Forty two morphological characters of 30 Citrus and 5 Fortunella species and clones, including original species in Japan, were computed by four multivariate techniques: Q-mode cluster analysis, Q-mode cluster analysis based on R-mode principal component analysis, nonlinear mapping algolithm (NLMA) and quantas type 3 analysis. NLMA couldn′t show a good result for theoretical reasons, but the other methods gave interesting information. We also considered that citron, mandarin and pummelo may, hypothetically, have originally been species of Citrus, because they surrounded other Citrus plants in quantas type 3 analysis. Grapefruit and ‘Hassaku’ were closely related to pummelo in our calculations. Mandarins were divided into two groups: one included satsuma mandarin and ‘Keraji’, and another included mediterranean mandarin, ‘Ponkan’, ‘Dancy’tangerin, ‘Clementine’, ‘Kisyu’ and ‘Tachibana’. ‘Natsudaidai’, ‘Kikudaidai’, ‘Iyo’, ‘Hyuganatsu’ and ‘Kabusu’ were more nearly related to sweet orange than to mandarin. Rangpur lime came between mandarin and Rough lemon. ‘Bergamot’ was far to ‘Mexican’ lime. Calamondin lay between Fortunella species and mandarin. Mame kumquat must be a unique kumquat in Fortunella species.
The sugar and organic acid components of satsuma mandarin (Citrus unshiu Marc.) fruit were investigated. ‘Okitsu Wase’, an early maturing cultivar, and ‘Silverhill’, a common cultivar, were employed in this study. Sugars were identified using a liquid chromatograph and organic acids were determined by a carboxylic acid analyzer. Fruit samples in both analysis were picked at half-month intervals. 1. Sugar The predominant sugars analysed were sucrose, fructose and glucose in the juice and peel of both cultivars. Juice: The most pronounced variation was observed in sucrose which increased from 1.08 to 7.53mg and 1.23 to 6.90mg per 100ml of juice in the early and common cultivars, respectively. During the maturation, fructose also increased from 0.81 to 2.06mg and 0.75 to 1.84mg per 100ml of juice in the early and common cultivars, respectively. Glucose remained relatively constant throughout all stages in both cultivars. The total sugars in the early and common cultivars increased from 2.81 to 10.89mg and 4.41 to 9.97mg per 100ml of juice, respectively. Peel: In the early stages of both cultivars, sucrose and glucose were the predominant sugars. Sucrose, fructose and glucose increased gradually during maturation. Sucrose, especially, increased rapidly as the fruit approached full maturity. The total sugars in the early and common cultivars increased from 1.61 to 10.00mg and 1.53 to 11.95mg per 100g of peel, respectively. 2. Organic acid The organic acids detected in both cultivars were glucronic, lactic, acetic, pyruvic, malic, citric, succinic and iso citric acid. In early stages of maturation of each cultivars, citric and malic acids were the predominant organic acids, followed by iso citric acid. The most pronounced variation was in citric acid, which decreased from 2, 022 to 802mg and 2, 148 to 896mg per 100ml juice in the early and common cultivars, respectively. During the maturation, malic acid also decreased from 122 to 39mg and 85 to 37mg per 100ml of juice and iso citric acid decreased from 18 to 5mg and 13 to 8mg per 100ml of juice, respectively, in the early and common cultivars. Glucronic acid decreased with maturation, lactic, acetic and succinic acid remained relatively constant throughout all stages in both cultivars. α-Ketoglutaric acid was not detected at the mature stage in either cultivar. The total organic acid content in the early and common cultivars decreased from 2, 180 to 870mg and 2, 262 to 910mg per 100ml of juice, respectively.
Upward and lateral movements of 14C-amino compounds in intact trees and excised shoots, and upward translocation of major amino compounds in intact shoots were examined in the early stage of new shoot development. The results were summarized as follows. 1. Uniformly 14C-labelled arginine, asparagine, aspartic acid and proline were steadily taken up by roots of intact trees, translocated to old leaves and new shoots, and appeared in the fed compound and its metabolized products in these organs. 2. 14C-arginine, asparagine and proline were translocated upward not only via the xylem but also via the phloem. Lateral movements, from the xylem to the phloem and from the phloem to the xylem, also occurred. These compounds showed different patterns in their movements. 14C-arginine and its metabolic products tended to accumulate in the xylem and translocate upward in the xylem. This was in contrast to 14C-proline and its metabolic products, which tended to accumulate in the phloem and translocate upward in the phloem. These findings were supported by the results obtained in intact shoots. 3. The 14C-amino compounds were metabolized to soluble and insoluble compounds during the translocation and in the new shoots. However, they differed significantly in the extent of metabolic conversion during translocation; proline was hardly metabolized, arginine and asparagine were moderately metabolized, and aspartic acid was almost completely metabolized.
The effects of ethychlozate on the rind puffing and its mechanism have been examined in this paper. Ethychlozate did not show any effect on the rind puffing, when it was used for fruit thinning. While, ethychlozate substantially suppressed the rind puffing, when it was sprayed at the beginning of coloration. Since 5-chloro-indazole carboxylic acid, a metabolite of ethychlozate, effectively inhibited the ethylene evolution, this phenomenon may be attributed to the action of this metabolite. The content of water-soluble pectin decreased, while the content of 0.4% sodium hexametaphosphate-soluble pectin or 0.05N-HCl-soluble pectin increased by application of ethychlozate.
Experiments were carried out to increase information about self-incompatibility in Hassaku(Citrus hassaku hort. ex Tanaka). The following results were obtained. 1. Using isoelectric focusing analysis, sequential changes of buffer-soluble glycoproteins in self-pollinated pistils were compared with buffer-soluble glycoproteins in the pistils that were cross-pollinated with Hyuganatsu(C. tamurana hort. ex Tanaka). Remarkable differences were observed in the band distribution as soon as 30 minutes after pollination in samples from stigmas, styles, and ovaries. 2. Several treatments were tried in search of an effective method of overcoming self-incompatibility. Self-pollination after smearing the Tris-saline buffer extract of the Hassaku or Hyuganatsu pollens onto the stigmas of immature flower buds was found to be the most effective of the treatments. Self-pollination onto the stigmas of mature flower buds 1 hour after cross-pollination with the pollen grains of trifoliate orange (Poncirus trifoliata Raf.) was also effective in producing self-fertilized seeds, though less practical than the former treatment.
Distribution of photosynthates from leaves into different plant parts was studied in potted 2-year-old ‘Delaware’ grape which were exposed to 14CO2 at different stages of berry development. In the first experiment, shoots, trunks, roots, berries and leaves were sampled 6, 24 and 72 hours after 14CO2 feeding and the 14C activities in the ethanol soluble and insoluble fractions were measured. In the second experiment, each ethanol soluble fraction of shoots, berries and leaves being sampled 6 hours after 14CO2 feeding was separated into individual compounds by paper and column chromatography, and the 14C activities were then estimated. The results are summarized as follow 1. 14C in the ethanol soluble and insoluble fractions in leaves decreased with time after 14CO2 feeding. The 14C labelled photosynthates translocated from leaves into shoots, trunks and roots increased in the ethanol insoluble fraction 24 and 72 hours after feeding, but did not increase in the ethanol soluble fraction. 2. The amount of 14C translocated into berries increased at Stage I and III, and appeared mostly in the ethanol soluble fraction in both stages. 3. In seeds, more 14C was found in the ethanol insoluble fraction than in the ethanol soluble fraction, and the incorporation ratio increased in the course of berry development from Stage I to Stage II. 4. In leaves and shoots, the 14C incorporated into the sugar fraction was mainly found in sucrose, glucose and fructose, and that in the organic acid fraction was mainly in malic acid and tartaric acid. In berries, the distribution of 14C into sugar and organic acid fractions was similar to that in leaves and shoots, except for sucrose. However, the 14C distribution ratio varied at different stages of berry development.
Morphological properties of 2 types of florets which appeared in the gibberellic acid(GA)-treated clusters of ‘Muscat Bailey A’ grape were examined. Further, the relation between the type of flowering and the induction of seedlessness was studied with 2 vines of ‘Muscat Bailey A’, which had been apparently different each other in the seedlessness ratios of GA-treated clusters in the past several years. 1. Florets in the GA-treated clusters were deviled into 2 types according to their flowering behavior. One was named normal type, in which the calyptra became detouched at the base as is the rule with most of the florets of GA-untreated clusters. Though stamens were a little longer in length than pistil in the florets of GA-untreated clusters, they were 2 times longer than it in the florets of normal type. The other was named abnormal type, in which the calyptra split or opened from the tip and did not become detouched at the base. This type was significantly larger in the size of ovary and also in the number of carpels and ovules per ovary than the normal one. Moreover, the stamens of this type were so short that the anthers located far below the stigma. 2. In vine H, which had shown high seedlessness ratios of GA-treated clusters in the past several years, the percents of abnormal florets were high in case GA was applied 17 or 14 days before full bloom. Further, the rates of berry set were extremely higher in the abnormal florets than in the normal ones, so that most of the set berries derived from the abnormal. In these treatments, the seedlessness ratios of the total berries were above 99%, and the berries derived from the abnormal florets were consistently higher in seedlessness ratio than those from the normal ones. In vine L, which had shown low seedlessness ratios, the percents of abnormal florets were as high as in vine H in case GA was applied 17 or 14 days before full bloom, though the values in vine L were lower than those in vine H. The rates of berry set were extremely higher in the abnormal florets than in the normal ones as in vine H. Irrespective of the time of GA application, the seedlessness ratios of the total berries were about 70%, which were much lower than those in vine H. The seedlessness ratios of berries derived from the abnormal florets were 29 to 44% lower than those in vine H. In addition, they were lower than the ratios of berries from the normal florets in the same vine, and this relation between the berries from the abnormal and normal florets in vine L was just opposite to that in vine H. 3. From these results, it can be said that a close relation exists between the time of pre-bloom GA application and the appearance of the abnormal florets and that the abnormal florets are higher in the rate of berry set than the normal ones. Further, the morphological properties of the abnormal florets explained above seem to be favorable for inducing seedless berries. However, it is unlikely that the type of flowering is a decisively controlling factor of the induction of seedlessness since the relation between the type of flowering and the seedlessness ratio was just opposite in the 2 vines as mentioned above.
This study was carried out to elucidate the mechanism of natural removal of astringency in pollination constant non-astringent (PCNA) type fruits of Japanese persimmon, especially focusing on development of the tannin cells. 1. Development of the tannin cells in plastic-embedded flesh sections was observed using an image analysis system. The tannin cells in PCNA type fruits stopped their enlargement at the end of June, whereas those in pollination variant nonastringent (PVNA) and astringent (PVA), and pollination constant astringent (PCA) type fruits continued to increase in size until the end of July. Thus, final size of tannin cells was much smaller in the former fruits than the latter. Number of tannin cells per unit area was little variable in all 4 type fruits at any stage, so that in PCNA cultivars the area occupied by tannin cells reduced with time after tannin cells stopped their development. Such a decreasing process was coincident with the decreasing process of soluble tannins in PCNA type fruits. 2. In PCNA and PVNA cultivars, the tannin cells of fresh pericarp sections stained with ferric chloride were observed in order to clarify whether or not tannins coagulated in early August. At this time soluble tannins in non-astringent type fruits were negligibly low in contents. The observation revealed that tannins in PCNA type fruits hardly coagulated by this time, although those in PVNA type fruits completely changed into insoluble complexes. 3. These results suggested that the decrease of astringency of PCNA type fruits on trees might be mainly attributable to the reduction in relative area occupied by tannin cells, but not their coagulation. Such a reduction in area occupied by tannin cells started when development of tannin cells stopped, as mentioned above.
Kiwifruits (Actinidia chinensis Planch. cv. Hayward) produced ethylene at an increasing rate at 21°C after exceeding a threshold level of 0.1μlkg-1h-1. There was a wide variation in time before the burst of ethylene production by individual fruits was evident after transferred from 1°C to 21°C. This variation became less and the time necessary for individual fruits to reach the increased level of ethylene became shorter and uniform as the storage period at a low temperature (1°C) extended. The increased rate of ethylene production was paralleled by the increased internal ethylene concentration and accompanied by the rise in respiration and soluble solids content and flesh softening. 1-Aminocyclopropane-1-carboxylic acid (ACC) content in the fruit tissue increased in parallel with the rise in the rate of ethylene production. ACC synthase activity also increased in the ethylene forming tissue. Ethylene forming enzyme (EFE) activity increased with the increase in the rate of ethylene production by the fruit. Ethylene production by the fruit tissue was strongly inhibited by aminoethoxyvinylglycine (AVG). EFE activity in the tissue was strongly inhibited by Co2+, n-propyl gallate (PG) and sodium caprylate (CAP). These results may indicate that ethylene biosynthesis in the kiwifruit proceeds along the methionine and ACC pathway.
Causal relationships between the occurrence of fruit curvature and the number of leaves per fruit and shading of plants were investigated with individual plants. When 1 fruit with 5 leaves attached was retained per plant, fruit showed normal growth and almost no curvature at harvest. On the other hand, fruit with 3 leaves or less was suppressed in growth and showed marked curvature at harvest. In addition, some of them became malformed or aborted. When 2 or 3 fruit with 6 or 9 leaves (3 per fruit), respectively, were retained per plant, all the fruit showed normal growth and almost no curvature at harvest. When 2 or 3 fruit with 2 or 3 leaves (1 per fruit), respectively, were retained per plant, however, most fruit were suppressed in growth, and showed marked curvature at harvest, while some of them showed relatively normal growth and only slight curvature. When 1 fruit with leaves, 1, 200 cm2 in total leaf area, was retained per plant, fruit showed normal growth and almost no curvature at harvest. On the other hand, fruit with leaves, 800cm2 or less in total leaf area, was suppressed in growth and showed marked curvature at harvest. When 1 fruit was retained per plant, shading with cheesecloth suppressed the fruit growth and increased the fruit curvature angle at harvest. These effects were greater on the fruit with 3 leaves than 5 leaves per fruit. From these results, it was concluded that the occurrence of the curvature in cucumber fruit was due to the insufficient production of photosynthates and, consequently, their poor supply to the fruit as the results of decreased leaf area, shading, etc.
Muskmelon cv. ‘Earl′s Favourite’ was grown using two kinds of bed soil (sub-soil of Ando soil, and Alluvial soil). Various amounts of bed soil (10, 15, 20 and 25kg per plant) were used to study the effect on growth and fruit quality in a plastic house. The results were as follows: 1. In the early stages plant growth in the plot using Ando sub-soil was inferior to that using alluvial soil, but this difference was minimized in the later stages. Plant growth was generally greater with increasing amounts of bed soil. 2. The external appearance, color and formation of surface netting of the fruits were more prominent in the plots using more than 15kg Ando sub-soil and more than 20kg alluvial soil. 3. There was no difference between the two soils in soluble solids, sucrose and fructose contents of fruits, but glucose content grown on Ando sub-soil was higher than that on alluvial soil. Total suger was the highest in the alluvial soil 25kg plot and in the Ando sub-soil 20kg. 4. The citric acid content of fruits increased with increasing amounts of bed soil used. However, citric acid content was lower in fruits grown on Ando sub-soil than on alluvial soil. 5. The soluble pectic acid calcium content of fruits grown on Ando sub-soil was slightly higher than that on alluvial soil. Little difference was found in this content among the plots using various amounts of bed soil in either soil. 6. The taste of fruits grown on Ando sub-soil was slightly inferior to that on alluvial soil. In both soils the fruit taste in the plots of 10kg bed soil was inferior to that in the plots of 15 and 20kg bed soils. 7. The phosphorus content in all plant tissues grown on Ando sub-soil was lower than that grown on alluvial soil, whereas contents of potassium, calcium and magnesium were higher in that grown on alluvial soil. With increasing bed soil amounts, potassium, calcium and magnesium contents increased in both soils. 8. From the results mentioned above, it was recognized that Ando sub-soil can be utilized as bed soil to produce fruits with high quality, if adequate amounts (15_??_20kg) of Ando sub-soil are used.
This paper was designed to study seed germination and embryogenesis in Calanthesieboldii, Calanthe elmeri, and Calanthe venusta. The results may be summarized as follows. 1. The ovaries of C. sieboldii, C. elmeri and C. venusta rapidly increased in size and reached their final size about 50 days, 60 days and 50 days, respectively after pollination. 2. The seeds and embryos of C. sieboldii, C. elmeri and C. venusta rapidly increased in size, and reached their final size 80 days, 60 days and 80 days, respectively after pollination. 3. Ovule formation occurred 43 to 45 days after pollination in C. sieboldii, 35 to 37 days after in C. elmeri and 30 to 31 days after in C. venusta. Double fertilization occurred 48 to 50 days after pollination in C. sieboldii, 40 to 41 days after in C. elmeri and 34 to 35 days after in C. venusta. The mature embryo sac was observed to contain 5 to 6 nuclei regardless of species. 4. Proembryos of C. sieboldii, C. elmeri and C. venusta at the tetrad stage were all classified as A2 type, according to Veyret′s classification. Similarly, embryos of C. sieboldii, C. elmeri and C. venusta at and after the tetrad stage seemed to belong to the E type (Liparis pulverlenta type). The mature embryo was observed to be derived from the apical cells of the proembryo in C. sieboldii, C. elmeri and C. venusta. 5. Three to five endosperm nuclei were observed in the embryo sac after fertilization in C. sieboldii, C. elmeri and C.venusta. 6. The seeds of C. sieboldii were able to germinate after the quadrant stage (70 days after pollination), those of C. elmeri before the tetrad stage (45 days after pollination) and those of C. venusta after the quadrant stage (55 days after pollination). The highest percentage of seed germination was obtained when the seeds were harvested at about the mature embryo stage, and Hyponex medium was better than Murashige and Skoog medium or Knudson C medium.
Cucumber fruits were stored for 9 days at 20°C under unsaturated vapour conditions. The rate of respiration in the pericarp tissue, as measured by O2 uptake, showed a rise following an initial decrease. The rise was associated with an increase in gas pressure and the formation of gas spaces. Respiration rate reached a peak earlier and then decreased faster than the gas pressure did. Gas spaces developed steadily in spite of a decline in respiration rate and gas pressure. Itsuggested that a decrease in membrane permeability might be involved in the development of gas spaces. In fruits stored at 7.5°C, gas pressure in the tissue did not rise and the respiration rate was constantly low when measured at 7.5°C. However, when measured at 20°C, the respiration rate changed in almost the same way as in fruits stored at 20°C.
In this paper, the influence of pre-storage conditioning (at 10°C or 20°C for 5 days, 10 days or 15 days, respectively) on the occurrence of chilling injury and the change of surface structures in eggplant fruits stored at 1°C was examined. The surface structures were examined by scanning electron microscopy. Pre-storage conditioning extended the shelf life of eggplant fruits stored at 1°C by retarding chilling injury. The occurrence of pitting, the first symptom of chilling injury, was delayed by 2-3 days. In fruits stored at 1°C after conditioning, two types of pitting were observed; in one the pits were larger in size (100μm-1500μm) and fewer in number (referred to as type I pitting), while in the other the pits were smaller in size (100μm-300μm) and larger in number (reffered to type II pitting). In fruits stored directly after harvest, only type I pitting was observed. When stored after conditioning, type II pitting occured more frequently in fruits packaged in perforated polyethylene bags than in those packaged in sealed ones, while the occurrence of type I pitting was the reverse. Pasteurization, by dipping in ethanol after conditioning, reduced the occurrence of type II pitting. Circular protuberances were observed on the surface of fruit stored at 20°C. A fungus (Alternaria sp) was frequently observed on and near the protuberances, through which it frequently penetrated into the eggplant fruits. Sectioning of fruit showed first in type I pitting there was no destruction of epidermal cells that the destruction of parenchyma cells was the main cause of the pitting. In type II pitting, penetration of fungus was observed, indicating that destruction of epidermal as well as parenchyma cell seemed to be the cause of the pitting.
The effect of fluctuating temperature (square-wave form) on the quality of asparagus, broad bean, edible podded pea, shallot, shii-take mushroom, enoki-take mushroom and ‘Muscat of Alexandria’ grape was investigated, in comparison with those held at a steady temperature. In the fluctuating temperature treatment, materials were kept under the following conditions: fluctuation amplitudes of ±5°C, ±3°C and ±1°C for periods of 12-hours and 6-hours, the standard temperature being 6°C. In asparagus, deterioration of appearance, increase in hardness and decrease of ascorbic acid content were hastened as fluctuating amplitude widened. The fluctuating temperature produced a reduction in quality of broad bean seeds rather than on visual freshness of the pod; browning of the hilum portion was promoted even with an amplitude of ±1°C. Fluctuating temperature did not have so much influence on the deterioration rate of edible podded pea. However, adverse effects of fluctuating temperature were observed in shallot, shii-take and enoki-take, and their deterioration rates were higher under conditions of fluctuating temperatures. While the browning of stems and pedicels of Muscat of Alexandria′ grape was slightly accelerated with fluctuating temperatures, little differences in deterioration rate were found between clusters stored at fluctuating temperatures and those stored at standard temperature of 6°C. From the results above, it is evident that the fluctuating-temperature tolerance of asparagus, broad bean, shallot, shii-take and enoki-take is low and that a steady low temperature is required to retain quality during low temperature storage. The fluctuating-temperature tolerance of edible podded pea and ‘Muscat of Alexandria’ grape is slightly higher than that of the above products and temperature fluctuation during storage is tolerated to a certain extent.
The mechanism of chlorophyll degradation by peroxidase in parsley leaves was studied. Chlorophylls present in the ethyl alcohol (EtOH) extract of parsley leaves were degraded by a peroxidase-hydrogen peroxide system. Purified chlorophylls, however, were not affected by the system, suggesting the existence of a substance which acts together with peroxidase to degrade chlorophyll in parsley leaves. The substance was isolated from the EtOH extract by the methods of solvent fractionation and column chromatography. After hydrolysis, it was identified as an apigenin, which is a major flavonoid contained in parsley, by measuring Rf value on thin layer chromatogram and spectral characteristics. From the results obtained, it is concluded that in parsley leaves chlorophylls are not degraded by peroxidase directly, but that peroxidase oxidizes the apigenin and then the oxidized apigenin degrades chlorophylls.