Olawuyi  Olawuyi O.J.¹ , Bello O.B.² , Abioye A.O.¹

1 Department of Botany, University of Ibadan, Ibadan, Nigeria
2 Department of Biological Sciences, Fountain University, Osogbo, Nigeria
Author    Correspondence author
Molecular Plant Breeding, 2016, Vol. 7, No. 1   doi: 10.5376/mpb.2016.07.0001
Received: 15 Sep., 2015    Accepted: 26 Oct., 2015    Published: 01 Jan., 2016

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Olawuyi O.J., Bello O.B., and Abioye A.O., 2016, Mutagenic effects of ultraviolet radiation on growth and agronomic characters in maize cultivars, Molecular Plant Breeding, 7(01): 1-10 (doi: 10.5376/mpb.2016.07.0001)

Ultraviolet light has strong genotoxic effect to induce mutations for developing high genetic variability in yields, early maturity and other characters in crops. The study investigated the mutagenic effects of ultraviolet (UV) radiation on growth, yield, agronomic and mutation tolerance of six maize cultivars. Maize seeds were exposed to UV radiation, and planted in 7 kg soils in the polythene bags, while unexposed served as control. The effect of UV radiation on the first order interaction between weeks after planting (WAP) and treatments was only significant (p<0.05) on plant height. The interaction between treatments and cultivars also produced significant effect on all growth characters except leaf width. There was reduction in growth characters at 8 and 10 WAP for number of leaves, and at 10 WAP for plant height, leaf length and leaf width. All the growth and agronomic characters at 100 minutes of UV radiation were significantly higher (p<0.05) than other exposure periods. The exposure period of stover weight at 100 minutes were significantly higher (p<0.05) than other periods, while grain weight and total number of grains at 20 minutes exposure significantly higher, but not different from control. The height of ART/OB/98/SW1 was significantly higher than other cultivars. ART/OB/98/SW6, 10–1–Y and ART/OB/98/SW1 were the most tolerant cultivars to the mutagenic effect of the UV radiation. OBA 98 had the most significant genotypic effect for yield characters, while the genotypic influence on plant stand, plant aspect, mutation tolerance and plant harvest was highly significant. The grain weight per stand for OBA 98 and ART/OB/98/SW1 were significantly (p<0.05) higher than other cultivars, while the total number of grains for ART/0B/98/SW1 and ART/OB/98/SW6 were significantly higher and different from other cultivars. ART/OB/98/SW6 had the least values of days to plant emergence, mutation tolerance and other agronomic characters compared to other cultivars. The plant height was positive and strongly correlated (p<0.01) with leaf length, leaf width and number of leaves with r = 0.95, 0.96, 0.89 respectively. Only the periods of exposure of the UV radiation was positive and strongly correlated with leaf width (r = 0.79). The association between the stover weight and periods of exposure was positive and insignificant, while the correlation between total numbers of grains and grain weight per stand was positive and strong (r = 0.99). Therefore, quality protein maize cultivars should be improved by introgression of favourable genes of drought tolerance, grain yield and related characters through induced mutation of UV radiation.

Maize tolerance; Mutation; Ultraviolet radiation; Yield