The genetic behavior of incompatibility in the Japanese radish is extremely complex. However, if the following items are assumed, these results may well be explained: (1) Sporophytic control of the pollen. (2) A single series of multiple S-alleles at one locus (S1_??_S10). (3) The dominance relations between S genes in the pollen and the pistil. Consequently, it is concluded that the incompatibility of the Japanese radish is of the Crepis-type. Note added in proof. The work by HARUTA and YAMASHITA cited above has recently been reported in great detail: HARUTA, T. 1962: Studies on the genetics of self- and cross-incompatibility in cruciferous vegetables (in Jap. with Eng. summ.). Res. Bull. Takii Plant Breed. & Exp. Stat., Kyot. 2:1-169.
Effect of sprayings of gibberellic acid (GA1) at anthesis on the development, ripening pattern, and respiration rates of tomato, pepper, tamasango (Jerusalem cherry), akanasu (tomato eggplant), tamago nasu (eggplant), and 'Wase-shinkuro' (eggplant) fruits were studied. GA1 significantly reduced the size of the tomato, tamago nasu, and 'Wase shinkuro.' No difference in the ripening pattern or in the respiration rates of GA1-sprayed fruits was found.
Excised tomato ovaries of which growth was induced parthenocarpically by 5ppm 2, 4-D treatment were planted in NITSCH'S basic medium supplemented with various plant saps and chemicals. Effects of supplements, light, temperature and the stages of floral development on the development of the ovaries were investigated. Except the plots treated in dark and by high temperature, all of cultures were incubated in a room kept at 20°C constant under natural day length condition. Cultured ovaries were harvested both 80 and 85 days after planting and then fruit weight, rooting, coloration of fruits and others were examined. 1. Among the supplements tested, crude apple juice as well as crude tomato juice promoted effectively the ovary development (Table 2, Fig. 1). 2. The ovaries cultured in the dark increased also their weight as well as those cultured in the natural day length. However, the percentage of rooted fruits is higher in the former than in the latter, but in the case of colored ones resulted reverse (Table 2). Even in the plot treated in dark, they showed some coloration of which ton was pink. 3. Non-pollinated ovaries planted on the medium containing 0.1ppm 2, 4-D developed much less than others, though callus formation was observed at the pedicel (Table 2). 4. The stages of floral development did not affect essentially upon ovary development (Table 3). 5. The ovaries cultured in dark kept at 30°C grew in weight more than those kept at 20°C (Table 4). It was observed also that in the former plot the degree of callus formation and the amounts of root emerged were much larger than in the latter. 6. In general, the fruits cultured were abnormal in shape (Fig. 4), some of which did not show any development of ovaries but their sepals were thickened abnormally and colored after a certain period (Fig. 7). Observing swollen part of the fruits it was found that the pericarp, gelatinous placental tissue and ovules were developed especially better than the other portions (Fig. 5).
The present study was carried out to investigate the effects of night temperature and soil moisture during four weeks immediately after cotyledon expansion on the growth and flower formation of tomato. The studies consisting of Exp. 1 and 2, gave the results on night temperature and soil moisture as presented in Tables 1 to 4 on Exp. I. and in Tables 5 to 12 on Exp. 2, respectively. 1.The number of nodes to the first flower cluster (leaf number) was found to be greatly affected by night temperature during the first two weeks after cotyledon expansion; it was minimized at low temperature and maximized at high one. Vegetative growth as measured by plant height and leaf number was also found to be greatly affected by temperature during the second two weeks after cotyledon expansion; it was minimized at low temperature and maximized at high one. 2.The experiment with varied night temperatures which enabled the sensitive phases for leaf and flower numbers to be defined more accurately proved that, from the fifth to tenth day after cotyledon expansion, the tomato seedling was sensitive to the night temperature in the leaf number but not of the flower number. On the contrary, from the tenth to fifteenth day, it was sensitive in the flower number but not of the leaf number. 3. The leaf number was greatly affected by soil moisture during two weeks after cotyledon expansion; it was minimized in its optimum condition. and maximized in dry condition. The interaction of night temperature and soil moisture was observed in the leaf number; when the soil moisture was kept in optimum condition, the leaf number was minimized at low night temperature and maximized at high one; but no significant difference was found when kept in dry condition. Moreover, the duration of dry soil moisture treatment also greatly affected the leaf number and it was minimized with two-weeks duration and maximized in three-weeks duration.
During 1961 and 1962, a series of experiments was conducted to study the effects of plant growth regulators and pinching on the branching in Pisumsativum L. The varieties used were GW (Pisum sativum L. var. arvense) and Alaska and Usui (Pisum sativum L. var. hortense). The seeds were sown in the field in October, 1961 (Experiment I.) and in April and May, 1962 (Experiment II, III). The plants were grown under natural daylength or under artificial 8-hour short-day condition. Pinching was realized by removing the terminal growing point of main shoot at the stage of 5_??_10 leaves. And at this stage, once or twice at one-week intervals, some plants were sprayed with water solutions of plant growth regulators(10ppm of gibberellin and 10 or 50 ppm of 2, 3, 5-triiodobenzoic acid). The solutions were applied whole in plant sprays. As the wetting agent was utilized 0.15% of carbowax (M.W.: 1500). The results are summarized in Tables 1_??_3 and Figs. 12 for the Experiment I, in Tables 4_??_5 and Figs. 3_??_5 for the Experiment II, and in Tables 6_??_9 and Figs. 6-8 for the Experiment III. In all the varieties tested, 2, 3, 5-triiodobenzoic acid (TIBA) increased significantly the number of primary branches and further in GW and Alaska accelerated the development of secondary branches. As the consequence, the total number of branches in these two varieties are always greater in the TIBA-treated lots, while in Usui, a variety that develops more dominantly secondary branches, a decrease of the total number of branches was observed in the lots treated with TIBA. The response of pea to gibberellin with reference to the branching varied among the varieties and according to the growing season. In the experiment from October to June, gibberellin decreased the effect of pinching in all the varieties, but in the experiment from May to June the spray of gibberellin nulified the pinching effect in Alaska and Usui but not in GW. Pinching accelerated the development of both primary and secondary branches for all the varieties tested. This trend was remarkably accentuated under long-day condition, though in Usui which is able to produce branches on higher nodes of main shoot, pinching inevitably resulted in a decrease of the total number of branches. TIBA, though in a lesser degree than gibberellin, encourages the growth of individual branches developed, resulting in an increase of total branch length per plant. TIBA and gibberellin exert a remakable influence on the distribution of branches on the main shoot: TIBA favours the production of branches on lower nodes and arrests the branching on higher ones, while on the contrary gibberellin stimulates the branching on higher nodes, restricting that on lower ones. These features lead us to visualize a similarity between the effect of daylength and that of the plant growth regulators in such a respect that gibberellin is comparable in its effect to long-day and TIBA to short-day. As for the effect of TIBA on the number of flowers per plant, no consistent trend was presented. for all the varieties tested. In GW, branching of which is remarkably stimulated by TIBA, the number of flowers is likewise significantly increased. In the plants treated with gibberellin, a decrease in the number of flowers was generally observed.
1. The intensity of supplemental light which affects the flower initial and vegetative growth of strawberry was studied using varieties Kogyoku and Red Star. The range of intensity of artificial light used was 2 to 100 luxes. The long day treatment (24 hours: all-night illumination in addition to natural day-length) was applied from September 1 to October 31. 2. The limit of light intensity which is able to inhibit the flower bud differentiation differs between the varieties. It seems to be about 20 luxes in Red Star and 10_??_20 luxes in Kogyoku. 3. The stronger the intensity of supplemental light, the more vigorous the vegetative growth, especially the growth of the crown. The limit of light intensity effective to vegetative growth seemed to be about 10 luxes.
Spinach and Chinese cabbage were grown in sand culture under glass and were supplied with NO3 (10m.e./l) or NH4+NO3 (5+5m.e./l) and with various Ca levels, both in the absence and presence of excess NaCl (100 millimol). The Ca levels used were: (a) 5m.e./l, (b) 5m.e./l plus foliar sprays (0.04M CaCl2, twice a week), and (c) 15 m.e./l, with CaCl2 being used as the Ca source. All of the solutions were adjusted to pH 6.2_??_6.4. 1. In spinach, when no NaCl was added, it was observed that the favourable Ca level in the nutrient solution was higher with NH4+NO3 than with NO3 alone, and Ca sprays had a slight effect to increase the yield when nitrogen was supplied as NH4+NO3. In the presence of excess NaCl, however, both increasing concentration of Ca in the nutrient solution and Ca sprays were not effective and rather caused slight reduction of yield irrespective of the form of nitrogen supplied, and NO3 gave higher yields than NH4+NO3. In Chinese cabbage, the application of NH4-N and excess NaCl caused increased prevalence and severity of marginal rot on younger leaves, a symptom of calcium deficiency, which had detrimental effects on heading, yield and quality. To prevent the occurrence of this disorder, Ca sprays into the heart were remarkably effective in any case, but the increasing concentration of Ca in the nutrient solution had scaresely any effect. 2. Contents of Ca, K or Mg in leaves were in antagonistic relations with Na or NH4. In spinach, Ca sprays or increasing concentration of Ca in the nutrient solution resulted in increased Ca content of leaves. In Chinese cabbage, however, Ca content of leaf blades of inner leaves was remarkably lower and less influenced by the treatments than that of outer leaves, and Ca sprays significantly increased the Ca content of leaf blades, while the increasing concentration of Ca in the nutrient solution had effect to increase Ca content of leaf blades only of outer leaves and rather decreased that of head leaves. And it was recognized that the Ca content or the Ca/N equivalent ratio in leaf blades of Chinese cabbage was closely related to the occurrence of the marginal rot.
It is very difficult to maintain three scaffold limbs of peach trees uniform, because the lowest one is apt to dominate over the others. This study was carried out to clarify the causes of unbalance among the limbs and to find out measures to overcome this trouble. The lowest scaffold limb was apt to become larger than the others especially when the limbs were set up leaving space between them, while when three limbs were set up nearly at the same level, the lowest one was not invariably larger than the others, and limbs tended to be relatively uniform. Recovery in the uniformity among the limbs was sometimes found on the trees planted on the deeply plowed soil, while on the trees planted on the soil not deeply plowed the lowest limb generally retained its dominance over the others. Trees with all fibrous roots removed before planting sent vigorous shoots from the lower part of trunk, while trees with fibrous roots from upper part. Observation on root growth revealed that roots of transplanted trees did not grow during two months after planting, then grew gradually, and a large amount of roots grew at the end of June. Unbalanced growth of limbs was observed since early July. Trees which were field-grafted on the seedling stocks and had tap-root, had relatively uniform scaffold limbs. In those trees, tap-root could be seen distinctly by the end of the season, but it was not distinguished in the next season, as lateralroots developed remarkably. Field grafting and deep plowing of soil may be effective measures to keep scaffold limbs of peach trees uniform in vigor, though even in these cases dominance of lower limbs sometimes observed. When trees are planted on the soil of poor conditions, it may be preferable to train the trees in such a way that the two main scaffold limbs are taken out, then two sub-scaffold limbs are set up on each main limb, forming four scaffold limbs.
1. The effect of defoliation on the vegetative growth and flower bud formation was observed with young potted peaches, variety Okayama-wase, by removing all the leaves artifically at certain intervals during the growing season from June to October in 1959. 2. When all the leaves were removed, terminal and secondary leaf buds came out from the axils and developed into new shoots, except on the trees defoliated in October. The earlier the defoliation, the sooner and the more the buds sprouted. These shoots grew so late in autumn that the leaves fell 30 to 50 days later than usual. Accordingly, the buds on these shoots sprouted late irregularly and ununiformly in the following spring. This tendency was most conspicuous in the trees defoliated on August 7. 3. No flower buds appeared both on the trees defoliated in June and July, and some flower-like buds in August. However, on the trees defoliated after September complete flower buds were formed. The earlier the time of defoliation, the more decreased the number of flower buds per tree and the more ununiform the flowering time in the following year. The trees defoliated in September bloomed in October of the treated year, and those defoliated in August bloomed most abnormally in the following year. 4. While the shoot growth was generally well in the treated year except the trees defoliated in July, the growth of the following year was strikingly bad except those defoliated in October. Moreover, the defoliation in July and August retarded the root growth greatly. 5. From the results obtained, it is evident that in the Okayama-wase peaches flower buds were formed completely in September. These flower buds were already in the rest period in mid to end of September and leaf buds in October. And so the trees defoliated untimely in previous growing season showed “prolonged dormancy”.
A study was carried out on the growth of chestnut fruit (nuts and bur) in relation to the nutrient content of fruit and leaves. Materials were collected from the trees (Gin-yose variety) growing at high and low levels of some sloping orchards in Hyogo Prefecture. Nut size was found to be correlating positively with nitrogen content of fruit or leaves. Better growth of nuts on the trees at low level seemed to be due to the higher content of nitrogen in fruit and leaves than those at high level. A negative correlation was also found between nut size and K/N ratio in fruit or in leaves. Ranges of nutrient contents for obtaining nuts of desirable size (20 to 25 grams) were estimated as follows: N in nut: 1.14 to 1.33%, N in leaves 1.98 to 2.34%, and K/N in nut: 0.97 to 0.68. Nut-shell/nut ratio was negatively correlated with nut size. No significant correlations were found between sugar content and size of nut, and between sugar and nitrogen contens of nut. An analysis of correlations between chemical compositions and nut or bur weight showed that the growth responses of nut and bur to the nutrients were different, but the growth of fruit as a whole was depending on nut growth. Based on the results obtained, amounts of nitrogen and potassium in 100kg of fruit, nut size of which was in the range of 20 to 25 grams, were estimated as follows: nitrogen 0.64 to 0.81kg and potassium 0.81 to 0.70 kg.
For 15 years from 1946 to '60, the experiment on the effects of application of green manure in Satsuma orange orchard of the bearing trees had been carried out. The effects of application of green manure on the fruit yield, tree growth and soil properties were already reported. This paper deals with the effects on soluble solid, total sugar and citric acid contents in the fruit juice. In the years 1948_??_'51, soluble solid and citric acid contents in the fruit juice in 100%-green manure plot, in which green manure alone with no chemical fertilizer had been applied every year, were generally lower than those in 0%-green manure plot with chemical fertilizers alone. In the following 6 years, the citric acid content in 100%-green manure plot also kept lower level than that in 0%-green manure plot, while the total sugar content varied yearly, showing no fixed tendency. The citric acid content in 50%-green manure plot was nearly intermediate between those in the 100% and 0%-green manure plots, but the total sugar and soluble solid contents showed no consistent tendency. To know accurately the difference in total sugar content of fruit juice among the 100%, 50% and 0%-green manure plots, various fruit sampling methods were tried in 1960. And it was found out that the total sugar content was becoming slightly higher in 0%-green manure plot than the other plots.
The causes of adventitious root formation in cutting have been studied by many workers since the last century. However, the problems in cutting have not been solved yet. The studies reported here deal with these problems using Portulaca grandiflora which shows the green, reddish or red stem color. The differences in stem color result in the differences of rooting power. Namely, the cutting with red color shows good rooting power, while the cutting with green color poor, and that with reddish color medium. The fact that the root inducing substance is present in leaves was comfirmed by an experiment as follows. Cuttings with red color were divided into two groups. One group was consisted of intact cuttings, while the other of cuttings with leaves removed. When roots initiate in each group, the base of each cutting was cut off, and each cutting was returned into a flask with water. The intact cutting without basal treatment, the control, were compared with the two groups. The control cuttings showed good results of rooting, while leafless cuttings with basal treatment showed no root. On the other hand, the intact cuttings with basal treatment showed the retardation of rooting. The results suggest the movement of root inducing substance from the leaves to basal portion. To ascertain how many leaves are necessary to induce the root was the next problem. Then, rooting percentage, mean root number and mean root length of the cuttings with 0, 1, 5, 10, 20 or over 30 leaves were observed. From the results of this series of experiments, it was demonstrated that 5 leaves are enough for 100 percent rooting and rooting of 50 percent was obtained even in one-leaved cutting. Changing the duration from the time of making cuttings to the time of removing leaves, the rooting percentage, number of roots and length of roots of cuttings were compared. The earlier the removing of the leaves from cuttings, the fewer the number of roots initiated. From the view point that the root inducing substance moves from leaves to basal part of cutting, an assumption that the longer the leaves remain attached to cutting the less the root promoting substance in leaves, may be made. This was proved as follows. Alcohol extracts from the leaves which were removed from cuttings were applied to the cutting with leaves removed. The extract from leaves remained on the cutting longer was less effective on root formation than that from leaves removed earlier.