The adhesion process between the pellicle and kernel under heat (62°C) and hypobaric (4 mm Hg) conditions was analyzed in the immature Japanese chestnut, which is easy to peel. The adhesion process under the experimental conditon was similar to that occurring in nature. The peeling time of the nuts heated for 10 hr was about 5 times longer than that of the nuts subjected to hypobaric treatments. Monophenolic substances in the water extracts from pellicle, composed mainly of (+)-catechin and gallic acid identified by GC and GC-MS, diffused to the outer cells of the kernel and the interface between the pellicle and kernel during the first 2 hr of both treatments. There the low molecular weight phenolic substances, including (+)-catechin, polymerized as noted by the shift of their peaks after 2-5 hr of heating. With continued heating, the content of phenolic substances in the alcohol insoluble solids (AIS) fraction of the pellicle increased rapidly and the pellicle tightly adhered to the kernel. Therefore, we postulate that the polyphenolic substances are the adhesive between pellicle and kernel. However, under hypobaric conditions, cell breakdown and migration of the phenolic substances in the tissues occurred during the initial 0-2 hr and ceased. Thus, little or no polyphenolic substances accumulated between the pellicle and kernel to cause their adhesion after 10 hr of treatment.

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'Muscat of Alexandria' grapevines, grown under heated greenhouses, show abnormal swelling on the peduncles and rachises during an early stage of berry growth. The cause of this abnormality was investigated by controlling the light intensity to the clusters. Complete shading of the peduncular nodes for 4 weeks after full bloom caused a noticeable swelling in all the treated peduncles. Fifty % shading caused swelling in half the number of the treated peduncles. The rate and the degree of swelling were reduced by the exposure of clusters to sunlight or by using a sunlight reflector film. In vitro culture of excised disks from swollen peduncles revealed active division of callus cells even on hormone-free MS medium. The division was stimulated when the cultures were kept in the dark. These results suggest that accumulation of some light-decomposable factors at the peduncular nodes causes this abnormality.

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An adhesive substance, H-2, isolated by HPLC is present in the pellicle of the Japanese chestnut which makes it difficult to peel. The adhesive force of H-2 was measured by applying it between two wooden test pieces and its hemagglutination activity using in sheep and rabbit erythrocytes. The hemagglutination of H-2 was not inhibited by sorbitol, glucose, sucrose, glucosamine, Nacetyl-glucosamine or (+)-catechin ; its was accelerated by divalent cations, Ca²⁺, Mg²⁺, and Mn²⁺. The pyrolysis-gas chromatogram pattern of H-2 was similar to that of (+)-catechin. The IR spectrum had peaks of 3450 cm^-1 (OH) and 1605, 1520 cm^-1 (aromatic ring). The molecular weight of H-2, determined by HPLC, was approximately 1500. These findings indicate that H-2 is a polymer containing (+)-catechin. This adhesive substance between the pellicle and kernel of the chestnut is called "Castahesion".

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We carried out RAPD analysis for classifying apricot cultivars and related species, such as P. sibirica L. and P. brigantina Vill. For this purpose, 225 Operon primers were screened by using five representative varieties and 18 primers which provide plural polymorphisms. Using these primers, 33 varieties of P. armeniaca L. and two related species were tested for RAPD, then classified by cluster analysis and quantification method of the third type, based on the absence or presence of corresponding bands. The apricots were classified into two large groups by both analyses ; "Western group" (A) and "Eastern group" (B). However, P. sibirica and P. brigantina, which are related to P. armeniaca, and two Chinese varieties, 'Bai-xing' and 'Ren-xing', did not belong to these two groups. Since RAPDs among Chinese apricots were very diverse, they were placed into both groups A and B. All Japanese apricots were classified into group B. Considering that Chinese apricots have large variations, we hypothesize that Chinese apricots may be the ancestors of Eastern and Western apricots.

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The effects of water stress and/or chemical growth retardant, paclobutrazol, applied either as foliar spray or soil drench, on photosynthesis, tree vegetative and reproductive growth in young ponkan trees (Citrus reticulata Blanco cv. Yoshida) were evaluated. Paclobutrazol was applied when spring shoots were about 5 mm in length, either as an 840 ppm foliar spray or as a soil drench (0.5 g active ingredient per tree). Soil water stress of up to pF 2.95 was gradually imposed on the trees before re-watering. Water stress improved fruit set, whereas paclobutrazol reduced it. The proportion of abnormal flowers was increased by applying paclobutrazol without water stress. Abnormal flowers were reduced when paclobutrazol was applied in combination with water stress. Tree height increased about 14% for soil drench and 60% for foliar applied paclobutrazol based on initial heights at beginning of the experiment. Water stress caused up to 20% reduction in leaf expansion, reduced photosynthesis, and moderately reduced tree growth. Application of paclobutrazol ameliorated photosynthetic reductions associated with water stress, by maintaining higher photosynthetic and transpiration rates during water stress and ensuring quicker recovery after re-watering.

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The S-genotype of 'Hosui', a self-incompatible cultivar of the Japanese pear (Pyrus pyrifolia Nakai), was determined by a combination of two-dimensional gel electrophoresis (2D-PAGE) and N-terminal sequence analysis for S-proteins. Four protein spots that migrated to the S-protein zone were detected and individually assigned to S₃a-, S₃b-, S₅a-, and S₅b-RNases by comparing their electrophoretic behavior with that of S₃- and S₅-RNases. Analyses of the amino acid sequences of the four proteins confirmed their assignments leading us to postulate that the S-genotype of 'Hosui' is S₃S₅.

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Callus was induced from leaves and petioles of in vitro cultred Fragaria moschata shoots. The highest callus formation rate was obtained on MS supplemented with NAA 1.0 mg·1^-1 and BA 0.025 mg·1^-1. These calli were transferred to eight MS media supplemented with different combinations of NAA and BA. After 18 months with periodic subcultures, callus growth was estimated by their area during a 8-week culture period. The highest growth rate was observed on medium supplemented with NAA 0.1 mg·1^-1 and BA 0.25 1 mg·1^-1 and the lowest on the one supplemented with NAA 0.5 mg·1^-1 and BA 0.025 mg·1^-1. Callus weight was measured to determine the fidelity of the callus area calculation method as a non-destructive way of estimation the grwoth rate. High correlation was observed between callus area and callus weight (r²=0.974 to 0.996). Afler 18 months in culture, calli were transferred to different regeneration-inducing media enriched with TDZ, BA, ZEA, IBA and NAA. After nearby four months on these media, the calli regenerated shoots which when transferred to a root-inducing medium, they formed normal roots.

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Soil from fig (Ficus carica L. cv. Masui dauphine) orchards exhibiting soil sickness symptoms were collected in Osaka Prefecture, mixed and assayed for growth inhibiting factors. 1. Sprouting, rooting, and shoot elongation of fig cuttings were inhibited when grown in 700 ml pot filled with sick soil or with virgin soil (Kanuma soil/Vermiculite) to which 50 g of sick soil were added. The degree of growth inhibition was reduced when the sick soil was boiled at 60°C for 2hr. 2. The growth of fig cuttings was also inhibited when grown in 700 ml pot filled with virgin soil (sertelized sand) to which 20 to 25 larvae of root-knot nematodes (Meloidogyne incognita Kofoid et White) were added. But the degree of growth inhibition attributable to nematodes was less than that expressed by sick soil which harbored similar number of nematodes. 3. The growth of fig cuttings was also inhibited when 50 ml extracts from sick soil were added to nutrient solution employing storage nutrient culture method (SNCM). The growth inhibition was disappeared after soil extracts were heated at 100°C in a microwave oven or were passed through a membrane filter. These results indicate that a part of the growth inhibition is related to pathogenic microorganisms because the soils continued to exhibit an inhibitory capacity even after nematodes were killed by boiling and didn't continued after the soil extracts were heated or filtered.

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The effect of the bearing angle of satsuma mandarin (Citrus unshiu Marc.) fruit to the branch (upward or sideward) on rind roughness, pigmentation, and sugar and organic acid concentrations in the juice was investigated. The results obtained were compared with those from different crop loads reported earlier (Kubo et al. 1996). The rind surface of sideward fruit became smoother as the fruit grew, whereas upward fruit developed a rough skin until late Sept.; a marked difference between them was observed from mid-July to early Sept. The time course curve of "roughness value", which is a plot of the numerical score of rind roughness transformed with an image analyzer, was examined among each treatment. Although upward fruit and those from lightly cropped trees have rough surfaces, they differed physiologically because the former became smooth between early Aug. and late Sept., whereas fruit from the latter remained rough into late Oct. Observation of rind roughness by paraffin section showed that the rind involved 2 types of convex protrusions ; one was a projection made just above an oil gland and another was between the oil glands. The former types are detected frequently on mature fruit surface, whereas latter occur on immature ones. Similar convexities were observed on upward bearing fruit and on fruit from trees with a low crop load. Compared to the rough rind fruit, that with smooth rinds contained a higher concentration of sugars from mid-Sept. to harvest, and a lower concentration of organic acids from early Aug. to early Sept. Just before the rind became smooth (Sept. 12), chlorophyll in the skin reached a maximum level and then decreased rapidly. Carotenoid synthesis began when chlorophyll concentration attained its maximum level ; the carotenoids continued to increase until harvest on Dec. 5. From these results, we conclude that the growth of satsuma mandarin fruit can be divided into 3 stages as follows : stage I ;(sideward fruit, flowering to mid-July ; upward fruit, flowering to early Aug.), the rind becomes rough and the sugar and organic acid concentrations in the juice are considerably low. stage II ;(sideward fruit, mid-July to mid-Sept.; upward fruit, early Aug. to late Sept.), the rind becomes smooth and organic acid accumulates rapidly in the juice sacs. stage III ;(sideward fruit, mid-Sept. to harvest ; upward fruit, late Sept. to harvest), the rind becomes even more smooth and thin ; the juice sacs accumulate sugars rapidly while organic acids decrease significantly. The onset of stage III, when the skin roughness disappears, represents a significant stage when fruit maturation in mandarin begins.

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In studying the mechanism of softening of in kiwifruit (Actinidia chinensis Planch. cv. Yellow Koshin) on the vine, the changes of cell wall polysaccharides were compared with those induced by ethylene treatment. Cell wall polysaccharides were prepared from 80% alcohol-insoluble residue (AIR) by extracting the AIR with water, EDTA, HCI, and KOH in succession as described by Yoshioka et al. (1992 ; 1994). The decrease in the amount of monosaccharides in the water-insoluble fraction (WIF) derived from EDTA, HCl, and KOH soluble fractions was followed. 1. Ethylene evolution was not detected in the fruit during softening on the tree. 2. Fruit softening on the vine was accompanied with a decrease in galacturonic acid, but not of neutral sugars in the WIF. 3. Ethylene treatment led to a drastic decrease in rhamnose, arabinose, and galactose levels in the WIF ; galacturonic-acid decreased with or without the ethylene treatment. These findings suggest that fruit softening on the vine is associated with the dissolution of homogalacturonan which is insensitive to ethylene. Furthermore, ethylene treatment seems to induce the solubilization of homogalacturonan and rhamunogalacturonan, followed by fruit softening.

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In 1967, two-year-old trees of 'Miyagawa Wase', an early ripening satsuma mandarin, were planted in a clay loam soil under four different densities, D-1 : 1, 250, D-2 : 2, 500, D-3 : 5, 000 and D-4 : 10, 000 trees/ha in 0.4 ha and grown for 16∿22 years without thinning. Differences in annual increment of growth and yield between planting distances were recorded to determine when growth competition began. At the end of the experiment, trees were dissected to record the distribution of foliage and fruit and canopy structure of trees in high density plantings. The results were as follows : 1. Differences in trunk girth, tree height and yield between a given tree density and the adjacent ones appeared in 5∿6 years in D-4, 7∿8 yr in D-3 and 10∿16 yr in D-2. Hence, the higher the density, the sooner the differences were observed. 2. With respect to vertical distributions of the foliage as leaf area index (LAI) in Fig.7, D-1 had higher leaf density exceeding LAI 1 but at a lower elevation than that of D-2, whereas D-4 had higher leaf density at a higher elevation than D-3. A similar distribution of fruit per unit land area existed (Fig.8), i.e. most of the fruits were bone at the layers of higher leaf density (Fig.7). 3. In the yield per leaf area (Fig.9), D-2 was higher than D-1 and D-4 was higher than D-3 at the ground elevation where the foliage layers were exceeding LAI 1 (Fig.7).

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Spinach (Spinacia oleracea L. cv. Sunlight) seedlings grown under the NFT system were administered 6 or 12 me·liter^-1 K from the onset of the experiment to which nitrate-free solution was added 6 days prior to harvest (Experiment 1) or K solutions were added with the nitrate-free solution simultaneously 6 days before harvest (Experiment 2). At harvest the leaf nitrate, ascorbic acid, potassium concentrations, and the residual mineral concentration in the hydroponic solution were determined. No significant reduction in the yield was observed in Exp. 1 in which plants grown in the NFT system were administered 12 me·liter^-1 K from the onset of the trial and supplemented with nitrate-N free solution 6 days before harvest. The leaf-nitrate content decreased significantly in plants adiministered 6 and 12 me·liter^-1 K with nitrate-free solution 6 days before harvest. The residual nitrate-N in the nutrient solution decreased by approximately 32% at 12 me·liter^-1 K as compared to plants exposed to 6 me·liter^-1 K in the supplemental nutrient solution. In Experiment 2, in which plants were supplied with low nitrate concentration and 6 or 12 me·liter^-1 K in the same hydroponic solution 6 days before harvest, an economically satisfactory yield was obtained. The leaf-nitrate content decreased significantly by lowering nitrate-N concentration, but no significant difference in the leaf-nitrate content was noted between the N-free and N-plus treatments whether the K concentration was 6 or 12 me·liter^-1. However, the nitrate-N level in the nutrient solution decreased by 24% at 12 me·liter^-1 as compared with that of the 6 me·liter^-1 K in the supplemental solution.

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The ability of calli induced from leaf disks and immature seeds of Aralia cordata Thunb. to undergo somatic embryogenesis was investigated. Calli of 'Aichi-bozu' which were induced by leaf disk culture all produced somatic embryos on solid MS medium (Murashige and Skoog, 1962) modified as follows : NH₄NO₃ (1/4 of original) and 68.435 g·liter^-1 (0.2 M) sucrose, supplemented with 1.0 mg·liter^-1 2, 4-D. However, of the calli derived from the leaf disks of 'Iseshiro' and 'Murasaki-menoshiro' less than 65% regenerated embryos on all media. Of the calli derived from immature seeds (3.0 mm length) of 'Iseshiro' and 'Murasaki-menoshiro' 100% and 88.9%, respectivery, produced somatic embryos. In the former the calli were induced on the solid MS medium supplemented with 0.5mg or 1.0mg·liter^-1 2, 4-D, whereas the latter contained 1.0mg·liter^-1 2, 4-D. From these results, we found that in 'Aichi-bozu' the callus from leaf disks can produce somatic embryos at a very high frequency on MS medium with a low concentration of NH₄NO₃ and a high concentration of sucrose, supplemented with 2, 4-D, whereas, in 'Iseshiro' and 'Murasaki-menoshiro', the calli from immature seeds cultured on MS medium supplemented with 2, 4-D produced somatic embryos at high frequency. These somatic embryos grew into complete plants.

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For the purpose of establishing an efficient somatic embryo induction from cell suspensions of Aralia cordata cv. Aichi-bozu, the effect of different factors and bioreactors on subcultured embryogenic cells and induction of somatic embryos were investigated. The highest rate of somatic embryogenesis was obtained from the suspension cells when cultured in MS liquid medium containing 0.5 mg·liter^-1 2, 4-D and subcultured at 3 weeks intervals. The number of somatic embryos obtained was affected by the type of bioreactors. With air lift or rotating drum bioreactors, about 189 somatic embryos were induced per 100 ml of medium, whereas in bubble column bioreactor, about 124 somatic embryos were induced. A 100-ml Erlenmeyer flask, compared with bioreactors, was more efficient, producing 653 somatic embryos or 3.5 to 5.3 times more than did the bioreactors. However, 95% and 66% of the somatic embryos from the bioreactors and Erlenmeyer flasks, respectively, were normal. These results demonstrate the economic advantage of scaling up the air lift or rotating drum bioreactors to produce normal somatic embryos.

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Airdried seeds of the tomato, purebred cultivar 'First', were radiated with gamma-rays for 5 hours at varying doses consisting of 100, 200 and 400Gy, respectively, depending on the distance from the source of ⁶⁰Co. Seeds from all radiation treatments germinated, however, those radiated with 400Gy died thereafter, before the expansion of the first leaf. In the first generation plants (M₁), seeds were obtained from 80% and 38% of plants raised from seeds radiated with 100 and 200Gy, respectively. Although pollen fertility in M₁ plants was lower in 200Gy than 100Gy, complete pollen sterility was not detected, and there was no correlation between the percentage of pollen fertility and the number of seeds in the fruit. In the second generation (M₂), three types of mutants were observed out of 188 lines for 100Gy ; narrow leaves, low pollen fertility of less than 10%, male sterility with the same staminal cornes as the original type. On the other hand, nine different types of mutants were observed out of 88 lines for 200Gy ; chlorophyll mutants-albino, viridis, xantha, and partial chlorophyll deficient, low pollen fertility, male sterility with original staminal type, with anther shrunken and brown in colour, with longer style and exerted stigma, and non germinable seeds. The results suggested that a gamma radiation dose of 200Gy to tomato seeds was effective enough to induce various types of mutants. One of the chlorophyll mutants, "partial chlorophyll-deficient" character segregated approximately to a 3 : 1 ratio of normal to deficient, which was observed in the third generation (M₃) selected from self-pollinated plants in the normal phenotype of M₂. This character, therefore, appears to be controlled by a single pair of recessive genes. Chlorophyll was regenerated mostly in the contracted leaves, which enabled the mutants to survive.

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Experiments were conducted to clarify why fruit yield decrease during the late growing-period of cucumber cultured in hydroponic nutrient solution which was not completely renewed but only restored (a non-renewal culture). Furthermore, means to recover the decrease in fruit yield in the non-renewal culture system were investigated. 1. Vegetative growth was unaffected by biweekly total renewal or non-renewal of the culture solution. 2. When the culture solution was supplemented, the yield of 'Shogoin-aonaga-fushinari' and 'PI 169391' decreased, whereas that of 'Hokushin' and 'Chojitu-ochiai 2 gou' did not. 3. No decrease in fruit yield was observed when the solution was supplemented with nutrients and activated charcoal. This result suggests that root exudates had induced the decrease in fruit yield, especially by affecting young fruits, because the decrease was reversible through removal of the root exudates by the activated charcoal.

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The effects of illuminating the liquid-shaking culture on the absorption of nutrients by enlarging miniature bulbs of Lilium japonicum Thunb. were investigated. When bulbs (0.3 to 0.4g FW) were cultured for 165 days under the light or dark condition in the three kinds of liquid media containing different types and concentrations of sugars, light promoted enlargement. A media with 3% glucose under light was optimum for bulb enlargement ; fresh bulb weight reached about 5.3 g by the end of the experiment. Cumulative absorption of sugars, NH₄⁺, NO₃^-, H₂PO₄^- and K⁺ by bulbs exposed to light and sucrose was significantly higher than those grown in the dark ; Light and sucrose had no effect on Ca²⁺ and Mg²⁺ absorption. The gain in fresh bulb weight in the light almost equalled that of sugar absorption by the bulb, which suggests that bulb enlargement was not related to photosynthesis but to promotion of sugar absorption from the medium. Thus, light illuminating the liquid-shaking culture enabled us to produce 5 g bulbs (about 9 cm in circumference) in 5-6 months.

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To compare the stimulative effects of mycorrhizal infection on the early growth of Habenaria radiata, protocorms of 'Aoba' and 'Gyokuryuka' grown from seeds were inoculated with fungal isolate No.931202A. The protocorm of 'Gyokuryuka' (2n=64) enlarged faster than those of 'Aoba' (2n=32). The difference is attributed to the following factors : (1) Protocorms of 'Gyokuryuka' were infected more easily ; (2), the conductive tissue in the protocorm of 'Gyokuryuka' differentiated and functioned earlier ; and (3) the degree of invasion of the fungus into the protocorm of 'Gyokuryuka' as measured by the staining intensity of Trypan Blue is much greater. Through these observations, we conclude that the interaction between the infectivity by the different isolate of mycorrhizal fungus and the susceptibility of different cultivars of Habenaria radiata are decisive factors affecting early seedling growth.

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'Sonia' roses grafted to the Rosa multiflora rootstock were grown in recirculating hydroponic systems at two concentrations (EC 1.2 and 2.1 mS·cm^-1) of the Japanese standard nutrient solution (Enshi-shohou). Changes of pH, EC, and uptake concentrations of macro elements were measured at twelve intervals varying from 11 to 51 days, depending on the season and plant sizes. Plant growth and cut flower yield were also recorded. The higher concentration of nutrient solution increased flower production and the cut flower length. The pH at both concentrations sharply increased up to 8.5 in the winter, but that of the higher concentration remained constant during periods of high temperature. The uptake of elements fluctuated seasonally and cyclically, descending in the summer and rising in the winter. The average uptake of the macro elements was NO₃^- 7.2, H₂PO₄^- 3.3, K⁺ 2.7, Ca²⁺ 4.2, Mg²⁺ 1.2, and SO₄^2- 1.0 (me·liter^-1). The lower uptake concentrations made in the summer months were from 44% (NO₃^-) to 56% (K⁺) of those absorbed in the winter months. The range of seasonal fluctuations in uptake concentrations depended on the elements, of which NO₃^- produced the most notable change ; thus the pH of solution at the end of the sampling date varied. The result illustrates that not only ion balance but also seasonal changes in uptake concentration, which may appertain to transpiration velocity, are important factors to know in order to keep the nutrient solution in the root environment constant. NH₄⁺ and H₂PO₄^- which tend to be absorbed preferentially beyond the level of nutrient concentrations, require further experiments to determine how to maintain the optimum concentration levels in the nutrient solution.

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Fresh-cut green tip bananas were prepared in several styles : 1) longitudinally cut sections with 10 cm long and 1 cm thick (LCS) and 2) sliced into 1 cm thick transverse sections (0 CCS), or sliced obtusely to the transverse at 3) 30 and 4) 60 degree, expressed as 30 CCS and 60 CCS, respectively. 1. The cut surface area and weight of LCS were the largest, and the weight and cut surface area of sections increased with an increase in the obtuse angle, but the ratio of the surface area/weight was not significantly different. 2. The concentration of C₂H₄ in polyethylene (PE) bags containing the intact green tip bananas was lowest, whereas that of the CCSs increased with an increase in angle and that of LCS was highest after 48 hr at 20°C. The color and Hunter L value of the cut surface of sections changed during 96 hr at 20°C. The LCS began to brown and soften most rapidly followed by 30 and 60 CCS ; the browning and softening in the 0 CCS was least rapid. The respiration rate (CO₂ production) of LCS was the highest and that of the CCSs did not show significant differences during 96 hr at 20°C. C₂H₄ production of all sections increased during storage. The C₂H₄ production rate of LCS was the highest, and those of the CCSs decreased with a decrease in angle. 3. All sections stored at 20°C under continuous flow of air or air including 20 ppm C₂H₄ turned brown and softened. The discoloration and softening rates followed the same pattern as that for color changes (Hunter L value) noted in Sec. 2, paragraph 2 above. It appears that the deterioration rate of sliced tissue from green tip banana depends on physiological changes associated with cutting direction. It seems that C₂H₄ dose not play a significant role in these processes.

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The effect of spraying electrolytic water on apple (Malus domestica Borkh.) 'Golden Delicious' and 'Fuji' from June to July on fruit growth and quality were studied. Anode water (pH 2.6, ORP+1000 mV) increased russeting of the skin on both cultivars, however, spray of anode water and cathode water alternately (pH 9.3, ORP-250 mV) reduced it. The results indicated that the effect of anode water persisted for about one week. It was not clear whether the main cause of russeting by anode water was attributable to the low pH or ORP. Fruit sprayed with cathode water was firmer and larger watercore compared to the control suggesting that electrolytic water could influence the fruit quality.

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