Because it has been known that azolides have generally higher chemical reactivity, the present authors synthesized TH-656[1-(α-naphthaleneacetyl) -3, 5-dimethylpyrazole] in expectation of new activity as a plant growth regulator, and compared biological activity of TH-656, NAA(α-naphthaleneacetic acid) and TH-564(3, 5-dimethylpyrazole). The results obtained were summarized as follows: 1. TH-656 showed higher biological activity (both promotion and inhibition) on the growth of Avena coleoptile sections, the 2nd leaf sheath and coleoptile of intact rice seedlings thanNAAat the same molar concentration. At the existence of externally applied gibberellin, TH-656 showed more remarkable inhibition of the growth of the 2nd leaf sheath of rice seedlings than NAA. On the other hand, the growth inhibition of the 2nd leaf sheath of rice seedlings caused withNAAwas restored with gibberellin but the inhibition with TH-656 was not. TH-564scarcely showed a biological activity on the growth of Avena coleoptile sections and intact rice seedlings even at the high concentrations without any relation to the existence of externally applied gibberellin. 2. Then, the effcets of TH-656, NAAand TH-564on the gibberellin-induced parthenocarpic fruits of Delaware grapes were compared at the concentrations of 1/2n mM (n=0-4) on 20, 30 and 44 days after the full bloom. As a result, TH-656 and NAA retarded maturity of the grape fruits, but NAA did not retard uniformly the maturity among the fruit clusters on a tree and the berries on a cluster at the all concentrations used in the present experiment and TH-656 also fell to retard uniformly at the treatments after 20 and 44 days from full bloom, but at the treatment after 30 days from full bloom the maturity was remarkably retarded by spraying of solutions at the higher concentrations than 1/8mM, that is, desirably at 1/2 or 1mM. TH-564did not affect the maturity of the fruits at all concentrations used in the present experiment.
Water sprouts developed usually from the portion of branches at which wood was removed, or from the headed back portion of the one-year-old water sprouts. These portions contained less Ca in the dormant period compared with the similiar portions of bearing shoots. Water sprouts began to grow earlier than the shoots of normal vigor. The former contained more lignin and less Ca than the latter throughout the growing season.
In Japan, the symptom of stem pitting of citrus has been found on trees suffered from dwarf virus disease of Hassaku (Citrus hassaku HORT. EX. TANAKA), Buntan (C. grandis OSBECK), Washington navel orange (C. sinensis OSBECK) and etc. In the present studies, stem pitting of one and two years old mexican lime (C. aurantifolia SWINGLE) seedlings, inoculated by bud graft infected with Hassaku dwarf virus taken from twenty five or twenty seven years old Hassaku trees suffering from Hassaku dwarf virus disease (at Wakayama prefecture), were observed anatomically and histochemically. Under the investigation of serial transverse sections of stem, hypertrophic and hyperplastic parenchymatous cells as previously noticed, were observed in the xylem and the phloem. These cells formed the disorganized abnormal tissue in the secondary vascular tissue (Fig. 1 and 2). In order to study the developmental change of this abnormal tissue, serial tangential sections of wood were made (Fig. 4 and 7). Examination of such material revealed that the ray initials in cambium reacted to virus initially, and these affected cells failed to differentiate into ray tissue, that is, elementary tissue of the xylem and the phloem. As the secondary thickening growth proceeded, these abnormal cells missed their normal organization, divisioned hyperplastically, and then formed abnormal tissue or lesions as previously described. Furthermore, as the thickness of wood increased, the walls of these abnormal tissue cells were delayed in lignification as compared with surrounding normal tissue cells (Fig. 2). Because of this delaying in lignification of cell wall, pitting was formed on the wood and remain in evidence if the bark was removed. However, in the case of abnormal tissues which composed only of lignified abnormal cells (Fig. 6 and 8), stem pitting were not shown even if the bark was peeled, and such examples were observed frequently in Hassaku trees growing in outdoor condition. Although annual rings in wood of Hassaku tree could not be identified surely, growth rings were recongnized. These rings were distinguished into two kinds. One was consisting mainly of fiber cells of fiberous tissues of vasicentric type (Fig. 5B and C). And the other was consisting mainly of parenchymatous cells or parenchymatous tissues of aliform type (Fig. 5D), diffused type (Fig. 5E), or terminal type (Fig. 5F). And lignified abnormal tissues in the wood of Hassaku trees, were recognized mostly lesions in growth rings of the latter kind. From the above anatomical observations the following hypothesis may put on: the abnormal initial cells in cambium underwent severe division by the time, when the cambium formed parenchymatous growth ring. On the other hand, at such time as the cambium separated fiberous cells, these abnormal initial cells in the cambium ceased their severe hyperplastic divisions. In other words, the formation of stem pitting of citrus trees might be under the control of the physiological situation of cambium.
The effects of manganese and nitrogen levels on the occrrence of so-called“Abnormal defoliation”of Satsuma orange were studied, using young trees in sand culture. The high levels of manganese in nutrient solution induced the increase of manganese content in fibrous fine roots and in leaves. In this case, the manganese content in leaves increased up to the same level in the trees showing the symptom of“Abnormal defoliation”in orchard, and the brown spots which are characteristic of“Abnormal defoliation”were observed on some leaves of the experimental trees, without accompanying any other injurious effects such as retardation of growth, decay of roots, and as defoliation. Manganese content in the fibrous roots was increased along with the increase of nitrogen concentration in nutrient solution, whereas the change of manganese content in leaves was not observed. From the results mentioned above, it was concluded that the excessive absorption of manganese may be due to the excess of available manganese in the culture media, and also that the brown spots appearing in leaves will be taken to be the primary or essential symptom of this disorder.
1. In order to investigate the response of Satsuma orange trees to phosphate fertilization in field condition, P rate experiments were carried out in two orchards on diluvial loamy land of Ehime Fruit Tree Exp. Sta. which had received phosphate fertilizer for past 10 years. 2. One experiment, Exp. 1, was started in 1960 in 11-year-old orchard, and consisted of 4 treatments receiving 0 (P0), 200 (P0.5) and 400g (P1) of P2O5 per tree annually under the mulching of rice straw, and 0 (P0-C) under the clean culture. The superphosphate was buried with the soil into 30 holes of 40cm in depth and 6-7cm in diameter around the trees. The tree vigor and yield were not appreciably affected by P rate during 9 years from 1960 to 1968. Fruit qualities were not greatly different among P treatments until the 5th year and also in the 7th year. Fruits grown on P1 treatment in the 6th, 8th and 9th year showed the delay of color development, and had lower soluble solids and acid content than fruits on P0-C and P0 treatment. Leaf P in P0-C and P0 treatment was maintained at the satisfactory level throughout 9 years period. Phosphate application increased P content of the leaves after the 8th year, but the increase was small. 3. Other experiment, Exp. 2, was started in 1963 in 3-year-old orchard, and consisted of 5 treatments receiving 0 (P0), 430 (P1B), 860 (P2) and 1, 720g (P4) of P2O5 per tree, and receiving 430g (P1A) of P2O5 by the surface application during 6 years. Superphosphate used in the P1B, P2 and P4 treatments was buried into soil layers of 40cm depth in the areas of 1 meter around the trees prior the transplanting. No significant response of tree growth and yield due to P rate occurred during 6 years from 1963 to 1968. After the 4th year, fruits showed that with increased amounts of applied phosphate, soluble solids and acid in juice were lowered, and ratio of soluble solids to acid increased slightly. In the 5th and 6th years, the delay in development of deep orange color became remarkable in fruits grown on high P treatments. No difference in leaf analysis was found until the 4 th year. However, there was the significant increase in leaf P during late 2 years in the P2 and P4 treatments, and the decrease in leaf N and K. 4. The significant difference in fruit qualities between no P and high P treatments was remarkable in 1967 where the rainfall during 6 months from late-spring to mid-autumn was very scarce, attaining only to one-sixth of the average precipitation for recent 10 years. This trend was recognized in both of Exps. 1 and 2. Especially, the decrease of acid content in fruits grown on P1 treatment of Exp. 1 and on P2 and P4 of Exp. 2, was greater than that in fruits grown on trees without the application of K fertilizer for 4 years. Above facts will suggest that the effect of P fertilization on fruit qualities may be accentuated greatly by the climatological condition.
In order to determine the cause of pollen abortion in male-sterile Satsuma orange, certain morphological and cyto-histological studies with anthers were undertaken as compared with the male-fertile Buntan and Natsudaidai. Cyto-histological observations on Satsuma orange treated with temperature and IAA were also carried out. 1. In the early stage of anther development, meiosis and microspore formation were quite similar in fertile and sterile species of Citrus. 2. Tapetum in fertile species started to degenerate soon after the liberation of microspores from the wall of tetrads and almost completely degenerated during the disappearance of vacuoles from the cytoplasm of microspore. 3. Tapetum in sterile Satsuma orange occassionally showed an extraordinary development of large vacuole at the vacuole appearing stage and completely disintegrated at the vacuole enlarging stage of microspore. However, tapetum which remained cellular without large vacuoles persisted unusually long and degenerated at the vacuole enlarging stage of microspore. So it may be suggested that the tapetum in sterile Satsuma orange can not play normal nutritive role and supplies less nutrients to the developing pollens. 4. Abnormal behavior of tapetum in Satsuma orange could be recovered partially and the pollen fertility could be increased by temperature (at 20°C minimum temperature) and IAA treatments (500 ppm) to those plants growing under unfavorable temperature condition.
1. The effects of CCC on vegetative growth and sex expression were investigated for raising a useful measure of applying CCC to the practical cucumber growing. Seven cultivars used were grown in a greenhouse during successive four seasons. 2. The effects of CCC and of various environmental factors to the sex expression in cucumbers were, in general, definitely smaller than those of genetic factors. Accordingly, the choice of suitable cultivars becomes to be a quite positive practice and CCC should be taken as an additional tool for modifying their genetic control. 3. CCC was applied in 3 different ways, i.e., 2, 4, and 6 times of applications with 2 days intervals using always the same concentration of 1000 ppm. A number of pistillate flowers were effectively induced by CCC throughout all the 4 seasons examined. It was noted that there was a quadratic relation of the number of pistillate flowers to the frequency of CCC treatments, and also that the preferable repetition for such induction became to be somewhat 4 in times. Each cultivar showed more or less different sensitivity to CCC application and also different behavior from season to season. And, it was made clear that such differential sensitivity of cultivars to CCC did not always correspond to their sensitiveness to environmental factors. 4. In the case where a rather large effect of CCC was observed there could be noticed a remarkable variation in the number of pistillate flowers from individual to individual in the control plot. This might mean that CCC can act more effectively in cases where plants are in an unstable situation for the sex expression. 5. The growth inhibitory effect of CCC was also appeared in both stem elongation and leaf expansion for each season. A cultivar showing a rather remarkable growth inhibitory effect of CCC had also a growing tendency of higher seasonal variation. 6. The exact relationship between the growth inhibition and the pistillate flower induction could not be made clear so far. But, it was duly suggested that the suppression of growth was not directly connected with the pistillate flower induction.
Experiments were carried out to compare the effects of anions on the growth and inorganic constituents of several vegetable crops supplied with different forms of nitrogen in sand culture. In the preliminary experiments with onion supplied with nitrate nitrogen, plants showed inferior growth with sulphur deficiency symptoms at sulphate (SO4) 0me, slightly inferior growth without deficiency symptoms at SO4 0.2me, and better growth was observed between 0.5 and 10me. While, there was detected no chlorine deficiency symptoms even at chloride (Cl) 0me, and plants showed normal growth between Cl 0 and 10me. In both sulphate and chloride series, plant growth was lowered at higher concentrations than 25me, and the higher the concentration, the less was the growth. In the next experiments of cabbage, turnip, and onion supplied with NaNO3, NH4NO3, or (NH4)2SO4 as nitrogen source (8me as N), there was no clear difference of growth between the treatments supplied with cations as sulphate or chloride (11me as SO4 or Cl except (NH4)2SO4 treatment). No difference of growth was found also between (NH4)2SO4 plants in which ammonium, in addition to other cations, was supplied as sulphate, and NH4Cl plants supplied as chloride (19me as SO4 and Cl, respectively). However, growth of plants in both treatments was markedly inferior to that in the treatments supplied with other forms of nitrogen. The sulphur concentration in the leaves was higher in the SO4 series than in the Cl series, and the chlorine concentration in the leaves was higher in the Cl series than in the SO4 series, irrespective of the forms of nitrogen and the kinds of vegetables tested. In the third experiment of onion and turnip supplied with NaNO3 or (NH4)2SO4, the effects of SO4 and Cl given as sodium salt on the growth were compared in the higher concentrations of 12-48me. The higher the concentration of SO4 or Cl, the lower was the growth, however, there was no difference of growth between SO4 and Cl series regardless of the forms of nitrogen supplied. Finally, the effects of different concentrations of phosphorus on the growth of cabbage supplied with different forms of nitrogen were investigated. Growth was increased up to P 0.6me, however, further increase was not observed at P 3me both in NaNO3 and NH4NO3 series. In (NH4)2SO4 series growth was not affected by phosphorus concentration, and their growth was markedly inferior to ones in the other forms of nitrogen. Phosphorus concentration in the leaves became higher with increasing concentration of phosphorus supplied, irrespective of the forms of nitrogen, and was the highest in (NH4)2SO4. However, phosphorus deficiency symptoms appeared on the plants both at P 0 and 0.2me, in any nitrogen form.
Rhizome-tips of Cymbidium goeringii REICHB. F. cultured on the basal medium (KNUDSON′s C with NITSCH′s microelement), developed into rhizomes without the shoot formation. However, the addition of 10mg/l kinetin to the medium induced shoot formation. Histological studies were carried out with the shoot formation in order to analyze the rhizome-shoot differentiation. Results of the observation were summarized as follows: During the growth of the rhizome, the apical meristem remained to a primitive appearance. A few mitotic figure was observed within the apical meristem from which small leaf primordia were porduced and developed into scale-like leaves. The cells in the leaf primordia appeared to be less meristematic and considerably vacuolated. A remarkable expansion of the cells in the subapical region could be responsible for elongation of the rhizome. In the course of the shoot formation, on the contrary, leaf primordia were produced with a short plastochron then developed into leaves with vascular tissues. Relatively abundant mitotic figures were observed not only within the apical meristem but also in the lower part and the leaf primordia. The cells in the leaf primordia and the subapical region were smaller and less vacuolated than those of the rhizome.
1. An extensive chromosome survey was carried out for the purpose of elucidating the actual variation procedure in chromosome structures of the present-day chrysanthemums, cultivated exclusively in Japan and especially for the exhibition use. 2. The cultivars of chrysanthemum used for the present study were as follows : Number of the large-flowered forms for the exhibition use attained to 80 in total, that of the medium-flowered forms to 32, and that of the small-flowered forms to 14. 3. Results of the present chromosome survey were compiled in Table 1, revealing the following several facts. 1) Throughout the whole exhibition forms 8 in chrysanthemums, there occurred various somatic chromosome numbers, ranging from 52 through 75+B. 2) The variation range in those chromosome numbers showed definite difference from type to type of the cultivars. In general, a still wider variation, ranging from 54 through 75 +B, was also obtained with certain large-flowered exhibition forms, but rather narrower variation could be noticed in some other cases. 3) It was quite remarkable that the varieties having the large single-petaled flowers, i.e., Hiro-mono, consisting of Hiro-noshi and Mino-giku, which belong to the large-flowered type, showed usually a much higher number of their chromosomes, ranging from 70 to 75+B, throughout 18 varieties out of 21 examined. 4) A rather slight variation, ranging from 52 to 56, was usually found with various medium-flowered exhibition forms, such as the mobile-petaled one (Edo-giku), the brushy-petaled one (Saga-giku), the thready-petaled one (Ise-giku), and as the single-petaled one (Higo-giku). 5) Chromosome constitutions of a large number of present-day cultivars in chrysanthemum, belonging to the incurved-petaled (Atsumono) and to the spider-petaled forms (Kudamono), were compared with those of old ones, which had been surveyed by SHIMOTOMAI ca. 35 years ago (1932). It have been disclosed by him that the varieties composed of 60 chromosomes were met with most frequently, and that of 53-59 chromo somes and of 60-67 chromosomes showed the quite similar rate of occurrence, respectively, throughout the whole cultivars studied. With the present-day chrysanthemums, in clearcut contrast, the variation range of somatic chromosomes was definitely broadened out, extending from 54 through 73. Generally, varieties having 54 or its approximate number were found most frequently. The present-day small-flowered form (Bunjin-giku), having 54±1 chromosomes, showed a remarkably slight variation in characteristics as compared to those of many old-fashioned forms.
The carotene content of freeze-dried carrots in storage was kept well at low-temperatures (-30 °C, -20°C). The increase in weight by absorption of moisture was proportional to storage period. In general, surface color of the products rapidly faded and became yellowish white, but the change was retarded for some period at low-temperatures of -20°C or -30°C. The rehydration rate of the dried carrots decreased with duration of storage period, and the change was considerably repressed by the low-temperature storage. To improve the rehydration, use of warm water (45°C) was preferable to cold water.
Relation between the ripening and the drift of carbon dioxide production of harvested fruits was investigated to reconsider the meaning of respiratory pattern. The materials used were as follows: strawberries(Donner)and peaches(Hakuto, white flesh variety) as the species of which respiratory pattern has not been necessarily clear, tomatoes (Fukuju No. 2) as a typical climacteric class, and Satsuma oranges (Sugiyama, Citrus unshiu) as a non-climacteric class. The respiratory activities of pulp (or peel) homogenates of these fruits were measured to investigate the changes of respiratory mechanisms during ripening. 1. It was proposed from the results obtained in the present and preceding experiments that the respiratory pattern of the harvested fruits should be classified in three types, not in two types of usual classification as climacteric and non-climacteric. It is as follows: (1) Respiratory rates gradually decrease through ripening process…… the gradual decrease type. (2) Respiratory rates increase temporarily, and full-ripe occurs after the peak of respiration…… the temporary rise type. (3) Maximum rate of respiration is shown from full-ripe to over-ripe stages…… the late peak type. According to the classification mentioned above, citrus fruits belong to the gradual decrease type, and the temporary rise type corresponds to the typical climacteric class including fruits such as tomatoes, bananas, pears, avocados, etc. Japanese persimmons, strawberries, and peaches belong to the late peak type. In the fruits of the late peak type, as a characterististics of the type, the relation between the time of respiratory maximum and the degree of ripeness is not clear as compared with temporary rise type, and the peak height of respiration varies remarkably among individual fruits. 2. Regardless of respiratory pattern, it was seemed that qualitative change of respiration took place in the course of ripening. The increasing effect of cofactors(NAD, AMP, ATP, cytochrome c) on the oxygen uptake in strawberry homogenates changed remarkably during ripening. In the tissue slices and the cell-free extract of Satsuma orange peel, the effect of organic acids application on oxygen uptake changed during yellowing of the fruits which had been harvested at almost-green stage. At immature stage, the addition of malic and succinic acids increased respiration greatly, but citric acid had no effect. At yellow-colored stage, the effect of the former two acids diminished, but citric acid showed the effect in a high degree.