ON THE LIGHT CONTROLLING FLOWER INITIATION OF SILENE ARMERIA

Silene armeria was cultured on a medium containing 5% sucrose,and subjected to various light conditions. 1. Plants subjected to continuous illumination of far-red radiantenergy exclusive of other spectral regions initiated flowerbuds most readily. Far-red light mixed with other spectral regionswas less effective in promoting flowering than far-red lightalone. 2. The plants subjected to short photoperiods initiated no flowerbuds irrespective of the quality of light in the light period. 3. Red light was more effective in promoting flowering thandaylight fluorescent light but was less effective than the far-redlight. (Received October 8, 1960; )     

EFFECT OF SUCROSE ON FLOWER INITIATION OF PHARBITIS NIL IN ASEPTIC CULTURE

1. Pharbitis plants were cultured on a nutrient medium containing5% sucrose or no sucrose. They were subjected to various lightconditions at temperatures of 10? or 20?.
2. All the plants culturedon the sucrose-medium at 10? initiatedflower buds independentlyof the light to which the plants wereexposed.
3. Plants culturedon the sucrose-free medium at 10? initiatedflower buds undershort photoperiods, but did not under continuousillumination.
4. Plants cultured on the sucrose-medium at 20? initiated flowerbuds in total darkness or under short photoperiods regardlessof the intensity and quality of the light, but those subjectedto continuous illumination did not.
5. Plants cultured on thesucrose-free medium at 20? initiatedflower buds under shortphotoperiods but did not initiate themunder continuous illumination.

(Received June 9, 1960; )     

Metabolism of (--)-kaurene-3H and (--)-kaurenol-3H during the photoperiodic floral induction in Pharbitis nil

(—)-Kaurene-U-³H was metabolized in seedlings of Pharbitisnil, a short-day plant, to labeled ( — )-kaurenol, ( —)-kaurenal, ( — )-kaurenoic acid, and unidentified polarsubstances, in this sequence. No significant effect of photoperiodicfloral induction upon the metabolism of ( — )-kaurene-U-³Hor ( — )-kaurenol-U-³H was observed, which suggests that( — )-kaurene metabolism is not involved in photoperiodicfloral induction ¹This work was supported in part by grants from the Ministryof Education. (Received September 24, 1970; )     

Clarification of the genetic component of hybrids between Phyllodoce caerulea and Phyllodoce aleutica (Ericaceae) in Hokkaido,northern Japan

Natural hybridization provides great opportunities to understand the interaction of genetics and ecology in determining species boundaries. We examined the genetic relationships of Phyllodoce taxa and revealed that most hybrids were fertile F₁s and an extremely small number of backcross and no F₂ plants were established in natural conditions. Because this trend was irrespective of regions, we conclude that negative endogenous selection may act after the germination of F₁ seeds and prevent the establishment of later‐generation hybrids. Based on these results, we discuss the ecological and evolutionary significance of natural hybridization in Phyllodoce taxa.     

Detection of Mouse Tyrosinase With a Monoclonal Antibody MAT-1 Against Human Tyrosinase

In this study we explored the possible application of MAT-1, which has been established as a monoclonal antibody against human tyrosinase, for detection of mouse tyrosinase. The MAT-1 reacted with B16 mouse melanoma cells, but not with tyrosinase-negative NIH-3T3 mouse fibroblasts. In western blot analysis of the large granule fraction (LGF) of B16 cells, MAT-1 detected a single protein of 80 kDa, whose size was close to that of human tyrosinase detected with MAT-1 in extracts of human melanocytes. Furthermore, the 80 kDa band that was detected with MAT-1 in the LGF of B16 cells was also detected by DOPA reaction. In order to confirm that the protein detected with MAT-1 is tyrosinase, a transient expression assay was carried out. When mouse tyrosinase or mouse tyrosinase-related protein 1, which shares high homology with human tyrosinase, was transiently expressed in tyrosinase-negative K1735 mouse melanoma cells by cDNA transfection, MAT-1 reacted only with the cells expressing mouse tyrosinase. These results indicate that MAT-1 specifically reacts with mouse tyrosinase.