title: Gibberellins and heterosis in maize : I. Endogenous gibberellin-like substances.
abstract: Under controlled environment and/or field conditions, vegetative growth (height, internode length, leaf area, shoot dry weight, grain yield) was greater in an F(1) maize hybrid than in either parental inbred. Endogenous gibberellin (GA)-like substances in apical meristem cylinders were also higher in the hybrid than in either inbred, both on a per plant and per gram dry weight basis. There were no apparent qualitative differences in GA-like substances, however. Levels of GA-like substances in all genotypes were highest prior to tassel initiation. Chromatographic comparisons of the GA-like substances and authentic standards of GA native to maize on gradient-eluted SiO(2) partition and reverse-phase C(18) high-pressure liquid chromatography columns are described. No consistent differences in abscisic acid levels of the three genotypes were observed. This correlation of heterosis for endogenous GA-like substances with heterosis for growth suggests that amounts of endogenous GA may be related to hybrid vigor in maize.
authors: Department of Biology, University of Calgary, Calgary Alberta T2N 1N4 Canada.
authors: S B
authors: SB
authors: Rood
authors: R P
authors: RP
authors: Pharis
authors: M
authors: M
authors: Koshioka
authors: D J
authors: DJ
authors: Major