摘要

Concentrations of endogenous abscisic acid (ABA) and indole-3-acetic acid (IAA) in Rosa hybrida seed coat and embryos were determined at 28, 35, 42, and 49 days after pollination (DAP), a period encompassing the early-middle stages of seed development. No studies on rose have ever documented simultaneous change in ABA and IAA during these developmental phases in both seed coat and embryo. Plant growth regulators were extracted and then quantified by using high performance liquid chromatography based on solid phase extraction purification. In both the seed coat and embryo, ABA content decreased from 28 DAP (4.39 and 1.36 pmol mg(-1), respectively) and onward. Endogenous IAA in seed coat followed the same trend. In contrast, IAA in embryo began to increase at 28 DAP (2.06 pmol mg(-1)), peaked at 42 DAP (5.06 pmol mg(-1)), and then declined dramatically at 49 DAP (1.17 pmol mg(-1)). In embryo, the IAA/ABA ratio was always[1.0 and showed a tendency to increase from 28 DAP to the maximum significant rate at 42 DAP (9.20). The ABA decrease associated with increased IAA levels in embryo could be a result of crosstalk between these two phytohormones. Such a change in the IAA/ABA ratio may signal the end of endodormancy caused by ABA at the pre-cotyledonary stage and the start of increased embryo cell division during the cotyledonary stage, which also results in increased hip weight.

  • 出版日期2015-1