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The molecular and enzymatic changes that follow harvesting of asparagus are important aspects for postharvest deterioration. To define the factors contributing to postharvest deterioration, the early changes in ethylene production and the activities and expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase, ACC oxidase, and phenylalanine ammonia-lyase (PAL) were studied in whole spears and in excised top and bottom portions. As a result of wounding, ethylene production was found higher in both top and bottom portions compared with whole spears but followed the same trend reaching the peak at 16 hours after harvest. ACC synthase was rapidly induced in excised top portions but no significant ACC synthase activity was observed in excised bottom portions. In top portions, ACC synthase reached a peak 8 hours after harvest and thereafter started to decline. In contrast to ACC synthase, ACC oxidase was induced markedly in both top and bottom portions and remained high until 16 hours after excision. On the other hand, PAL greatly increased in activity in bottom portions but not in excised tops. Northern blot analysis showed that increased mRNA levels coincided well with the excision-promoted increases in enzyme activity and ethylene production.

Six kinds of powder samples with a different particle size and its distribution have been prepared from coprecipitated precursors by light grinding followed by sieving, and calcined in air to form the barium ferrite (BaFe 1 2 O 1 9 ) phase. Correlation between the particle morphology and Fe/Ba molar ratio or magnetic properties has been examined. The results indicated that the powders consisting of coarse particles (100-200 μm) exhibit a single phase of BaFe 1 2 O 1 9 , and a higher saturation magnetization and coercivity than the powders having fine particles or a wide size distribution. The optimized powders showed a high coercivity of 5.85 kOe and a saturation magnetization of 71 emu/g that are closed to the theoretical values.

Background: A retrospective endoscopic follow-up study was conducted to elucidate the development of minute or superficial-type cancers. Methods: The development of eight colorectal cancers that were followed up by endoscopy was evaluated. Results: (i) Cancer with high-grade atypia frequently developed from lesions diagnosed histologically by biopsy as adenoma; (ii) two polypoid adenomas developed into invasive cancers with non-polypoid configuration; (iii) a superficial elevated-type cancer with high-grade atypia remained a mucosal cancer for more than 1 year; (iv) a superficial depressed (SD)-type cancer that had a concomitant adenomatous component grew slowly, maintaining the same configuration for more than 2 years. Another SD-type cancer grew rapidly to an advanced cancer; and (v) a superficial elevated adenoma developed into a IIa + IIc-type submucosally invasive cancer while maintaining the size of the initial tumor. From the analysis of the literature, 35 lesions were collected, but it was impossible to speculate which specific type of tumor grew rapidly. Conclusions: From the endoscopic observations of the present study and the review of the literature, developments of superficial type cancers were diverse, sessile-type cancers with marked configurational change, and early cancers developed slowly, although the speed of their growth accelerated according to the downward invasion of the cancer.

The diagnostic accuracy of the determination of anti-Saccharomyces cerevisiae antibodies (ASCA) and its clinical significance in Crohn's disease (CD) have been reported in Western countries, but scarcely reported in Japan, where the dietary habits of people differ markedly from those of Western countries. Th present study was undertaken to examine the diagnostic accuracy and clinical significance of ASCA determination in Japanese patients with CD or ulcerative colitis (UC). Methods: Seventy-five serum samples obtained from 68 patients with CD, 34 serum samples obtained from 30 patients with UC, 35 serum samples from 35 patients with liver cirrhosis, and 31 serum samples from 31 healthy controls were examined. The optical density of each sample was measured by an enzyme-linked immunosorbent assay (ELISA) method to quantify ASCA IgA and IgG. Results: The cutoff level, as determined by discriminant analysis of the data, was 0.1502 for ASCA IgA and 0.156 for ASCA IgG. Of the 68 patients with CD, 31 (45.6%) were ASCA-positive, and of the 30 patients with UC, 4 (13.3%) were ASCA-positive according to these cutoff levels. The sensitivity and specificity of ASCA determination for the differential diagnosis of CD from UC were 45.6% and 86.7%, respectively. When the relationship between ASCA and the clinical features of CD was analyzed, ASCA positivity was found to be correlated with duration of illness. Conclusions: The specificity of ASCA was high; however, the sensitivity was not. ASCA titers were generally low in the Japanese population examined. It would be desirable to determine cutoff levels for ASCA tailored to the Japanese people for the diagnosis of inflammatory bowel disease.

Postharvest application of 35-90% ethanol is reported to remove astringency and improve sweetness of banana. In order to determine the specific pattern and localization of gene expression, banana fruits were treated with 60% ethanol and control and then the total RNA extracted from the banana was hybridized with the RNA probe of ACC synthase gene. The highest ACC synthase activity was observed at 6 days after the ethanol treatment, while the accumulation of MA-ACS 1 mRNA (encoding banana ACC synthase during ripening) was observed in 9 days after the same treatment. In this experiment, the date of highest ethylene production coincided with the date of highest ACC synthase activity. The expression of ACC synthase gene is considered to occur firstly in pulp and then it occur in the peel on the basis of the signal intensity by Northern blot analysis.

To study dry sliding wear behavior and its relation to microstructure, Ti–50Al alloys and Ti–47Al–3W alloy and its composite with varying reinforcement of Ti2AlC were prepared by reactive arc-melting. Dispersion of fine B2 particles is obtained by the addition of tungsten to TiAl alloy, which improves both the hardness and wear resistance of the matrix. By adding carbon to Ti–47Al–3W alloy, composite can be produced having a random distribution of reacted rod-like Ti2AlC particles and smaller Ti2AlC precipitates with fine B2 particles in the matrix. The Ti–47Al–3W/3.5 vol%Ti2AlC intermetallic composite features excellent wear resistance compared to 10 and 18 vol% composites, and fine dispersion of the Ti2AlC and B2 particles in the matrix has improved the wear resistance properties.

The growth of single crystalline oxides on silicon substrates still remains a subject of significant technological interest, since fruitful achievements can be expected by their use in various silicon device technologies. We have examined the possibility of the epitaxial growth of BaZrO3 films on Si(001) substrates by pulsed laser beam deposition. It was found that the 3-ML-thick Ba-rich Ba–Zr–O layer could act as an excellent buffer layer leading to epitaxial growth of the subsequently deposited stoichiometric BaZrO3 layer. We succeeded in obtaining the heteroepitaxially grown BaZrO3 films on Si(001) substrates.

Asparagus spears (Asparagus officinalis L. cv. Welcome) were harvested from a greenhouse using the mother stalk cultivation method, from March to October and held at 1.5 °C to evaluate the effect of an extended harvest season on storage quality and shelf life. Both storage quality and shelf life declined over the harvest season. The deterioration of textural quality during storage took place for all harvest months, in general being higher for cooler months, and less at the top portion of the spear than at the bottom. During the harvest season, the soluble sugars and organic acid content of freshly harvested spears significantly declined by up to 53% after a 7-day storage period, and the losses were greater in the top portion than in the bottom portion. Shelf life declined by 50% from a maximum of 2.7 weeks.

Background: The color change observed endoscopically in early gastric cancer is thought to correlate with vascular density and architecture. This study investigated the endoscopic microvascular architecture in intramucosal gastric carcinoma in vivo. Methods: Intramucosal gastric carcinomas without ulceration in 27 patients were studied by using a new magnifying upper endoscope with attention to microvascular findings. The carcinomas were divided into two major types histologically: differentiated (18) and undifferentiated (9). Results: A regular subepithelial capillary network was demonstrated in noncancerous mucosa. The appearance of the carcinomas differed depending on histologic differentiation. With all of the differentiated carcinomas, there was a well-demarcated area where the regular capillary pattern of noncancerous mucosa had disappeared and irregular microvessels were proliferating. In contrast, with undifferentiated carcinomas there was only an ill-defined area with disappearance or a reduction in the density of capillaries in the noncancerous mucosa. Conclusions: Magnified endoscopic observation of microvessels may be of assistance in the identification of intramucosal gastric carcinomas that exhibit only subtle changes in color and shape at standard endoscopy.

We have proposed the use of YMnO 3 as a ferroelectric layer and of Y 2 O 3 as an insulator layer for ferroelectric gate transistor applications. Insertion of the Y 2 O 3 layer at the YMnO 3 /Si interface significantly improves the crystallinity of the YMnO 3 layer. Although we have used [1 1 1]-oriented Y 2 O 3 layers so far, the epitaxially grown Y 2 O 3 films have a potential to improve the ferroelectricity of the ferroelectric film. Furthermore, the Y 2 O 3 films have a relatively large dielectric constant ( e =14–17), as well as good thermal stability. However, it still remains unknown what the relationship is between dielectric properties and interfacial structure of epitaxial Y 2 O 3 /Si films. We have recently succeeded in obtaining epitaxially grown (1 1 1)Y 2 O 3 on (1 1 1)Si surface by pulsed laser deposition method. In this report, the relationship between the crystallinity of the Y 2 O 3 epitaxial film and the dielectric properties is discussed.

Background: The purpose of this study was to evaluate the accuracy and reproducibility of measurements obtained with a new 3-dimensional stereoscopic endoscopy system in vitro and in vivo. Methods: The system includes an electronic stereoscopic endoscope and a personal computer. After correction of barrel distortion by an image-processing technique, 3-dimensional data are computed with triangulation. Initially, graph paper and models of gastric lesions, both elevated and depressed, were used as objects. For evaluating accuracy and reproducibility, the absolute error (|E|) and the coefficient of variation (CV) were calculated: |E| = average value of absolute value (measured value − true value)/true value. Then, the sizes of 50 gastric lesions were measured by 2 endoscopists, one experienced and the other inexperienced, and the findings were compared with measurements made radiographically. Results: The maximum for |E| and for the CV for the distance on the graph paper were, respectively, 5.6% and 7.0%. The |E| and CV for the diameter and for the height of the elevated model were, respectively, 5.9% and 5.7% for the former and, respectively, 16.8% and 16.5% for the latter. The |E| and CV for the area of the depressed model were, respectively, 9.0% and 1.6%. The correlation coefficients between the sizes of lesions measured by stereoscopic endoscopy and radiographically were 0.91: 99% CI [0.81, 1.00], and 0.98: 99% CI [0.85, 1.00], respectively, for the experienced and inexperienced endoscopists. Conclusions: The new stereoscopic endoscopy system is useful for measuring gastric lesion size in clinical practice.

本実験は, マルチ栽培における植被とマルチが地温に及ぼす影響を, 伏性と立性の両植被構造の違いから明らかにすることを目的とした。実験は1998年10月から1999年3月にかけて行った。実験区は黒色マルチの有無, 伏性植被と立性植被の別, およびLAIの違いから計18区を設けた。得られた結果は下記の通りである。(1) 伏性植被と立性植被による地温効果の相違を地温差でみると, 無マルチ畦の最高地温では各LAIを通じていずれも立性>伏性の高低関係であった。最低地温では, 対照区の特定の地温において, 伏性植被と立性植被の高低関係が逆転した。それら逆転時の地温は, LAIが大きくなるにつれて上昇した。最低地温では両植被の保温効果がより大きくなり, さらにLAIが2.0以外では伏性>立性の関係が得られた。(2) 植被とマルチによる複合効果を地温差からみると, 最高地温では全般的に立性は対照区よりも高く, 伏性は低く経過した。最低地温では立性と伏性間の差は明確でなかった。(3) 植被の地温への影響を地温日較差比からみると, 無マルチ畦では全般的にいずれのLAIの区においても, 伏性 (各LAI平均の日較差比0.47) の方が立性 (0.65) より日較差比は小さかった。マルチ畦の各区では無マルチ畦と比べて LAI1.0以上の平均で約0.04大きく, 地温変化への影響度は減少したが, 立性と伏性間の差は明確でなかった。植被にマルチが加わると日較差比は小さくなり, 地温変化への影響度は増した。

Ti-B-N cast alloys were prepared by a reactive arc-melting technique using elemental titanium and boron nitride powders. The alloys obtained were composites of titanium matrix containing nitrogen of 3 mol% or less and a small amount of TiB reinforcement. The microstructure of the matrix was a cellular structure consisting of elongated dislocation cells with 1-2 μm in width and 5-10 μm in length, for Ti-1B-1N alloy. The TiB particles were rod-like in shape with size of less than 0.5 μm in diameter and agglomerated to form clusters along the grain boundary. The mechanical properties were mainly dependent on the content of nitrogen and the influence of TiB on the mechanical properties was relatively small. The Ti-B-N cast alloys containing suitable concentration of nitrogen, Ti-0.58-0.5N alloys, had a high strength of 920 MPa with adequate ductility of more than 5%.

The genetic relationship of 20 Chinese kale cultivars (Brassica oleracea L. var. alboglabra L. H. Bailey) was examined by RAPD analysis using 12 dodecamer oligonucleotide primers singly or in combination. The cultivars examined were classified into three groups based on the numerous polymorphisms of DNA fingerprints. The first group consisted of nine cultivars with white petals and wrinkled leaves (8 cultivars), such as 'Large leaf kailaan' and a cultivar with white or yellow petals, 'Nanjing huanghua (huang)'. The second group included six cultivars with yellow petals and dark green leaves (2 cultivars), such as 'Huanghualenye' and those with yellow petals and pale green leaves (4 cultivars), such as 'Huanghuagelin'. The third group included five cultivars with white or yellow petals (1 cultivar), such as 'Nanjing huanghua (bai)', and white petals without wrinkled leaves (4 cultivars), such as 'Hei' and 'Small leaf kailaan'. These results suggest that the Chinese kale cultivars with yellow petals diverged from those with white petals when they were introduced into Taiwan from China.

Adalimumab (ADA) is a self-injectable anti-tumor necrosis factor-α antibody used for treating Crohn’s disease (CD). Although self-injecting ADA may be convenient for patients, few reports have assessed patients receiving ADA self-injection therapy.We conducted a questionnaire survey involving outpatients on ADA self-injection therapy at four university hospitals. We analyzed the degree of satisfaction with and adherence to the self-injection therapy and performed sub-analyses.Responses were obtained from 124 patients. Before treatment initiation, 38% patients replied that they were unwilling to accept the self-injection therapy. However, after treatment initiation, 75% patients were satisfied with the treatment. 66 patients previously treated with infliximab (IFX), the degree of treatment satisfaction was significantly higher in patients who felt burdened to the time required for IFX infusion than in those who had not felt burdened (P0.05). Patient adherence to ADA was high (85%). Multivariate analysis regarding adherence revealed that duration of disease (OR, 0.99), degree of treatment efficacy satisfaction (OR, 13.42), and schedule registration (OR, 7.95) were significant. Safety assessment results were within the range of those already reported.ADA self-injection was thought to have good adherence and a safe administration method according to patients’ assessments.

Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn’s disease (CD), can develop various complications during the chronic remitting course. In the long-term course of the disease process, colorectal cancer (CRC) represents the most serious and life-threatening hazard. Evaluation of the incidence, risk factors, and confounding factors has been discussed, and surveillance methods have been established to lessen the burden on IBD patients. In this chapter, recent epidemiological trends and risk factors for CRC in IBD are discussed, and radiographic and endoscopic pictures of malignancies in UC and CD are presented.

Currently, we have two balloon-assisted enteroscopy (BAE) systems to observe the entire small bowel. One is double balloon enteroscopy (Fujifilm Medical Co., Tokyo, Japan) that Dr. Yamamoto developed, and the other one is single balloon enteroscopy (Olympus Co., Tokyo, Japan). Both of them enable the endoscopist not only to observe the small bowel directly but also to perform the endoscopic treatments in the small bowel. This new modality led us to obtain much knowledge about small bowel diseases. BAE has some advantages, including the ability of directly observing the small bowel and performing biopsy, compared with other small bowel modalities. CT and MRI are the least invasive methods; however, these methods are not able to evaluate the small bowel mucosal lesions directly or in detail. Capsule endoscopy (CE) is also a noninvasive method, and it can directly observe the small bowel mucosa. Therefore, this modality has been frequently used for evaluating small bowel disorders in the world. However, it has several limitations including the possibility of retention in case of intestinal strictures and impossibility of the biopsy. On the other hand, the biopsy can be done easily by using the BAE. BAE is quite useful for the correct diagnosis of small bowel diseases, particularly small bowel tumors and inflammatory diseases. However, BAE also has some disadvantages in terms of its invasiveness and technical difficulty of insertion. We should select the best one among these modalities for small bowel observation according to the status, indication, purpose, and suspicious diagnosis of each case.

Colorectal endoscopic submucosal dissection (ESD) has become common in recent years. Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also many types of precarcinomatous adenomas. It is important to establish practical guidelines in which the preoperative diagnosis of colorectal neoplasia and the selection of endoscopic treatment procedures are properly outlined, and to ensure that the actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with the guidelines. In cooperation with the Japanese Society for Cancer of the Colon and Rectum, the Japanese Society of Coloproctology, and the Japanese Society of Gastroenterology, the Japan Gastroenterological Endoscopy Society has recently compiled a set of colorectal ESD/endoscopic mucosal resection (EMR) guidelines using evidence-based methods. The guidelines focus on the diagnostic and therapeutic strategies and caveat before, during, and after ESD/EMR and, in this regard, exclude the specific procedures, types and proper use of instruments, devices, and drugs. Although eight areas, ranging from indication to pathology, were originally planned for inclusion in these guidelines, evidence was scarce in each area. Therefore, grades of recommendation were determined largely through expert consensus in these areas.

Recently, the need for sedation in gastrointestinal endoscopy has been increasing. However, the National Health Insurance Drug Price list in Japan does not include any drug specifically used for the sedation. Although benzodiazepines are the main medication, their use in cases of gastrointestinal endoscopy has not been approved. This has led the Japan Gastrointestinal Endoscopy Society to develop the first set of guidelines for sedation in gastrointestinal endoscopy on the basis of evidence-based medicine in collaboration with the Japanese Society for Anesthesiologists. The present guidelines comprise 14 statements, five of which were judged to be valid on the highest evidence level and three on the second highest level. The guidelines are not intended to strongly recommend the use of sedation for gastrointestinal endoscopy, but rather to indicate the policy as to the choice of appropriate procedures when such sedation is deemed necessary. In clinical practice, the final decision as to the use of sedation should be made by physicians considering patient willingness and physical condition.

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society (JGES), in collaboration with the Japanese Gastric Cancer Association (JGCA), has produced 'Guidelines for ESD and EMR for Early Gastric Cancer', as a set of basic guidelines in accordance with the principles of evidence-based medicine. These Guidelines cover the present state of knowledge and are divided into the following seven categories: Indications, Preoperative diagnosis, Techniques, Evaluation of curability, Complications, Long-term postoperative surveillance, and Histology. Twenty-three statements were finally accepted as guidelines, and the majority of these were obtained from descriptive studies with lower evidence levels. A number of statements had to be created by consensus (the lowest evidence level), as evidence levels remain low for many specific areas in this field.

Intestinal complications of stenosis or fistula may occur during the course of Crohn's disease (CD), and surgery is performed in a fair number of patients. The risk factors for initial surgery in a Japanese hospital-based cohort of CD patients were evaluated.This study was a single-center, retrospective, cohort study. The subjects were 520 patients who underwent inpatient and outpatient treatment at our hospital, had a definitive diagnosis of CD, and no previous surgery. Three parameters were investigated: (i) cumulative incidence of stenosis and fistula; (ii) cumulative rate of initial surgery for each disease type; and (iii) risk factors at diagnosis for initial surgery.(i) Stenosis and fistula increased with time, with stenosis or fistula appearing in about half of the patients after 5 years. (ii) The cumulative rate of initial surgery was about 50% after 10 years. (iii) The patient factors at diagnosis of current smoker, upper gastrointestinal disease, stricturing, penetrating, moderate to severe stenosis of the jejunum, moderate to severe stenosis of the ileum, and moderate to severe stenosis of the terminal ileum were risk factors for initial surgery.Stenosis or fistula appeared in about half of the patients after 5 years from diagnosis. When upper gastrointestinal disease or complicated small intestinal lesions are seen at the time of diagnosis, the cumulative rate of initial surgery is significantly higher.

Mesenteric phlebosclerosis (MP) is a relatively rare disease of the colon. An association between MP and Chinese herbal medicine intake has recently been recognized.In the present study, we investigated the association between MP and Chinese herbal medicine intake in 42 patients, including those reported in the literature as well as those treated by us.Approximately 90% patients treated by us reported a history of Chinese herbal medicine intake, particularly kamishoyosan, orengedokuto, and sanshishi (gardeniae fructus), the lattermost being consumed by the majority of patients as a crude herbal medicine.Several MP patients report a history of Chinese herbal medicine intake. Furthermore, symptoms are exacerbated in MP patients who continue to consume the medicine after onset. Interestingly, MP was reported to develop in a married couple who had consumed the same Chinese herbal medicine for a prolonged period. These findings suggest that the intake of Chinese herbal medicine, particularly sanshishi, is strongly associated with MP development.

Seasonal changes in the activities of acid invertase, sucrose synthase (SS) and sucrose phosphate synthase (SPS) along with the sugar content were studied in asparagus spears (Asparagus officinalis L. cvs. E414 and Welcome) grown in the greenhouse. The primary objective of this study was to understand the effect of long-term harvesting on the quality of green asparagus spears. Both soluble and cell wall-bound acid invertase increased in activity until June after which they changed very little. Similarly, SS activity increased to a maximum in June and changed little after this time. SPS activity changed little throughout the season. Sucrose concentration declined from March to a minimum in June and increased again in October. On the other hand glucose and fructose concentrations increased to a maximum in June and thereafter changed little except for a possible decline in October. A highly significant negative correlation was found between acid invertase and SS activities and sucrose content accounting well for the relation between the substrate and the activity. There were no significant differences between the cultivars.

膠原線維性大腸炎(collagenous colitis,以下CC)は1976年にLindstromによって最初に報告された水様性下痢を主徴とする大腸の炎症性疾患である.その後欧米を中心に同様の臨床症状を呈するリンパ球性大腸炎(lymphocytic colitis,以下LC)の概念も提唱され現在では両者とも広く認められている.両者は慢性の水様性下痢を主訴として発症し,大腸内視鏡や注腸造影で明らかな異常所見に乏しく,生検によって確定診断がなされるとされている.その病理学的特徴はCCでは粘膜上皮直下の厚いcollagen bandの証明,LCにおいては粘膜上皮内のリンパ球の増加を証明することによってなされる.本邦では少数の症例報告が見られるのみであるが,今後本症の疾患概念が広く認識され,本邦におけるその実態が明らかにされることが期待される.

The purpose of this paper is to clarify the effect of the amount of contact between film mulch and row surface upon the variations of 10 soil temperatures and their deviations at the same 10cm depth, and thereby properly compare the soil temperatures of two plots.Three process zones, consisting of a zone without mulch, a zone with black polyethylene mulch, and a zone with transparent polyethylene mulch, were established. Each zone was divided into three sub-zones whose contact percentages, that is, the amount of contact between the variations of mulch and the soil, were set to 100%, 70%, and 50%, respectively. Each sub-zone was further divided into two plots: one where no vegetation would be grown, and the other where radish plants would be grown. In all, 18 experimental plots were prepared.The daily range in soil temperature was measured beneath each of the 18 plots. The order relation of the daily ranges among the plots was transparent mulch (1.8°C to 2.7°C)>no mulch (1.2°C to 1.9°C)>black mulch (0.8°C to 1.1°C).The soil temperature order of the two plots based on t-test was as follows : The soil temperature at no mulch zone at 6:00 was 100% plot >70% plot >50% plot. The temperature at 15:00 was 50% plot >70% plot >100% plot. Accordingly, temperature change in the 50% plot was most significant. Soil temperature in the black mulch zone at 6:00 was highest in the 50% plot. Therefore, the insulating effect at the black mulch zone was the greatest. At 15:00, temperature rise in the 70% plot was most significant. In the transparent mulch zone, the 100% and 70% plots showed an equivalent insulating effect at 6:00, and the temperature rise in the 50% plot at 15:00 was largest.The soil temperature difference between two plots for each mulch zone, the distribution range of the difference between the 100% plot and the 70% plot, and that between the 100% plot and the 50% plot, all increased with increasing amounts of solar radiation. In particular beneath the black mulch with vegetation, the kurtosis of the soil temperature distribution decreased with increasing amounts of solar radiation. Beneath the transparent mulch without vegetation, the tendency toward decreases in the largest frequency became evident with the same variation.

ワサビ'だるま-3号'について形態的観察を行った。ワサビは日本など温帯アジア原産植物で, アブラナ科に属し, 宿根性である。通常葉と茎の基部が可食部として収穫される。可食部は通常根茎と呼ばれることが多いが, 肥厚して短縮化した茎である。肥厚した茎は地中で成育することが多い。葉柄の基部も肥厚している。いくつかの子株が茎の基部から伸張して, 繁殖に用いられる。花には4枚の白色の花弁, 6本の雄ずいと1本の雌ずいがある。, Morphological characteristics of wasabi were investigated. Wasabi, which is originated in temperate Asian area such as Japan, belongs to crucifer and is perennial. Leaf and lower stem are usually harvested. An edible portion of wasabi, which is commonly stated as a rhizome is suitable to name a shortened and swollen stem. Swollen stem is grown usually underground. Bottom part of petiole is also swollen. Some offshoots are arising from basal nodes of stem and are used for propagation. There are four petals, six stamen and a pistil in the flower.