The growth of vegetative organs in Japanese persimmon, Diospyros kaki cv. Fuyu, was investigated by examining the growth rates of the current shoots and leaves. Leaf growth was related to development of the tissue systems. The development of current shoots, in terms of elongation and weight, was different according their position on the mother shoot (two year old branches), with distal shoots displaying greater development than proximal shoots. The rate of both elongation and growth in fresh weight of the shoots was highest in early May, and declined rapidly thereafter. The rate of dry weight growth peaked in mid-May. Leaf area increased markedly during the early stage of shoot development (mid-May), and the rate of leaf area growth declined in late May. The increase in fruit diameter growth typically commenced in mid-June, one to two weeks after the leaf area maximum was attained. The growth of basal leaves both began and finished earlier than that of upper leaves, even though the surface areas of leaves in upper positions were generally larger. The maximum growth rate in whole-leaf dry weight appeared in late May, thereafter decreasing throughout the growing season. Shoots began to decline in dry matter percentage immediately after the start of shoot elongation, until mid-May. Thereafter the dry matter percentage of the shoots increased markedly until early July, and continued to increase gradually until the ripening stage. On the other hand, the dry matter percentage of the leaves was low during the period from leaf opening to mid-May, and increased gradually until early July. The maximum growth rate of the fruit, in terms of fresh weight, appeared in mid-July, about two weeks behind the maximum in the dry matter percentage of the leaf. Development of the mesophyll (palisade and spongy tissue) was almost completed by mid-June, when the leaf surface area on the shoots had attained a maximum. The development of vascular tissues, especially xylem, in both the petiole and midrib began simultaneously after leaf opening, and was nearly finished by mid-June, about two weeks after the maximum in leaf area.
This experiment was conducted to reappraise more thoroughly the development of Japanese persimmon fruit, Diospyros kaki cv. Fuyu, by measuring the growth rate and the relative growth rate (RGR) of fruit diameter and weight, in relation to the vascular development of the fruit stalk. Cumulative diameter and weight increases have a double sigmoid pattern corresponding with changes in growth rate. Fruit development was classified into three distinct stages. Stage I was completed by early August, 10 weeks after anthesis. The increase to a peak in the growth rate of fruit diameter preceded by several weeks the peak in the growth rate of fresh fruit weight. Furthermore, the maximum rate of fresh weight growth occurred one week earlier than the maximum rate of dry weight growth. The whole fruit declined in dry matter percentage during the middle of this period when fruit diameter increased rapidly. The low percentage of dry matter in the fruit lasted during the period of July, when the growth rate of fresh weigh typically increased. On the other hand, the fruit increased in dry matter percentage during the two weeks in the early period of stage I, accompanying tannin cell development. During stage II, in which the overall growth rate slowed down markedly, the fruit increased in dry matter percentage. Both seed weight and the dry matter percentage of seed increased markedly during this stage. During stage III, a period of vapid growth, fruit continued to grow and to increase in dry matter percentage for as long as it was left on the tree. Initially in stage III, a rapid increase of fruit diameter commenced almost simultaneously with the weight increase. The rate of fruit diameter increase was higher in stage I than in stage III, but the rate of fresh weight growth was nearly the same in stage I and III. Contrarily, the dry weight increase in stage III was markedly higher than in stage I. There appeared to be little difference in the fruit growth curves among fruits which had different numbers of seeds, although there was a significant positive correlation between seed and fruit weight until July, during the early stage of fruit development. The maximum peak of the RGR of fruit diameter and fruit weight appeared several days after full bloom, and a small RGR peak appeared again during the ripening stage. The growth of the stalk diameter increased markedly during stage I of the fruit development, and lasted until mid-August. The differentiation of vascular tissue (transverse section)in the fruit stalk had already begun one month before blooming. However, this development was only slight: xylem vessel diameter averaged about 9μm and phloem differentiation had progressed enough to display a large nucleus. Thereafter, vascular tissue (xylem vessels, sieve tubes and companion cells) was developed strikingly until blooming, and continued to grow markedly until approximately 4 weeks after blooming. Although the growth of vascular tissue appeared to slow down gradually during the decelerated period of fruit growth, it increased again duting the ripening stage. The development of the vascular bundle in the stalk region corresponded to the fruit growth.
The ethylene production and abscission of Japanese persimmon fruits following NAA and ethephon applications as affected by seed number per fruit and exogenous gibberellin were investigated in 1976 and 1977. 1) The application of either NAA or ethephon at 50ppm 20 days after full bloom induced the ethylene production and abscission more distinctively in the open-pollinated fruits (mean seed number per fruit; 1.9) than in the hand-pollinated fruits (mean seed number per fruit; 5.6). Further, the effect of seed number on the ethylene production was more pronounced in the case of ethephon application, where very low level of ethylene was released from the hand-pollinated fruits. 2) NAA spray about 10 days after full bloom with the application of GA3 at 500ppm 15 hrs prior to the NAA spray accelerated the ethylene evolution and abscission of fruits to a greater degree than the NAA spray alone. On the contrary, the pre-application of GA3 depressed the ethylene evolution caused by the ethephon spray and completely eliminated its thinning action. 3) The application of GA3 at 200ppm 48, 24 or 6hrs prior to the NAA spray slightly increased the NAA-induced ethylene production, but all the treatments, particularly those applied 48 and 6hrs prior to the NAA spray decreased the cumulative fruit drop to the level almost similar with that of control. Eventhough the application of GA3 at 200ppm 20hrs after the NAA spray had hardly any effect on the NAA-induced ethylene production, the resultant fruit drop was completely restrained by the supplementary GA3 application.
Allium wakegi Araki is only propagated asexually, by planting bulbs, and is supposed to be developed into a vegetable population consisting of various clones over a long history of cultivation. The authors have cultivated 202 clones collected from western Japan, Taiwan, and South Korea, and investigated their various characteristics. The results are summarised as follows: 1. Collected clones were classified into 22 cultivars with differing characteristics. These cultivars were grouped into two ecotypes, namely the“Japanese”and the “Southern”types. 2. Cultivars of the“Japanese”type were collected from western Japan (including the Ryukyu Islands) and South Korea. Plants belonging to this type showed retarded growth in winter and grew luxuriantly in spring. Becoming dormant at maturity, their bulbs could be stored in good condition over the summer. The cultivars of this type were classified into four groups according to morphological similarities in leaf character. 3. Cultivars of the“Southern”type were collected from Taiwan and Ryukyu Islands. Plants belonging to this type, though affected by cold weather, continued to grow through the winter. Bulb formation in these plants was earlier than in those of the“Japanese”type. Their maturation was disturbed by cold and moist weather in early spring, and these bulbs did not achieve a state of full dormancy. 4. The 19 local forms of A. wakegi Araki used in this investigation could be karyotypically divided into the five types, as reported previously: K(2n)=14V+J+jT, =14V+Jt+jT, =14V+Jt+j, =14V+J+iTand =14V+J+j. The cultivar classification reported here was not in accord with the karyotypic grouping. Intraspecific differentiation of A. wakegi Araki is considered to have occurred mainly at the genic level.
Changes in the capsaicin content of pepper fruit during development were investigated with three cultivars and their F1 hybrids. The capsaicin content of‘Fushimiamanaga’ was always less than 0.1 percent in dry matter, showing limited changes. In the other, ‘Takanotsume’and‘Punggak’, the capsaicin content increased rapidly until 4 or 5 weeks after flowering and then decreased gradually, followed by a moderate increase at the fully ripened stage. The capsaicin content of F1 hybrids varied in a pattern intermediate between both parents′ patterns, although the F1 hybrids between‘Fushimi-amanaga’and‘Takanotsume’generally inclined to the former′s pattern. The genetic effects of parental cultivars on the phenotype of F1 hybrids with regard to the capsaicin content of the ripened fruit were studied by a diallel cross analysis with six cultivars. Though there was little difference between the mean value of the parental cultivars and that of the F1 hybrids, it was found that the direction of dominancy and the percentage of heterosis for the capsaicin content differed with the parental combination. From the analysis of variance of heterosis effects, it was concluded that major component of variance significantly associated with the general combining ability. In addition to these findings, a significant negative correlation was found between the fresh weight and the capsaicin content of fruit in both the parental cultivars and the F1 hybrids.
Solution culture experiments were conducted in order to investigate the effect of form of N supplied and pH level of the nutrient solution on Mn toxicities in vegetable crops. Materials tested were cucumber, tomato, spinach, cabbage, lettuce, and celery. Manganese was supplied at levels of 0.5, 30, and 100ppm. At each Mn level, NO3, NO3+NH4(1:1), and NH4 were supplied, with the total N concentration being held constant at 12me/l. The pH of the nutrient solution was adjusted to two levels, 4 and 6. Plants were grown under different treatments for about three weeks. 1. At the normal Mn level (0.5ppm), plants supplied with NH4 developed various injury symptoms, which were more severe at pH4 than at pH6. Excess Mn associated with NO3 and NO3+NH4 induced interveinal chlorosis on upper leaves in tomato and spinach, and marginal chlorosis on lower leaves in cabbage, lettuce, and celery. Both types of Mn-induced chlorosis were generally less severe with NO3+NH4 than with NO3, and in some cases these symptoms were less severe at pH4 than at pH 6. The incidence of necrotic brown spots due to Mn excess was reduced by increasing proportion of NH4 supply. 2. At the normal Mn level, the growth of plants supplied with NO3 and NO3+NH4 was almost equally good, but NH4 plants produced much more inhibited growth. With increasing Mn level in the nutrient solution the growth of plants supplied with NO3 and NO3+NH4 was inhibited, but in most cases NO3+NH4 produced better growth than NO3. In general, the growth of plants supplied with NH4 was almost constantly poor regardless of the Mn level in the nutrient solution. At the normal Mn level, plant growth at pH4 was generally inferior to that at pH6. At excess Mn levels, however, the difference of growth between two pH levels was reduced as compared with the normal Mn level, and pH4 often produced better growth than pH6 in NO3 and NO3+NH4 treatments. 3. Increasing Mn level in the nutrient solution increased leaf Mn concentration, but increasing proportion of NH4 supply inhibited excess accumulation of Mn in leaves. The leaf Mn concentration was generally lower at pH4 than at pH6. 4. In general, the growth of plants supplied with NH4 was almost constantly poor regardless of leaf Mn concentration. On the other hand, in NO3 and NO3+NH4 treatments, the more the accumulation of Mn in leaves increased, the more the growth was inhibited regardless of N treatments. In spinach, however, the growth of plants supplied with NO3 and NO3+NH4 at pH 4 was more strongly affected by low pH than by leaf Mn concentration. 5. It may be concluded that NH4+ and H+, unless their own levels are injurious, exert marked effects in reducing Mn uptake and Mn toxicities in vegetable crops.
Vernalization treatment to pea seeds (cv. Atsumi-kinusaya) at 5°C for 20 days exerted flower promotion by 2.4 nodes. Endogenous gibberellins were found to increase in response to vernalization treatment although no difference could be detected in the plant height between vernalized and nonvernalized plants. Gibberellin activities were also detected in the water which contained materials that had diffused out of the vernalizing seeds. Bioassay data suggested that detected gibberellins from vernalized seeds and shoots are gibberellins possessing no OH substitution on C-3 position of ent-gibberellane ring. Exogenously applied gibberellin A3 and A7, possessing OH-substitution at the position, increased stem length but rather acted in inhibitory manner to the flowering as indicated by increase of the first flower nodes.
Induction of hereditary changes by grafting in tomato was reconfirmed by combination of the cultivar Jubilee (yellow skin-orange flesh) as scion and the cultivar Tiny Tim (yellow skin-red flesh) as stock. The phenotypic change from yellow-orange (Jubilee type) to yellow-red (Tiny Tim type) was observed in the grafted scion (G0) on the Tiny Tim stock. In the selfed progeny (G1) from this Tiny Tim type variant fruit on the Jubilee scion, new type (colorless-red) was segregated in addition to Jubilee type (yellow-orange) and Tiny Tim type (yellow-red). The genotypic change of skin and flesh color is assumed to have occurred from Yyrr (yellow-orange) to YyRr (yellow-red) in the grafted scion and in the first self ed progeny, Y-R-(yellow-red), Y-rr (yellow-orange) and yyR-(colorless-red) were segregated from the YyRr variant (G0). Most of the successive progenies (G2 and G3) obtained from the segregants in the G1 generation accorded with Mendelian inheritance. But the phenotypic changes inexplicable in terms of Mendelism were assumed to have changed from yyR-(G1) to Y-R-(G2), from Y-rr (G2) to Y-R-(G3) and from yyR-(G2) to Y-R-(G3). But yyrr (colorless-orange) was not detected in all successive progenies. No other characters than skin and flesh color have been changed in the present study. It is likely to suppose that the transmission of genetic material from stock to scion would have occurred, though the mechanism is quite obscure yet.
Effects of diurnal variation of temperature on the curd formation of′Nozaki-wase′ cauliflower and′Wase-midori′broccoli were investigated in temperature-controlled conditions, using platns with the 7th or 8th unfolded leaf. 1. The plants were grown for 35 days at various temperatures in the 1st period of a day (8 hours from 9:00a.m. to 5:00p.m. ) and at 10°C in the 2nd period of a day (16 hours from 5:00p.m. to 9:00a.m.). Curds of cauliflower were formed when the plants were grown at 15° and 20°C in the 1st period, but not when grown at 10°, 25° and 30°C. The number of nodes to the curd was larger at 20°C than at 15°C. Flower heads of broccoli were formed when the plants were grown at 15°, 20°, 25° and 30°C in the 1st period, and the number of nodes to the flower head was larger as the temperature increased. 2. Curds were formed on cauliflower plants, when the plants were grown for 45 days at 10° and 15°C in the 2nd period (15 hours from 5:30p.m. to 8:30a.m.) in combination with the temperatures of 15° and 20°C in the 1st period, but not when grown in combination with the temperatures of 25° and 30°C in the 1st period. Flower heads were formed on broccoli plants, when the plants were grown for 45 days at 20°C in the 2nd period in combination with the temperatures of 15° and 20°C in the 1st period, but not when grown in combination with the temperatures of 25° and 30°C in the 1st period. 3. Curds were not formed on cauliflower plants when they were grown for 6 weeks at 25°C in the 1st period (12 hours from 7:00a.m. to 7:00p.m.) in combination with the temperatures of 15° and 25°C in the 2nd period. The plants of cauliflower grown at 15°C in the 2nd period for 6 weeks formed curds earlier than those grown at 25°C in the 2nd period when they were exposed to natural outdoor temperatures. 4. The plants of cauliflower were kept for 10 weeks at 25°C in the 1st period (12 hours from 7:00a.m. to 7:00p.m. ) and at 15° and 25°C in the 2nd period. Both the plants grown at 15° and 25°C in the 2nd period did not form curds by the 7th week. Plants grown at 15°C in the 2nd period eventually formed curds in the 10th week. 5. From these results, it is deduced that the stimulus of low temperature given in a certain period of a day is reduced but not nullified by subsequent high temperature in a day under the condition with diurnal temperature variations. And the plants form curds when the stimulus of low temperature is accumulated day by day and reaches a certain level.
In the previous paper of 1979, the author reported that cyclamen could be vegetatively propagated by means of notching on the cut surface after the upper part of the planted tuber was scooped. In the present paper, the suitable site of tuber scooping and size of tuber notching for the vegetative propagation are examined. And the initial points of the adventitious buds developed on the scooping surface of the tuber and its margin, and of the adventitious bud occurring on the epidermis of the tuber are further observed from an anatomical viewpoint. The results are as follows: 1. The site of scooping and the size of notching. It seems to be suitable for this propagation that the tuber was scooped at one third of the upper part and the cut surface notched into one centimeter squares. 2. The point of initiation of adventitious bud primordia. In the case of adventitious buds growing from the scooping surface, the original body of the bud occurred in the vascular cut end and its periphery. On the other hand, in the case of adventitious buds growing from the margin of the scooping surface, the original body occurred in the meristematic layer, where old periderm and new wound-periderm joined together. And moreover, in the case of adventitious buds growing from the epidermis, the leaf primordia of the bud originated from the neighborhood of the cork cambium in the periderm.
Excised tulip bulb scale segments were able to generate adventitious buds when cultured on a modified Murashige-Skoog medium fortified with auxin and kinetin. Transferring the buds to a medium low in auxin and kinetin induced further development. Bulb formation occured at the proximal end of buds receiving a chilling treatment at 5°C, but failed to occur in unchilled buds. The optimal duration of the chilling period was found to be about 80-100 days. Bulb formation was enhanced by the application of NAA together with kinetin at low concentrations, although at high concentrations formation was delayed. Sucrose was also necessary for bulb formation, and its optimum concentration was found to be range between 4 and 6%. Culture temperature for the bulb formation was optimal at 25°C.
The external characteristics and fertilities of 11 new interspecific hybrids which were obtained through embryo culture following the intrastylar (cut-style) pollination technique were observed. 1. Several interesting phenomena were observed in some of the hybrids, especially in relation to flower colors. 2. Relatively high pollen fertilities of the hybrids resulting from crosses between L. auratum platyphyllum and L. henryi, L. longiflorum and L. candidum, and L. ′6542′and L. candidum, respectively, may show the paired species to be closely related to each other. 3. In backcrosses using the hybrids as female parents, the crosses were found to be more successful when the species which had been used as male parents in obtaining F1 were used again as pollen parents.
Uncolored detached- and intact-petals of floribunda rose ′Ehigasa′ were subjected to various light treatments. In vitro culture of the detached petals, sucrose concentration of 10 to 20% in medium was favorable to anthocyanin formation. The petals remained colorless in darkness and under irradiation of light excluding UV. Anthocyanins were produced by the irradiation with UV region below 330nm and were increased with increases in duration and intensity of UV irradiation. When the total amount of UV radiant energy was equal, UV irradiation of long duration at low intensity produced considerably more anthocyanins than that of short duration at high intensity. Irradiation with visible light before or along with UV markedly stimulated anthocyanin formation as compared to UV irradiation alone. Furthermore, increased intensity of visible light along with UV irradiation enhanced anthocyanin formation. In the intact petals, UV irradiation in the daytime was more effective for anthocyanin formation than that in the nighttime.
Changes in fruit quality and some components, especially organic acid content, in satsuma mandarin (Citrus unshiu Marc.) after 140 days cold and controlled atmosphere (C. A.) storages were studied. Analysis of organic acid content was performed using silicic acid column chromatography. The results are summarized as follows: 1. Under low humidity condition, some fruits became dry and browned. Under high carbon dioxide conditions, physiological disorders which indicated carbon dioxide injury were clearly observed. Pitting was found in some fruits stored at low temperature and 10-10 (C. A.) conditions. 2. Under high carbon dioxide conditions, the percentage of peel, ‘kahi-budomari’ and the ratio of ‘rind puffing’ were larger than under other conditions. The free acid in the flesh was also a little larger than under other conditions, and under low humidity and high carbon dioxide conditions, total acid and total sugar in the peel were a little larger than under other conditions. 3. In the flesh of the fruits, citric acid composed about 90% of the organic acid content; malic acid was the second most abundant acid. During storage, formic acid and α-ketoglutaric acid fractions increased, while oxalic acid and malic acid decreased. Even under high carbon dioxide conditions, no distinct difference in organic acid composition was found. In the peel of the fruits, malic acid composed about 50% of the organic acid content; citric acid was the second most abundant acid. During storage, formic acid increased and oxalic acid decreased. Under high carbon dioxide conditions, and also when ‘stem-end rot’ occurred, the malic acid decreased markedly, and the citric acid increased markedly.
In this paper, storability of eggplant fruits of 9 cultivars were observed, and relationship between storability and contents of phenolic compounds was studied. Proper storage temperature and proper maturity at harvest time for eggplant were discussed by using purple pigmented cultivar ′Senryo′. 1) All eggplant fruits used in this experiment displayed pitting injury and browning of peel accompanied by the occurrence of pitting injury during the storage at 1°C, and holding period of their acceptable freshness was 8-13 days at 1°C. Deep purple cultivars displayed dark sheet subside under 1°C, but green fruited cultivars didn′t display it. Dark sheet subside also made fruits depreciate their freshness. Wilting was the main cause of deterioration of all eggplant fruits during early storage period at 20°C. And during late storage period, decay of calyx in cv. ′Senryo′, ′Osaka-sennarinaga′, ′Kubotamaru′, ′Ooserikawa′, and ′Shiro-daiennasu′, secession of whole calyx in ′B. H.′, whole browning of peel in ′Shiro-oonaganasu′, and spotted browning of peel in ′Sensyu-mizunasu′ were the major causes of deterioration of stored eggplant fruits, respectively. Of all eggplant fruits, fruits cv. ′Sensyumizunasu′ could be stored for longest period at 20°C. 2) Occurrence of pitting injury which was the main cause of deterioration for stored eggplant fruits at 1°C was little frequent on small fruits and most frequent on marketing size fruits in 9 cultivars. Large fruits of cv. ′Shiro-oonaganasu′, ′Sensyu-mizunasu′, and ′Shiro-daiennasu′ displayed similar pitting injury to marketing size fruits, but large fruits of other cultivars hardly displayed pitting injury. 3) Fruits cv. ′Senryo′ were sackaged with perforated polyethylene bag and stored at 1°C, 10°C, 15°C, and 20°C. At given temperature, slightly small marketing size fruits lost their freshness rapidly than slightly large marketing size fruits. At 15°C, slightly large marketing size fruits retained their freshness longer than others, and they showed less frequence of calyx decay and no occurrence of pitting injury. 4) The fruits containing high levels of o-diphenols were apt to display pitting injury at 1°C, and to develop browning of peel at 20°C regardless of cultivars except ′Sensyu-mizunasu′. Higher activity of polyphenol oxidase may be correlated to the extent of storage injury which occurs in fruits different of maturity or crop season, but not in fruits different of cultivars.
Physiological changes associated with the maturation of apples on the tree were investigated using three apple cultivars: Jonathan (medium maturing, short shelf life), Indo (late, intermediate shelf life), and Ralls Janet (late, long shelf life). Fruits were picked 5-13 times at weekly intervals during the maturing period, and changes in respiration (CO2 evolution), ethylene emanation, and internal ethylene concentrations were determined in relation to several criteria of maturation, such as fruit weight, titratable acidity, content of soluble solids, starch, water soluble pectin, total pectin, and firmness of flesh. The changes in amylase and pectin methyl esterase activities were also determined. 1. While a climacteric rise in respiration was clearly observed during maturation on the tree in Jonathan and Indo apples, it did not occurr in Ralls Janet apples until the normal harvest period. Ralls Janet apples, however, showed a typical climacteric rise both when they were stored at 20°C, or attached to the tree, far beyond the usual harvesting time until the time when most fruits had naturally dropped. 2. Internal ethylene concentration was found to increase two weeks before the climacteric onset of respiration, reaching a levels of 4ppm at the climacteric minimum in Jonathan apples. In Indo and Rails Janet apples, a range of 0.3-0.5ppm predominated from a month before the climacteric onset. A sharp increase was found almost simultaneously with the climacteric rise in Indo; in Ralls Janet, the increase occurred at the time of climacteric minimum, reaching levels of several ppm. 3. Rapid increases in ethylene emanation occurred almost simultaneously with the climacteric rise in Jonathan and Indo, but only a slight increase was observed in Rails Janet even after the increase in respiration and internal ethylene concentration. 4. The relationship between maturity and the change in respiration was also compared among the three. With Jonathan, maturation advanced rapidly and the fruit became edible at the climacteric minimum of respiration. Indo apples became edible after the rise of respiration; the fruits contained high levels of starch and total pectin, and their decomposition progressed slowly. With Ralls Janet, while maturation advanced slowly, the rise of respiration occurred very late, and the climacteric peak was found a month after the fruits were edible. 5. Respiration rates and internal ethylene concentrations in Ralls Janet apples were much lowr than those of Jonathan and Indo apples through the pre-and post- climacteric phases. This fact seems to be related to the fact that Ralls Janet apples have a longer shelf life in comparison with the other two cultivars.