Kiyotoshi Takeno

Diversity in seed germination behavior in relation to heterocarpy in Salsola komarovii Iljin

Seed germination behavior in two types of dimorphic fruits inSalsola komarovii Iljin (Chenopodiaceae) was studied. The germination percentage was much higher in the long-winged type than in the short-winged type when the fruits were tested for germinability. If lignified perianths were removed from the fruits, seeds of both types germinated at higher percentages and the difference in the germination percentage between two types decreased. The extract of the perianths inhibited the seed germination. Abscisic acid was detected in the extract of the perianths by enzyme-linked immunosorbent assay and its level was higher in the short-winged type than in the long-winged type. Germinability in both types was lost one year after harvest when the fruits were stored at room temperature and the germination was tested with fruits. When the seeds were tested, however, the short-winged type germinated even two years after the harvest; the germinability of the short-winged type lasted one year longer than that of the long-winged type. Light irradiation was not required for the seed germination in either type regardless of presence or absence of the perianths. No clear difference between the two types was observed either in optimal temperature for the germination or in strength of the resistance to salinity.

Diversities in morphological characteristics and seed germination behavior in fruits ofSalsola komarovii Iljin

Two different types of dispersal units (called fruits in this study) were observed inSalsola komarovii Iljin. One is a fruit which has dark brown lignified tepals with long wings and a green seed and falls easily from the mother plant (long-winged type). Another has light brown lignified tepals with short wings and a yellow seed and attaches tightly to the mother plant (short-winged type). This difference of fruit type appeared independently from maturity of fruit. Seeds in the short-winged fruits were in dormancy for a longer period of time than those in the long-winged fruits. The germination rate was significantly higher in the seeds of long-winged fruits. The dormancy in seeds of the long-winged fruits was effectively terminated by reducing the temperature but the effect of chilling was very weak in seeds of the short-winged fruits. It was concluded from these observations that there exists a dimorphism in the fruits of, or a heterocarpy in,S. komarovii. The plants grown under water stress produced mostly short-winged fruits and those grown under well-watered conditions bore fruits of both types. Exogenously applied abscisic acid (ABA) tended to produce the short-winged fruits, suggesting that the heterocarpy was, at least partly, regulated by ABA.

Biological activity of antheridic acid, an antheridiogen of anemia phyllitidis

Abstract The biological activities of synthetic antheridiogen of Anemia phyllitidis , (±)-antheridic acid, and naturally derived antheridic acid with regard to induction of antheridial formation and dark spore germination in A. phyllitidis were closely similar. The activity of (±)-3- epi -antheridic acid was weaker than that of (±)-antheridic acid in inducing these phenomena. (±)-Antheridic acid was active in inducing elongation growth in the dwarf rice bioassay system, although its activity was weaker than that of GA 3 . In this bioassay system, (±)-3- epi -antheridic acid showed higher activity than did (±)-antheridic acid.

Flowering Response of an Intermediate-day Plant, Salsolakomarovii Iljin under Different Photoperiodic Conditions

Summary The photoperiodic flowering response of Salsola komarovii Iljin (Chenopodiaceae) was studied. Theplants flowered earliest under an intermediate-day photoperiodic regime of 12-h light and 12-h dark. The flowering response was strongest under these conditions when the response was observed during an early stage of development, whereas the same level of response was obtained even under short-days when observed at a later stage. The nodes on the main stem at which the first flowers were formed were lowest under photoperiodic regimes with dark periods of 12 h and longer. The flowering response was stronger under a prolonged cycle of 12-h light and 16-h dark regime than under the 12-h light and 12-h dark regime. A light-break given at the middle of a 16-h dark period completely inhibited flowering. The results indicate that S. komarovii is an intermediate-day plant and that the intermediate-day plant is a variation of a short-day plant response that has a requirement for a long light period.