Theoretical and Applied Genetics

, Volume 102, Issue 2, pp 307–319

Identification of genomic regions that affect grain-mould incidence and other traits of agronomic importance in sorghum

  • R. R. Klein
  • R. Rodriguez-Herrera
  • J. A. Schlueter
  • P. E. Klein
  • Z. H. Yu
  • W. L. Rooney
Original Paper

DOI: 10.1007/s001220051647

Cite this article as:
Klein, R., Rodriguez-Herrera, R., Schlueter, J. et al. Theor Appl Genet (2001) 102: 307. doi:10.1007/s001220051647

Abstract 

Grain-mould is a major problem in grain sorghum utilization as mouldy grain has a reduced quality due to the deterioration of the endosperm and reduced embryo viability. Here, our objective was to use genome mapping to improve knowledge of genetic variation and co-variation for grain-mould incidence and other inter-related agronomic traits. Grain-mould incidence, kernel-milling hardness, grain density, plant height, panicle peduncle length, foliar-disease incidence, and plant color were measured on 125 F5 genotypes derived from a cross of Sureño and RTx430. Quantitative trait loci were detected by means of 130 mapped markers (44 microsatellites, 85 AFLPs, one morphological-trait locus) distributed among ten linkage groups covering 970 cM. One to five QTLs affected each trait, with the exception of grain density for which no QTLs were detected. Grain-mould incidence was affected by five QTLs each accounting for between 10 and 23% of the phenotypic variance. The effects and relative positions of QTLs for grain-mould incidence were in accordance with the QTL distribution of several inter-related agronomic traits (e.g., plant height, peduncle length) and with the correlation between these phenotypic traits and grain-mould incidence. The detection of QTLs for grain-mould incidence was dependent on the environment, which is consistent with heritibility estimates that show strong environmental and genotype × environment effects. Several genomic regions affected multiple traits including one region that affected grain-mould incidence, plant height, panicle peduncle length, and grain-milling hardness, and a second region that influenced grain-mould (in four environments) and plant height. One genomic region, which harbors loci for plant color, influenced the severity of foliar disease symptoms and the incidence of grain-mould in one environment. Collectively QTLs detected in the present population explained between 10% and 55% of the phenotypic variance observed for a given trait.

Keywords SorghumRecombinant inbred lineMolecular markersQTLs

Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • R. R. Klein
    • 1
  • R. Rodriguez-Herrera
    • 2
  • J. A. Schlueter
    • 2
  • P. E. Klein
    • 3
  • Z. H. Yu
    • 1
  • W. L. Rooney
    • 2
  1. 1.USDA-ARS, Southern Plains Agricultural Research Center, College Station TX 77845, USA e-mail: bob@algodon.tamu.edu Tel.: +1 (979) 777 4470, Fax: +1 (979) 260 9333US
  2. 2.Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USAUS
  3. 3.Department of Biochemistry-Biophysics and Crop Biotechnology Center, Texas A&M University, College Station, TX 77843, USAUS