Phenotypic and molecular variability of maize (<i>Zea mays</i> L.) Induced with X-ray

Abstract

Ten genotypes of maize collected from National Center for Genetic Resources and Biotechnology (NACGRAB) were induced with X-ray for morphological and molecular assessment. The experimental design was complete randomized design with four replicates. Morphological and molecular statistical analyses of treated genotypes were conducted using SAS and Power Maker Packages, respectively while dendrogram was generated using Jaccards similarity coefficient using Unweighted Paired Group Method and Arithmetic Averages (UPGMA). The study revealed significant difference which is an indication of genetic variation of characters in treated maize. Genotype DTSR-Wco performed best in plant height (62.35 cm), leaf length (62.35 cm), number of leaves (3.15), leaf width (7.55 cm) and dry leaf biomass (0.24 g). X-ray at 90 Kv/mass, 95 Kv/mass and 100 Kv/mass decreased plant heights to 54.25cm, 53.87cm and 54.10cm respectively compared to Control. Heritability estimate was greater than 70% for all characters evaluated. Genotype TZM 1551 at 0 Kv/mass yielded the highest concentration of DNA at 2841.60 ng/ul and the highest genomic DNA concentration was obtained at 95 Kv/mass for TZM 132 with 1.91%. Primer BMC 1755 was most polymorphic with 58.77% in treated maize genotypes. The plant height was strongly correlated with leaf length (r=0.9), leaf width (r=0.76) and number of leaves (r=0.77). Principal component analysis showed close relationship between plant height (-0.03) and leaf length (0.05) compared with leaf width (-0.67) and number of leaves (0.69). Dry shoot biomass (0.05) was closely related to dry root biomass (-0.03) and dry leaf biomass (-0.04).