In the previous papers, ^{8, 9)} it was reported that the gross and internal morphology of leaves of Chinese cabbage changed according to temperature conditions, and the effect of temperature on the formation of the“small head” (embryonic head) was observed.
In this paper the author undertook to clarify the effect of temperature on the morphology of the shoot apex and tiny projections composed of larger cells.⁷⁾
Seedlings of Chinese cabbage (cv. Nozaki-kohai No. 3) were grown in phytotron, the temperature conditions of which were as follows: high 30-25°C, medium 23-18°C, and low 15-10°C, for day and night, respectively. For histological observations, slides were prepared from shoot apices collected at different growth stages of the plants by the paraffin microtechnique.
The size of the shoot apices increased as the plants grew and changed according to temperature conditions; the lower the temperature, the larger the shoot apices. Organization of the shoot apices also changed with the plant growth and the temperature conditions. The number of tunica layers increased and zonation became clear as the plants grew. The number of tunica layers was larger and the zonation was more distinct at lower temperatures. It is thought that leaf initial (the first periclinal division) went deeper and the leaf primordium at its inception became larger as the number of tunica layers increased. It is reasoned that the difference in the age of the cells between adaxial and abaxial sides, which caused the hyponastic curvature of the leaf primordium, ⁹⁾ becomes larger as the size of the leaf primordium at its inception increases.
Growth of the tiny projections was slower at lower temperatures, whereas the vacuolation in the larger cells, as an indicator of aging, progressed faster. And, the size of nucleoli seems to vary according to temperature condition in figures. While the aging of leaf primordia was retarded until they grew larger at lower temperatures. There appeared significant contrast between the growth of tiny projections and the development of leaf primordia.
Considering the characteristics of the tiny projection and leaf morphogensis⁹⁾ in relation to temperature condition, a possibility was suggested that resolvents of DNA and RNA in large nuclei and nucleoli effected the development of leaf primordia as cytokinin and its work was more active at lower temperatures.

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Effects of little solar radiation on vegetative growth of plants and fruits and quality in fruits of‘Prince’melon were investigated by limitation of solar radiation with blackcheesecloth, of limitation ratio of about 50%, in this study. Leaf area of secondary vines was retarded by limitation of solar radiation in growth period of fruits. Leaf area of tertiary vines increased by limitation of solar radiation in maturation period of fruits. But the thickness of leaves of tertiary vines was thin. Dry weight of each organ of plants, as vines, leaves and fruits was a decrease of 20 to 30% and dry weight of axillary bud was a decrease of about 50% in plots of limitation of solar radiation as compared with control plots. The size of fruits became small and form of many fruits became abnormal, like a bottle gourd by limitation of solar radiation in growth period of fruits. But the soluble solids in these fruits became higher than those in fruits in control plots, because limitation of solar radiation was stopped in maturation period of fruits. By limitation of solar radiation in maturation period of fruits, the quality of fruits deteriorated, namely, reserve of sugar, formation of salmon pink pigment or aroma in fruit flesh were retarded. Mineral nutrient as nitrogen, phosphorus, potassium, calcium, magnesium in fruits, as nitrogen and phosphorus in leaves were increased by limitation of solar radiation.

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In the seeds of wild type inTriticumandAegilopsdeveloped dormancy more strongly than the cultivated type in the diploid, tetraploid and hexaploid inTriticum. The dormancy in the seeds of cultivated type in the tetraploid and hexaploid widely varied not only with the difference in species, but also with the harvest year. The dormancy in the seeds of wild type, however, is hardly influenced by the environmental factors. The dormancy inTriticumandAegilopsseeds is released with the progress of after-ripening. The aged seeds ofTr. compactum (AABBDD, cultivated), Tr. macha (AABBDD, cultivated), andTr. aestivum (AABBDD, cultivated) with 48 months after harvest showed higher germination percentage than the seeds ofTr. boeoticum (AA, wild), Tr. dicoccoides (AABB, wild), Tr. timopheevi (AAGG, cultivated), Ae, bicornis (SbSb, wild) andAe, squarrosa (DD, wild) . The effects of GA₃or thiourea on germination in the seeds ofTriticumandAegilopscan be divided into two functions: 1) dormancy-releasing effect on dormant seeds, and 2) stimulating effect on aged seeds which have reduced their vitality.

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Plantlets ofDaianthus caryophyllusL. were cultured on a half strength MS basal medium (Murashige & Skoog, 1962) with 2% sucrose and an Enshi component of nutrient solution for hydroponics (Hori, 1966) without sucrose in vessels with different numbers of air exchanges per hour of vessels under different PPF (photosynthetic photon flux) conditions. Time courses of fresh and dry weights, number of leaves, plantlet shoot length, and CO₂concentrations inside and outside the vessels were measured. The relative growth rate, net photosynthetic rate, and total chlorophyll content of the plantlets were estimated.
The final fresh weight of the plantlets was the highest on sucrose-free Enshi medium with a high number of air exchange and high PPF, and was the lowest on the same medium with a low number of air exchange and low PPF.
The results obtained in the present experiment suggest the need to develop a basal medium composition optimal for photoautotrophic tissue culture. Because, the optimal basal media for photoautotrophic and photomixotrophic growth appears to be different from those developed for heterotrophic growth of tissue or organ, such as MS basal medium.

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