Developmental Differences Between Germinating After-ripened and Dormant Excised Avena fatua L. Embryos

Author： Myers S.P. Foley M.E. Nichols M.B.

ISSN： 0305-7364

Source： Annals of Botany, Vol.79, Iss.1, 1997-01, pp. : 19-23

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Based on physiological and molecular differences associated with the germination of after-ripened and dormant caryopses and excised embryos, it has been hypothesized that various methods of after-ripening are the only treatments that facilitate the transition of dormant wild oat embryos to a non-dormant state. To further investigate this hypothesis, analytical methods were used to evaluate physical and temporal changes associated with germination and subsequent growth of after-ripened and dormant excised embryos (AR-embryos and D-embryos, respectively) induced to germinate with fructose (Fru) and/or gibberellic acid (GA). While chemical treatments of Fru, GA, and Fru+GA have little effect on the germination and short-term growth of AR-embryos, they do induce germination of D-embryos. Growth following germination of D-embryos varied according to treatment with the combination of Fru+GA inducing the greatest growth over the duration of the experiment. Even considering differences in the time to complete germination, growth of D-embryos was not comparable with that of AR-embryos. This provides physical evidence that chemical treatments induce germination without fulfilling the requirements for normal after-ripening-enhanced germination/growth, and indicates that fructose and/or gibberellic acid do not remove the dormancy-block or rate limiting step in the same manner as after-ripening.