Abstract:
Groundnut (Arachishypogaea L.) is an important global oilseed crop and a major source of protein and vitamins in many rural areas of Africa. In Zambia, the production of groundnut is limited by several factors, among which Early Leaf Spot (ELS) caused by Cercosporaarachidicola Hori, is a major destructive disease. Development of resistant varieties to ELS remains the most viable disease management strategy. The objective of this study was to investigate the type of gene action conditioning resistance to C. arachidicolain order to generate information for breeding of ELS resistant groundnut varieties in Zambia. The field work was conducted at Chitedze Research Station in Malawi which is a known hot spot for groundnut foliar diseases. A recombinant inbred line (RIL) population developed from a biparental cross (Robut 33-1, susceptible and ICGV-SM 95714, resistant) and consisting of 110 F8 RILs was used in the study. Data for analysis was generated by phenotyping of the RIL population and this was conducted during the 2013/14 season under field conditions supplemented by irrigation. To ensure that there was disease infection in the experimental field, diseased debris was used as primary inoculums. The nature of gene action was established by generating a distribution curve while the Chi-square test was used to confirm the generation level of the population. These were done using the area under disease progress curves (AUDPCs) and the results suggested additive gene action. The study thus concluded that the gene action conditioning resistance to ELS was additive and breeding schemes such as pedigree and single seed decent can be used in breeding for resistance to Cercosporaarachidicola |
