ARS | Publication request: Characterization of Gibberellin Requirements for Various Diploid and Tetraploid Gibberellin Deficient Mutants

Submitted to: Potato Association Of America Proceedings
Publication Acceptance Date: April 15, 2004
Publication Date: August 10, 2004
Citation: Vega, S.E., Bamberg, J.B., Palta, J.P. 2004. Characterization Of Gibberellin Requirements For Various Diploid And Tetraploid Gibberellin Deficient Mutants. Potato Association Of America. Paper No. G70.

Technical Abstract: GA-deficient mutants lack the ability to produce adequate amounts of gibberellin for normal growth, resulting in a rosette type growth and very short internodes. GA-deficient mutants from Solanum species were isolated and studied. Diploid mutants were obtained by crossing haploid S. andigena with S. chacoense, the progeny was then bulked and intermated to produce F2 individuals. Tetraploid mutants were obtained by crossing S. andigena with S. sucrense and with S. gourlayi, the two resulting progenies were then bulked and intermated. Diploid and tetraploid GA-deficient mutants were grown on MS media containing different levels of gibberellin (GA3). Plant height and internode length were utilized as a way to assess the effects of the different GA concentrations on plant growth. Concentration of 0.1 'M GA3 and lower failed to restore normal growth in both diploid and tetraploid genotypes. Normal growth was restored in most of the GA-deficient mutants when concentrations between 0.7 and 1.0 'M GA3 were used. Diploid genotypes showed shorter internodes at the top of the plant as it got further away from the media. However, this was not seen in the tetraploid hybrids. These observations suggest: a) there are perhaps minor modifier genes for dwarfness in these mutants; b) researchers using dwarfs for bioassay or other research purposes need to select the best standards and clonally replicate them.