GENETIC DIVERSITY AND CORRELATED RESPONSE TO SELECTION OF GRAIN YIELD AND ASSOCIATED CHARACTERS IN MAIZE (Zea mays L.)

Sixteen genotypes of maize were evaluated for genetic variability and character associations in the Research Farm of the Department of Botany, University of Ibadan, Nigeria for 90 days in the 2012, 2013 and 2014 cropping seasons. Perforated polythene bags (18 × 9 cm) were filled with 6kg sandy-loam soil and were spaced at a distance of 10 cm apart between rows. Three seeds from each genotype were then planted per bag without treatment in three replicates. Data on plant and stem height, leaf width, leaf length and number of leaves were collected after planting at 14 days interval on each replicate for a particular genotype. The plant height of EVDT.Y200STRQPM genotype was significantly (p < 0.05) different from other genotypes, while genotype pairs; TZE-OR2DTSTRQPM and 2009TZE-ORIDTSTRQPM, TZEI 22, TZEI 98 and OBANTAPA, TZEI 4, TZEI 161, BODIJA as well as EVDT-W99STR, OJO, 98SYNWECSTRQPM were similar to each other. The result of correlation coefficient shows that stem height was highly significant and positively correlated with the plant height (p < 0.01; r = 0.91). The genotype is negative and non-correlated with plant height, stem height, leaf width and number of leaves, but positive and non-significantly associated with leaf length, replicate and week after planting.