About Us | Help Videos | Contact Us | Subscriptions

Crop Science Abstract - CROP BREEDING & GENETICS

Genetic Improvement of Sorghum as a Biofuel Feedstock: I. QTL for Stem Sugar and Grain Nonstructural Carbohydrates


This article in CS

  1. Vol. 48 No. 6, p. 2165-2179
    Received: Jan 8, 2008

    * Corresponding author(s): sk20@cornell.edu
Request Permissions

  1. Seth C. Murraya,
  2. Arun Sharmab,
  3. William L. Rooneyc,
  4. Patricia E. Kleinb,
  5. John E. Mulletb,
  6. Sharon E. Mitchella and
  7. Stephen Kresovich *a
  1. a Institute for Genomic Diversity and Dep. of Plant Breeding and Genetics, Cornell Univ., Ithaca, NY 14853
    b Institute for Plant Genomics and Biotechnology, Texas A&M Univ., College Station, TX 77843
    c Dep. of Soil and Crop Sciences, Texas A&M Univ., College Station, TX 77843


Genetic improvement of sorghum [Sorghum bicolor (L.) Moench] has traditionally focused on a single nonstructural carbohydrate, either grain starch or stem sugar. Sorghum starch and sugar may both be used as feedstocks for biofuel production. To investigate genetic tradeoffs between grain and stem sugar, a population derived from sweet sorghum cultivar Rio and grain sorghum ‘BTx623’ was evaluated for 27 traits related to grain and stem sugar yield and composition. Across three environments, a total of 129 quantitative trait loci (QTL) were identified. Tradeoffs identified between grain and stem sugar yield QTL colocalized with height and flowering time QTL. Most importantly, QTL were identified that increased yield and altered the composition of stem sugar and grain without pleiotropic effects. For example, a QTL on chromosome 3 that explained 25% of the genetic variance for stem sugar concentration did not colocalize with any grain QTL. These results suggest that total nonstructural carbohydrate yield could be increased by selecting for major QTL from both grain and sweet sorghum types. We conclude that altering grain and stem sugar genetic potential for yield traits should lead to greater feedstock improvement than altering composition traits.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2008. Crop Science Society of AmericaCrop Science Society of America