1. In order to investigate the mechanism of gibberellin action, effects of gibberellin on the respiration metabolism were observed with the leaves of Muscat of Alexandria grape. 2. In the case of the excised leaves immersed in 100ppm gibberellin aqueous solution, respiration showed no significant difference in O2 uptake but a sharp rise in CO2 output, compared with non treatment. Respiration quotient was 1.3-1.6. 3. In the case of the attached leaves sprayed with 100ppm gibberellin aqueous solution, respiration on the first day after treatment showed a decrease in O2 uptake and an increase in CO2 output. These abnormal respiration activities were restored as before, on the third day. 4. The organic acids of leaves on the first day after treatment with 100ppm gibberellin aqueous solution had been fractionated by column chromatography. As a result, the treated leaves, compared with non treated, contained more pyrvic, glyoxyric, acetic, fumaric, oxalic, malic and tartaric, but less oxaloacetic, α-ketoglutaric, citric and isocitric acid, while succinic acid occured in approximately equal amounts in both treated and non treated. 5. In view of above results, firstly malic dehydrogenase activity, in vitro, was measured with and without addition of gibberellin. As a result, gibberellin in a concentration of 1ppm inhibited malic dehydrogenase activity almost completely.
1. In order to confirm the toxic effect of old peach soil, peach seedlings were grown in 1954 and 1955, respectively, in the pots which contained the soil added with fresh or dried rootlets and leaves of peaches. In 1954 the growth was inferior only in the fresh and the 15-day air-dried rootlet plots. Therefore, in 1955 the amount of addition was increased so much that the growth was greatly decreased in all the treated plots. The trend was marked both in the fresh rootlet and leaf plots, and the longer the time for the storage of rootlets and leaves before addition, the less retarded the growth of seedlings. 2. When peach leaves was dried, heated or crushed before addition to the soil, the growth of peach seedlings in the treated plots except the crushed plot was depressed in order of the heated, dried and fresh leaf plots at the beginning of treatments, while the order became reversed as the season advanced. The crushed leaf plot grew as well as, or sometimes better than the non-treated plot throughout the growing season. 3. The germination of raddish seeds was greatly inhibited in the both water extracts of fresh and crushed peach leaves. The condition was, however, lightened somewhat when the extracts were boiled at 100°C for 10 minutes before the treatments, and markedly when for 30 to 60 minutes. The germination was also not affected in the water extract of crushed leaves when the leaves had been kept in the air for 30 minutes following crushing. 4. When treated with the active carbon, the water extract of peach leaves had no marked inhibiting effect on the growth of peach seedlings and on the germination of radish seeds. However, when treated with the Japanese acid clay or clay, the water extract retarded well both of them.
1. The trees used for the experiments were Tujimura Unshiu orange of 18-year-old. The trees had been very vigorus and the difference between production in the“on”and“off”years had been quite pronounced. 2. Treatment (1) Fruit-thinning Fruits were thinned on July 18th and 19th. The number of fruit left on a tree at thinning was determined by the amount of leaf surface. Fruits were reduced so as to have 20 to 25 leaves to each fruit left. (2) Fertilizer application (a) Abundant amount application : Orchard was sod-mulched and nitrogen (18.6kg), phosphorus (16.8kg) and potassium (20.4kg) per 10 are were applied in three applications, at the beginning of spring, summer and fall. (b) Small amount application : Orchard was non-mulched and nitrogen (13.5kg), phosphorus (11.25kg) and potassium (11.25kg) per 10 are were applied at the beginning of spring. (3) Pruning The trees were pruned in March. (Table 3) (a) Moderate pruning: In the case of the on-year tree in the preceding season, shoots were thinned out moderately and the fruited shoots were cut back. In the case of the off-year tree in the preceding season, spring flush, summer and fall flushes were moderately thinned out. (b) Heavy pruning : Shoots were rather heavily cut back. 3. Results Heavy crop caused the depletion of food supply and reduced the storage of carbohydrates and other substances in the plant body. It reduced the growth of all parts of the tree and the formation of flower buds in the succeeding year. The reduction of the crop had a favorable effect in maintaining annual bearing condition. Fruit thinning changed most effectively alternate bearing habit to annual bearing condition. The trees which had shown strong alternate bearing tendency in the past several seasons required moderate pruning and abundant application of fertilizer in addition to the fruit thinning to recover. The fertilizer application promoted the vegetative growth and also fruit growth. Pruning with a moderate thinning stimulated the flowering shoot growth in the succeeding year.
The experiment was performed to study the effects of pH, calcium concentrations and sources of nitrogen on the growth and inorganic compositions of natsudaidai (Citrus natsudaidai HAYATA) seedlings in solution culture under glass. Nitrogen was supplied with NaNO3 or NH4NO3 in the concentration of 112ppm, pH of solution was adjusted at 4, 5.5 and 7, and calcium concentrations supplied were low, medium and high, totalling 18 combination treatments. The appearance of leaves of the seedlings at pH 5.5 in NaNO3 series was normal, however, it was rather dark green in NH4NO3 series. At pH 4, leaves became somewhat dull green, and at pH 7 they tended to become chlorotic in both forms of nitrogen. Chlorosis was more remarkable in NaNO3 series. Roots were white in pH 5.5, however, at pH 4 or pH 7 they turned light brown in NaNO3 series. The elongation of roots at pH 4 was inferior to those at other pHs, and tips of laterals became stubby. In NH4NO3 series, roots generally became brown, and their elongation was less than that in NaNO3 series. At pH 4, tips of laterals became stubby, and in advanced stage the cortex disintegrated and sloughed off. These symptoms were more remarkable in the treatment supplied with low Ca. In general, seedlings supplied with NaNO3 made better growth than those supplied with NH4NO3. In both forms of nitrogen, growth of seedlings was the minimum at pH 4. In NaNO3 series, growth of seedlings was the maximum at pH 5.5, and intermediate at pH 7. However, there was no clear difference of growth between pH 5.5 and pH 7 in NH4NO3 series except Ca low treatment. As for calcium concentration, seedlings supplied with medium Ca showed better growth at every pH in NaNO3 series. On the other hand, no consistent difference of growth due to calcium concentration was observed in NH4NO3 series. NaNO3 plants had generally higher concentrations of K and Ca, and lower concentrations of N, P, and Mg as compared with NH4NO3 plants in their leaves. While, in their roots, NaNO3 plants showed higher concentrations of P, Ca, and Mg, and lower concentrations of K than those of NH4NO3 plants. With the rise of pH level in the solution, concentrations of N, Ca, and Mg increased and K decreased in the leaves irrespective of nitrogen forms. In their roots also, concentrations of Ca, Mg, and P increased, and K decreased with the rise of pH. When Ca level in the solution was raised, only Ca concentration in the seedlings increased.
1. Cucumber variety“Higan-fushinari”which bore female flowers in longer photoperiods than 16 hours was grown in various photoperiodic combinations of white, blue, red lights, being of the same intensity of 0.04gcal/cm2, min., and darkness at the temperature of 28±1.5°C. The effects on the expansion of leaves, elongation and also on the sex differentiation were examined. 2. In any light qualities, the longer the photoperiod was, the more the number of unfolded leaves became. In 16 and 8 hours photoperiod, it was the most in white and the least in blue light. In continuous illumination of a single light, number of unfolded leaves did not show variation. In that of photoperiodic combinations of various lights, it was much larger than that of a single light. This tendency was most prominent when the part of continuous light was given with blue light. 3. In any light qualities, stem elongation was greater when the photoperiod was longer. In continuous light of a single light, blue light was more effective for elongation compared with others. In 16 hours photoperiod it was the greatest in white and the least in red light, and in 8 hours photoperiod it was the greatest in white and the least in blue light. In the continuous light of the periodic combinations of lights, the stem elongation was greater when plants were irradiated with blue light than with others. 4. In any light qualities, flower buds were initiated. In general, they developed and the sexuality of flowers was distinguished at the higher nodes than 10th on the main stem. In a single light of red, no development of initiated flower-buds was observed and the sexuality of flowers was not distinguished. In continuous illumination and 16 hours of white or blue light, male flowers were observed at the higher nodes than 10th, but few female ones were observed. In 8 hours of blue light, only male flowers were observed at the very low nodes on the main stem.
Four male sterile tomato mutants have been found in the progenies of gamma irradiated plants, two from variety“Shugyoku”and one each from both of“Okitsu No.3”and“Okitsu No.6”. These mutants, except one of Shugyoku, were found in the next generation (M 2) derived from fruits set on lateral branches which regenerated after“internal disbudding”by semilethal gamma exposure. The rate of appearance of ms segregating strains observed, was approximately 3 percent. Breeding results have approved that the male sterility of each mutant is determined by a single recessive gene. No appreciable ovule sterility in any mutant was found. Through the experimental results, the following scheme for the production of ms mutants has been established. 1) Preparation of seedlings in a strain promissing as a female parent of F1 variety. 2) Irradiating them with ca. 10kR of gamma rays, at an exposure rate of 1-2kR/day, shortly before the blooming of first inflorescence. 3) Releasing them until regenerated buds being appeared about a month later from the exposure. One fruit cluster is left on each regenerated branch, and then the seeds are harvested from a fruit in each fruit cluster. 4) Raising the plants of next generation as M1 fruit strains. Detecting unfruitful plants and observation on their pollen fertility. Pollination on non pollen plants with use of normal pollen sampled from each of the every fertile plants in the same strain. Test on the fruit set of pollinated flowers, and selection of the normal fruiting plants as ms mutants. 5) Raising the next (M3) generation as male parental strains. The ms segregating strains (F1: S1) can be expected in a rate two times higher than that of non segregating strains. 6) Investigation on the alternation in any other characters than pollen fertility, especially in crossing ability for F1 hybrid.
The effects of nitrogen withheld for one month each in various growth stages from the transplanting early in June to the termination of harvest early in October, on the growth, flowering and yield of egg-plant were investigated in the sand culture outdoors. Soon after nitrogen removal at any stage of growth, the percentage of flowers with short style increased, and after two weeks number of flowers decreased. While, shortly after nitrogen was supplied again, the percentage of flowers with long style increased, and after two weeks number of flowers increased, and recovery of yield was found after four weeks. Fruit yield was the least, when nitrogen was not supplied for the period, from early in August to early in September, in which flowering and fruiting were active. The earlier the period in which nitrogen supply was withheld, the slighter was the lowering of fruit yield. On the other hand, there was no significant difference in yield between the control supplied with nitrogen throughout all growth stages and the treatment supplied with no nitrogen in the last stage after early in September.
Only one plant of onion having yellow-green stripes on leaves was found under field conditions in 1960. Because of male sterility, it was propagated vegetatively to maintain the clonal line. Fortunately, male-fertile variegated plants were found out of those male-sterile clones in 1965. The variegated leaves were striped alternately with green and yellow bands. The width of the stripes varied considerably as shown in Fig. 1. These male-fertile variegated plants were used as materials in the present experiments to clear up the genetic behavior. The results of self-pollination in the variegated plants are shown in Table 1. When self-pollinated the variegated plant produced green and yellowish white seedlings. The yellowish white seedlings perished immediately after germination. The variegated plants were distinguished from the green plants during the late stage of growth. The green plants obtained from the original variegated plants by vegetative propagation bred true for green in the first generation of selfing (Table 1). The results of the reciprocal crosses between variegated and normal green plants are shown in Table 2. The F1 generation from the cross variegated plant _??_×normal green plant _??_ segregated green and yellowish white in seedling stage, and green and variegated in adult stage. The self-pollinated green F1 plants bred true for green in F2. The variegated F1 plants produced green, yellowish white, and variegated plants in the F2 and F3 generations. The F1 plants of the cross normal green plants _??_×variegated plant _??_ were green, which produced only green plants with the exception of a single variegated plant in the F2 generation. From these results the leaf variegation of onion seems to be maternally inherited, and controlled by plastogenes. A genetical mechanism is not known by which the male-fertile variegated plants were induced from the male-sterile ones. It would be due to somatic segregation during vegetative propagation (Smsms→SMsms, cf. JONES and CLARKE, 1943). The genetic interrelation between male sterility and variegation requires further study.
In this paper the results are presented on method of overcoming self-incompatibility in Petunia hybrida by means of repetition of self-pollinations. As for the materials Petunia hybrida, clone W 116 K, W 166H and K 146BH which belong to the gametophytic incompatibility system were used. 1. None of those three clones have self-fertility at anthesis and the inter-clonal pollination showed perfect fertility, namely the complete self-incompatibility was confirmed. 2. The pollen tubes in the compatible pollination have reached the ovary about 36 hours after pollination, while in the incompatible pollination the pollen tubes have ceased their growth at the style. The tips of the pollen tubes positioned at 67% of the total length of style 56% in W 166K, in W 166 H, 17% in K 146BH. 3. In all three clones the pseudo-fertility by bud pollination was recognized, namely the self-fertility appeared on 6 days before anthesis, reaching its maximum on 5th day and disappeared completely 3 days before anthesis. The pseudo-fertility was the highest in W 166K, followed by W 166H and was the lowest in K 146BH. 4. Three days before anthesis when the pseudo-fertility by bud pollination had disappeard completely, the self-pollination was carried out repeatedly with 24 hours interval, which resulted in the induction of the pseudo-fertility in the both clones W 166K and W 166H. The rate of fertilization and yield of seeds have increased as the frequency of pollination have increased. The method to induce the pseudo-fertility by repetition of the incompatible pollination was designated as“repeated pollination”. 5. It was assumed from the results of the combination of incompatible and compatible pollination that the pollen tubes which have ceased their growth once in the style after the first pollination have not resumed the growth, but the pollination after the second time made pollen tubes grow, and they penetrated into the conducting tissue, thus taking part in the fertilization and seed formation.
1. Common stocks had been recognized to require low temperature below 15°C for 3 weeks at the stage having ten or more fully developed leaves to form flower-bud. The present studies were undertaken to ascertain whether the effect of the low temperature on flower formation differed with different cultivars of the common stocks, and to compare the growth and flowering behavior among individuals of several cultivars grown at four different seasons of the year under natural light and temperature conditions.
It has been demonstrated that the pigment composition in lily flowers has been associated with the several horticultural problems, e. g., a) cross-incompatibility, b) fading of flower color (e. g. Lilium brownii var. brownii), c) breeding of new flower color. In the previous paper(3), the author reported that the anthocyanins in lily flowers were keracyanin (Cyanidin-3-rutinoside) and a minor anthocyanin. In the present paper, experiments were made to identify carotenoid pigments in flowers of 21 different kinds of lily by the thin layer chromatographic and column chromatographic separation, and subsequent spectrophotometric partition test and color test. The results obtained were as follows: 1. The carotenoids identified in 18 varieties out of 21, were β-carotene, cryptoxanthin, echinenone-like carotenoid, zeaxanthin, capsanthin and capsorubin. 2. The phenotipic pigments of the yellow flowered natural species (L. hansonii, L. tigrinum var. flavifiorum) were β-carotene, cryptoxanthin and zeaxanthin. On the basis of their compositions, the orange flowered natural species were classified into 2 groups, namely one containing echinenone-like carotenoid to which 2 species (L. dauricum, L. henryi) belonged, the other containing capsanthin and capsorubin were found 5 species (L. pumilum, L. amabile, L. maculatum, L. tigrinum, L. leichtliniivar. maximowiczii). 3. The carotenoid found in 2 inter-specific hybrid lilies (L. maculatum cv.‘Chigusa’, L. umbellatum cv. ‘Vermilion Brilliant’) were echinenone-like carotenoid, capsanthin and capsorubin. 4. The co-existence of anthocyanin and carotenoid was not recognized in the orange flowered natural species with the exception of L. tigrinum. On the other hand, these two pigments co-existed in 3 inter-specific hybrid lilies (L. maculatum cv. ‘Chigusa’, L. umbellatum cv. Vermilion Brilliant′, L.‘Hagoromo’). 5. From the fact above mentioned, the pigment composition of lily flowers was not always associated with the cross-incompatibilily between anthocyanin and carotenoid lily groups.
1) An increase of ethyl alcohol, methyl alcohol and acetaldehyde was recognized gas chromatographically by immersing immature astringent fruits in warm water to remove astringency. 2) When non-enzymatic fruit was treated with ethyl alcohol, methyl alcohol and acetaldehyde, only acetaldehyde was effective in removal of the astringency. 3) During the warm water treatment, as the acetaldehyde was formed in the fruit, the astringency disappeared from the fruit. 4) Observing the treated fruit tissue histochemically, it was found that the protoplast of tannin cells coagulated and the acetaldehyde stain was confined to the tannin cells. 5) When mature astringent fruit was treated with acetaldehyde, the astringency disappeared very rapidly. For example, when the fruit was treated with 20% acetaldehyde solution the astringency disappeared in 12 hours. 6) Therefore, it seems that acetaldehyde which is formed as the result of anaerobic respiration during the warm water treatment coagulates protoplast in the tannin cells and removes the astringency.
Citrus fruits such as oranges, lemons, and grapefruits suffer physiological injury when subjected to low but non-freezing storage temperatures. On natsudaidai fruits, of which production is a considerable amount among Japanese citrus fruits, there has been little available report concerning low temperature storage. Our preliminary experiments, purported to establish optimum storage temperature, showed occurrence of typical chilling injury on natsudaidai fruits. The present study was carried out to confirm this phenomenon in reference to its physiological aspects. (1) When natsudaidai fruits were stored at 1-1.5°C for two month or longer, chilling injury developed gradually. On the peel of chilled fruits brown pitting appeared and the fruits became susceptible to decay. Darkening of whole peel color was also found. Furthermore, prior to the appearing of visible injury during low temperature storage, the fruits increased susceptibility to microorganisms, and when transferred to 20°C severe decay took place rapidly. At 6°C, the fruits were stored without chilling injury and kept good external appearance for three months. At 13°C, half of fruits decayed during the storage of three months. (2) Respiration rate of fruits decreased with duration of storage at 6°C, showing the same tendency as ordinary citrus fruits. On the contrary, the respiration of fruits stored at 1°C exhibited continuous increase, and reached higher rate than that of the fruits at 6°C in the latter portion of storage period. When the fruits transferred from 1°C to 20°C, spur of carbon dioxide output was observed, and the degree of stimulation was more conspicuous with increasing exposure time at low temperature. (3) Respiration of flavedo tissue slices was measured at 30°C. Respiration rate of the slices prepared from 1°C-stored fruits was higher than that from 6°C- or 13°C-stored fruits especially in the latter portion of storage period. Respiratory quotient became lower than unity in the tissues from non-chilled fruits. However, at 1°C the RQ value remained at high level throughout the storage period. (4) Because the measurement was carried out with externally sound fruits, the results mentioned above suggest that abnormality of metabolism may have occurred in the healthy-appearing fruits during the 1°C storage. (5) Ascorbic acid content remained higher in the fruits stored at low temperature, indicating no relation to mechanism of chilling injury. (6) Potassium ion leakage from flavedo tissue slices suspended in water or sucrose solution was measured to detect the change of cellular permeability during the low temperature storage. However, no relation was found between the leakage and cause of chilling injury. (7) Prior to low temperature storage, a portion of fruits were treated with N6-benzyladenine, gibberellin, indoleacetic acid, and fruit wax. No effect was found to prevent the development of chilling injury with all chemicals used.
This paper reports the investigation on the changes of some chemical contents, the metabolism and the qualities of tomatoes (Ogata Fukuju; mature green and breaker stages) stored in air and CA-conditions. 1) Mature green tomatoes during CA-storage (5% CO2-10% O2, 10% CO2-10% O2, 25% CO2-10% O2 short term treatment, at 6.5±0.5°C) were ripening slowly and reached a light pink stage after 6 weeks. The surface colour of tomatos stored in air turned fair red and the tomatoes in CA-storage (5% CO2; 10% CO2) showed retardation of colour development by postponing after-ripening, but the fruits were weakened and more subject to decay by Alternaria after transfer to room temperature(18°C). 2) Also after-ripening of tomatoes treated at breaker stage was inhibited by CA-condition at 6.5±0.5 and 7.5±0.5°C. Tomatoes stored in air reached a soft ripe stage after 2-3 weeks and the surface colour turned red. On the other hand, tomatoes stored under CA-conditions (5% CO2 and 10% CO2) reached a dark pink stage after 4 weeks and the fruits were edible after 5 weeks. It was found that tomatoes at breaker stage might be suitable for CA-storage. 3) The L-ascorbic acid content in tomatoes treated at breaker stage decreased gradually at 7.5°C in all plots, especially at the end of the storage period under CA-conditions. The organic acid content in the tomatoes decreased during storage in all plots. The decreases of total acid content in the fruits was not inhibited by CA-conditions but the decreases of malic acid content was inhibited under the CA-conditions. 4) O2 uptake and CO2 output in Warburg espirometer measurements of tomato pulp slices decreased gradually during storage. The O2 uptake of the tissue slices stored in 10% CO2 plot was small in comparison with other plots. The effect of addiiton of pyruvate on CO2 output of pulp slices from the tomatoes in CA-condition was higher than that of tomatoes in air, indicating that high concentration of CO2 in an atomosphere might stimulate pyruvate carboxylase activity of tomatoes. 5) In pulp slices, succinic-1, 4-14C was converted into the other acids in the TCA-cycle. From this tracer method, it was observed, that succinic dehydrogenase might be inhibited in tomatoes stored under CA-conditions.