This study investigated a clonal variations in sprouting times of Allium victorialis L. collected from 28 habitats around Hokkaido, Japan, propagated vegetatively and grown in Sapporo. For comparing clones, plant height is a useful index of sprouting time. Results of a two-year survey from 2000 to 2001 indicated that the sprouting time of Allium victorialis L. was a stable genetic trait and the clones were divided into 3 groups based on the results. Random amplified polymorphic DNA (RAPD) analysis was successfully performed on these clones utilizing 20 different primers. The clones were divided into 6 groups accoding to result from RAPD analysis. There was no relationship between the classification based on sprouting time and that based on RAPD analysis. However, both results indicated that genetic distance between 2 clones originating in a same region was short. The difference in sprouting times among these clones seems to be available for breeding new cultivars of Allium victorialis L.

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To obtain fundamental data for improving Crataegus fruit trees, the chemical components in fruits from three Crataegus species (C. pinnatifida Bge., C. dahurica Koehne and C. maximowiczii Schneid.) originating in east Asia were examined. High concentrations of β-carotene (2.2-2.4 mg/100 gFW) were detected in fruits of each species, showing values higher than those of major fruit trees. Oxalic acid was detected at concentrations of 103.9-116.1 mg/100 gFW and was a typical organic acid in Charaegus fruits. The concentration of α-tocopherol (6.6-9.0 mg/100 gFW), citric acid (426.3 mg/100 gFW), anthocyanin (283.1 mg/100 gFW) and total polyphenol (769.0 mg/100 gFW) in C. maximowiczii fruits were much higher than those of other species. C. maximowiczii seems to be a useful parent for breeding new Crataegus cultivars with abundant functional elements.

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This experiment was conducted to artificially induce loquat tetraploids by applying amiprofos-methyl (APM) and colchicine for chromosome doubling agents to diploid loquat shoot apex.
Germinated shoot tips from the seeds of the diploid loquat ‘Kusunoki’ were immersed in aqueous solutions of APM or colchicine, and one tetraploid was produced by either immersing 14 shoot tips in a 0.2% colchicine solution for 14 days, 48 shoot tips in a 2% colchicine solution for 4 days, or 30 shoot tips in a 0.005% APM solution for 14 days. Young intact on-tree shoot tips of an 11-year-old diploid loquat ‘Tomifusa’ were immersed in a 0.005% APM solution for 14 days, one tetraploid was obtained from 50 shoots treated. ‘Kusunoki’ seeds on growing young roots were planted on a culture plate containing 0.005% APM solution for 14 days, and one tetraploid was obtained from 50 seeds treated. Apical meristems removed from young intact on-tree shoots of ‘Kusunoki’ cultured on Murashige and Skoog (MS) agar medium for 14 days were treated with APM by transplanting on MS agar medium containing 0.005% APM for 7 days. By this treatment, one tetraploid was obtained from 21 meristems treated.

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Reciprocal crossing between tetraploids and octaploids of Dendranthema yoshinaganthum Kitam. were performed. Tetraploid × tetraploid was compatible, but no seedlings were obtained from octaploid × octaploid. The tetraploid × octaploid was partially compatible. The ploidy level of the progenies was almost intermediate between that of the parents. Some progenies had a larger chromosome number than expected. Male-sterile traits appeared in progenies derived from specific cross combinations between tetraploid and octaploid.

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The influence of transformed kiwifruit with glucanase or chitinase genes on the non-rhizosphere and rhizosphere soil were investigated to accumulate basic information in terms of allelopathic effects and soil microflola. When the allelopathic effects were evaluated using lettuce sprouts that are sensitive to allelopathic substances, there was no detectable difference in the growth of the lettuce sprouts with root and shoot tissue of both transformants and non-transformants, There was also no difference on the soil microflora of pot soil between transformants and non-transformants, in which the number of mold fungi, actinomycetes and bacteria in the non-rhizosphere and rhizosphere were not significantly different from transformants and non-transformants. Kanamycin-resistant bacteria were present in soils from both transformants and non-transformants. To identify the origin of kanamysin-resistance, PCR using primer combinations corresponding to transformant-specific marker genes were carried out. The results showed that the kanamycin-resistant bacteria were not due to horizontal gene transfer of transgenes from transforfmants to microorganism, indicating that these bacteria were present in the soil regardless of transformants or non- transformants. Collectively, these results suggested that the influences of transformed kiwifruit with glucanase or chitinase genes on the non-rhizosphere and rhizosphere soil are substantially the same as those of non- transformants.

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Root segments of plantlets (Aralia elata) grown by in vitro culture, were used as explants and cultured in the dark at 25 °C on MS medium supplemented with growth regulators. About 80-100 % of root segments formed calli on MS medium supplemented with 0.05-4.0 mg/l 2, 4- dichlorophenoxyacetic acid (2, 4-D). After 30 days of culture, calli formed on MS medium containing 0.05 mg/l 2, 4-D, were transferred on hormone-free MS medium and cultured at 25 °C in 16 h light (3,000 lux). Somatic embryogenesis was observed from the calli formed on medium supplemented with more than 0.5 mg/l 2, 4-D. Many somatic embryos and adventitious shoots were induced from the calli and developed into small plantlets by a subculture of 20-30 days interval. After acclimatization on vermiculite, regenerated plantlets were transplanted to a mixture of sandy masa soil/bark compost (3: 1, v/v). Nearly all plants were established and grew in to nursery stocks after 45 days.

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An efficient mass propagation system using the petiole and root culture were established in Angelica keiskei (Miq.) Koidz. In petiole culture, the basal portion was cultured on MS medium supplemented with 1-2 mg/l 2, 4-dichlorophenoxyacetic acid (2, 4-D) and 0, 0.01 and 0.1 mg/l N⁶-benzyladenine (BA) at 25 °C in the light. Callus formation was observed on all media tested and these calli were transferred on MS hormone-free medium. Adventitious buds were induced and developed into normal plantlets. In petiole culture, the number of regenerated plants per petiole section ranged from four to ten.
In root culture, root sections from aseptically generated plants, were used as explants and cultured on MS medium supplemented with 0, 0.05, 0.1, 0.5, 1.0 and 2.0 mg/l 2, 4-D at 25 °C in the dark. Embryogenic calli were induced on medium supplemented with more than 0.05 mg/l 2, 4-D. Furthermore, many embryos were observed on the calli which were formed on medium supplemented with more than 0.5 mg/l 2, 4-D, irrespective of BA addition. These embryogenic calli and embryos were transferred onto MS hormone-free medium at 25 °C in 16 h light. Many embryos and adventitious shoots formed vigorously, then developed into normal plants by subculture on the same medium. After acclimatization, regenerated plants were transplanted to soil and nearly all plants rooted and developed to young plants 45 days later.

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Flower bud formation in shoot apex cultures was investigated using vegetative buds from the leafing and dormant stages in Gentiana triflora Pall. var. japonica Hara and Gentiana scabra Bunge var. buergeri Maxim. A few plantlets had flower buds 105 days after starting the in vitro culture. When buds from the dormant stage were used for the culture, 6 % or less of the plantlets had flower buds in all lines. After 165 days, more than 50 % of plantlets from buds from the leafing stage had flower buds, while flower bud formation was lower in plantlets from buds at the dormant stage. There were no flower buds found on plantlets from buds at the dormant stage during the culture period in Gentiana scabra.
The effects of flower buds and of plant growth regulators on shoot formation were examined using in vitro node culture. The growth of shoots at the upper nodes from plantlets with flower buds was poorer than that from plantlets without flower buds. By contrast, shoots at the lower nodes from plantlets with flower buds were rather long. In culture medium containing forchlorfenuron and naphthalene acetic acid (NAA), many shoots formed from the nodal segments of plantlets without flower buds. Plant growth regulators also enhanced shoot formation from the nodal segments of plantlets with flower buds. The lengths of the shoots were similar between plantlets with and without flower buds. These results suggest that plantlets with flower buds are still useful for node culture, especially with the addition of forchlorfenuron and NAA.

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To examine the possibility of cultivation on highly compacted soil, tomato and cucumber were grown under three types of soil condition; soil cultivated in a routine manner with ridges; soil cultivated in a routine manner without ridges; soil compacted by paddling without ridges. The hardness of each type soil by Yamanaka’s soil hardness tester was 4-8 mm, 20-24 mm and 25-28 mm, respectively. At the early stage of cultivation, plants cultivated on the soil compacted by paddling required additional watering and the use of liquid fertilizers to achieve the same level of growth as that of the other soil conditions. In accordance with the increased soil hardness, the total yield and the yield of high quality product were increased in cucumber cultivation. In tomatoes a similar increase in the yield of high quality product was also observed. The gaseous phase ratio were remarkably decreased in the plots without ridges, and it was less than 10 % in the soil that was compacted by paddling. The values of an exchangeable base and cation exchange capacity (CEC) at the end of cultivation were highest in the plot with compacted soil. The total root area decreased with the hardness of the soil. However, the distribution of roots in each plot was similar despite the significant difference in physical properties. Cultivation of plants on compacted soil does not require machinery to make ridges, and moreover, there was a remarkable improvement in the efficiency of field labor.

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We investigated the effects of summer pruning and fertilization on nutrient absorption and regenerated shoot growth after harvest of ‘Muscat of Alexandria’ grape grown under forcing culture from December using a soilless culture system.
The shoot regeneration in summer was slightly delayed in summer-pruned vines compared to non-pruned vines. The absorption of nitrogen, phosphate and potassium in summer-pruned vines during the post-harvest period in summer was also delayed. However, there was no difference observed between both treatments in total amount of nutrients absorbed from June to September. The leaf-area of regenerated shoot from each cane and the LAI on each vine in the summer-pruned treatment were smaller than those on non-pruned vines. The phosphate concentration in leaves in summer-pruned vines was lower than non-pruned vines in late September. On the contrary, those of nitrogen and potassium were not affected by summer pruning.
The total amount of nitrogen absorbed in summer was less with the low level fertilizer treatment (5 g nitrogen · m⁻²) than with either the middle or high level fertilizer treatments (10 g and 15 g nitrogen · m⁻² respectively). However, there was no difference observed in the total absorption of nitrogen between the middle and high-level fertilizer treatments. The ratio of absorbed nitrogen to applied nitrogen was lower in the high-level fertilizer treatment than those in the low and middle fertilizer treatments. The fertilizer level clearly affected the nitrogen and potassium concentrations in leaves sampled in September, even though, differences in the fertilizer level did not affect the leaf-area and the LAI in this experiment. The nitrogen concentration in leaves was lowest receiving the low-level fertilizer treatment. The potassium concentration was highest in leaves receiving the high-level fertilizer treatment.

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Growth habits, fruit production efficiency and dry matter production of columnar-type tree ‘Maypole’ on ‘Marubakaido’ (Malus. prunifolia Bork. var. ringo Asami) trained to a Y-trellis system were compared with those trained to a central leader.
The spread of the tree width of the trees on a Y-trellis was faster than that of the trees on a central leader, and the number of flower buds, shoot numbers, total shoot length and total lateral branch numbers on a Y-trellis increased more than those of the trees on a central leader. The tree height on a central leader was greater.
As regards the maximal distribution area of fruits, leaves shoots and branches except shoot from the ground, the trees on a central leader gradually shifted to the upper area in proportion with increasing tree-age, but the area of the 5-year-old to 7-year-old trees on a Y-trellis were maintained at about 200 cm. The yield per trees on a Y-trellis from 6-year-old was greater than that of trees on a central leader.
The cumulative yield of trees per area on a central leader was greater than that of trees on a Y-trellis, but the difference decreased gradually from 6-year-old tress. Fruit weight of the trees on a Y-trellis was heavier than that of trees on central leader.
The percent instantaneous incident photosynthetic photon flux density of trees grown by both systems decreased gradually in the lower and middle area in proportion to increasing tree age, but the degree of decreased was higher in trees on a central leader.
Total leaf area and leaf area index perm² of 7-year-old trees on a central leader and Y-trellis were 10.3 cm², 11.8 and 14.5 cm², 7.6, respectively.
Total dry matter production per year of 7-year-old treeson a central leader and Y-trellis was 3,282 g and 5,579 g, respectively. There was no difference in the percentage distribution of dry matter in each organ.
It is considered that the columnar-type apple ‘Maypole’ trees on a Y-trellis facilitates labor reduction in the orchard and promote production of high quality fruit compared to trees on a central leader.

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The mechanism of photosynhetic inhibition in sink-limited leaves of young apple trees by continuous light (CL) was investigated. By 3 days after CL, the photosynthetic rate (A), stomatal conductance and intercellular CO₂ concentration (Ci) had decreased by 38 %, 58 % and 9 %, respectively, while leaf starch concentration accumulated up to 2.8-fold. Therefore, CL trees were sink-limited. However, A, Ci and stomatal conductance approximately recovered after only 1 day of continuous dark (CD) following 3 days of CL, wihile leaf starch concentration was markedly reduced to the control level. Therefore, CL trees were rescued from sink-limit. After 3 days of exposure to CL, the initial slope of the A-Ci curve in CL trees was 17 % lower than that in the controls; that is to say, the carboxylation efficiency of CL trees was reduced. However, the initial slope of the A-Ci curve in CL trees was completely recovered after only 1 day of CD following 3 days of CL. In addition, both the activity and concentration of ribulose-1, 5-bisphosphate carboxylase (RuBPcase) were not significantly affected by 3 days of CL. These results suggested that CL-induced photosynthetic inhibition was due to stomatal limitation, rather than decreased activity of RuBPcase.

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Plant growth as well as the morphological and physiological traits of ‘Wasadauri’ a native melon variety grown in Yamagata were compared with those of ‘Prince’ melon cultivar.
1. ‘Wasadauri’ had shorter vines but bigger leaves than ‘Prince’.
2. The chlorophyll concentration in ‘Wasadauri’ leaves was lower than that in ‘Prince’ leaves but there was no significant difference detected on photosynthetic rates between the two plants.
3. ‘Wasadauri’ blooms consisted of male and complete flowers on the same vine.
4. ‘Wasadauri’ fruit grew spherically or somewhat elliptically.
5. Approximately 70 % of ‘Wasadauri’ fruit had five carpels.
6. Edible part of ‘Wasadauri’ fruit was less than that of ‘Prince’.
7. ‘Wasadauri’ fruit had a larger number of seeds than ‘Prince’, but the mean weight per seed was lighter than that of ‘Prince’.
8. Fructose concentration in ‘Wasadauri’ flesh was lower than that of ‘Prince’.

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We investigated a method of repairing inclined peduncles of next-to-top flower buds when the top flower buds were lost in cut-flower-growing of large-flowering chrysanthemum (Dendranthema grandiflorum (Ramat.) Kitamura). When the top flower buds were pinched in July, lateral buds near the top produced some leaves and then flowered in ‘Fukashinotakumi’. Peduncles of next-to-top flower buds inclined at 24.5-34.2° when leaves and tissues of the nodes were removed at the bottom of peduncles in the pinched plants. The inclination was reduced at 9.1-15.2° by removing leaves and tissues at the nodes that attached the next-to-top flower buds, by removing the remaining peduncles of the top flower buds. Combination of the two removal treatments effectively reduced the inclination. Removal time did not affect the degree of the inclination reduced by the combination of the two removal treatments. in ‘Madobe’ and ‘Seiun’.
As a result, it is possible to repair inclined peduncles of next-to-top flower buds by removing leaves and tissues at the nodes that attached the next-to-top flower buds, by removing the remaining peduncles of the top flower in large-flowering chrysanthemums.

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Axillary buds were collected at 2-week intervals from middle portion of short, intermediate, long and water shoots of ‘Nankoh’ Japanese apricot trees grown in the field. Inner morphological change of these buds was examined with using scanning electron microscopy. The structure of axils subtended by folded and just unfolded leaves at upper portion of young shoot was also examined.
In the axils at the upper portion of the shoot, a larger tissue was formed in the center and two smaller tissues existed facing each other with the central tissue between. The central tissue had a meristem with broad lobed bracts and the lateral tissues had a meristem with slender bracts, the former and the latter developed as a primary bud and accessory buds, respectively. In the accessory buds, the meristem, which did not show any morphological change until early August, flattened in late August and sepals formed around the flattened meristem in September. The size of the accessory bud became larger than that of the primary bud at this time. Formation of floral organs continued without rest until December when ovule was formed. However, little morphological change occurred in the primary bud until early December. These results indicate that the compound bud is formed early time in the axil, flower differentiation started in the accessory bud from mid-August, and the developmental pattern was very different between primary and accessory bud in ‘Nankoh’ Japanese apricot.

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Oxalic acid concentrations in the fruits and leaves of a tart cultivar and a sweet cultivar of carambola (Averrhoa carambola L.) ware determined. (1) The concentrations of soluble and insoluble oxalic acids in the leaves of the tart cultivar ware higher than those of the sweet cultivar. The highest concentration of total oxalic acid, 7.6 g/100 g fr. wt. was detected in the mature leaves of the tart cultivar. (2) The oxalic acid concentration gradually decreased with fruit maturation. As compared with leaves, varietal difference in soluble or insoluble oxalic acid of fruits was apparent. A larger proportion of insoluble to total oxalic acid was obtained in the sweet cultivar, although the total oxalic acid concentrations in both cultivars were similar. Therefore, the soluble oxalic acid concentration would be consistent with the relative sourness of fruits. (3) Enzyme activity of glyoxlate oxidase or ascorbate oxidase, which relates to the biosynthetic pathways of oxalic acid production changed with the growth stages of leaves and fruits of carambola. The highest activity of glyoxlate oxidase was obtained in the mature yellow green leaves and a five-fold difference was recognized between tart and the sweet cultivars. Activity of glyoxlate oxidase was predominantly in any growth stages; therefore, it may locate on the main route for oxalic acid biosynthesis in carambola.

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This study investigated change in fruit quality and antioxidative activity of the flavedo tissue of fruit skin, to clarify intermittent warming (IW) effects on the storage life of ‘Kiyomi’ tangor (Satsuma mandarin × sweet orange) stored in a low temperature room at 5 °C, 95 % RH.
1) IW treatments were conducted at 3 °C, 6 °C, 13 °C, 23 °C and 30 °C for four days on fruits stored at 5 °C, 95 % RH for 3 months. Subsequently, the fruits were transferred back to the low temperature room at 5 °C, 95 % RH for 6 months. As a result, there was less weight loss due to IW at 23 °C and 30 °C than those at 3 °C, 6 °C and 13 °C. However, the rate of chilling injury increased with IW at 23 °C and 30 °C.
2) Differences in fruit quality among the different IW treatments were slight after about 9 months storage. Every fruit from each treatment was capable of being eaten despite long-term storage.
3) Both antioxidative activity by the β-carotene bleaching test (BHA equivalent per 100 g FW) and the concentration of total phenolic compounds (calculated as chlorogenic acid equivalents) were determined on the flavedo tissue of fruit after long-term storage. There were no effects observed among different IW treatments. However, fruits with chilling injury exhibited a lower level of antioxidative activity and total phenolic concentration.

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Texture is one of the most important factors in evaluating the palatability of cucumber (Cucumis sativus L.) fruit. We proposed a method of evaluating the physical characteristics of the flesh (mesocarp) of cucumber fruit. A stick-like plunger was inserted into the flesh, and the force was monitored during insertion. Fluctuation in the force during insertion was calculated as an index, which was defined as CI (crispness index). CI is the total of the absolute values of the secondary differentiation values of force. Crispy cucumber fruits showed higher CI values. While ‘firmness (the force of the destruction of the tissue)’ is popularly used as an index of the texture of many fruits, it was supposed that the characteristics expressed by CI are different from ‘firmness’. Since CI can be measured using the same instrument as used to test ‘firmness’, it is expected that the physical quality of the fruit can be evaluated more accurately using these two indices.

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