Numerical evaluation of local and exotic maize genotypes in arid conditions

To identify the major parameters which account for variation among hundred genotypes of maize (Zea mays L.), they were studied using single linkage cluster analysis (SLCA) and principle component analysis (PCA). Fourteen characteristics were studied: plant height (PH), tiller length (TL), tiller branches (TB), days to tillering (DT), days to earing (DE), days to maturity (DM), leaf area (LA), cob height (CH), cobs per plant (C/P), cobs length (CL), kernels per row (K/R), kernels per cob (K/C), 1000-kernel weight (1000-KW) and grain yield per plant (G/P). The first four components, with eigen values >1 contributed 74.46% of the variability among the genotypes. The first PC was more related to four characters (DE, DT, DM and TL) whereas the second PC relates to two characters (C/P and 1000-KW). The third PC exhibited positive effect for seven parameters (CL, K/R, DE, DM, 1000-KW, K/C and G/P) but fourth PC was positive to seven characters (TB, CL, TL, 1000-KW, CH, K/R and K/C). Highest estimates of heritability were found in K/C (0.996) and CH (0.994). Values of genetic advance ranged between 170.93 for K/C and 3.07 for DE. Greater magnitude of broad sense heritability coupled with higher genetic advance in characters under study provided the evidence that these plant characters were under the control of additive genetic effects. Indicating that selection should lead to a fast genetic improvement of the material. Clusters with superior agronomic types identified, may be exploited for genetic potential to transfer the desirable genes to improve yield potential of the maize crop.