Mapping resistance to spot blotch in a CIMMYT synthetic-derived bread wheat

Spot blotch, caused by Cochliobolus sativus, is an important foliar disease of wheat in warmer wheat-growing regions leading to significant reductions in grain yield and quality. Although inoculum levels can be reduced by planting disease-free seed, treatment of plants with fungicides and crop rotation, genetic resistance is likely to be a robust, economical and environmentally friendly tool in the control of spot blotch. The spot blotch resistant synthetic derivative ‘SYN1’ was developed from a cross between two resistance sources, Mayoor and the primary synthetic bread wheat Tksn1081/Ae. squarrosa (222) that are likely to form an important component of resistance in many elite CIMMYT bread wheats. In order to map the loci underlying the resistance of ‘SYN1’, a doubled-haploid population produced from a cross between ‘SYN1’ and the susceptible CIMMYT-derived variety Ocoroni-86 was evaluated in artificially inoculated field nurseries in the 2010–2011 and 2011–2012 crop seasons at CIMMYT’s research station in Agua Fría, Mexico. Disease assessment was performed on three or four occasions and subsequently area under disease progress curve (AUDPC) calculated. Genotyping was with genotyping by sequencing and simple sequence repeat markers. Using inclusive composite interval mapping, three genomic regions were found to have a significant effect on spot blotch AUDPC in each of the 2 years of trials with phenotypic variation explained by QSb.cim-1B of 8.5 %, 17.6 % by QSb.cim-3B and 12.3 % by QSb.cim-5A. The quantitative trait loci (QTL) mapping results showed that the favorable alleles of QSb.cim-1B, QSb.cim-3B and QSb.cim-5A were derived from the synthetic-derived bread wheat SYN1. Genotypes of the parents of SYN1 indicated that the favorable alleles at these three QTLs were all inherited from Mayoor.

[1]  A. Siddique,et al.  Associations of environments in south asia based on spot blotch disease of wheat caused by Cochliobolus sativus , 2007 .

[2]  Shuangcheng Li,et al.  Effects of missing marker and segregation distortion on QTL mapping in F2 populations , 2010, Theoretical and Applied Genetics.

[3]  Int. Cimmyt.  Laboratory protocols: CIMMYT Applied molecular genetics laboratory , 2005 .

[4]  R. Chand,et al.  Relationship of plant height and days to maturity with resistance to spot blotch in wheat , 2004, Euphytica.

[5]  E. Saari.  Leaf blight diseases and associated soilborne fungal pathogens of wheat in South and Southeast Asia , 1998 .

[6]  M. Ganal,et al.  Microsatellite and SNP Markers in Wheat Breeding , 2007 .

[7]  E. Duveiller,et al.  Heritability estimates of spot blotch resistance and its association with other traits in spring wheat crosses , 2006, Euphytica.

[8]  M. Lorieux,et al.  Maximum-likelihood models for mapping genetic markers showing segregation distortion. 1. Backcross populations , 2004, Theoretical and Applied Genetics.

[9]  U. Rosyara,et al.  Photochemical efficiency and SPAD value as indirect selection criteria for combined selection of spot blotch and terminal heat stress in wheat , 2010 .

[10]  J. M. Prescott,et al.  The septoria diseases of wheat : concepts and methods of disease management , 1987 .

[11]  R. Chand,et al.  Mapping of resistance to spot blotch disease caused by Bipolaris sorokiniana in spring wheat , 2009, Theoretical and Applied Genetics.

[12]  M. Lillemo,et al.  QTL for spot blotch resistance in bread wheat line Saar co-locate to the biotrophic disease resistance loci Lr34 and Lr46 , 2012, Theoretical and Applied Genetics.

[13]  R. Chand,et al.  Quantitative trait loci for resistance to spot blotch caused by Bipolarissorokiniana in wheat (T.aestivum L.) lines ‘Ning 8201’ and ‘Chirya 3’ , 2010, Molecular Breeding.

[14]  R. Varshney,et al.  Genomics-Assisted Crop Improvement , 2007 .

[15]  Roeland E. Voorrips,et al.  Software for the calculation of genetic linkage maps , 2001 .

[16]  E. Duveiller,et al.  Helminthosporium blights of wheat: spot blotch and tan spot. Proceedings of an International Workshop held at CIMMYT, El Batan, Mexico, 9-14 February 1997. , 1998 .

[17]  J. M. Prescott,et al.  A scale for appraising the foliar intensity of wheat diseases , 1975 .

[18]  A. Mujeeb-Kazi,et al.  Registration of five synthetic hexaploid wheat and seven bread wheat lines resistant to wheat spot blotch , 2001 .

[19]  A. Mujeeb-Kazi,et al.  Yield loss to spot blotch in spring bread wheat in warm nontraditional wheat production areas. , 1995 .

[20]  M. Jeger,et al.  Analysis of disease progress as a basis for evaluating disease management practices. , 2004, Annual review of phytopathology.

[21]  Robert J. Elshire,et al.  A Robust, Simple Genotyping-by-Sequencing (GBS) Approach for High Diversity Species , 2011, PloS one.

[22]  Shizhong Xu.  Quantitative Trait Locus Mapping Can Benefit From Segregation Distortion , 2008, Genetics.

[23]  X. Perrier,et al.  Maximum-likelihood models for mapping genetic markers showing segregation distortion. 2. F2 populations , 2004, Theoretical and Applied Genetics.

[24]  J. Seabrook,et al.  Linkage analysis of anther-derived monoploids showing distorted segregation of molecular markers , 2000, Theoretical and Applied Genetics.

[25]  R. Chand,et al.  Leaf Tip Necrosis , 2004 .

[26]  P. Hedrick,et al.  Linkage of viability genes to marker loci in selfing organisms , 1990, Heredity.

[27]  A. Joshi,et al.  Inheritance And Allelic Relationship Of Resistance Genes To Spot Blotch Of Wheat Caused By Bipolaris Sorokiniana , 2007 .

[28]  S. Gurung,et al.  Assessing genetic resistance to spot blotch, Stagonospora nodorum blotch and tan spot in wheat from Nepal , 2011, European Journal of Plant Pathology.

[29]  L. Yan,et al.  Allelic variation at the VRN-1 promoter region in polyploid wheat , 2004, Theoretical and Applied Genetics.

[30]  R. Varshney,et al.  Genomics applications in crops , 2007 .

[31]  R. Chand,et al.  Variation and inheritance of leaf angle, and its association with spot blotch (Bipolaris sorokiniana) severity in wheat (Triticum aestivum) , 2002, Euphytica.

[32]  K. Edwards,et al.  A high-density microsatellite consensus map for bread wheat (Triticum aestivum L.) , 2004, Theoretical and Applied Genetics.

[33]  U. Rosyara,et al.  Field resistance to spot blotch is not associated with undesirable physio-morphological traits in three spring wheat populations , 2009 .

[34]  M. Goddard,et al.  Prediction of total genetic value using genome-wide dense marker maps. , 2001, Genetics.

[35]  E. Duveiller,et al.  Advancement toward new spot blotch resistant wheats in South Asia , 2007 .

[36]  R. Parsad,et al.  Combining superior agronomic performance and terminal heat tolerance with resistance to spot blotch (Bipolaris sorokiniana) of wheat in the warm humid Gangetic Plains of South Asia , 2007 .

[37]  R. Park,et al.  Wheat Rusts: An Atlas of Resistance Genes , 1995 .

[38]  W. M. Ross,et al.  Exact Confidence Intervals for Heritability on a Progeny Mean Basis1 , 1983 .

[39]  E. Duveiller,et al.  Spot Blotch Continues to Cause Substantial Grain Yield Reductions under Resource-limited Farming Conditions , 2006 .

[40]  D. Bhandari,et al.  Major Gene Controls of Field Resistance to Spot Blotch in Wheat Genotypes 'Milan/Shanghai #7' and 'Chirya.3'. , 2007, Plant disease.

[41]  E. Duveiller.  Controlling Foliar Blights of Wheat in the Rice-Wheat Systems of Asia. , 2004, Plant disease.

[42]  W. Spielmeyer,et al.  Identification and Validation of Markers Linked to Broad‐Spectrum Stem Rust Resistance Gene Sr2 in Wheat (Triticum aestivum L.) , 2003 .