The influence of nutritional balances on growth and chlorophyll production was studied with six strains of callus tissue originating from five edible, higher plant species: carrot root, endive embryo, lettuce petiole, lettuce stem, parsley petiole and spinach petiole. A modified White's medium (tobacco high salts) was used as a basal synthetic medium. Generally this medium did not support good growth or good chlorophyll formation for these tissues. Addition of coconut milk to the medium instead of sugar improved growth and chlorophyll formation. Additions of 100mg/1 thiamine•HCl, 10mg/l ascorbic acid and 1g/1 casein hydrolysate to the basic medium with coconut milk, indole-3-acetic acid and kinetin favored growth and chlorophyll formation. Greatest chlorophyll formation was obtained (73.3γ/g wet weight) with spinach callus after a few transfers on this kind of medium. Growth in light and in darkness under sugar-limited conditions was studied using three modified tobacco high salts media. Generally growth of callus tissues depended on the quantities of sugar in the medium. Callus growth, with sugar present, was as good in darkness as in light. Chlorophyllous callus pieces in lightgrew slowly autotrophically under sugar-limited conditions.

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If the relative intensity of red (600-700mμ), green (500-600mμ), blue (400-500 mμ), and white (400-700mμ) light is 12:30:1000:30, each spectral region exerts a similar effect for both light break and the reversion of the far-red effect.
Low-intensity light of 8hours or more inhibits flowering when applied before an inductive dark period. The relative intensity of each colored light required to exert maximum inhibition is similar to that obtained for the light-break effect and the reversion of the far-red effect. Maximum inhibition was obtained with 10, 40, 200-1000, and 20μw/cm² of red, green, blue, and white light, respectively.
Blue light was very inhibitory when given for 8hours before the dark period and this inhibition was reversed by subsequent exposure to red light. Inhibition caused by low-intensity white, green, or red light was not reversed by red, however.
When 15 minutes of blue light (1000μw/cm²) was given at different times in a 24-hour dark period, it was most inhibitory at the 8th hour, and the response was very similar to that caused by red light.

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Accessory chromosomes were found in Aster ageratoides subsp. leiophyllus collected at Mt. Minobu, Yamanashi Pref. About 50% of the 98 clones studied had accessory chromosomes varying from 1 to 6 in number. The accessory chromosomes of this species showed variation in length and in the position of the primary constriction. These chromosomes could be classified into 6 types. Each of the 6 types of the accessory chromosomes was found to pair with each other at meiosis in PMCs. The standard accessory chromosome of this species was the second longest among the accessory chromosomes and possessed a primary constriction located in the subterminal position. The other accessory chromosomes were presumed to be derivatives of the standard accessory chromosome. Differentiation among the 6 types of the accessory chromosomes are discussed (Fig. 6).

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Chromosomes in the root nodule cells and root tip cells of three species of Alnus, A. hirsuta, A. firma and A. pendula were observed. It was found in each species that the root nodule cells possessed diploid chromosomes which closely resembled in form and size to those of the root tip cells. These observations are comparable with those of the diploid nodules of leguminous plants. Somatic chromosome numbers of the present three species were determined for the first time to be A. pendula 2n=28, A. hirsuta 2n=56 and A. firma 2n=112. It was found that A. hirsuta of Japan was a tetraploid form of this species.

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