysis were used on 15 selected characters to assess agro-morphological variability among tepary bean landraces collected in Botswana. Few characters were statistically significant which suggest lower genetic diversity among the Botswana tepary beans. The first three PCA accounted for 77.12% of accumulated variation. Traits which revealed significant contribution to variation among accessions were number of leaves, plant spread, pod width, 100 seed weight and seeds per pod. The dendrogram results also showed that these characters contributed significantly to the grouping of accessions into three clusters. Three accessions GK011, MTS (Motsumi) and GK012 were separated from the rest of the accessions. However, GK012 and MTS (Motsumi) with highest number of valuable traits are recommended for plant breeders to use as parents in future breeding programs