Evaluation of the quality of agricultural products is important because this is the basis for consumer purchases. Consumers may evaluate products on the basis of factors such as fragrance, appearance, and hardness. Texture is one of the most important factors, especially as an indication of freshness. For agricultural products that ripen after harvest, the degree of ripeness is an important factor for optimum edibility. Ripeness evaluation ideally needs to be nondestructive. Various methods have been proposed to evaluate food texture and the nondestructive evaluation of fruit ripeness. This paper reviews such methods and recent developments, focusing on those that use acoustic vibration techniques.

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To obtain cytogenetic information on sexual intergeneric hybrid progenies between Citropsis schweinfurthii and ‘Nanpu’ tangor (Citrus spp.), we conducted Chromomycin A₃ (CMA) chromosome banding and genomic in situ hybridization (GISH) analyses. The CMA karyotype composition of C. schweinfurthii was very simple (14D + 4E), while that of ‘Nanpu’ tangor showed more complicated chromosome types (1A + 4C + 5D + 8E). Two progenies with C. schweinfurthii as the maternal parent showed a karyotype of 1A + 1C + 11D + 5E, suggesting that each of the type A and C chromosomes was inherited from ‘Nanpu’ tangor. GISH-CMA analysis in one of these progenies showed a clear distinction between parental chromosomes, and revealed that the hybrid progeny arose due to fertilization between a female gamete with a CMA karyotype composition of 7D + 2E from C. schweinfurthii and a male 1A + 1C + 4D + 3E gamete from ‘Nanpu’ tangor. The result suggests that C. schweinfurthii had homomorphic homologous chromosomes as a wild species, while ‘Nanpu’ tangor had heteromorphic homologous chromosomes.

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Pitaya is a crassulacean acid metabolism (CAM) plant that is normally grown in subtropical regions, but it would be useful to cultivate this crop in temperate regions. In this study, we measured concentrations of organic acids and carbohydrates, and activities of the enzymes phosphoenolpyruvate carboxylase (PEPC), malic enzyme (ME), and malate dehydrogenase (MDH) in pitaya grown in a temperate zone, and compared the diurnal changes in these components between winter and summer. In summer, the diurnal changes in malate, citrate, and starch in pitaya were typical of starch-using CAM plants. Activities of PEPC and ME also showed typical CAM-type diurnal patterns in summer. In particular, changes in ME activity were closely associated with changes in malate content. In winter, changes in malate content showed a typical CAM pattern, although the amount accumulated was only half of that accumulated in summer, however, the citrate content in winter remained at an almost constant low level throughout the day. PEPC and ME activities were almost constant through the day in winter, however, PEPC activity in winter was similar to its minimum level in summer, whereas ME activity in winter was similar to its maximum level in summer. MDH activity was higher in summer than in winter, but there was no distinct diurnal pattern observed in either summer or winter. These results suggest that pitaya shows normal photosynthesis and metabolism in summer. In winter, however, malate accumulation is restricted, result in decreased concentrations of downstream products and metabolites. This may be because of decreased PEPC activity and increased ME activity during the night in winter. Our results suggest that temperature is not the only factor that affects CAM in this plant, because the summer temperature in this study was similar to the winter temperature in our previous study, which was carried out in a subtropical region (Ishigaki Island). Furthermore, diurnal profiles of metabolites and enzyme activities in both regions were similar in summer and winter; therefore, daylength may also be an important environmental factor.

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To assist in the breeding and identification of Rhus succedanea L., which is cultivated in Japan to produce wax from its fruit, 12 microsatellite markers were developed from 96 clones sequenced from a genomic library generated from the traditional cultivar ‘Ikichi’. Using these markers, 50 genotypes were identified in 82 individuals (designated “the western group”) representing traditional cultivars and associated materials that have been selected from populations in western Japan and conserved for use in a breeding program. In a further analysis, of the 82 previously mentioned individuals and others from Chiba and Okinawa populations, 88 different genotypes were detected, with numbers of alleles per locus ranging from 3 to 19 and expected heterozygosity ranging from 0.22 to 0.85. Each traditional cultivar and old individual in the western group was closely genetically related to other trees in the group. In addition, according to Principal Coordinate Analysis, using Dice similarity coefficients based on the 88 genotypes, and pairwise F_ST values, the western group and the Chiba populations were considerably more closely related to each other than to the Okinawa populations. The implications of the findings for the future breeding of R. succedanea in Japan are discussed.

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In previous studies, we have developed molecular markers linked to the AST locus that controls fruit astringency type in persimmon; however, these markers are not feasible for practical application to breeding programs since they are not fully effective for discriminating the pollination constant and non-astringent (PCNA) genotype from the non-PCNA genotype in a progeny derived from ‘Kurokuma’. Here we developed new sequence characterized amplified region (SCAR) markers that enable easy and reliable selection of the PCNA genotype from breeding populations. Genomic regions adjacent to probe 5R, which showed polymorphic fragments between PCNA and non-PCNA genotypes in restriction fragment length polymorphism (RFLP) analysis, were isolated from the genomic libraries of ‘Nishimura-wase’, ‘Jiro’, and ‘Kurokuma’-derived offspring. The isolated genomic regions were characterized and 3 insertion/deletion mutations were observed between ast- and AST-linked regions. Several primers were designed in the flanking region of Indel-3 and, in multiplex PCR, it was shown that using 2 forward primers, AST-F and PCNA-F and a reverse primer, 5R3R, is the most useful and reliable primer set. The AST-linked 220-bp fragment proved to be a common marker of ‘Kurokuma’-, ‘Nisimura-wase’- and ‘Aizumishirazu’-derived progenies. This multiplex PCR is considered the most practical tool for marker-assisted selection (MAS) and can enhance and accelerate progress in persimmon breeding.

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Lodged seedlings unfit as transplanters and harvesters are often grown in cabbage cultures. These seedlings cause transplanting and harvesting losses and reduce working efficiency. Why such lodging of the seedlings occurs is unknown. It is thought that the seedling’s own weight, the growing environment such as rain and wind after transplanting, and the accuracy of the seedling transplanter are possible causes. We therefore focused on the hypocotyl of the plug seedling given how soft it is and how susceptible it may be to damage from the weight of the cabbage. Additionally, the flexural rigidity of the hypocotyl—a mechanical characteristic indicating pliability—was measured and was considered in relation to parameters such as the length and diameter of the hypocotyl and the fresh weight of the seedling. Given that the hypocotyl is relatively soft and deflection may be large, numerical calculations with a large deflection equation were used to measure flexural rigidity. The results showed that the hypocotyl diameter and the seedling fresh weight in all cultivars increased more slowly later in the seedling stage, with the flexural rigidity of the hypocotyl increasing exponentially. It was inferred that Young’s modulus increases in proportion to the number of days that elapse after the day of sowing, since the increase in flexural rigidity was greater than what would be proportional to the hypocotyl diameter in theory. Moreover, it was suggested that the cabbage plug seedling would not be easily lodged given its weight as the seedling grows.

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We investigated the variation in rutin and total polyphenol contents in asparagus spears under different conditions of mother-fern culture. Rutin and polyphenol contents were highest at early spring harvest at all test sites. The contents gradually decreased during the harvest season. In particular, a considerable decrease was observed after the growth of mother ferns. The absorption of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was weaker in summer. Rutin content in the spears of plants grown outdoors was generally higher than in these grown in a greenhouse, except at early spring harvest. Rutin contents decreased in the spears of plants grown under a shading net or an ultraviolet (UV) radiation-filtering film. These results suggest that cultivation conditions, especially light conditions, have a great influence on rutin and polyphenol contents. We evaluated two new methods to increase rutin content by improving light conditions. Light conditions in asparagus rows were improved by using light-reflecting sheets and net screens; however, a significant increase in rutin content was observed only when net screening was used, implying that this method is better than light reflecting sheets to increase the rutin content.

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The correlation between several fruit characters and the degree of polysomaty, i.e., the number of peaks in flow cytometric analysis, was examined using mature fruits of 12 genotypes from three species of Capsicum. Capsicum chacoense PI260429, which had the smallest fruit with the thinnest pericarp, showed the least number of peaks in ploidy levels, i.e., four ploidies ranging from 2C to 16C, whereas Capsicum annuum ‘Édes alma’ had the thickest pericarp and the highest peak numbers of eight ploidy levels, ranging from 2C to 256C. Among the morphological traits of fruit examined, pericarp thickness showed the highest correlation with the degree of polysomaty (r = 0.88).

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Tolerance to fusarium wilt and anthracnose and the changes in antioxidative abilities in mycorrhizal strawberry plants were investigated. Strawberry (Fragaria × ananassa Duch., ‘Nohime’) runner plants were inoculated with arbuscular mycorrhizal fungus (Glomus mosseae, AMF) and treated with a split root system. Ten weeks after AMF inoculation, Fusarium oxysporum f. sp. fragariae and Colletotrichum gloeosporioides were inoculated. Mycorrhizal plants accumulated a higher dry weight of shoots and roots than non-mycorrhizal plants 10 weeks after AMF inoculation. Four weeks after pathogen inoculation, disease incidence and severity of symptoms were eased in shoots and roots of mycorrhizal plants, especially with fusarium wilt; induced tolerance also appeared in split root-treated mycorrhizal plants. No major difference in antioxidative abilities took place before pathogen inoculation among plots; however, 4 weeks after pathogen inoculation, mycorrhizal plants showed higher values in the following items; SOD activity, DPPH radical scavenging activity, total polyphenol content, ascorbic acid content, effects differed with plant parts. From these findings, plant growth enhancement and tolerance to fusarium wilt, including induced tolerance, and anthracnose occurred in mycorrhizal strawberry plants. In this case, antioxidative abilities increased under pathogen-stressed conditions, so that disease tolerance might be associated with the increase in such antioxidative factors.

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In Japan, the use of forced culture conditions to produce sweetpea (Lathyrus odoratus L.) cut flowers has flourished. The tendril-less trait that results in compound leaves instead of tendrils is a very important trait for forced flower production because removing unnecessary tendrils markedly increases the amount of labor and production management costs. Thirty-five morphological and cultural characteristics were examined in 38 sweetpea cultivars. We analyzed the relationship between characteristics, especially those deemed important for reducing labor costs such as the tendril-less trait, and calculated correlation coefficients. Cluster analysis was also employed to evaluate the dataset and it showed that 38 cultivars could be classified into 3 clusters. Cluster I cultivars are recommended as garden-type plants because their initial flower buds were too late to be forced. Cluster II cultivars are suitable as cut flower type plants. Cluster III cultivars are appropriate as garden or container-type plants because the peduncles were too short to use as cut flowers. Furthermore, the results of principal component analysis indicated some important factors for classification of cultivars. These were consistent with the results of cluster analysis. Our analysis of the morphological and cultural characteristics of sweetpea grown under conditions to force flowering provides a foundation for the efficient breeding of this important horticultural plant.

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This study aimed to clarify the morphological properties and the role of homeotic genes in the development of paracorolla, a petaloid organ fused with stamens at the base in Antirrhinum majus. Two primordia of paracorolla initiated at the lateral and slightly outer (i.e., basal) position of a stamen primordium, suggesting that the paracorolla is a stipule of the stamen. In the developed paracorolla, expression of the A-class gene SQUAMOSA (SQUA) and the B-class genes DEFICIENS (DEF) and GLOBOSA (GLO) were high, while those of the C-class genes PLENA (PLE) and FARINELLI (FAR) were very low. In contrast, in the paracorolla primordia, expressions of SQUA and PLE were not detected. Thus, the expression patterns of homeotic genes in the paracorolla were basically the same as those of the petal, and this pattern was established during paracorolla development. In the stamen, which fused with the paracorolla at the base, DEF, GLO, PLE, and FAR were expressed in the anther. However, in the filament, SQUA was also expressed at a higher level in addition to these genes, indicating that the expression pattern shifted from the stamen type in the anther, to the petal type in the paracorolla, through the intermediate type in the filament. This gradient of expression pattern among these organs, which apparently belong to the same whorl of the flower, may be essential for the development of the paracorolla into a petaloid organ.

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Mental health and physical condition of residents in newly built apartment houses in Seoul, Korea were evaluated considering indoor plant placement for two terms of observation. Residents demonstrated severe symptoms of sick building syndrome (SBS) for at least two years. Indoor plant placement alleviated the degree of SBS symptoms along with ventilation. Residents showed improvements in mental health during the period of ventilation, which was facilitated by the placement of indoor plants. The placement of indoor plants failed to make significant differences in the vital capacity or blood indices of residents, but led to slight improvements in some factors like forced vital capacity (FVC) and change in total immunoglobulin E levels (T-IgE). From the results above, it could be postulated that the placement of indoor plants alone was not enough to reduce the level of indoor toxic chemical substances. Therefore, the placement of indoor plants could be an environmentally friendly method to reduce the levels of toxic chemical substances with the supplementary application of ventilation.

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Pigment and molecular analyses were carried out to elucidate how the white marginal picotee in the petals of Camellia japonica ‘Tamanoura’ is expressed. HPLC analyses showed that two major anthocyanins (cyanidin 3-glucoside and cyanidin 3-galactoside) were accumulated in the red part of the petals of ‘Tamanoura’, as found in those of wild type C. japonica, whereas no anthocyanins were detected in the white picotee part, indicating that the anthocyanin biosynthetic pathway might be blocked at some steps in the white part. Transcriptional levels of the genes involved in anthocyanin biosynthesis were investigated by RT-PCR. Most genes were equally expressed in both red and white parts of ‘Tamanoura’ petals, but the expression of chalcone synthase (CHS) was strongly suppressed only in the white picotee part. Full-length cDNA sequence of CjCHS was determined using the 5' and 3' RACE approach. The deduced amino acid sequence of CjCHS shared high homology with those of several woody plants. cDNA RT-PCR and genomic DNA PCR revealed no length differences in PCR products between red and white picotee parts in the petals of ‘Tamanoura’, suggesting that no insertion of transposable elements and DNA rearrangement occurred in CjCHS in the white part.

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A novel acylated anthocyanin was identified from the violet flowers of Bletilla striata ‘Murasaki Shikibu’ as a major floral anthocyanin. This pigment was based on cyanidin 3,7-diglucoside as its deacylanthocyanin, and was acylated with two molecules of caffeic acid. The structure was unambiguously elucidated by chemical and spectroscopic methods to be cyanidin 3-O-(β-glucopyranoside)-7-O-[6-O-(4-O-(6-O-(4-O-(β-glucopyranosyl)-trans-caffeoyl)-β-glucopyranosyl)-trans-caffeoyl)-β-glucopyranoside]. Based on the results of the present study, the bluing effect was discussed for the violet flowers of a given cultivar.

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