title: Tracing QTLs for Leaf Blast Resistance and Agronomic Performance of Finger Millet (Eleusine coracana (L.) Gaertn.) Genotypes through Association Mapping and in silico Comparative Genomics Analyses.
abstract: Finger millet is one of the small millets with high nutritive value. This crop is vulnerable to blast disease caused by Pyricularia grisea, which occurs annually during rainy and winter seasons. Leaf blast occurs at early crop stage and is highly damaging. Mapping of resistance genes and other quantitative trait loci (QTLs) for agronomic performance can be of great use for improving finger millet genotypes. Evaluation of one hundred and twenty-eight finger millet genotypes in natural field conditions revealed that leaf blast caused severe setback on agronomic performance for susceptible genotypes, most significant traits being plant height and root length. Plant height was reduced under disease severity while root length was increased. Among the genotypes, IE4795 showed superior response in terms of both disease resistance and better agronomic performance. A total of seven unambiguous QTLs were found to be associated with various agronomic traits including leaf blast resistance by association mapping analysis. The markers, UGEP101 and UGEP95, were strongly associated with blast resistance. UGEP98 was associated with tiller number and UGEP9 was associated with root length and seed yield. Cross species validation of markers revealed that 12 candidate genes were associated with 8 QTLs in the genomes of grass species such as rice, foxtail millet, maize, Brachypodium stacei, B. distachyon, Panicum hallii and switchgrass. Several candidate genes were found proximal to orthologous sequences of the identified QTLs such as 1,4-β-glucanase for leaf blast resistance, cytokinin dehydrogenase (CKX) for tiller production, calmodulin (CaM) binding protein for seed yield and pectin methylesterase inhibitor (PMEI) for root growth and development. Most of these QTLs and their putatively associated candidate genes are reported for first time in finger millet. On validation, these novel QTLs may be utilized in future for marker assisted breeding for the development of fungal resistant and high yielding varieties of finger millet.
authors.affiliation: Division of Plant Biotechnology, Entomology Research Institute, Loyola College, Chennai, India.
authors.forename: M
authors.initials: M
authors.lastname: Ramakrishnan
authors.affiliation: Division of Plant Biotechnology, Entomology Research Institute, Loyola College, Chennai, India.|Centre for Plant Sciences and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Antony Ceasar
authors.affiliation: Division of Plant Biotechnology, Entomology Research Institute, Loyola College, Chennai, India.|Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia.
authors.forename: V
authors.initials: V
authors.lastname: Duraipandiyan
authors.affiliation: Rice Breeding and Genetics Research Centre, Division of Genetics, ICAR-Indian Agricultural Research Institute, Aduthurai, India.
authors.forename: K K
authors.initials: KK
authors.lastname: Vinod
authors.affiliation: Regional Research Station, Tamil Nadu Agricultural University, Paiyur, India.
authors.forename: Krishnan
authors.initials: K
authors.lastname: Kalpana
authors.affiliation: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia.
authors.forename: N A
authors.initials: NA
authors.lastname: Al-Dhabi
authors.affiliation: Division of Plant Biotechnology, Entomology Research Institute, Loyola College, Chennai, India.|The International Scientific Partnership Program (ISPP) at King Saud University, Vice-Rectorate for Graduate studies and Research, Riyadh, Kingdom of Saudi Arabia.
authors.forename: S
authors.initials: S
authors.lastname: Ignacimuthu
mesh_terms: D003198:Computer Simulation; D000069599:Crop Production; D060467:Disease Resistance / Q000235:genetics*; D031748:Eleusine / Q000235:genetics* / Q000254:growth & development / Q000382:microbiology; D055106:Genome-Wide Association Study; D005838:Genotype; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D055685:Pyricularia grisea / Q000472:pathogenicity; D040641:Quantitative Trait Loci / Q000235:genetics*