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Volume 69, Issue 5
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Akiko Ito, Hiroko Hayama, Hirohito Yoshioka2000 Volume 69 Issue 5 Pages 529-535
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSEffects of several plant growth regulators on flower bud initiation on current shoots in Japanese pear (Pyrus pyrifolia Nakai) cv. Kosui were investigated. The applications of maleic hydrazide (C-MH, 1, 2-dihydro-3, 6-pyridazinedione choline) ; uniconazole-P (UCZ, (E)-(S)-1-(4-chlorophenyl)-4, 4-dimethyl-2-(1H-1, 2, 4-triazol-1-yl) pent-1-en-3-ol) ; benzylaminopurine (BA, N-(phenylmethyl)-1H-purin-6-amine) ; and abscisic acid (ABA) from early June to early August promoted flower bud formation or were ineffective depending on the time of application. C-MH increased flower bud number when applied in July, whereas UCZ was effective only when applied before or in early July. BA and ABA applications increased flower bud number when applied between early June and late July. The effect of gibberellin (GA4) application differed depending on the application date. Compared to the control, fewer flower buds were initiated by early June application ; whereas more were formed by an early August spray. The possible mechanism (s) on how these regulators affect flower bud initiation on shoots of Japanese pear 'Kosui' are discussed.View full abstractDownload PDF (843K) -
Takehiko Shimada, Toshiya Yamamoto, Hiroko Hayama, Masami Yamaguchi, T ...2000 Volume 69 Issue 5 Pages 536-542
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSA linkage map of the peach (Prunus persica (L.) Batsch), was constructed by using 133 F2 plants from the intraspecific cross between the rootstock cultivar, 'Akame', and the flowering ornamental peach, 'Juseitou'. This map contains 83 markers, including 3 morphological trait loci, brachytic dwarf (dw), red leaf (Gr) and narrow leaf (nl), 41 RAPD markers, 30 AFLP markers, and Inter-SSR, PCR-RFLP markers. Ten linkage groups were found, ranging from 17 to 244 cM in genetic distance ; among these, the 6 major groups had genetic distances of more than 60 cM. The map covers more than 960 cM with an average density of 12 cM between markers. A newly designated morphological characteristic, narrow leaf character (designated nl) was found to co-segregate with the dw locus. We found that 3 morphological traits, dw (nl) were located on the same linkage group as the Gr locus at a distance of 65 cM. Several DNA markers were linked to Gr and dw loci, which could be utilized not only for selecting morphological traits but also for evaluating homozygosity or heterozygosity. For example, the 95 bp AFLP fragment produced from the E-AGT/M-CAA primer combination, is tightly linked to the Gr locus at a distance of 5.0 cM. The DNA markers obtained are horticulturally very important and will be utilized for peach breeding.View full abstractDownload PDF (1002K) -
Kazunori Notsuka, Takekazu Tsuru, Mikio Shiraishi2000 Volume 69 Issue 5 Pages 543-551
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSIn vitro chromosome doubling of the 29 diploid-, 3 triploid-, and 1 tetraploid-grape accession, Vitis spp. were performed using the axillary buds of growing shoots. Treatment with 0.05% colchicine for one or two days is suitable to induce tetraploids (4X). Shoots, arising from treated-buds, often exhibited abnormal leaves, and part of them turned out to be cytochimeras (2X+4X). Additional tetraploids were isolated from parts of cytochimeras by three-divided stem cuttings. A different response to colchicine was educed in diploid cultivars, and the percentage acquisition of induced tetraploids was relatively higher in V. vinifera than in the American hybrid. Induced hexaploids (6X) were found to have a less satisfactory root system, but cytochimera, having only 3X cells in root tips, rooted well. No induced octoploids (8X) were obtained, and the growth of cytochimera, partly having 8X cells, were slow and dwarfed. Induced tetraploids were vigorous, rooted easily, and stable over many years, whereas cytochimera of 3X+6X and 4X+8X were likely to be lost during ex vitro cultivation, reverting to the source triploid and tetraploid, respectively. A comparision of induced tetraploids and the source diploids revealed no significant difference in time of full maturity, cluster and berry shape, skin color, Brix, and acidity. However, depending on the variety, the increase in berry size in the 4X to 2X ranged from 1.1 to 1.5 fold with an average of 1.3.View full abstractDownload PDF (1320K) -
Yohichi Matsubara, Yumi Kayukawa, Muneharu Yano, Hirokazu Fukui2000 Volume 69 Issue 5 Pages 552-556
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSTolerance of seedlings of asparagus (Asparagus officinalis L., cv. Mary Washington 500W) inoculated with four arbuscular mycorrhizal (AM) fungi [Gigaspora margarita (GM), Glomus fasciculatum (gf), Glomus mosseae (gm) and Glomus sp. R10 (gr)] to violet root rot caused by Helicobasidium mompa Tanaka was investigated. Twelve weeks after AM fungal inoculation, the infected asparagus seedlings grew better than did the noninoculated ones ; the effect was more pronounced with GM and gr than with gf and gm. AM fungal infection level in the root system was highest with gr and lowest with gm. Symptoms of violet root rot appeared in all the treatments 12 weeks after H. mompa inoculation, but the severity of the incidence was less in AM fungus-inoculated plants (9.1-45.5%) excluding gm-inoculated plants (63.6%) than AM fungus-noninoculated plants (54.5%). The disease indices revealed that the incidence was remarkably low, especially, in gr-inoculated plants. Moreover, healthy plants of AM fungus-inoculated plants grew more vigorously than did the noninoculated ones. These results reveal that plant growth promotion occurred in asparagus seedlings infected with the four AM fungal species and the tolerance to violet root rot appeared with most of the AM fungal species, though the effects differed with the AM fungal species.View full abstractDownload PDF (860K) -
Masaharu Masuda, Koji Uchida, Kenji Kato, Stephen G. Agong2000 Volume 69 Issue 5 Pages 557-562
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSThe effect of environmental conditions in the spring and autumn on the restoration of male fertility in T-4 male sterile mutant plants which were obtained via gamma (γ)-irradiation of tomato cv. First was investigated. Vegetatively propagated sterile plants gave rise to all male sterile plants in the spring, but the same T-4 plants cultivated under uncontrolled environmental conditions in autumn yielded fertile male. Self-pollination with these fertile males resulted in 50% fruit set and 26 seeds per fruit. The selfed seeds grown in the spring and with exposure to the natural environment developed into sterile males. When these male sterile plants were selfpollinated under natural conditions in autumn, they gave rise to normal male fertile plants with an average of over 35 seeds per fruit. Short or long day treatments had no effects on the male fertility restoration. The pollen germination percentage on artificial medium was relatively higher in autumn plants compared to that grown in the spring in the T-4 mutant plants, but it remained distinctly lower than the original cv. First in the spring and autumn. Pollen tube growth following germination in the mutant plants was lacked vigor and grew slowly in the spring compared to autumn. No difference in the final pollen tube length between the mutant and normal plants was noted in autumn. We conclude from these results that pollen and seed viability in the T-4 male sterile mutant plants was restored when exposed to low temperatures in autumn.View full abstractDownload PDF (700K) -
Takashi Nishizawa, Ayumi Ito, Yoshie Motomura, Masanori Ito, Masahiro ...2000 Volume 69 Issue 5 Pages 563-569
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSBiochemical changes in ripening netted melon fruits (Cucumis melo L. 'Andesu' and 'Luster') as influenced by shading were determined. Shading resulted in a rapid loss of flesh firmness in both cultivars which was positively correlated with ethylene production. The rapid accumulation of sucrose observed by sun-exposed plants was significantly inhibited by shading. Almost no significant difference, however, occurred in glucose and fructose concentrations between shaded and unshaded plants. Shading accelerated the formation of the "water-soaked" symptom in the flesh. Our results show that sunlight for netted melon plants during fruit maturation is important not only for sucrose accumulation but also for the maintenance of fruit firmness.View full abstractDownload PDF (781K) -
Yohichi Matsubara, Yumi Kayukawa, Hirokazu Fukui2000 Volume 69 Issue 5 Pages 570-575
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSTemperature-stress tolerance through symbiosis with arbuscular mycorrhizal (AM) fungi [Gigaspora margarita (GM) and Glomus sp. R10 (GR)] in seedlings of asparagus (Asparagus officinalis L., cv. Mary Washington 500W) was investigated. Seven weeks after inoculation under a bed soil kept at 25°C/20°C (day/night) under a 16-hr photoperiod, AM fungus-infection levels in a root system reached 63.0% in GM and 20.0% in GR. AM fungus-infected plants were taller, produced more shoots, accumulated more dry matter and attained higher P concentration in both shoots and roots than the noninoculated plants. Under a constant 15°C bed soil for 4 weeks followed by an elevation to 25°C/20°C, shoot elongation was promoted in AM fungus-infected plants, especially after the third emergence ; the effect was more pronounced in GR than in GM plots. Eleven weeks after inoculation, AM fungus infection levels reached 48.9% in GM and 58.9% in GR. Plant height, no. of shoots, no. of crowns, dry weight, and phosphorus concentration in shoots and roots became greater in AM fungus-infected plants than in noninoculated ones. When bed soil was heated to 30°C, shoot growth after the fourth emergence became restricted in noninoculated plants, whereas shoot emergence and elongation were promoted, especially after the fifth and fourth emergences in GM and in GR plots, respectively. Eleven weeks after inoculation, AM fungus infection levels reached 66.3% in GM and 36.7% in GR. All measured parameters in AM fungus-infected plants were larger than in the noninoculated plants ; the effect appeared significantly greater in GM than in GR plots. These results reveal that the asparagus seedlings infected with AM fungus tolerated greater temperature stress through symbiosis and that the degree of tolerance differed with the fungal species.View full abstractDownload PDF (709K) -
Genaro A. Reynoso, Masahiro Morokuma, Yoshie Miura, Atsushi Hasegawa, ...2000 Volume 69 Issue 5 Pages 576-583
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSTo gather some data adaptable for the cultivation of Proteaceae in southwestern Japan, the leafgas exchange characteristics of the potted plants were monitored under artificial light and natural environmental conditions. Under artificial light, photosynthetic measurements of 1-year-old seedlings of Banksia speciosa, Protea compacta, P. cynaroides, P. longifolia, P. macrocephala, P. neriifolia, P. repens, and Telopea speciosissima revealed that B. speciosa had the highest assimilation rate (8.81μmol·m-2·sec-1), while T. speciosissima had the lowest (1.39μmol·m-2·sec-1) with a chlorophyll content of 317.66 mg·m-2. The seasonal and diurnal patterns in carbon assimilation under field conditions from May 1998 to April 1999 were obtained for B. speciosa, P. compacta, P. cynaroides, P. macrocephala, and T. speciosissima. Seasonal trends in the assimilation rate (Anet) varied substantially among the species, but they can be divided into 3 types : 1) A decline in the assimilation rate in summer and winter and an increase in spring and autumn (B. speciosa and P. macrocephala), 2) a decline in the assimilation rate in winter and an increase in summer and autumn (P. compacta and T. speciosissima juvenile and mature) and 3) a small fluctuating assimilation rate throughout the year (P. cynaroides). A decrease in dark respiration occurred in all species in summer. Small differences were observed in the diurnal gas exchange patterns between autumn (November 1998) and spring (April 1999). In autumn, the diurnal curve was similar for all species, with a peak around 09 : 00-10 : 00 for each physiological parameter. A significant linear relationship exists between the assimilation rate and the natural log-transformed values of stomatal conductance. B. speciosa exhibited a steeper slope than did the other species, suggesting that additional factors besides stomatal conductance are involved in causing this more efficient carbon gain.View full abstractDownload PDF (1051K) -
Motoaki Doi, Yuxiao Hu, Hideo Imanishi2000 Volume 69 Issue 5 Pages 584-589
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSFreshly harvested 'Bridal Pink' roses (Rosa hybrida L.), with their stem bases in test tubes containing deionized water, were placed in a glass tank and held in a controlled environment room at 14, 20, or 30°C. The vapor pressure deficit (VPD) in the tank was maintained at nearly 0 kPa (no VPD : NVPD) or 0.9 kPa (intermediate VPD : IVPD). At all temperatures and VPDs, the fresh weight of cut roses increased initially and then decreased ; the decrease occurred earlier in IVPD than in NVPD and at higher temperatures. Necks of all flowers placed in IVPD became bent within 48, 144, and 312 hr of postharvest at 30, 20, and 14°C, respectively ; whereas, bent neck did not develop in NVPD. Irrespective of temperature, transpiration and water uptake rates of the roses placed in IVPD were markedly higher than those in NVPD. In IVPD, these rates increased initially, but decreased after 48, 72, and 96 hr at 30, 20, and 14°C, respectively. Petal water potential gradually decreased during the first 36 hr at 30°C in IVPD, but did not change at 14°C. The osmotic potential increased with time and was higher at 30°C than at 14°C. Fructose, glucose, and sucrose were the major sugars in petals. Concentrations of these sugars decreased during the first 36 hr, the decrease being greater at 30°C than at 14°C. The contribution of these sugars to the petal osmotic potentials was only 10%. These data indicate that the water relations of cut roses, immediately after harvest, was greatly influenced by high VPD by hastening the transpiration rate, and subsequently by increasing temperature through rise in the osmotic potential which was partly attributable to the consumption of respiratory substrate.View full abstractDownload PDF (742K) -
Akihide Okamoto, Mizuo Nonaka, Kenichi Suto2000 Volume 69 Issue 5 Pages 590-597
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSThe variation on aspartate aminotransferase (AAT) isozymes of flower buds of Rhododendron kiusianum, R. kiusianum var. sataense, and R. kaempferi, which are considered to be the parental species of Kurume azalea (R. obtusum), and Kurume azalea cultivars was studied by polyacrylamide gel electrophoresis. AAT isozymes of Kurume azalea were compared with those of three wild evergreen azaleas to seek information on the origin of the domestic cultivars. Three loci (Aat-1, Aat-2, and Aat-3) were identified for AAT. The Aat-2 locus in the three wild evergreen azaleas had two common presumptive alleles (Aat-2100 and Aat-280), and two species-specific presumptive alleles ; Aat-286 for R. kiusianum var. sataense and Aat-290 for R. kaempferi. Aat-3 locus shared the common presumptive alleles (Aat-367, Aat-358, and Aat-349) with three species. Aat-2 locus of Kurume azalea contained four alleles detected in the above three species and also Aat-2112 and Aat-2104 alleles which were not found in R. kiusianum, R. kiusianum var. sataense, and R. kaempferi. These results indicate that Kurume azalea contains genes from R. kiusianum var. sataense and R. kaempferi, and some other related species than the above three wild ones.View full abstractDownload PDF (906K) -
Shunsuke Takeuchi, Kazunari Nomura, Hiroshi Uchiyama, Kazuo Yoneda2000 Volume 69 Issue 5 Pages 598-604
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSTo plot the phylogenetic relationship within the genus Rosa, we compared the restriction sites of chloroplast DNAs among 32 species. With the use of 14 restriction endonucleases, restriction fragment patterns of cpDNAs were obtained from 32 lines of Rosa species and compared with each other. Three hundred thirty-five restriction sites were surveyed. Thirty-three sites were phylogenetically informative. Among the chloroplast genome types, 18 primary groups are formed. The majority rule consensus tree established by the Wagner parsimony method indicated that the species in sections Synstylase and Indica, and sections Carolinae and Cinnamomeae belong to a monophyletic clade, which agrees with the morphological classification. Sections Carolinae, Cinnamomeae, and Pimpinelifoliae lie distantly from the other sections, suggesting that these sections may have differentiated in an early stage of evolution followed by the appearance of other sections. A comparison of the previous classification of Rosa species with that in this study, revealed several discrepancies. R. gigantea, R. moschata, and R. damascena, which appear to be monophyletic, were grouped into one cluster apart from section Gallicanae, to which R. damascena was formerly classified. The present molecular data indicate that the maternal ancestor of R. centifolia 'Japonica' may be R. canina. It is proposed that R. roxburghiin and R. roxburghiin hirtula are separated, based on their differences in cpDNA. Interspecific cpDNA variation is common, a great deal of variability was detected in Rosa. Excessive dependence on one particular cytoplasm may be undesirable, we suggest that the methods described in this paper be used to survey the cytoplasmic base of modern rose cultivars.View full abstractDownload PDF (813K) -
Kazushi Watanabe, Tomoko Kamo, Fumie Nishikawa, Hiroshi Hyodo2000 Volume 69 Issue 5 Pages 605-610
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSBroccoli (Brassica oleracea L. cv Italica) florets senesced rapidly after harvest at ambient temperatures. During senescence at 20°C, the rate of ethylene production of florets significantly increased, concurrent with a rapid yellowing of sepals ascribed to chlorophyll degradation. 1-Aminocyclopropane-1-carboxylic acid (ACC) oxidase activity in florets also rapidly increased to a peak ; the enzyme activity then declined sharply, paralleling the increased pattern of ethylene production. Treatment of florets with 1 mM methyl jasmonate (MJ) significantly promoted ethylene production and ACC oxidase activity during senescence, attaining a higher peak faster than the control. Chlorophyll loss and a concurrent enhancement of ACC synthase activity by exogenous 1 mM MJ were accelerated to a greater extent than those of the control. The rise in ethylene production was reduced and delayed by treatment with 10 mM diethyldithiocarbamate (DIECA) that is thought to be an inhibitor of jasmonate biosynthesis. These results suggest that jasmonates may be associated with promoting senescence by enhancing ethylene production in broccoli florets.View full abstractDownload PDF (737K) -
Atsushi Yamasaki, Kazuo Tanaka, Mio Yoshida, Hiroyuki Miura2000 Volume 69 Issue 5 Pages 611-613
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSTo investigate the devernalization of mid-season flowering cultivars of Japanese bunching onion (Allium fistulosum L.), 'Kincho' and 'Asagi-kujo' were grown at 20/7°C and 35/7°C (day/night) for 40 and 60 days. The effect of a high day temperature on subsequent growth, flowerbud formation, and bolting was examined. The plant height of 'Kincho' was smaller at 35/7°C than at 20/7°C, but that of 'Asagi-kujo' was unaffected by day temperatures. In both cultivars, the leaf sheath diameter at 35/7°C was smaller than that at 20/7°C, but more leaves expanded at 35/7°C than at 20/7°C. In both cultivars, 54.3% to 75.0% of plants formed flower buds at 35/7°C, whereas 100% formed flower buds at 20/7°C but furthermore, their development was retarded at the higher temperature. In the 60-day treatment, the retardation of flower-bud formation at 35/7°C was similar to that in the 40-day treatment ; 75% of the seedlings of both cultivars bolted. We conclude that a high temperature treatment (35/7°C) can induce devernalization in the mid-season flowering cultivars 'Kincho' and 'Asagi-kujo'.View full abstractDownload PDF (484K) -
Seiichi Fukai, Takashi Shimomura, Tetsuya Kondo2000 Volume 69 Issue 5 Pages 614-616
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSDuring the development of polyembryony in Ophiopogon japonicus (L.f.) Ker-Gawl, no embryo was differentiated for the first two months after flowering. A meristematic structure appeared at the distal end of the embryo sac from the end of August to early September and developed into a globular embryo. New embryos appeared from within the embryo, which continued to produce additional embryos until October and resulted in a polyembryo consisting of different-sized embryos.View full abstractDownload PDF (810K) -
Kenzo Komamura, Akira Suzuki, Masashi Fukumoto, Kiminori Kato, Yuo Sat ...2000 Volume 69 Issue 5 Pages 617-623
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSA nitrogen application trial was conducted from 1973 (10-year-old trees) to 1995 (32-year-old trees) to analyze its effect on the growth, yield, and fruit quality of 'Jonathan' apple trees in a sod orchard. The treatments included no nitrogen application (-N), 5kg N (1N), 10kg N (2N), and 20kg N·10a-1·year-1 (4N). The leaf nitrogen content closely correlated with the amount of nitrogen applied. Differences in leaf nitrogen content appeared significant among all treatments after 1975. The increase of trunk girth in 4N was greater than in the other treatments ; the difference became significant after 1977. The fruit yield increased about two-fold from 1973 to 1990 in all the treatments but no significant difference was found in the yield among the treatments except for 1990-1992. The percentage of highly colored fruit was lower in 2N and 4N than in the -N and 1N plots. The poorly colored fruit had low soluble solids and firmness, compared with the well colored one. These results indicate that excessive nitrogen application increases growth and leaf nitrogen content, but negatively affects both fruit coloring and quality. The optimum amount of nitrogen application in this orchard is estimated to be less than 10kg·10a-1·year-1. Furthermore, apple trees grown with sufficient soil nitrogen fertility can grow vigorously and produce fruits for long term without any nitrogen fertilizer.View full abstractDownload PDF (832K) -
Hiroo Mukai, Toshihiko Takagi, Nobuaki Kajita, Saori Nishikawa, Hisash ...2000 Volume 69 Issue 5 Pages 624-628
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSSugar contents in the juice and peel of very early to late ripening satsuma mandarin cultivars were determined by HPLC. There was little difference in the seasonal change in the juice sugar contents among eight cultivars. In all cultivars there was a peak of glucose : fructose ratio during ripening, which was not related with ripening time of these cultivars. In 'Miyagawa Wase' (early ripening) and 'Aoshima' (late ripening), the sucrose content in the juice began to increase in September. However, an increase of total sugar content in the peel of 'Aoshima' was delayed compared to that of 'Miyagawa Wase', but the pattern of sugar accumulation by the juice differed little among the satsuma mandarin cultivars.View full abstractDownload PDF (599K) -
Toshiro Ono, Yasuhiro Fujiwara, Seishi Yoda, Nobutomo Takagi, Naohiro ...2000 Volume 69 Issue 5 Pages 629-634
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSScions from two mature 'Pione' vines, which bore well-colored berries (vines A and B, superior berry color, SBC) and two with poorly colored ones (vines C and D, inferior berry color, IBC) annually, were grafted on Teleki 5BB rootstocks. The vines of the two strains were then planted in the same vineyard. Shoot growth and berry development on each vine were recorded throughout the growing season. The partitioning of 13C-photosynthates from leaves into the various parts of the shoot of the two strains, which were exposed to 13CO2 at two weeks after veraison, was investigated. No significant differences in shoot elongation, increment of leaf area per shoot, and changes in chlorophyll content of leaves between the two strains were observed. No notable difference in berry enlargement between the two strains was observed, although the berries at harvest from vines B and D were significantly heavier than those from vines A and C. The total soluble solids contents of the juice and anthocyanin levels of the skins were higher in berries from SBC vines than in those from IBC vines throughout the ripening stage ; they increased significantly in the SBC vines two to three weeks after veraison. At harvest, anthocyanin content in the berry skins from vines of SBC was two to three times higher than in those from vines of IBC. At the end of 13CO2 feeding, the leaves on the main shoot of the SBC vines contained significantly more 13C label than those of the IBC vines. 13C concentration in leaves on both main and lateral shoots on all vines decreased rapidly for 24 hr after feeding followed by a gradual decrease, whereas it increased in berries with time. At 72 hr and 120 hr after feeding, 13C-photosynthates were translocated into berries larger in SBC vines than those in IBC vines. At 120 hr after feeding, the distribution ratio of 13C-photosynthates in the berries was higher in SBC vines than in IBC vines, while it was the reverse in the leaves on the main shoot. The relationship between translocation and partitioning of photosynthates and the accumulation of sugar and anthocyanin in berries, which differed between vines of the two strains, is discussed.View full abstractDownload PDF (835K) -
Soon Ja Yang, Wakanori Amaki, Haruzo Higuchi2000 Volume 69 Issue 5 Pages 635-640
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSIn in vitro-cultured Kalanchoe blossfeldiana Poelln. 'Singapore', the minimum number of short-day cycles required for flowering and the effect of explant size and long-day treatment duration before flower induction on the flowering response were compared with plants cultured in vivo. Although it took 5 weeks to induce flowering for in vitro cultured explant and two weeks for in vivo one, the relationship between short-day treatment duration and flower bud appearance were similar ; the longer the short-day treatment, the earlier the buds were induced to flower. Explant size made no difference on the time of flower bud appearance between in vitro and in vivo cultures. However, under in vivo, explants with two leaves initiated flower buds later than the ones with four to six leaves. The more long-day cycles the plants were administered before given the short-day treatment, the faster the flower buds appeared under both in vitro and in vivo cultures. These results reveal that the in vitro-cultured rooted cuttings with two leaves of Kalanchoe blossfeldiana 'Singapore' performed similarly but more efficiently than did plants grown in vivo in regard to their qualitative flowering responses.View full abstractDownload PDF (772K) -
Yoshihiro Takahashi, Yoshiyuki Maeda, Hirofumi Kurata, Rie Azuma, Keis ...2000 Volume 69 Issue 5 Pages 641-645
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSA chlorophyll a degradating enzyme was obtained from crude extracts of ethylene-treated Citrus unshiu peel. This enzyme catabolizes chlorophyll a in the presence of H2O2 and p-coumaric acid. The optimum pH value was 4.0 in an acetate buffer. A straight line relationship between the degradation rate and protein concentration existed over the range of 60∿180μg protein per 3.0ml of the reaction mixture. The Km for the chlorophyll a, p-coumaric acid and H2O2 was ca. 26.1μM, ca. 103.6μM and ca. 184.2μM, respectively. Reaction was inhibited by tiron, Mn2+, hydroquinone, ascorbate, n-propyl gallate, KCN, and azide, indicating that the reaction may involve free radicals and superoxide anions. Little C132-hydroxy-chlorophyll a, which was the primary reaction product, accumulated in the presence of p-coumaric acid compared to the amount of chlorophyll a degraded. Chlorophyll a catabolism by the enzyme was followed by opening of the chlorophyll-porphyrin ring. It was accompanied by a decrease in the red and Soret band of UV/VIS differential spectrum of the reaction mixture during the catabolism. When reacted with 2, 4-dichlorophenol (DCP), a colorless, open-ring, fluorescent chlorophyll catabolite (FCCs) formed. The same product did not appear with p-coumaric acid as the reactant. These results indicate that most of the chlorophyll a was degraded into an open-ring catabolite without an accumulation of intermediates such as C132-hydroxy-chlorophyll a or FCCs.View full abstractDownload PDF (673K) -
Koichi Akimoto, Toshitaka Uchino, Kohei Nakano, Eriko Yasunaga, Shinic ...2000 Volume 69 Issue 5 Pages 646-652
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSA proposed new method is effective for measuring the respiration rates of fruits and vegetables not only under stable temperature or gas component but under a dynamically changing environment, such as during cultivation in an open field or during transit after harvest. The gaseous components within a flexible plastic film bag, in which the horticultural product or its parts is enclosed, are measured continuously or periodically. The method is called the flexible chamber method for measuring respiration rates. By using fresh air or some component gas initially, and adjusting the ratio of the air volume and that of the reaction product, this method can control the internal gas concentration of the chamber and the turnover rates. In this research, cucumber was used. A decrease in oxygen concentration from 21 to 8% repressed the respiration rate while increasing the carbon dioxide concentration from the ambient 0.03 to 6%. This respiration repression was caused by the high CO2 and low O2 concentrations rather than by the interaction between the two gases. At 8% oxygen (Fig. 5), the oxygen consumption rate decreased more slowly than did the carbon dioxide emission rate so that the final carbon dioxide concentration approached 5%. Hence, the respiratory quotient (RQ) increased from 1.0 to about 1.5. The oxygen concentrations seem to border the anaerobic respiration phase. When the pressure in the chamber was increased from the ambient atmospheric pressure, the respiration rate tended to be repressed temporarily which indicates fluctuating pressure may influences the respiration process. The new proposed method of measuring the respiration rate is adaptable to a diverse environment as mentioned above, especially when the atmospheric pressure is under an unsteady state.View full abstractDownload PDF (921K) -
Akira Nukaya, Hong Gi Jang2000 Volume 69 Issue 5 Pages 653-655
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSEffects of composition and concentration of nutrient solution on the uptake of nutrients by muskmelon (Cucumis melo L. cv. Earl's Favourite) grown in rockwool in the fall were compared with those grown in the spring (Jang and Nukaya, 1997). Muskmelons were supplied full and half strength Enshi solution and full strength of Shizudai solution. Leaf and stem fresh weights were greater at full strength of Shizudai and half strength of Enshi solution than those given full strength Enshi. The plants absorbed more mineral elements (me·plant-1·day-1) and the uptake concentration (uptake ratio of mineral elements to nutrient solution, me·liter-1) were greater at earlier growth stages, and less at later ones in all solutions. The absorption rate tended to be faster at full strength of Enshi solution than with other solutions. Our data reveal that the uptake rate and concentration were similar to those reported in the spring experiment. However, the uptake rate and concentration by the fall crop tended to be slightly lower at earlier stages and higher at later stages compared with those in the spring crop.View full abstractDownload PDF (476K) -
Tadashi Fujioka, Masayoshi Fujita, Kazuya Iwamoto2000 Volume 69 Issue 5 Pages 656-658
Published: September 15, 2000
Released on J-STAGE: January 31, 2008
JOURNAL FREE ACCESSTo establish a cultural method for regenerating Japanese pea (Pisum sativum L.) cultivars, varietal differences in callus formation, shoot and root regeneration by in vitro culture of immature leaflets were investigated. The effects of the developmental stage of pea explants on these processes were also examined. 1. Shoot regeneration occurred in 5 of 6 Japanese pea cultivars from primary calli induced from immature leaflets cultured in vitro. 2. More than 30% of explants from young leaflets of 2 to 3-day old seedlings regenerated shoots. But no morphogenesis was observed when leaflets from 5 or 10-day old seedlings were excised. 3. Plant regeneration can be done sequentially by inducing shoot and root formation.View full abstractDownload PDF (510K)
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