A sinapoylglucoside and two kaempferol glycosides were isolated from Matthiola incana ‘Vintage white’, and determined to be 1-O-(trans-sinapoyl)-β-glucopyranoside, kaempferol 3-O-(2-O-α-rhamnopyranosyl)-β-glucopyranoside-7-O-α-rhamnopyranoside, and kaempferol 3-O-(2-O-α-rhamnopyranosyl)-β-arabinopyranoside-7-O-α-rhamnopyranoside as major components by chemical and spectroscopic methods. The quantitative distribution of these three compounds from ‘Vintage white’ was equally detected in eight other cyanic color cultivars of the Vintage series. It is known that 1-O-(trans-sinapoyl)-β-glucopyranoside is an important donor to synthesize the sinapoyl anthocyanin in Arabidopsis. Our previous study showed that the higher the ratio of sinapoyl anthocyanin, the greater the activity of intramolecular copigmentation, resulting in advanced blue coloration in nonwhite flowers of Matthiola incana. Thus, 1-O-(trans-sinapoyl)-β-glucopyranoside may play an important role in the blue coloration caused by intramolecular copigmentation in flowers of Matthiola incana.

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The relationship between fruit skin coloration under the calyx and differences in fruit skin coloration under common and near ultraviolet ray-absorbing (UVA) films was investigated for the establishment of parthenocarpic eggplant cultivars which can be cultivated under UVA films. The difference in skin coloration of deep-colored fruits under the calyx of double haploids was significantly smaller than in light-colored ones. F₁ plants from crosses between lines that were deep-colored under the calyx of double haploids showed smaller differences in fruit skin coloration under different films than F₁ plants from crosses between lines that were light-colored under the calyx of double haploids. These results indicate that fruit skin coloration under the calyx is hereditarily related to fruit skin coloration under UVA films. Additionally, fruit skin coloration under the calyx is useful as an index of the breeding of parthenocarpic eggplant varieties with deep-colored fruit skin in a greenhouse covered with UVA film.

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In order to develop new cultivars adaptable to Japan with high quality and functionality, we attempted to produce interspecific hybrids between Vaccinium uliginosum L. (2n = 6x = 72) of the genus Vaccinium, a wild species native to Japan, and some highbush blueberry cultivars (2n = 4x = 48) of the genus Cyanococcus, using reciprocal crossing. Fertile seeds were obtained from 8 of 9 cross combinations, and 13 seedlings were obtained from 5 cross combinations when V. uliginosum were used as a seed parent, but only 7 seedlings from 2 of 9 cross combinations as pollen parent. It was revealed that seeds were easier to obtain when V. uliginosum was used as a seed parent compared with pollen parent, and unilateral cross incompatibility occurred in the reciprocal cross. These seeds germinated in vitro after pretreatment with gibberellin or in a seed bed after stratification. Four resultant seedlings (KB4: KB-2, 7, 9, 10) from the cross of V. uliginosum and ‘Bluecrop’ were grafted on rootstock and evaluated regarding their hybridity, ploidy level, morphological characteristics of the flower and fruit, and fruit quality. RAPD analysis showed that KB4 was a hybrid between Vaccinium and Cyanococcus. The hybrids were also confirmed to be pentaploid by flow cytometry and observation of the chromosome number in shoot tip cells; however, they produced fertile pollen and set fruits in an open field without artificial pollination. Fruit of all hybrids also had a peduncle with a pair of leaflets differing from one of their parents. Although the contents of anthocyanin and polyphenol and antioxidant capacity of fruit were different among their hybrids, those values of KB-2 were significantly higher than in ‘Bluecrop’. In the future, these hybrids may be useful as breeding material to establish new cultivars with high quality and functionality.

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To identify the cause of poor fruit set in the triploid Japanese plum ‘Kiyo’ (Prunus salicina Lindl.), we performed morphological observation of the inside of ovules using histological techniques. Early fruit drop of ‘Kiyo’ occurred at a higher rate than that of ‘Taiyo’. The fruit drop rates of ‘Taiyo’ and ‘Kiyo’ at 42 days after hand pollination (DAHP) were 77.8 and 88.0%, respectively. Even during the flowering time, the embryo sac of 60% or more of ‘Kiyo’ remained undifferentiated. Regarding the plums with embryo sacs other than those undifferentiated, while many ‘Kiyo’ managed to develop in the same manner as ‘Taiyo’, we observed a higher rate of ‘Kiyo’ embryo sacs with developmental delay and/or degeneration compared with ‘Taiyo’. With regard to the development of the embryo and endosperm at 14 DAHP, we observed a higher rate of developmental delay as well as problems such as embryo sacs without a zygote and/or endosperm nucleus in ‘Kiyo’. In the observation at 35 DAHP, the rate of ovules with both a proembryo and endosperm nucleus was 91.7% in ‘Taiyo’, whereas it was 75.0% in ‘Kiyo’. Moreover, while most of the ovules of dropping fruits in ‘Taiyo’ were merely undifferentiated, those of ‘Kiyo’ also had the problems of embryo sacs with developmental delay and/or degeneration as well as a non-divided zygote and/or endosperm nucleus.

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For Ranunculus asiaticus L., a tuberous root plant, the cutting propagation method has not been used. Therefore, we investigated the feasibility of applying the cutting propagation method to R. asiaticus L. and the effects of this method at three different air temperatures of 10°C, 15°C, and 20°C on rooting, growth, and flowering in rooted cuttings after setting in pots in a greenhouse. Root formation was observed at all temperatures. The total root length was greater at 20°C than at 10°C and 15°C. The first flowering date was earlier at 10°C and 15°C than at 20°C. However, no difference was observed in the weight of dried tuberous roots among the three temperatures. We conclude that the cutting propagation method is suitable for R. asiaticus L. The temperature during the cutting period affects root formation in the cutting, growth, and flowering stages of rooted cuttings after setting but does not affect the weight of dried tuberous roots.

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The frequency of vegetative propagation of sweet pepper (Capsicum annuum L.) from scions is about 1.5 times per week under standard conditions. We developed a novel procedure to increase the rate of scion production to accelerate the utilization of sweet pepper cultivars via vegetative propagation. Pinching off the main stem above a higher node increased the number of scions, and all of the scions successfully developed roots. The number of scions produced was significantly increased by harvesting the primary and secondary lateral shoots, because the number of lateral shoots that developed was dependent on the number of axillary buds. The number of scions also increased with increasing the amount of fertilizer applied. The maximum frequency of propagation from scions achieved in this study was about 4.5 times per week.

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The effects of the groundwater table level controlled by the Farm-Oriented Enhancing Aquatic System (FOEAS) in an upland field converted from a paddy field on the soil water content, soil oxygen concentration, and growth of autumn-sowing cabbage were evaluated. We created two plots with groundwater tables maintained at -30 cm (HIGH) and -60 cm (LOW) from the soil surface. Although the LOW plot showed higher soil moisture suction than the HIGH plot, there was only a mild increase up to about 40 kPa. The groundwater tables in both plots fluctuated owing to rainfall. Increases in the soil water content and groundwater table by rainfall followed by a decrease in the oxygen concentration of soil gas as well as the air ratio were noted. In the HIGH plot, the oxygen concentration often dropped to 0% during the latter growth stage. In winter, plants in the HIGH plot had a slightly larger vertically projected area than those in the LOW plot, probably due to maintaining a high water content, but showed growth suppression later, resulting in a smaller head weight (about 60% of plants in the LOW plot). The results indicate that a constantly high groundwater table controlled by FOEAS would likely increase the incidence of excess-moisture injury and reduce the yield of cabbage.

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The radiocesium concentrations in acorns and leaves of Shirakashi (Quercus myrsinifolia) were studied in order to clarify their contamination levels and the transfer pathways of cesium radionuclides following the accident at the Fukushima Daiichi Nuclear Power Plant. The results obtained showed that the contamination level of radiocesium measured in old leaves (grown before 2010) which existed before the accident were still very high, i.e., higher than 12,000 Bq・kg^-1 (sum of ¹³⁴Cs and ¹³⁷Cs concentrations on a fresh weight basis). However, the radiocesium concentrations in young leaves (grown 2012) were less than 300 Bq・kg^-1. The concentration of radiocesium in acorns was a maximum of 305 ± 8 Bq・kg^-1 in 2012. The contamination did not appear to be surface deposition because there was no difference in the concentrations between unwashed and washed acorns or between the husk and acorn nut (seed). A correlation was found in the radiocesium concentrations between old and young leaves, and also between acorns and young leaves. The ratio between acorns and young leaves was approximately 0.85. A relationship was observed between the radiocesium contamination of acorns and the area of the exposed root zone not covered with concrete on the pavement. This suggests that the root-uptake pathway should also be considered in addition to translocation from the contaminated canopy to acorns and young leaves of the trees.

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The effects of hydrogen cyanamide on budbreaking and flowering in the potted Japanese pears ‘Kosui’ and ‘Hosui’ cultivated under field conditions were studied during 4 periods: 2007 to 08, 2009 to 10, 2010 to 11, and 2011 to 12 seasons. The plants were treated with hydrogen cyanamide after accumulating several levels of chilling, and then budbreaking and flowering were evaluated by forcing in a greenhouse maintained at 22°C. The DeVelopmental Index (DVI) model, which was calculated according to the DeVelopmental Rate (DVR) and chilling hours below 7.2°C, was employed as an index to predict the effective timing of hydrogen cyanamide treatments. The DVI₁ model, described by Oya (2006) and Sugiura (1997), refers to temperatures between -6～12°C during the period of dormancy. In this study, we refer to the DVI₁ as DVI_(old) model. Moreover, Sugiura et al. (2003) reported that temperatures between 21～24°C during dormancy override accumulated chilling hours in periods of dormancy. We call this the DVI_(new) model. The results showed that hydrogen cyanamide treatment at 400～600 hours below 7.2°C promoted the breaking bud endodormancy of ‘Kosui’ and ‘Hosui’. The greatest effect of hydrogen cyanamide on budbreaking and flowering corresponded to a DVI_(new) range between 0.65 and 0.70 for both cultivars. Moreover, the results for old DVI_(old) were higher than 1.03 and those for DVI_(new) were higher than 0.8, i.e., the effects of the treatment became weaker. Since hours above 21°C were higher than in other seasons in 2011 (October to February), negation of the chilling might have confounded the estimation of the application timing of cyanamide. Therefore, the value of DVI_(old) was over-estimated compared to DVI_(new) due to the influence of the high temperature even at the same number of chilling hours. These results suggest that DVI_(new) is a suitable method for hydrogen cyanamide application as a measure against global warming.

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Effects of temperature, phytohormones, and light on the coloring of fruit were examined in sweet pepper (Capsicum annuum L). Although coloring was promoted at 20 to 25°C in the dark, the fruit reached only a pale red. In addition, reduction in the chlorophyll content was retarded not only below 10°C, but also above 30°C, yielding dark-colored fruit. Changes in the color were not promoted when either ethylene or methyl jasmonate was applied under a dark condition. Although the color value increased when both phytohormones were simultaneously applied, the effects were insufficient for the force-ripening of fruit. On the other hand, irradiation with a fluorescent light under 20°C markedly promoted the coloring of the fruit. The fruit achieved a bright red color more quickly with a higher irradiance (200 µmol quanta・m^-2・s^-1). These results indicate that light irradiation plays an important role in the coloring of sweet pepper fruit at an optimal temperature.

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This study investigated the effect of the minimum air temperature on the occurrence of abnormal inflorescences in Gypsophila paniculata ‘Altair’. Abnormal inflorescences could be classified into three types: Type 1 (short flower stalk), Type 2 (coalescent two-flower stalk), and Type 3 (looping and irregular flower stalk). Abnormal inflorescences increased from early winter to early spring. Type 1 and 2 inflorescences could be observed at a constant rate, regardless of the flowering time, whereas markedly abnormal inflorescences (Type 3) increased significantly in March. Subsequent investigation of the effect of the minimum air temperature (7, 11, and 15°C) revealed that Type 3 increased at a lower air temperature; however, a lower air temperature improved the volume, length, and weight of cut flowers. In conclusion, a minimum air temperature of 11°C may be optimum to produce high-quality cut flowers of ‘Altair’. The cumulative number of chill hours (<9°C) from pinching to budding was more strongly correlated with the incidence of Type 3 abnormalities than that from budding to flowering. Thus, the occurrence of Type 3 abnormalities is affected by the minimum air temperature from pinching to budding.

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Curing and long-term storage are essential postharvest treatments for the year-round shipping of garlic bulbs. We examined the postharvest conditions that induce concavities on the scales of long-term-stored garlic bulbs using ‘Fukuchi White’, a major cultivar in Japan. Bulbs were cured by a tempering method which consisted of heating at about 34°C during the day and nonheating at night under forced ventilation, and were stored at -3, -2, and -1°C under standard and low-humidity regimes for a maximum of 10 months. Some bulbs stored at -3°C had concavities on the scales, but few bulbs stored at -2 and -1°C had concavities regardless of the storage humidity. Bulbs were cured by continuous heating at 33°C or by the tempering method, and were stored at -3, -2, and 0°C for a maximum of 8 months. The mean temperature during tempering was about 30°C. After curing by continuous heating at 33°C, most of the bulbs stored at -3, -2, and 0°C had concavities, but few bulbs stored at -2 and 0°C after curing by tempering had concavities. Severe concavities were observed on the bulbs stored at -2 and -3°C after curing by continuous heating at 33°C. These results suggest that curing at a high temperature and storage at a low temperature induce the occurrence of concavities, and that the curing condition markedly affects the occurrence of concavities when bulbs are stored at -2°C, which is the current storage temperature used for the year-round shipping of garlic bulbs in Aomori Prefecture. This method of curing by tempering combined with storage at -2°C may provide high-quality garlic bulbs throughout the year.

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