The relation between flower color and anthocyanin composition of the perianth was investigated for 15 orange-red Alstroemeria cultivars that were newly bred in Japan. Their characteristic orange-red colors are in the region of Red 41-Red 46 by RHS C. C., and their hue values (b*/a*) are 0.64-1.02. These cultivars were classified into two groups by the results of their anthocyanin components and λ max values of the 0.1% HCl-MeOH extracts. The first group gathered with five cultivars was composed of 6-hydroxypelargonidin 3-rutinoside as their main pigment and showed λ max (0.1% HCl-MeOH) in the region of 493-498 nm. Another one with ten cultivars was composed with 6-hydroxycyanidin 3-rutinoside as their main anthocyanin and showed λ max in the region of 502-509 nm. The orange-red flower color of the latter group mainly depends on an anthocyanins of 6-hydroxycyanidin 3-rutinoside and some carotenoid pigments.
In vitro chromosome doubling of nucellar embryos was investigated in Meiwa kumquat (Fortunella crassifolia Swingle). Nucellar embryos were aseptically treated with two antimitotic agents, colchicine and oryzalin at different concentrations and times. After these treatments, nucellar embryos were successively cultured on MT medium containing 500 mg/liter−1 malt extract. Ploidy levels of seedlings were evaluated by both flow cytometry and chromosome counting of root tips. Frequency of tetraploid production depended on the kind of antimitotic agents as well as on the concentration and time of treatment. Among the treatment conditions tested, colchicine gave better results than oryzalin on inducing chromosome doubling. Tetraploid plants were obtained from approximately 50% of the nucellar seedlings treated with colchicine at 0.05% for 48 hours. These tetraploids showed poor growth during the early stage after acclimatization, but grew as vigorously as the diploid plants when grafted onto 3-year-old seedlings of trifoliate orange. These results showed that colchicine treatment combined with embryo culture is particularly efficient to induce chromosome doubling of nucellar embryos in Meiwa kumquat.
Cabbage plug seedlings were stored for 9 weeks at 5°C or 10°C under cyclic dim lighting (1.7-7.6 μmol·m−2·s−1 of photosynthetic photon flux density with a 1 h-light: 23 h-dark cycle) or darkness. Shoot length and fresh weight of seedlings stored in darkness at 10°C decreased after a transient increase due to etiolation, while those of seedlings subjected to other treatments remained almost constant during the storage period. Dry weights of all seedlings, mainly in the shoots, decreased during the first 5 weeks in storage. The decrease in dry weight was greater in seedlings stored in darkness at 10°C than in seedlings subjected to other treatments. Leaf color of the true leaves was maintained to a higher degree in seedlings stored under light than in seedlings stored in darkness at both 5°C and 10°C. Percent survival after transplantation of seedlings stored at 10°C in darkness decreased with increase in the number of weeks in storage, but percent survival after transplantation of seedlings subjected to other treatments did not decrease throughout the storage period. Head weight at harvest decreased with increase in the number of weeks in storage. Light reduced the head weight loss of seedlings stored at 10°C. These results indicate that cyclic dim lighting is effective for preservation of the quality of cabbage plug seedlings stored for a long period at 10°C.
The effect of fertilizer application methods on cut flower quality and nutrient uptake of spray chrysanthemums were investigated in bench culture. Plants were fertilized once a week by the following four application methods with the same amounts of total fertilization. 1) NASC: nutrient application based on the nitrogen application standard curve, 2) Three concentrations: 3 application levels calculated by the simplified NASC, 3) One concentration: same application levels at all fertilization time, 4) First term high concentration: half the nutrient amounts were applied 4 weeks after pinching and the other half were applied 8 weeks after pinching. High quality cut flowers were produced regardless of the nutrient application method. In all treatments, there was only slight accumulation of nutrient elements in the medium at harvest. Thus, we concluded that to produce high quality cut flowers in spray chrysanthemum bench culture, NASC methods were not always necessary and it seemed to be possible to simplify fertilization methods by same concentration application.
Alkalized organic waste was applied to ‘Prince’ melon cultivation at different growing stages. Alkalized organic waste inhibited the initial growth of the germinated seeds. When small seedlings with cotyledon were transplanted into the waste, subsequent plant growth was also inhibited and growth did not recover at least for 2 weeks even after setting into waste-free sand. Growth inhibition by the waste resulted in delayed fruit harvest. Harvest date and fruit weight were not inhibited when seedlings with three expanded leaves were set into alkalized organic waste. Moreover, the waste effectively inhibited both development of water-soaking mesocarp tissue and soil acidification when the plants were repeatedly grown under the same cultivation medium.
New cultivation system using drip irrigation and liquid fertilization methods combined with year-round plastic mulching was developed, expecting high quality and stable fruit production of satsuma mandarin. Water and/or nutrient solution is automatically supplied through the drip tubes that are laid under the mulching sheets to give adequate water stress. Extensive studies regarding to effect of the system on fruit quality, seasonal change in soil temperature, salt accumulation in soil and labor saving for the grower were conducted. Fruit quality was well controlled through the system, e.g. it raised sugar content by about 2 (Brix%). Functional components such as β-cryptoxanthin and β-carotene increased about 50% compared to juice from fruit grown by non-mulched cultivation. In addition, the system saved about 17.5 hr/10 a/year of labor time in orchard management. Salt in the surface soil had not significantly accumulated 3 years after this system introduced. Year-round mulching diminished the range of soil temperature, particularly in the summer season.
Organic waste was hydrolyzed by adding calcium oxide and used as bed soil for ‘Prince’ melon cultivation. When plants were grown in bed soil mixed with alkalized organic waste and sand (1:1 v/v), flesh firmness of the fruit became higher than that of the fruit grown in sand. Alkalized organic waste resulted in significantly higher calcium concentration in both fruit and matured leaves than in those of plants grown in sand or sand with added Ca(OH)2. Potassium accumulation in both fruit and expanded leaves, however, was not inhibited by alkalized organic waste. Alkalized organic waste contained far higher total calcium compared with that in sand even at fruit harvest. The exchangeable/total calcium ratio, however, was similar or rather lower than that of sand. Although alkalized organic waste raised the soil pH above 8.0, fruit growth was not inhibited.
Novel growing system using drip irrigation and liquid fertilization system combined with year-round plastic mulching was developed, expecting high quality and stable fruit production of satsuma mandarin. Extensive studies regarding the effects of introducing the system: e.g. fruit quality, nutritional efficiency to the trees, labor saving management of grower, showed that the production system was profitable for high quality and stable fruit production of satsuma mandarin. Characteristics of different drip irrigation tubes, relationship between tube setting and water efflux, and the index of watering and fertilizer management were investigated.
The growth and graft union strength of apple trees grafted on extremely dwarfing rootstocks, JM5 and M. 27, were investigated. The scion growth of ‘Tsugaru’, ‘Sansa’, ‘New Jonagold’, ‘Hokuto’, ‘Orin’ and ‘Fuji’ apples grafted on the JM5/Marubakaido (Malus prunifolia Borkh. var. ringo Asami) rootstock was less than the scion growth of the same variety of apples on the M. 27/Marubakaido rootstock. Overgrowth of the rootstock JM5 was shown with all scion varieties. However, remarkable enlargement of the graft union was observed on the scions of ‘Tsugaru’, ‘Sansa’, ‘New Jonagold’ or ‘Orin’ grafted on the M. 27 rootstock. When a weight was hung on each scion grafted on the JM5 rootstock, either the scion or the rootstock broke. The amount of weight causing the break varied according to the kind of scion. In the case of the M. 27 rootstock, all scions except for ‘Fuji’ separated from the M. 27 rootstock at the graft union.
For development of forcing culture and late raising in an edible chrysanthemum, ‘Iwakaze’, the effects of low temperature on breaking rosette and long-day photoperiod on inflorescence quality were investigated. We determined that both forcing culture and late raising were possible because the harvest started in the last ten days of February with early warming after exposure to natural temperature during the second ten days of December. Thus, harvest was considerably prolonged without delaying flowering by preventing the occurrence of ‘roshinka’ inflorescence, which increased in tubulous flowers with continuous illumination starting the last ten days of August.
For the purpose of systematic production in an open field, small-flowered chrysanthemums responding to day-length were selected from cultivars of the July-flowering type, and the possibility of shipping during the peak demand period facilitated by the night-break lighting treatment was examined. 1. Small-flowered chrysanthemums of 13 cultivars responding to day-length were selected from 14 cultivars that flowered in July under natural conditions. When 8 small-flowered chrysanthemum cultivars responding to day-length were planted on April 19th with night-break lighting treatment discontinued on June 11th, 4 small-flowered chrysanthemum cultivars flowered in early August, fulfilling high consumer demand. 2. Systematic production of the combined small-flowered chrysanthemum which flowers in July under night-break lighting facilitated shipping in time for the Lantern festival, because the annual difference in the response period for flowering after the night-break lighting treatment was small. 3. The flowering response period after night-break lighting treatment during the high-temperature season from June to August fluctuated in proportion to changes of the natural day-length. This result suggested the possibility of shipping for the equinoctial week as well as continuous shipping of the same cultivar.
Effects of daylength, growing temperature and shading on the growth, flowering and essential oil concentration and composition in sweet basil (Ocimum basilicum L.) and spearmint (Mentha spicata L.) were examined, and the main essential oil components were analyzed by gas chromatography. Sweet basil and spearmint are recognized as quantitative and qualitative long day plant, respectively. The number of leaves, fresh top weight and essential oil concentrations were increased by growing at a high temperature 30/25°C. The optimal conditions for fresh herb production of sweet basil and spearmint were 30/25°C and 12-h daylength.
This experiment was conducted to determine the relation between the volume of rockwool cube and the root density in the cube during seedling growth, and the plant growth and yield of tomatoes after transplanting to the rockwool system. Tomato seedlings were grown in three rockwool cubes with three different volumes (500 ml (large), 281 ml (medium) and 125 ml (small)). The cubes were piled to the same height of 5 cm. Shoot dry weight increased with the cube size, and differences in shoot dry weight between different cube sizes increased with the period of seedling growth. However, root dry weights were not significantly affected by the volume of rockwool cubes. The results indicated that shoot growth was restricted when the ratio of root dry weight to cube volume (rdw/cv) was over 2.0 mg/ml. The highest marketable yields in each cube size were observed when seedlings were grown for 4, 3 and 2 weeks in large, medium and small cubes, respectively. Regression analysis estimated that the highest yield could be produced when the seedlings were transplanted at rdw/cv ≒ 1.64 mg/ml.
Bulbs of Allium caeruleum were stored at 5°C for 0, 3, 6, 9 or 12 weeks from 20 September, then planted in plastic containers in a greenhouse kept at min. 10°C or 15°C. None of the bulbs flowered when they were chilled for 0 or 3 weeks. The earliest flowering with a good quality flower was obtained when the bulbs were chilled for 9 weeks. High growing temperature (15°C) hastened flowering but decreased flowering percentage and flower quality. The minimal bulb size required for 100% flowering 0.3 g. As the mother bulb weight increased, the number of the daughter bulbs increased and the rate of increased bulb weight decreased.
The effects of the duration of a 24-hr photoperiod and gibberellin or uniconazole application on inflorescence formation in turnip plants (Brassica rapa L. cv. ‘Hikari’) were investigated using the flower formation index (Saito and Saito, 2001). Plants were grown under 24-hr photoperiods for 0, 10, 20, 30, 40 or 75 days. The percentage of plants with terminal inflorescences and the flower formation index increased as the 24-hr photoperiodic duration was prolonged. The percentage of plants with terminal inflorescences was 100% in all gibberellin treatments and the flower formation index was highest for application of gibberellin throughout the whole period in each photoperiodic treatment. Gibberellin promoted the effect of inflorescence formation. With application of uniconazole, the percentage of plants with terminal inflorescences was suppressed and the flower formation index decreased remarkably. We thought that the effect of flower induction was accumulated by 24-hr photoperiodic treatment but its effect was smaller than that of low temperature. Moreover, we thought that gibberellin substituted for the effect of the long-day treatment on inflorescence formation, although the effect of gibberellin was not strong.
Using selected marketable strains of Oenanthe javanica (Blume) DC., the effect of the photoperiod on the growth of ‘Aomori-kei’, ‘Sendai-kei’, ‘Shimane-midori’ and ‘Miyagi VWD 1’ was investigated. Nursery shoots were planted in plant boxes on October 6, and grown under natural ambient temperature and a natural photoperiod. From November to March, plant boxes were set in a greenhouse in which a minimum temperature of 10°C and an 8- or 24-hr photoperiod were maintained. Runner development was not affected by photoperiod. Elongation of the basal internode was facilitated by 24-hr photoperiod, especially in ‘Sendai-kei’ and ‘Aomori-kei’. Late transfer to the greenhouse promoted elongation of the internode, and diminished differences between the photoperiods and strains, respectively. Flower buds were formed only under the 24-hr photoperiod. The results show that marketable O. javanica plants with short internode will be harvested when plants are grown under a short photoperiod without chilling. Though retarding runner development would be labor saving in preparation for shipment, runner development could not control by photoperiod.
The experiments were conducted to determine the influence of fruit exposure to sun on fruit temperature, sorbitol content, and early watercore development in ‘Orin’ apples, using a simple measuring system of total integrated solar radiation. The system provided th correct measurement of solar radiation under high daytime temperature conditions above 30°C, the typical summer climate in Matsuyama. Positive correlations were found between the relative amount of fruit insolation measured from three directions (east, south and west) of the fruit equator and mean fruit temperature, although the correlation coefficients in experiments with R-type film were much higher than those with Y-type film. Analysis of 26 apples obtained from three experiments, two with R-type and one with Y-type film, also demonstrated positive correlations between the relative amount of fruit insolation and the mean and daily maximal fruit temperature, watercore rating, flesh firmness, fructose, glucose, sorbitol, and total sugars. Correlations between the degree of watercore and fruit temperatures (mean and maximum), flesh firmness, and sorbitol content were also significant. These results suggest that early watercore in ‘Orin’ apples is promoted by fruit exposure to sun mediated through increased fruit temperature and sorbitol accumulation.
Fusarium ‘F959’, a pathogenic sensitive strain to taro, was inoculated on ‘Celebes’. The inoculated corms were kept in the dark at 25°C for 15 days. Paraffin sections were made from the inoculated corms and observed cytologically under a light microscope. In control specimens, about 1 mm transparent cell layers and meristematic cell layers (normal periderm) were formed under the wound surface. The cells of all transparent layers were significantly lignified. When Fusarium was inoculated to the wound, the transparent cell layers expanded to 2-5 mm and were not lignified. It was considered that periderm formation was not normally performed by Fusarium. Further, it was investigated whether delaying the time of inoculation after wounding would influence the response of corm to the pathogen. When the interval between wounding and inoculation was 12 hours or more, there was no expansion of transparent cell layers observed. It was considered that normal periderm formation was facilitated by some kind of defense responses occurring in the tissue of the taro.
Cut flowers of rose (Rosa hybrida Hort. cv. Noblesse) with a leaf-less short stem in vase water containing various additives were incubated in a growth chamber (23°C, a 12-hr photoperiod, 75% relative humidity, and a PPFD of 20 μmol·m−2·s−1) for about 2 weeks. The vase life of cut flowers fed with a solution of sucrose + HQS (30 g·liter−1 of sucrose and 0.2 g·liter−1 8-hydroxyquinoline sulfate) was about 4 days longer than those fed distilled water alone. However, cut flowers fed with a solution of putrescine (Put), spermidine (Spd) or spermine (Spm) at 0.1 mM withered earlier than those fed distilled water alone. The addition of 0.1 mM Put to the sucrose + HQS solution resulted in increased vase life by 2 days compared with that of those fed sucrose + HQS solution alone. Spd and Spm did not induce such an effect. Flowers fed Put-supplemented sucrose + HQS solution showed a much slower rate of petal unfolding and significantly lower content of fructose in the petals than those fed sucrose + HQS solution. The results suggest that Put induced alteration of sucrose metabolism in the petals, resulting in retardation of petal cell growth and unfolding of petals, thereby extending the vase life of cut rose flowers.