1. Studies were carried out in 1955, in order to investigate the dormancy of seeds of domestic and wild udos (Aralia cordata THUNB.) gathered in Japan. 2. Udo seeds scarecely germinated immediately after harvesting and when they had been in dry storage, while seeds stored in the cold wet sand germinated well. Domestic udo seeds germinated more easily than wild ones. 3. Chilling treatments (0_??_2°C) were very effec-tive to break the dormancy of udo seeds in dry storage. In this case also, domestic udo seeds germinated more easily than wild ones. Varietal differences were observed in the dormancy of do-mestic udo seeds, while there were wide variations in wild ones. 4. Injuring seed coats, soaking in the concen-trated sulphuric acid, thiourea treatment (0.2%), alternating temperature, and washing in the running water were not effective to break the dormancy. Light had no decisive effect on the germination.
1. In these experiments two varieties of the Japan-wese radish, Miyashige and Tenma, were used as materials. Fertility was determined by pollen be-havior on stigmas instead of by seed counts. 2. The results of self-and cross-pollinations in variety Miyashige were very complex. Ten plants examined were divided into eight classes on the basis of cross-relations. All these plants were self-incompatible. In inter-class pollinations there were both cross-compatible and-incompatible combinati-ons. Differences in the reciprocal reactions between certain classes were also found (Diagram 4). 3. These results closely resemble those of the previous papers (TATEBE 1944, 1956), and may well be explained if the following items are assumed: (a) Self-and cross-incompatibility is controlled by multiple appositional alleles at two loci (S and I). S is assumed to be epistatic to I, but hypostatic to II (S>I, S<II). (b) The reaction of the pollen is sporophytically determined. A genetic explanation for the results was given in diagram 5. This interpretation is analogous to RILEY's hypothesis on Capsella (1936). 4. On the other hand, the results of self-and cross-pollinations in variety Tenma were much more simple than those of variety Miyashige. All these plants were self-incompatible. Excepting two incom-patible matings, all other combinations were cross-compatible (Diagram 1). 5. These results may well be explained by the following hypothesis (Personate type): (a) Self-and cross-incompatibility is controlled by multiple oppositional alleles at one locus (S). (b) The reaction of the pollen is gametophytic-ally determined. A genetic explanation for the results was given diagram 2. 6. However, it is a well known fact that in numerous self-incompatible Cruciferous species the reaction of pollen is sporophytically determined. Judging from this standpoint, it might be assumed that the genetic interpretation of self-incompatibility in variety Tenma was perhaps erroneous, for the data obtained were rather meagre. A solution of the problem still awaits the future.
Ample storage of nitrates was found in the lea-ves and stems of most kinds of vegetable crop tested, except Allium, in the leaves of which nitrates were scarecely found. Experimental results revealed that nitrate content of the leaves and stems was affected by various factors such as age of plant, nitrogen supply, as well as their position on the plant. High-er nitrate content was found in the mature leaves, especially in the petioles, and lower portion of the stems, while nitrate content decreased as age of the leaf became younger, or as the portion of the stem approached to the tip. As to the age of the plant, it was found that nitrate content started low in young age, reached its maximum in the middle stage, then decreased as the plant grew older, in the plants grown in sand culture with the constant levels of nitrate. Diurnal change and change during storage up to for three days in room temperature in darkness or in difused light were not significant in nitrate content in the petioles of the turnip leaves. Effects of the amount of nitrogen fertilizer on the nitrate content in the leaves of several kinds of vegetable tested were significant. Nitrates could not be detected in the plants sup-plied with ammonium nitrogen only. In the early stage of growth of radish and chinese cabbage, nitrate content was low in the plants applied with:, higher amount of ammonium sulfate in the field. Nitrification of ammonium ion should be proceeded in the soil, before positive correlation between the amount of nitrogen applied and nitrate content in, the plants was established. Changes in the nitrate concentration in the cul-tural solution were rapidly reflected in the nitrate content in the leaves of komatsuna in the sand cul-ture. Nitrate reduction process in the plants was dis-cussed in relation to the diagnosis of nutritional status of nitrogen. Rapid tissue tests by the BRAY's reagent methods and the diphenylamine method are simple and con-venient for diagnosing nitrogen deficiency of vege-table crops in the field, if the portion of the plant: to be tested are properly selected. Tissue analysis method using phenyldisulphonic acid is more accurate and reliable for diagnosing: nitrogenous nutrition, if the portion of the plant and time of sampling are adequatly selected and definate standards for critical levels were provided. by fertilizer experiments.
The experiment were carried out in sand culture 10 clarify the effects of phosphorus and potassium supplied for the various stages of growth, on the yield and quality of seeds of chinese cabbage. Phos-phorus concentration in the nutrient solution was 15ppm as P, and potassium concentration was 120 ppm as K. All other nutrient elements were given during all stages of growth in every treatment. The results obtained are as follows. (1) Phosphorus experiment The plants which were supplied with phosphorus from the planting time (Sept. 26) to the end of flo-wering stage (Apr. 26), had about the same seed yield as control plants supplied with phosphorus throughout all stages of growth. But the plants which were supplied with phosphorus until the ear-ly flowering stage (Mar. 28) or until the bolting stage (Feb.18), produced pretty lower yield due to smaller size of seeds compared with that of control plants. And the plants which were supplied with phosphorus during the period only from the plant-ing time to the flower bud differentiation stage (Dec. 17), had remarkably lower seed yield (only 2/5 of the control). The causes for this consisted in inferior development of the secondary and the tertiary lateral shoots, and furthermore in smaller size of seeds in the pods. When phosphrus supply was withheld in the ear-ly stage, plant growth was retarded remarkably. And even in case of phosphorus application after Dec. 17 or after Feb. 18, growth recovery was slow, and seed yield was inferior to that of above-mentioned treatments. The plants which were withheld phosphorus supply during all growth stages, had scarcely any seed. As for seed quality, the earlier the stage of growth which was stopped phosphorus supply, the lower was seed phosphorus concentration. And there was no differences of percentage germination among treatments, but incipient elongation rate of radicles was inferior in the treatments having smaller size of seeds. From the results obtained, it is concluded that phosphorus supply from the planting time to the end of flowering stage, especially in the early stage, is necessary for good yield and quality of seeds. (2) Potassium experiment The plants which were supplied with potassium from the planting time (Sept. 26) to the full bloom ing stage (Mar. 22), had much the same seed yield as control plants supplied with potassium throughout all stages of growth. Even the plants which were supplied with potassium until the bolt-ing stage (Feb. 15) made no great difference in seed yield compared with the control. But in the treatment supplied with potassium during the period only from the planting time to the flower bud dif-ferentiation stage (Dec. 17), plants suffered from severe potassium deficiency and had remakably lower seed yield (about 1/3 of the control). The causes for this consisted in inferior development of the secondary and the tertiary lateral shoots. Seed size in this treatment was about the same as cont-rol, but some of seeds germinated within the pods. Even if potassium supply was withheld in the early stage, plant growth became vigorus and seed yield also approached to that of the control, by the later application of potassium after Dec. 17. But potassium application after Feb. 15 was too late to recover the plant growth and seed yield. The plant which were withheld potassium supply throughout all stages of growth, had by far lower seed yield than other treatments. As to seed potassium concentration, percentage germination and incipient elongation rate of radi-cles, there were no differences among treatments. From the above results, potassium supply is ne-cessary at the least until the bolting stage for good yield and quality of the seeds.
Penicillium decays of Satsuma orange fruits in storage were observed in Tokushima from 1954 to 1958. Green mold caused by Penicillium digitatum occur-red in higher rate than blue mold caused by P. italicum. Green mold was commonly observed in early period of storage, and blue mold occurred later. From the inoculation experiments under storage condition, it was found that the incubation period of green mold was shorter than that of blue mold. Very easy infection of Penicillium was obtained when the oil glands were pricked. Freshness of wound of fruit rind was necessary for the infection of P. digitatum, while it was un; necessary in the case of P. italicum.
Following our previous work, successive experi-ments were performed to study the effects of gib-berellin on several flower crops, mainly on flower hastening, from the end of 1957 to the beginning of 1958. Gibberellin was applied to the plants as an aqueous solution and the concentrations of spray-ed solution were 25, 50 and 100 ppm. Potted plants in glasshouses were used for this experiment. 1. Gibberellin effects on flower hastening and flower-stalk elongation of cyclamen (Cyclamen Persicum MILL.) and that on vegetative growth stimu-lation of petunia (Petunia hybrida VILM.) were all apparent. These effects were already found in our previous experiment. As it seems that flowering of treated cyclamen was about 20_??_25 days earlier than control plant in this experiment, the effect of flower hastening on cyclamen was more remark-able than in the previous case, probably because of the applications of earlier spraying and more con-centrated solution. In petunia, its vegetative growth was not only stimulated, but flowering was also hastened. 2. Concerning the experiments with the mono-cotyledonous and bulbous plants, there were seen also flower hastening effects on freesia (Freesia refracta KLATT.), trumpet narcissus (Narcissus Pseudo-Narcissus L.) and Dutch iris(Iris hollandica HORT.), and the greatest extent of flower hastening on each plant was about 3 to 7 days. But there were hardly any effects on Easter lily (Lilium longi florum THUNB. var. giganteum HORT). As a matter of fact, flower hastening effect in the early spray-ing was more remarkable than that in the later spraying in case of freesia (Fujinomine) and Dutch iris. In regard to the plant height increase or flower-stem elongation of these plants, gibberellin had little or no effect. 3. Flowering of pansy (Viola tricolor L.) was hastened. Furthermore, plant height and peduncle length were markedly increased. 4. Flowering of Primula malacoides FRANCH. was also hastened. In addition to this effect, length of main Sower-stalk was remarkably increased and petiole length was also increased slightly, but these influences did not seem to cause an unfavour-able result to the market value of potted plants. 5. Young plant growth of calceolarria (Calceolarria rugosa RUIZ et PAV.) was stimulated by the application of gibberellin. Flowering of Amuradonis (Adonis amurensis REGEL et RADDE.) was hastened and vegetative growth was strikingly increased afterward. When the pruned branches of hydrangea (Hydrangea macrophylla SER.) were dipped into glass bottles containing gibberellin solution, bud, sprouting and leaf expansion were hastened by such gibberellin treatment. 6. There were no effects of injury or damage on the germination of pollen grains taken from treated plants of cyclamen and Primula malacoides FRANCH.
The experiments presented here were designed to investigate the methods for the breaking of the dormancy of Portulaca grandiflora seeds, and the results are summarized as follows: 1. The moist low-temperature stratification was very effective in hastening the after-ripening of Portulaca seeds. But, when the moist seeds were exposed to 30°C before or during the stratification, the after-ripening of the seeds did not proceed at all. The stratification under oxygen deficiency de-layed the after-ripening of the seeds, and the seeds stratified under the saturation of oxygen or carbon dioxide almost remained in the dormant state. In addition, the seeds which were stratified after one year's storage at room temperature showed the decreased after-ripening as compared with those stratified immediately after the harvesting. 2. The drying of the seeds after the stratifica-tion increased the germination capacity significantly and this increased germination capacity were main-tained for as long as 5 weeks. The germination capacity once endowed by the drying after the stra-tification, however, was decreased by the moisten ing after the drying, and thus the germination ca-pacity was reversed repeatedly by the alternative drying and moistening. 3. The dormant seeds did not germinate during 5 months when they were kept on the moist sub-stratum at 30°C. 4. The optimum temperature for the germination of Portulaca grandiftora seeds seems to be rather high. The germination was obtained even at 40°C though it was decreased at such high temperature. 5. The solution of thiourea and KNO3 or the fumigation by CN-gas increased the germination, though their effects were not so great. Moreover, the high concentration of thiourea and KNO3 inclined to delay the germination at low-temperature. But, this tendency was undetectable when the seeds were germinated at high temperature. 6. The time required for the maturation of seeds was about 10 days, but it was shortened when the period of maturation was shifted so later that the temperature became higher.
In order to get new ornamental types in Hibiscus, interspecific crosses were made with 6 different species (Table 2. Tachibana et al. 1957). Three combinations H. mutabils×H. Moscheutos, H. coccineus×H. Moscheutos and H. Moscheutos×H. Coccineus, pro-duced fertile F1 seeds(Table 3). This paper concerns the characteristics of F1 plants obtained from the first cross which seems unusual and interesting because the parent species are entirely different in their chromosome numbers and status (mutabilis: woody shrub; 2n=92, 100. Moscheutos: pereenial herb; 2n=38). 1) The F1 plants were markedly poor in vegeta-tive development and about half of them died during earlier stages of growth, although wide variations in vitality were found among them (Table 5). 2) The F1 plants developed several woody shoots in the second year and had very late flowering (Fig. 2). Other characteristics such as leaf shape, color and size of flowers, size and pubescence of seeds, etc. were generally intermediate between those of the parents or more or less mother-like (Tables 6_??_9). 3) Since they showed a high degree of sterility, only a very few seeds were obtained from F1 plants having Moscheutos-K strain as father plant which seemed somewhat heterozygous. Back-crosses with mutabilis pollen yielded slightly more seeds. 4) A greater part of the pollens of F1 plants was transparent and abortive (Fig. 4). Remarkable abnormality was observed in the tetrad formation stage (Fig.5). 5) A few F1 plants seemed somewhat promising for ornamental use owing to their long flowering season and increased flower numbers
This experiment was carried out to clarify the effect of the high temperature treatment on the new bulb formation and development in tulip bulbs, and to find out the most desirable degree of injury in flower bud for getting the high yield of the new bulbs. The bulbs were treated at 35°C before planting. The varieties used were Feu Brilliant and William Copeland. The plants dug up at the end of the growing season, and the relation between the development of the floral and vegetative organs and the number and yield of the new bulds was studied. The plants which had developed flower stalks and flower buds, but had not bloomed, produced highest yield: 23_??_30 percent increase over that of the control plants. The plants, which developed flower stalks, but not flower buds, got largest number of new bulbs, 20_??_26 percent over the control, but their weight was not so high as in the plants above mentioned. The plants which failed to develop flower stalks porduced poor yield of new bulbs. The central nose was most sensitive to the treatment. When the treatment was given, the flower bud was affected at first, and as the length of the treatment was prolonged, flower stalk and vegetative organs became to be affected successively. When the flower bud was slightly injured, the growth of the ventral bud and offsets was accelerated and the yield of the new bulbs was increased. When the treatment was drastic enough to injure other parts, new growth was retarded and the yield was reduced. The most desirable degree of the treatment was long enough to make the flower bud fail to open, but not to affect furthermore. In this case, highest increase of yield of new bulbs is expected over that of the control.
The paper reported here deals with the experiments on the differences in the response of the tulip bulbs to the high temperature treatment for making the plants blind to get high yield of new bulbs in relation to the variety, size and dormancy of the bulbs. The bulbs of 12 varieties were treated at 35°C for 13 or 16 days from September 27. It was found that the varieties the bulb of which had short dormant period were sensitive to the treatment, and the shorter term treatment was enough for those varieties to get high yield of new bulbs. In the second experiment, bulbs of three sizes, 9, 11, and 13 cm up in round, were treated at 35°C for 10, 13, or 16 days. The result showed that the smaller the bulbs the more sensitive to the treatment. This may be due to the fact that the small bulbs have shorter dormant period, and also, they have poorer storage of nutrients in them. In the third experiment, three sets of the bulbs, which had been stored under different conditions from July 25 to September 26, one in the storage-room of natural temperature, one in the cellar, and the other suspended in the well, were treated at 35°C for 13 days. The result showed that the bulbs stored in the well were most sensitive to the treatment, the ones stored in the cellar came next, and the ones stored in the the storage room came last in the order. Low temperature in the well seemed to be effective to break the dormancy of the bulbs, then to make them more sensitive to the treatment. Those experiments revealed that the dose of the high temperature treatment should be varied depending on the variety, size and dormancy of the bulbs in order to get the highest yield of the new bulbs for propagation of tulips.