OMPRAKASH*, KAILASH CHANDRA, S. K. BAIRWA, PRERNA DOGRA AND H. S. JATAV
Sri Karan Narendra Agriculture University, Jobner-303329 (Jaipur)
*(e-mail : omprakash.pbg@sknau.ac.in)
(Received : 9 May 2021; Accepted : 25 June 2021)
SUMMARY
Maize (Zea Mays) plant is affected by number of foliar diseases among of them, Southern Corn Leaf Blight (SCLB) or Maydis Leaf Blight (MLB) incited by the Helminthosporium maydis anamorph: Bipolaris maydis, telomorph: Cochliobolus heterostrophus is one of the most devastating disease of maize in India as well as in the world. Three different races namely race O, T and C of helminthosporium are found responsible for causing this disease. Bipolaris has the potential to reduce the yield significantly up to 70% depending upon the susceptibility, race of pathogen and environmental conditions.Genetic architecture of maize possess the diverse source of resistance against Helminthosporium which are qualitative, quantitative and multiple disease resistance types in nature but often represents quantitative nature of resistance. A single gene, rhm, imparts a qualitative-like resistance against race O which inherits recessively with additive gene action predominantly. It is implied at the seedling stage but quantitative resistance is needed after silking stage. An additional two resistance genes have been identified in the inbred NC250 that are not allelic to rhm and this resistance is maintained in mature plants. Plenty of attempts have been made to identify the resistance source and to dissect the quantitative trait loci (QTL) responsible for resistance or multiple disease resistance to SLB across different maize populations. QTLs responsible for multiple disease resistance were identified of elucidated with the help of meta analysis of available studies.
Key words:Maize, Helminthosporium maydis, genetic architecture, QTL mapping, rhm allele, qualitative and quantitative resistance gene and meta analysis