2,6-Diisopropylphenoxyacetic acid (DIPA) as well as gibberellins (GAs) was found to promote shoot growth and flowering in a perennial paddy weed Saggitaria pygmaea. In this paper, plant growth regulators, which have phytohormonal activities including 2,4-D, S-abscisic acid (S-ABA), ethephon and benzyladenine (BA) or inhibitors of GA biosynthesis (paclobutrazol and prohexadione), were tested alone or in combination with DIPA to examine their effects on shoot growth and flowering in S. pygmaea. 2,4-D inhibited the shoot growth of S. pygmaea, increased the number of leaves, and reduced shoot elongation induced by DIPA. Ethephon increased shoot growth of the weed. On flowering of S. pygmaea, 2,4-D reduced the promotive effect induced by DIPA. In contrast, ethephon slightly enhanced the promotive effect. These results indicate that in addition to GAs, auxin and ethylene play roles in the shoot growth and flowering of S. pygmaea.
- 2,6-Diisopropylphenoxyacetic acid (DIPA)
- Plant growth regulators
- Sagittaria pygmaea
- Shoot growth
ASJC Scopus subject areas
- Insect Science
- Health, Toxicology and Mutagenesis