Quantitative-genetic parameters of sorghum growth under striga infestation in Mali and Kenya uri icon

abstract

  • To estimate quantitative genetic parameters of sorghum for resistance to the hemi-parasitic weed striga (Striga hermonthica) and for agronomic traits, 36 diallel F2 populations including their nine parental lines (cultivars N 13, Framida, 555, IS 9830, Seredo, M35-1, E 36-1, DJ 1195 and IS 1037) and five local cultivars as controls (Wagita, Nakhadabo, CSM 335, CSM 228 and Bengou Local), were evaluated under severe striga infestation at two locations each in Mali (Samanko and Cinzana) and Kenya (Kibos and Alupe). Location means for grain yield ranged from 132 to 254 g/m2. F2 populations outyielded lines on average by 18%. For striga emergence traits, F2 heterosis values ranged from -36% to 232% among populations. Genetic and genotype × environment interaction variances of lines and F2s were highly significant for all traits. Broad sense heritabilities for areas under striga severity progress curves and grain yield were 0.83 and 0.90 in lines, and 0.81 and 0.89 in F2s, respectively. General and specific combining ability, and their interaction effects with locations were significant for most traits. F2 superiority for grain yield under striga infestation demonstrates the potential merit of heterozygous cultivars in the target areas. Significant genotype × environment interaction entails multilocational testing to identify stable resistance. A combination of resistance with striga tolerance is recommended to breeders

publication date

  • 2001
  • 2001