Biochemical variations in some striga resistant and susceptible maize germplasm.

Abstract

Rapid human population growth, increased demand for food supplies and intensified land use has led to reduced crop rotation and hence reduction of soil fertility. The decline in soil fertility has in turn intensified the extent of Striga infestation, causing the parasite to become a threat to food production. The Striga species decimates tropical crops such as maize, sorghum, millet, rice and cowpeas. Maize is specifically attacked by Striga hermonthica. In this study, biochemical markers of Striga resistant maize such as protein profiles, amino acid profiles and total phenolic contents were examined in F4 generation. Five lines of azide mutated maize, one line of pure inbred resistant maize, one line of pure inbred susceptible maize and the control H513 were grown in a Striga-infested area. The protein analysis showed that the maize mutants had an additional low molecular weight protein. This was lacking in the control and in the susceptible cultivar that only had a high molecular weight protein present in all the cultivars. This protein band was very prominent and distinct in all the analysis carried out. The mutants and the resistant cultivar showed significantly higher concentrations (P>0.500) of phenolics in comparison to the control and the susceptible cultivar. This was shown by the high absorbance values obtained. The mutants, resistant and tolerant varieties cultivars had the amino acids Asparagine and Alanine during the early stages of growth. However the susceptible and control cultivars lacked Alanine during this stage. In the post pollination period the maize cultivars lacked Asparagine but their growth was normal. Attempts have been made to correlate variations in protein profiles, amino acids and phenolic concentrations with the resistance to Striga hermonthica or lack of Strigal attack