title: Dormancy in somatic embryos and seeds ofVitis: changes in endogenous abscisic acid during embryogeny and germination.
abstract: Abscisic acid (ABA) in extracts of somatic embryos and seeds of Gloryvine (Vitis vinifera L.xV. rupestris Scheele) was measured by gas chromatography-mass spectrometry-selected ion monitoring using deuterated ABA, (±)-[C-3Me-(2)H3]ABA, ([(2)H3]ABA) as internal standard. The ABA content increased rapidly during embryogeny (0.035 ng/embryo at the globular stage to 0.22 ng/embryo at the mature stage). The level of ABA in the tissues of somatic embryos, expressed in ng/mg dry weight, decreased from the globular stage (0.76 ng/mg) to the mature stage (0.25 ng/mg). Chilling (4° C) induced normal germination of seeds and mature somatic embryos and precocious germination of globular, heart-shaped and torpedoshaped somatic embryos. In all cases chilling led to a marked reduction in endogenous ABA. Exogenous (±)-ABA inhibited the germination of chilled somatic embryos.
authors.affiliation: Department of Agronomy and Horticultural Sciences, University of Sydney, 2006, N S.W., Australia.
authors.forename: K
authors.initials: K
authors.lastname: Rajasekaran
authors.forename: J
authors.initials: J
authors.lastname: Vine
authors.forename: M G
authors.initials: MG
authors.lastname: Mullins