Blue Pattern Flower in Common Bean Expressed by Interaction of Prpi-2 with a New Gene tbp

Authors: BASSETT, MARK - UNIV OF FLORIDA; Miklas, Phillip - Phil

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/11/2009
Publication Date: 7/1/2009
Citation: Bassett, M.J., Miklas, P.N. 2009. Blue Pattern Flower in Common Bean Expressed by Interaction of Prpi-2 with a New Gene tbp. Journal of the American Society for Horticultural Science. 134: 423-427.

Interpretive Summary: Genes which condition plant pigmentation in dry bean control flower color, seed color, and intensification of color in leaves and stems. These pigments can be associated with disease resistance and compounds that contribute to human health such as antioxidants. A new gene was discovered tbp which conditions blue petals and blue veins in the bean flower. The effect of this gene on human health is unknown. The association of this gene with other genes conditioning plant pigmentation intensity and patterning was elucidated. This research furthers our knowledge of the genetics of plant pigmentation in dry bean which may lead to development of beans with better nutritional attributes.

Technical Abstract: The inheritance of blue pattern flower (BPF) expression was investigated in common bean (Phaseolus vulgaris L.). The BPF trait was derived from accession line G07262, and the flowers express blue banner petal and white wings with blue veins. Crosses between a BPF stock and three other parents - t pmic long micropyle stripe BC3 5-593, t z Fib arcus BC4 5-593, and t Z bipana Fib marginata BC3 5-593 - all segregated in F2 for either BPF or white flowers in a 9:7 ratio, respectively. Progeny tests in F3 from two of the crosses supported the hypothesis that two complementary dominant genes control BPF expression and permitted a genetic linkage estimate of cM = 32.4 ' 7.91 map units between pmic and one of the two genes for BPF. A cross between t z fib virgarcus BC3 5-593 and T Prpi-2 V BC2 5-593 demonstrated that t Prpi-2 did not express BPF. Two crosses - T Prpi-2 V BC2 5-593 x t pmic BC3 5-593 and 5-593 x a BPF stock - both segregated in F2 for plants expressing BPF in a 3/16 frequency. The combined experimental data demonstrated that a new gene tbp (bp = blue pattern) interacts with Prpi-2 to express BPF and that P is linked with Prpi-2 by 32 map units. The dominance order at the T locus is T > tbp > t. The pedigree source of the tbp gene and the heterogeneity of PI 632736 (t pmic long micropyle stripe BC3 5-593) are discussed.