In order to clarify biochemical natures of the resistance on the chestnuts tree to chestnut gall wasp, polyphenolic substances were estimated as compared with the resistant wild Japanese chestnuts and the susceptible ones. Furthermore, contents in the barks of both current year shoots were determined every month. The results obtained were summarized as follows: 1) In wild Japanese chestnuts similarly in the cultural varieties, catechol tannins and leucoanthocyanidins are abundant, but pyrogallol tannins are a little in the resistant varieties. 2) Total tannins decrease accordnig to ageing and the amount of decrease from June to August in the resistant trees are less than of the susceptible. 3) Catechol tannins are poor within the current year shoots are young, but increase their content with maturing the tissues, and trend are most remarkable increase during the period from middle or late June to early August, that is, from before the laying eggs of chestnut gall wasp through the period of hatching to the gall formation. The resistant varieties contain more catechol tannins every time than the susceptible ones, and are more active in biosynthesis. 4) As for leucoanthocyanidins, the same inclination with catechol tannins was observed. 5) Pyrogallol tannins contain more in the susceptible trees and in immature tissues, and decrease seasonaly, and their decrement is greater in the resistant.
The mechanism of the Citrus pollen-tube growth into style and ovary, fertilization and development of embryo were studied. The results obtained were summarized as follows: 1. The pollen tubes of Natsudaidai grew faster than Satsuma orange in pistil of Natsudaidai or Satsuma orange. 2. The fertilization took place about 8 days in selfed Natsudaidai, 12 days in the crossing of Satsuma orange with Natsudaidai, and 14 days in self-pollination of Satsuma orange after pollination, respectively. 3. The fertilized eggs and nucellar cells began to divide 40 to 50 days after pollination both in selfed Natsudaidai and crossed Satsuma orange with Natsudaidai. 4. In Natsudaidai, embryo development was very slow and reached the globular stage 58 days, heart-shape embryo stage 72 days, and the complete embryo stage 120 days after self-pollination. 5. The nucellar cells of one to three layers near the micropylar of embryo sac and the region of the micropylar end to one-third of embryo sac have the ability to form nucellar embryos.
1. To clarify the effects of fruiting on the manganese content and other mineral compositions of spring cycle leaves, four 67-year-old trees were selected in an orchard. In 1963, two trees (No. 22 and 25) of them were in“off”year in fruiting and the others (No. 1 and 42) were in“on”year as referred to Fig. 1. From each tree, eight 2-year-old fruiting shoots (F) and non-fruiting shoots (V) were taken just before the harvest time in the middle of November. On the 2-year-old fruiting shoot, 7-month-old leaves of spring cycle growth were divided into three types (FFF, VFF and VVF) as referred in Fig. 2. There was only one type of 7-month-old leaves (VVV) on the 2-year-old non-fruiting shoot. 2. Mean dry weight of leaves on new shoot from“off”year trees was considerably higher than that of“on”year trees, while the mean dry weight of leaves was lower on new fruiting shoot (FFF) compared with those of other three types of new non-fruiting shoot (VFF, VVF and VVV). 3. Leaves from“on”year trees had significantly higher contents of N, Ca and Mn, and lower content of K than those from“off”year trees. There was no significant difference in the levels of P and Mg between“on”and“off”year trees. 4. Leaves on new fruiting shoot (FFF) were significantly higher in Mg, and lower in N, P and K than those on new non-fruiting shoot (VFF, VVF and VVV). No significant difference was found in the levels of Ca and Mn between fruiting and non-fruiting shoots. 5. The adjacency of a fruit affected most strongly the concentration of K in the leaf, viz. the lowest K concentration in the leaves behind fruits (FFF) and the highest K concentration in the leaves from“VVV”shoots. There were not clear gradients in the concentrations of another elements between the leaves from four different types of shoot. 6. In the experiment of 1966, highly significant difference was found in the manganese content of leaves on non-fruiting shoots (VVV) between“on” and“off”year trees growing on four different groves which had fairly low available manganese in soils. 7. Results from the present study suggest that differing from potassium, the manganese concentration of Satsuma orange leaves is not affected directly by the fruiting, but, is fluctuated by tree growth habits in the previous season.
Annual variations in the acid and soluble solids contents in Satsuma orange fruits were determined from the 8 year′s data in fertilizer and soil experiments which had been carried out over 10 years in Ehime Fruit Tree Experiment Station. The acid content of fruit juice varied with year of production, while the variation of soluble solids content was not so distinctive. In the fertilizer experiment, for example, acid content varied from 0.82 to 1.41g as citric acid per 100ml of juice, and soluble solids varied from 11.23 to 14.51g per 100ml of juice. Hence the acid largely affected on the ratio of solids to acid which varied from 10.0 to 13.7. Such tendency was similarly recognized in 3 different experiments. Summation of available heat above 13°C per month differed considerably from year to year. The diversity was most apparent in September, followed by June and July in order. To know the relations between monthly heat units and the acid or soluble solids content, correlation analysis has been made. Negative relation between the heat units and the acid contents was found in June, July and October, especially significant correlation in June. Similar trend was also shown in the results of experiment that air temperature was slightly raised by the covering of vinyl-cloth on the tree crown of Satsuma orange. Judging from the data obtained herein, acid contents appear to be affected by the temperature more than the fertilizer and soils. However, there was no significant correlation between available heat units and soluble solids or ratio of solids to acid.
This study was carried out to prove whether the symptoms of so-called“Abnormal defoliation”in Honshu and Shikoku districts are the same as that in Kyushu district or not. In our observation, it was recognized that the symptoms were the same among these districts. But in Honshu and Shikoku, the symptoms of “Abnormal defoliation”were confused with that of greasy spot, phoma rot or defoliation by cold damages. The Satsuma orange tree which showed the symptoms of“Abnormal defoliation”contained more than 100ppm of manganese in its leaves, as observed in Kyushu. High content of manganese in the leaves may be caused by the increase of water soluble manganese in the soil. It was observed that the water soluble manganese content in the soil is closely related to the soil pH. It was not possible, however, to clarify the relationship between the soil acidity or water soluble manganese content in the soil and the occurence of“Abnormal defoliation”in the present investigation. It would be suggested that the soil acidity or water soluble manganese content in the soil observed was not the same as that at the time of the occurrence of“Abnormal defoliation”.
1. It has been known that the strawberry plants forced early in winter develop small leaves with short petioles, short flower stalks, and few runners, due to shortage of chilling period to break“dormancy”. In this study, ten varieties were transferred from the open to a greenhouse, in which night temperature was maintained above 10°C, on Jan. 4, Jan. 18 and Feb. 1, and their subsequent developments of leaves, flower clusters and runners were observed in order to elucidate varietal differences in chilling requirement. 2. The later the plants were transferred to the greenhouse, the longer were the lengths of petioles and leaf blades, and this tendency was outstanding especially in Fresno, Donner, Kogyoku, Victoria, Shikinari, Fairfax and Otome varieties. 3. The number of flowers increased with the delay of the transfer in Shikinari, Victoria, Kogyoku, Donner and Fresno varieties, while it decreased in Benizuru, Hotta Wonder, Fukuba, Otome and Fairfax varieties. The number of days from the transfer to the flowering decreased with the delay of the transfer, except Benizuru, Hotta Wonder, Fukuba and Otome, in which the number of days was the least in the plot transferred on Jan. 4. 4. The number of runners produced increased as the date of transfer was delayed. Fresno and Donner varieties produced no runners during the experimental period in the treated plots. 5. Based on the results obtained it may be concluded that Benizuru, Hotta Wonder and Fukuba varieties, which have been used for forcing culture, have shallow dormancy, Kogyoku and Donner, which have been used for semi-forcing culture, have medium one, and Fresno has the deepest one.
1. A plastic house in which strawberries were grown was subjected to the present investigation. It was of an east-west orientation, composed of four bamboo-supported unit houses interconnected side by side. The house was built on a slope inclined at an angle of 35°. The total area it covered was about 200m2. Measurements were carried out chiefly for temperature and air circulation in the house from the 28th to the 30th of January, 1966. 2. At noon (from 11.00 to 14.00) on a fine day, the highest temperature in the house was 34.2°C in the third unit house. At night (from 22.00 to 5.30) the lower the location of the unit house was, the lower the temperature. There was an ascending air stream over the stone-wall during day and night, which caused the difference of temperature among the unit houses. 3. It seemed quite possible that the difference of temperature had a considerable influence on the growth and production of strawberries in the house.
Field experiments were conducted for two years to evaluate the effect of growth regulating substances such as p-chlorophenoxyacetic acid (CPA), gibberellic acid (GA3), and N6-benzyladenine (BA) on the fruit set and yield of tomato plants treated by high temperature. In the first year a high temperature of 40°C for five hours markedly reduced the fruit set and yield. Fruit set of flower when treated by high temperature at anthesis recovered after CPA spray (50ppm), whereas when treated at bud formation they failed to respond to CPA spray and did not develop further. BA spray (10ppm) before high temperature treatment combined with CPA spray showed a remarkably favorable effect on fruit set of flowers treated by high temperature not only at anthesis, but also at bud formation. Consequently, the spray with CPA and BA increased considerably the yield of high temperature treated plants. In the second year high temperature of 40°C applied for four hours reduced the fruit set and yield only of the first flower cluster of plants subjected to high temperature when its first flower just began to open. The spray with CPA or CPA plus BA remarkably increased the yield of the first and second clusters of plants treated by high temperature. There was no favorable effect of combination of CPA plus BA over CPA alone. Occurrence of puffy fruits increased by CPA or CPA plus BA spray regardless of high temperature treatment in both years.
Experiments were planned to ascertain the practical use of plastic materials as a substitute of straw mat, which has been used mostly as an outside covering of plant beds for protection from low night temperature. The air and soil temperatures inside the tunnel coverings with various plastic materials, were compared with those of straw mat covering during the early spring season. The plastic materials used in this study were as follows. A-mat: Foamed polyethylene sheet, 0.35mm thick. B-mat: Wadded polyethylene sheet, made from double layers of 0.05mm polyethylene film, with inserted Tevilon (PVC) fibre, 0.25mm thick, between them. C-mat: Laminated polyethylene film, made from double layers of 0.05mm polyethylene film, and re-inforced with polyethylene net. D-mat: Laminated polyethylene film, made from triple layers of 0.05mm polyethylene film. E-mat: Laminated polyethylene film, made from two layers of ordinary and one layer of corrugated polyethylene film, each 0.5 mm thick. F-mat: PVC film 0.1mm thick, filling aluminium foil. G-mat: Laminated polyethylene film, made from one layer of 0.05mm ordinary film and one layer of 0.025mm pneumatic polyethylene film, containing many small air-filled knobs. The best heat-keeping was obtained with straw mat on a clear night, that is, heat loss under such covering was less than under other plastic mats. On rainy and snowy nights, however, every plastic mat showed higher heat-keeping property than straw mat. Minimum inside temperature of the PVC tunnel covered with moist straw mat was occasionally lower than in beds without cover. The amounts of sunlight transmitted through straw mat and F-mat were less than under other coverings, so the soil temperatures under PVC tunnels covered with them were lower than under other mats. Using pneumatic mat (G-mat), the inside temperatures were higher with the increase of air volume, on cloudy or rainy days, but there were no significant differences among them on clear nights. The amounts of heat insulating material inserted between two layers of polyethylene film (B-mat), influenced transmittability of solar radiation. So they showed high heat-keeping propertiy, according to their quantities, on clear than on rainy or snowy nights. In addition to heat-keeping property as a covering material, light-transmittability, water-proof-ness, tear strength and aging resistance should be considered.
To ascertain the effects of boron on growth, boron and sugar accumulations, several cruciferous vegetables were grown in sand cultures with 0, 0.005, 0.01, 0.05, 0.3-0.5 and 3-5ppm of boron (B). 1. The symptoms of boron deficiency in the forms of curling, rolling and deforming were frequently found in the upper leaves of plants supplied with 0-0.005ppm B in most of the vegetables tested. In the middle leaves of Chinese cabbage and cauliflower, the inner surface of midribs were cracked crosswise, and turned brown. Boron deficiency also inhibited growth of roots, especially development of lateral roots. In root crops such as turnip, radish, and Japanese radish, the surface of fleshy roots split and turned rusty brown because of being covered with cork. In addition, the shape of fleshy root of turnip and radish was transformed into a slender type as compared with the normal, round type. Only in the turnip roots, brown core was observed. In boron deficient cauliflower and broccoli, water-soaked portions appeared inside of heads, and at the advanced stage in cauliflower, internal split or hollow stem was observed, and the surface of heads turned brown. In broccoli, healing with callus formation was slower on the cut end of stems after harvest of heads. In seed production of Chinese cabbage, boron deficient plants supplied with 0.01ppm B were bushy, having flower buds with protruding stigmas. Pod set was reduced, and seeds were small. Consequently, seed yield was also remarkably lowered. 2. Injury due to excessive boron was shown by marginal yellowing and burning of the lower leaves in plants supplied with 3-5ppm B in all vegetables examined. Symptoms of boron excess in cabbage were slighter than in other vegetables. 3. Growth and yield of plants supplied with 0-0.005ppm B were considerably inferior to those of the control plants supplied with 0.3-0.5ppm B. The degree of growth reduction was more remarkable in fleshy roots or heads than in leaves. Because of slighter deficiency symptoms and less growth reduction of plants supplied with 0-0.005ppm B, cabbage and broccoli seemed to be more tolerant of boron deficiency than other vegetables. Significant reduction of growth and yield was not found in plants supplied with 3-5ppm B. 4. Boron concentrations of leaves, fleshy roots and heads which showed deficiency symptoms were less than 10ppm (dry weight basis). Plants containing more than 20ppm in their leaves were normal and healthy. Boron concentrations of leaves manifesting injury due to boron excess were roughly higher than 100ppm. There were small differences of boron concentrations among organs or leaf positions in boron deficient plants, but when sufficient boron was supplied, it was accumlated in leaves, especially in the lower ones. 5. There were no distinct difference in sugar concentration in leaves due to boron level in the solution. But sugar concentrations of both fleshy roots of root crops and heads of cauliflower were remarkably lower at 0-0.005ppm B applications as compared with the control. As for broccoli, there was no difference of sugar concentration in heads among the boron treatments. Except in cauliflower heads, the sugars consisted mostly of reducing sugars.
The purpose of the experiments reported here was to study the process of bulb formation at the depth of 6-10cm underground and the effects of temperature on cotyledon growth of A. rosenbachianum REGEL in wooden boxes, glass root-boxes and petridishes respectively. Observations indicate that the emerged epigeal cotyledon keeps the seedling green for about two months without sprouting leaves. The hypogeal cotyledon, especially its part 2-4mm from the base grows geotropically and rapidly for about thirty days. When the hypogeal cotyledon reaches to 6-10cm underground, the primary-root appears at the base of the cotyledon without lateral roots and it does not elongate over 3-5cm. At the growing point the first and second leaves differentiate succesively and develop into protective-and storage-leaf respectively, and at their base a small bulb develops at the depth of 6-10cm underground. The cotyledon develops normally at 5-25°C and grows more rapidly at 20-25°C than 5°C. Also, the mode of penetration of the growing point and desirable methods of seeding were discussed.
Budding and rooting of leaf cuttings treated with kinetin, TIBA and their combination have been examined using four species of Begonia. Leaf cuttings with the petiole were used in B. erythrophylla and B. evansiana, while square explants of the leaf in B. rex and an unknown species of Begonia. There were differences in response to kinetin and TIBA among the species. TIBA inhibited root formation in each species, while kinetin inhibited it in three species. B. erythrophylla, however, showed no response to kinetin. In B. erythrophylla, bud formation was promoted by TIBA treatment. On the contrary, the other three species were not affected by TIBA. However, by its higher doses there was an inhibition in their bud formation. Kinetin caused bud formation in the three species, while it did not affect that of B. erythrophylla. A combination of kinetin and TIBA was able to form buds in all the species, and showed more promotive effect than kinetin or TIBA alone.
Tin has been often found to be dissolved in large amount in canned tomato juice, and it is also known that nitrate in tomato fruits causes tin-dissolving. This study was carried out to investigate the factors influencing the accumulation of nitrate in tomato fruits and the relation between the initial nitrate content and detinning in canned tomato juice. The results obtained are as follows: (1) Nitrate-nitrogen content should be below 5 ppm to minimize the abnormal tin-dissolving in canned tomato juice. (2) Nitrate-nitrogen content in the fruits examined was in the range of nil to 20ppm, but that in the petiole was 100 to 1, 000ppm, and even that in the calyx, which is adjacent to the fruit, was 10 to 500ppm. (3) The accumlation of nitrate in the peptiole and calyx was influenced by nitrate level in the fertilizer, but that in the fruit was not significantly affected. (4) Nitrate content in the fruits increased in process of the maturation and reached to a maximum at the mature green stage and then decreased. Nitrate content in the calyx also increased and reached to a maximum at the early mature green stage and then decreased to a minimum at the breaker stage and increased again. These indicate that the nitrate reductase activity is lower in the immatured fruit and become higher as ripeness develops. (5) Modified Hoagland′s solution was used to make the tomato plants grow in sand culture with and without molybdenum, containing 120ppm nitrate-nitrogen which was raised to 360ppm from 7 th to 12th day after the first flower of each cluster opened. The nitrate-nitrogen content in the fruits grown with molybdenum was found to be lower (4.8ppm) than without molybdenum (6.5ppm). On the contrary, nitrate-nitrogen content in the fruits grown in the constant higher level of nitrate (360 ppm nitrate-nitrogen) with molybdenum was only 3.6ppm and that grown without molybdenum was 4.8ppm. From these results, it may be said that nitrate would accumulate in the tomato fruits grown in molybdenum deficiency and with the additional fertilization of nitrate.