Title: Evaluation of quality protein maize inbred lines for resistance to maize weevil Sitophilus zeamais (Coleoptera: curculionidae) and other important agronomic traits

Abstract:

Maize is the most important crop in Ethiopia since it is a staple food crop which is widely grown by most smallholder farmers. The necessity to increase maize production cannot be over emphasized; in Ethiopia it ranks first in terms of production, productivity, number of producers and next to teff in area coverage. Subsistence maize farming accounts for more than 95% of the total maize area and production, with 75% of all maize produced being consumed by the farming household. Despite its high productivity, maize grain is a poor source of balanced protein for human consumption. QPM is a variety of maize with elevated levels of the amino acids tryptophan and lysine, which translates to a nutritionally-beneficial protein quality of double typical maize. This fact allows QPM maize to have an impact on the nutrition of families subsisting on diets consisting mainly of maize. Maize weevil is the cause of major storage loss and significantly affects household food security of the small-holder sector in Ethiopia. It can cause great losses to the grains, quantitatively and qualitatively. In Ethiopia grain loss between 20 and 30 % is common. Under severe infestations and inadequate control measures, maize weevil can cause up to 100% loss of stored grain after 6–8 months of storage. Although synthetic pesticides can control it, majority of communal farmers are resource-poor and have no means and proper skills to acquire and handle them. Moreover, pesticides are expensive and pose health problems to consumers due to their toxicity. Host plant resistance is user friendly and ecologically sound alternative as the technology is embedded in the seed. This study was undertaken to evaluate resistance in 28 quality protein maize (QPM) inbred lines against Sitophilus zeamais infestation and their important agronomic attributes, and consequently their value for use in breeding programs to develop resistant QPM hybrids. Susceptibility index (SI) was used to categorize lines in to different susceptibility group. Out of the 28 inbred lines tested, one inbred line (CML-142) was resistant, three (CML-144/144-7-b (F2)-4-2-1-1-1-1-1, POOL 15QPFS-693-B-2-B-#-B-B-B-# and CML-149) were moderately resistant and the remaining 24 inbred lines were categorized as susceptible to highly susceptible. Importantly, those inbred lines that are resistant and moderately resistant had better yield potentials as compared to the susceptible ones. These resistant and moderately resistant inbred lines showed considerable reduction in grain damage and losses for S. zeamais, suggesting that they contained genes that confer resistance to the pest. Correlations between kernel size, breadth and texture with some important susceptibility parameters were found to be significant, indicating possible influence of these factors together with others in determining the susceptibility of the inbred lines to S. zeamais. Identification of QPM lines resistant to S. zeamais in the present study offers an opportunity for developing QPM hybrid with enhanced resistance to S. zeamais.

Biography:

Girma Demissie is an agricultural entomologist by profession and working for Ethiopian Institute of Agricultural Research, Holetta Agricultural Research Center. He received his BSc and MSc from Haramaya University, and received his PhD from Maharana Pratap University of Agriculture and Technology, India. Since 2002, he has researched on maize entomology at Bako. He was in charge of the maize entomology research projects conducted at national level from 2002-2011. From 2008 to 2011 he was served as country coordinator of CIMMYT funded “Insect Resistant Maize for Africa” project. From 2016 to May 2018 he was served as coordinator of ICIPE funded Integrated Termite Management project. Since 2017 he has also been serving as coordinator of FAO and PRC funded Fall Armyworm research projects. In addition to his professional expertise he was served as Director of Bako National Maize Research Center from Feb. 2015 to Feb. 2018. He has wide ranging experience in administering, leading and coordinating several research projects. Besides he has good skills in establishing strong partnership with various national and international stakeholders in obtaining grants, collaborative research work and capacity building. Dr. Girma has been doing substantial research on maize protection and authored or co-authored several proceedings and over 18 publications in peer reviewed referred journals.