Seed Science Research

Research Papers

Seed development, the accumulation of abscisic acid and desiccation tolerance in the aquatic grasses Porteresia coarctata (Roxb.) Tateoka and Oryza sativa L.

C. D. Aldridgea1 and R. J. Proberta1 c1

a1 Jodrell Laboratory, Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK

Abstract

Seeds of Oryza sativa L. (desiccation tolerant, orthodox) completed each of five distinct stages of development approximately 7 days earlier than seeds of Porteresia coarctata (Roxb.) Tateoka (desiccation intolerant, recalcitrant), despite the fact that O. sativa plants matured under cooler conditions. Isolated embryos of O. sativa were more sensitive to rapid desiccation at 6 days post anthesis (DPA) compared with naked caryopses. More than 90% of the latter were desiccation tolerant at 8 DPA and at all stages tested the germination capacity and/or rate of germination was greater following drying. In contrast, drying resulted in a complete loss of viability in seeds of P. coarctata at all stages tested. In both species, abscisic acid (ABA) began to accumulate in embryos mid-way through development. At the respective peaks, the concentration of ABA in P. coarctata was twice that recorded in O. sativa confirming that ABA levels per se do not determine desiccation tolerance in seeds. The possibility that desiccation tolerance is linked to sensitivity to ABA is discussed.

(Received October 29 1992)

(Accepted February 04 1993)

Keywords

  • ABA;
  • desiccation tolerance;
  • Oryza sativa;
  • Porteresia coarctata;
  • seed development

Correspondence:

c1 Correspondence

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