The sporeling pattern of Fossombronia japonica Schiffn. was described and discussed with reference to that of the Marchantiales. The sporeling of F. japonica mostly produced a much reduced and many-celled protonema, but occasionally it produced a filamentous protonema which had several septa, as described previously in other species. The globose protonema seems to be an extreme form caused by certain environmental conditions, probably by light intensity. The sporeling pattern of Fossombronia much resembles that of some members of the Marchantiales in some essential features. This may serve for Mehra's theory. The mucilage cells are observed at an earlier stage and they contain oil-bodies up to the later stage.
The flower inhibitory effect of low intensity light preceding the dark period of adequate length (16 hours) was investigated in Pharbitis seedlings. 1) Eight hour incandescent light of 10lux inhibits flower formation. 2) The incandescent light of 10-25lux given for 8 hours suppresses the inductive effect of the following dark period entirely, and even that of 1000lux is not strong enough to bring about maximum photoperiodic response. 3) Spectral sensitivity of the low intensity light for flower inhibition was studied. Far-red light has the highest inhibitory effect and red light the lowest. 4) Daylight fluorescent light of 10lux which comprises little far-red light inhibits flowering far less than the incandescent light of the same intensity. 5) The daylight fluorescent light of 10lux mixed with the far-red light of 120 erg/cm2./sec. inhibits flowering remarkably when given for 8 hours. 6) Flower inhibitory effect of the incandescent light of 10lux is reversed by red light applied just before the dark period. But the red light mixed with the far-red light has little reversing effect for the flower inhibitory effect of the incandescent light. Flower inhibitory effect of the incandescent light is attributable to the action of the far-red light comprised in it. “Red-far-red absorbing pigment system” is supposed to play an important role in the reaction preceding inductive dark period.
The morphogenesis of the isolated internodal cell of Nitella flexilis cultured in vitro was promoted by application of adenylic acid, gibberellin and most amino acids, e.g., leucine, methionine, glutamic acid, aspartic acid and arginine in appropriate concentrations. Amino acids had a positive effect on the formation and the elongation of both the shoot and rhizoid. Adenylic acid was favorable for shoot and rhizoid formation. Gibberellin was suitable for the elongation of the shoot. Colchicine exerted no effect on formation of shoot and rhizoid at whatever concentrations, but it could accelerate the elongation of both the shoot and rhizoid already formed.
(1) Curvature of Avena coleoptile induced by IAA is increased in presence of ferrous sulfate. The optimum concentration of ferrous sulfate for the promotion of Avena coleoptile curvature is about 5×10-3M. (2) And in this concentration, ferrous sulfate increases the sensitivity of Avena curvature test about three times. (3) Curvature of Avena coleoptile induced by NAA is also increased in presence of ferrous sulfate. (4) The auxin diffused from Avena coleoptile tips into agar blocks is identified as IAA according to the above mentioned sensitive Avena curvature test. And no growth substance other than IAA was found in agar blocks.
1. The species of which seed pigments were studied are as follows: Nelumbonucifera, Pisum sativum, Glycine Max, some species of Citrus and Cucurbita, and Fortunellamargarita. The properties of the green pigments in seeds were examined. These were observed in the plumule of Nelumbo, the cotyledons of Pisum and Glycine, the embryos of Citrus and Fortunella, and the inner part of the seed-coat of Cucurbita. 2. These green pigments were extracted and paper chromatographically studied. The absorption curves of the pigments were also taken with a spectrophotometer. 3. In the seeds of Nelumbo, Glycine, Pisum, some species of Citrus and Fortunella, both of chlorophyll a and b were evidently observed, while only chlorophyll b was found in the seed of Cucurbita moschata and C. maxima. 4. The fruit-coat and seed-coat of Pisum and Glycine seem to be somewhat translucent to the sunlight, while seeds of Nelumbo and Cucurbita seem to be cut off from the light. None the less chlorophyll a and b are apparently detected in these seeds.
The mating system of Coprinus macrorhizus f. microsporus was analyzed, using two stocks X and d. As shown in Table 1a, in matings between monosporous mycelia having unlike incompatibility factors at both loci, clamp-bearing hyphae are observed not only in the contact zone between two mated mycelia but also on both sides of it (complete dikaryotization). Clamps are also found in all matings where theB-factors but not the A-factors are identical (common B-factor mating). In the latter case, however, the formation of clamps is restricted only to the contact zone (limited dikaryotization). Therefore, when only the contact zone is examined for the presence or absence of clamps, a bipolar mating-pattern is obtained. However, when the mycelia on either side of it as well are tested for clamps, tetrapolarity is unmasked. Such tetrapolarity may be called “masked tetrapolarity”. All matings where hyphae with clamps had been observed were tested for their capacity to produce fruit-bodies under the same culture conditions. As shown in Table 1b, perfectly developed fruit-bodies with abundant basidiospores were obtained not only in all matings showing complete dikaryotization but also in some pairings showing limited dikaryotization. Fruit-bodies from the former matings produced spores of all four mating types ; whereas, from fruit-bodies formed in the latter pairings, only spores of the two parental types were produced (Table 2). Pairings between the monosporous mycelia of illegitimate origin show bipolar pattern, where only limited dikaryotization, but never complete dikaryotization, regularly occurs (Table 3a). In common B-factor matings, when two mycelia are inoculated 1-2cm. apart, a clear line of demarcation which is called “barrage” always appears between them, as shown in Fig. 1; whereas, when the two inocula are brought into contact with each other, a sector composed of dikaryotic mycelium develops occasionally in some matings, as shown in Fig. 2. Barrages develop with regular manner in all common B-factor matings, but the sectoring dikaryons are rather of haphazard occurrence.