title: Drought susceptibility of modern rice varieties: an effect of linkage of drought tolerance with undesirable traits.
abstract: Green Revolution (GR) rice varieties are high yielding but typically drought sensitive. This is partly due to the tight linkage between the loci governing plant height and drought tolerance. This linkage is illustrated here through characterization of qDTY1.1, a QTL for grain yield under drought that co-segregates with the GR gene sd1 for semi-dwarf plant height. We report that the loss of the qDTY1.1 allele during the GR was due to its tight linkage in repulsion with the sd1 allele. Other drought-yield QTLs (qDTY) also showed tight linkage with traits rejected in GR varieties. Genetic diversity analysis for 11 different qDTY regions grouped GR varieties separately from traditional drought-tolerant varieties, and showed lower frequency of drought tolerance alleles. The increased understanding and breaking of the linkage between drought tolerance and undesirable traits has led to the development of high-yielding drought-tolerant dwarf lines with positive qDTY alleles and provides new hope for extending the benefits of the GR to drought-prone rice-growing regions.
authors.affiliation: Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines.
authors.forename: Prashant
authors.initials: P
authors.lastname: Vikram
authors.affiliation: Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines.
authors.forename: B P Mallikarjuna
authors.initials: BP
authors.lastname: Swamy
authors.affiliation: Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines.
authors.forename: Shalabh
authors.initials: S
authors.lastname: Dixit
authors.affiliation: National Research Center for Plant Biology, Indian Agricultural Research Institute, New Delhi, India 110012.
authors.forename: Renu
authors.initials: R
authors.lastname: Singh
authors.affiliation: National Research Center for Plant Biology, Indian Agricultural Research Institute, New Delhi, India 110012.
authors.forename: Bikram P
authors.initials: BP
authors.lastname: Singh
authors.affiliation: Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines.
authors.forename: Berta
authors.initials: B
authors.lastname: Miro
authors.affiliation: Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines.
authors.forename: Ajay
authors.initials: A
authors.lastname: Kohli
authors.affiliation: Crop and Environmental Sciences Division, International Rice Research Institute, Los Baños, Philippines.
authors.forename: Amelia
authors.initials: A
authors.lastname: Henry
authors.affiliation: National Research Center for Plant Biology, Indian Agricultural Research Institute, New Delhi, India 110012.
authors.forename: N K
authors.initials: NK
authors.lastname: Singh
authors.affiliation: Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines.
authors.forename: Arvind
authors.initials: A
authors.lastname: Kumar
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics*; D000483:Alleles; D056905:Chromosome Breakpoints; D002874:Chromosome Mapping; D016000:Cluster Analysis; D055864:Droughts; D005787:Gene Frequency; D008040:Genetic Linkage; D018745:Genome, Plant; D005838:Genotype; D006239:Haplotypes; D008126:Lod Score; D012275:Oryza / Q000235:genetics* / Q000378:metabolism*; D010641:Phenotype; D040641:Quantitative Trait Loci; D019655:Quantitative Trait, Heritable; D011995:Recombination, Genetic