Agronomic performance and breeding potential of selected inbred lines for improvement of protein quality of adapted Ugandan maize germoplasm

Abstract

The use of exotic Quality Protein Maize (QPM) donors to broaden the germplasm base used by breeders is important. This study evaluated the potential QPM inbred donors from CIMMYT for improvement of the protein quality of adapted maize lines in Uganda. Experimental plots were planted at Namulinge Agricultural and Animal Research Institute (NAARI) which is a known hot spot several foliar diseases. Six QPM and six non QPM inbreds were planted in a Randomised Complete Block Design (RCBD) design with 3 replicates in 5-m rows. The twelve árental materials were crossed in a 6 X 6 half diallel mating design with QPM donors as males. Incidence and severity pf major diseases were scored 4 times during the season while key agronomic descriptors were recorded. The field evaluation revealed that CML159 and CML144 are very susceptible to Maize strak virus (MSVD) and Turcicum leaf blight (TLB, two of the major foliar diseases in Uganda. CML176 with the exception of high MSV severity had moderate resistances to other diseases, good plant aspects, high protein quality and quantity. CML182 was very susceptible to MSVD, TLB and had a poor plant aspects. Significant genotype sum of squares were divided into general (GCA) and specific (SCA) combining ability. Results indicated the existance of genetic divergence for all the diseases analysed, where additive effects were predominant. QPM donors CML176 and CML173 were superior in terms of GCA for the major foliar diseases, plant aspects and protein quality and quantity. We, therefore, recommend these lines for inclusion in Ugandan QPM breeding programs.