The stylar proteins of 22 varieties of Japanese pear (Pyrus serotina Rehd., 21 selfincompatible and one self-compatible) were analyzed by isoelectric focusing-polyacrylamidegel electrophoresis (IEF-PAGE) to identify the S-allele proteins (S-proteins) associated withself-incompatibility (SI). The corresponding relationships between the protein bands and thefour alleles S₂, S₃, S₄ and S₅, were examined for each variety for which the allele composition was already known.
Experiment 1 comprised the IEFs on the four major varieties. Analysis of the band patterns, isolated at intervals pH 310, 58 and 46.5 revealed that three bands (hereafter, tentatively referred to as) (a) at isoelectric point (pI) 6.6, (c) at pI 5.3 and (d) at pI 5.0 werethe putative proteins corresponding to the S₄ allele. Band (b) at pI 5.6 and (e) at pI 6.0 werealso the putative proteins corresponding to the S₂ allele and the S₅ allele, respectively. Allthe bands described above exhibited a positive periodic acid Schiff's (PAS) reaction. Thereforethe presence of glycoproteins was suspected. Experiment 2 comprised IEFs on the other 18varieties. The results compiled from both experiments showed that among 21 varieties (otherthan one self-compatible variety), the correspondence between the bands and S-alleles wasrelatively high on band (c) in 19 varieties. This band was thought to be associated with theS₄ allele. Other bands demonstrated rather low correspondences; band (a) exhibited the relationship in 15 varieties, band (b) in 13 varieties and band (d) in 13 varieties. No differencein protein band patterns was exhibited between the self-incompatible variety 'Nijisseiki' andits self-compatible strain 'Osa-Nijisseiki', which was assumed to be a stylar part mutant ofthe S-gene. Our discussion compares the results of this study with research on S-proteinsin other species, and includes suggestions for future research methods.

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In a previous experiment, dry matter production per unit dry weight leaf (DM/L) increased more than twofold with the increment in the fruit load on apple trees. Fruits on three 10-year-old 'Tsugaru' and 'Fuji' trees/M. 9 were enveloped in bags, and the dry matter production rate of the trees (DM) were compared with the control trees with non-bagged fruits during the 1990 growing season. The purpose of this experiment was to assess the effect of fruit photosynthesis on the total dry matter production rate of the trees.
1. There were significant correlations between the trunk girth measured early in the growing season and a) the total leaf area (r=0.89) and b) the total leaf numbers (r=0.90), independent of cultivars and the treatments.
2. Total dry matter production per tree (DM) was highly correlated with the fruit dry weight (F), whose regression lines were Y=1.21X +5441.0 (r=0.87) for the bagging treatment and Y=1.50X +5164.6 (r =0.99) for the non-bagging treatment (control), respectively. The gradient of the regression lines did not differ significantly between both treatments.
3. A highly significant correlation (r=0.87) existed between the fruit/leaf dry weight ratio (F/L) and the dry matter production per unit dry weight leaf (DM/L) of the trees, even if the bagging and the non-bagging treatments were combined. A smaller but significant negative correlation was also found between the leaf area per fruit and DM/L (r= -0.49). The fact that the bagging treatment did not alter these correlations also suggests that the dry matter production by the fruit was not so large as to enhance the total dry matter production rate of the tree significantly.
4. The total dry matter production rate per leaf area was higher in 'Tsugaru' than in 'Fuji'.

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Two experiments were designed to examine the effects of root temperature under forced conditions on the utilization of nitrogen and on vine growth of potted 'Muscat of Alexandria' vines grafted on 'Hybrid Franc' rootstock. In Experiment 1, a set of vines was administered K¹⁵NO₃ from mid-October until December when forcing was begun (application before forcing). Another set of vines was fertilized with ¹⁵N from December when the forcing was begun and continued until the berries began to set (application after forcing). In Experiment 2, a set of vines was administered K¹⁵NO₃ from mid-October until February when the vines were forced (application before forcing), whereas another set was fed ¹⁵N from February, the beginning of forcing, until the berries began to set (application after forcing). In both Exps. 1 and 2, each set of vines was subdivided into two subgroups in which the root temperature of one sub group was kept at 13°C and the other at 27°C. ¹⁵N content and vine growth were monitored periodically.
In Exp. 1, budbreak began earlier and shoot growth and cluster development were more vigorous in vines whose roots were exposed to 27°C than those in which roots were kept at 13°C. In Exp. 2, no differences in the time of budbreak and the rates of vegetative and reproductive growth of vines were observed at both root temperatures. In vines given ¹⁵N after forcing in both Exps. 1 and 2, ¹⁵N content in the canes and small roots increased greatly at 27°C toward budbreak and berry setting stages, especially in Exp. 1. However, in vines administered ¹⁵N before forcing, little difference was found between the two root temperature treatments. Contrarily, in vines given ¹⁵N after forcing, total ¹⁵N content of vines at the setting stage was markedly greater at 27°C than it was at 13°C in both experiments; and the percent ¹⁵N recovered from young shoots of ¹⁵N-treated plants was also higher at 27°C than at 13°C. Distribution ratio of ¹⁵N in shoots at the setting stage was higher in vines given ¹⁵N after forcing than in those administered ¹⁵N before forcing except in the 13°C plot in Exp. 2.
We conclude from these findings that level of nitrogen absorbed after the beginning of forcing and its translocation to the upper parts are closely related to shoot growth and cluster development of vines forced from December.

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To determine the optimum pollination time in Japanese chestnut (Castanea crenata Sieb.et Zucc.) 'Yamato-Wase', female flowers were pollinated with 'Ginyose' 11 times at intervals of 34 days on and after 19 June when styles of the central female flower emerged from the involucre. The relation among the optimum pollination time, style elongation, and ovule development was investigated.
1. Early bur abscission until late July was rather severe after pollination on 19 June, although it became less severe after later pollinations. Preharvest bur abscission began after 25 August and was severe from 28 August to 1 September regardless of pollination time, although it decreased to 20, 35, and 50% after pollinations on 17, 21, and 24 July, respectively.
2. Percentage of burs with nut (s) set at harvest on 11 September attained a maximum of 80% after pollination on 17 July, which was succeeded by 65 and 35% after pollinations on 21 and 24 July, respectively. Most burs resulting from pollinations on and before 14 July contained only one nut. After pollinations on 17 and 21 July, burs with 3 nuts appeared and those with 2 nuts increased, but no burs with 3 nuts appeared after pollination on 24 July. Consequently, the period between 17 to 21 July was considered to be optimum for pollination.
3. Styles of central and lateral female flowers appeared on involucres on 19 and 23 June, respectively. They both began to spread out on 7 July, and on 14 July they ceased to elongate, attaining a length of about 4 mm. Thus, the optimum pollination time seems to be between 3 to 7 days after styles ceased to elongate, when scales of the involucre began to spread out.
4. In the ovary of the lateral female flower, outer and inner integuments and nucellus were differentiated in all ovules on 28 July. In the largest ovule in each ovary, the embryo sac was found on 4 August and the nucellus was gone after 11 August.

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Polyacrylamide gel electrophoretic separations of peroxidase isozymes from leaves of Asian Pyrus species showed patterns that are reproducible for species and cultivars; that are independent of sampling time and the development stage of the leaf.
The 187 Pyrus representations were reproducibly classified into five groups by 130 peroxidase isozyme phenotypes composed of 32 bands.
Bud sports could be distinguished from the original cultivars, i. e., 'Osa-nijisseiki', 'Wasenijisseiki' 'Akakei-nijisseiki' from 'Nijisseki', 'Aokei-niitaka' from 'Niitaka', and 'Kiyosumi' from 'Shinsui'.
Comparison of peroxidase isozyme phenotypes showed that the hybrids cultivars inherited some bands from their parents.
Close genetic relationships among the cultivars existed within the group consisting of old cultivars from the region and hybrids of 'Nijisseiki'.
The old cultivars of the region were divided into two groups. However, a few geographic variations in isozyme phenotypes within each groups observed among the cultivars.

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Two-year-old potted 'Tosa Buntan' pomelo (Citrus grandis (L.) Osbeck) trees on trifoliate orange (Poncirus trifoliata Raf.) rootstock grown in a plastic house were used in this study. The temperature of the plastic house was maintained at a maximum of 20°C during the day and 10°C minimum at night from November 1990 to mid-February 1991. On December 1990, a set of potted trees was transferred to each growth chamber which was kept at day/night temperature of 15°/5°C and 10°/10°C. A subgroup of these trees was exposed to these con-dition for 15, 30, 45, 60, and 75 days and then transferred to another growth chamber main-tained at 30°/25°C (day/night). On 1 December 1990, 15 January, and 15 February 1991, a set of potted trees was transferred directly without chilling from the plastic house to the 30°/25°C growth chamber.
No trees sprouted during the low temperature treatments. New buds sprouted early and more buds sprouted during subsequent exposure to 30°/25°C treatment as the low temper-ature was prolonged. The number of new shoots for 75-day exposure was greater at 15°/5°C than it was at 10°/10°C regimen and those kept in the plastic house. The number of inflores-cences, flower buds, and flowers increased for the 60-day and over exposures, but very few flowers developed after a 15- or 30-day exposure. The numbers of flower buds and flowers per node were 2.27 and 2.05, respectively, for a 75-day exposure under the 15°/5°C regi-men, whereas they were 0.81 and 0.76, respectively, in the 10°/10°C regimen. Sugar and carbohydrate contents in leaves increased while the N content decreased under prolonged low temperature treatments.

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1. The milky-white and needle-shaped styles of Japanese chestnut (Castanea crenata Sieb. et Zucc.) have epidermal cells with thick and hard cell walls covered with cuticle. No dis-tinct stigma-like part was seen macroscopically at the tip of style, but microscopically a shal-low cavity was visible. Only pollen grains which land on this cavity germinate and the pollen tube penetrates the style, indicating that this cavity is stigma. Pollen tubes grow down the stylar canal surrounded by vascular bundles and penetrate into the ovary.
2. In 'Yamato-Wase', the inner diameter of the stigma remains about 0.05 mm through-out July. The diameters of pollen grains are 0.012 to 0.013 mm in four cultivars, including 'Yamato-Wase'.
3. Pollen germination on the stigma and pollen tube growth began as the style ceased to elongate and for about a week thereafter. If pollinated while the styles are still elongating, pollen germination and/or pollen tube growth were retarded. In open-pollination, pollen ger-mination also occurred at the time styles ceased to elongate. Open-pollination excelled artificial-pollination both in the number of pollen grains which germinated and pollen tubes which grew.
4. The largest numbers of pollen tubes per style were 2 3 and 45 at upper part of the style, and 12 and 34 at the lower part in artificial- and open-pollinated flowers, respec-tively. In open-pollinated central female flower, the pollen tubes which reached the ovary was found 9 days after cessation of style elongation. Three days later, 10 to 30 pollen tubes were observed at the upper part of the ovary.
5. From 18 to 26% of pollen grains of 'Ginyose' used for the artificial-pollination germi-nated on agar medium. No difference was found in their germinability among pollination dates.

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A persimmon (Diospyros kaki) tree may manifest three types of flowers; female, male, and perfect (hermaphrodite). Most cultivars bear only female flowers but others have both female and male and sometimes perfect flowers as well. In monoecious or polygamous cultivars, sex expression has been observed to be modified by the previous year's fruit load and the nutri-tional status of the tree. Our results demonstrate that presence of a flower type in one sea-son's branch affects the following year's flower type.
1. Using monoecious cvs. Fujiwara-gosho, Zenji-maru, Toh-hachi, and Hana-gosho, the in-fluence of flower types in a branch on the flower types occurring on the new shoots arising from this branch was determined for 3 successive years. In 'Fujiwara-gosho' and 'Zenji-maru', male flowers were predominantly formed on the shoots from a branch that had borne male flowers, whereas female flowers differentiated on shoots from a branch that had borne fe-male flowers. Male flowers in 'Fujiwara-gosho' were formed only on the shoots from a branch that had borne male flowers. Such a tendency was also observed with 'Toh-hachi' and 'Hana-gosho'. However, new shoots arising from upper buds on a branch that had borne male flow-ers tend to form female flowers, especially with 'Hana-gosho'.
2. When the relationship between the length or diameter of a nonflowering branch and flow-er types occurring on shoots from the branch were examined with 'Toh-hachi', 'Hana-gosho', and 'Zenji-maru', there was no obvious correlation between the branch length and the flow-er type that differentiated on the new shoots. With respect to branch diameters, 'Zenji-maru' and 'Toh-hachi' formed male flowers on shoots from thinner branches and conversely, there was weak positive correlations between large branch diameter and the occurrence of female flowers. These relationships did not hold for 'Hana-gosho'.
These results suggest that the previous year's flower types and bud positions from which new shoots arise are more influential in determinig sex expression than in branch size that has often been used as a criterion of the nutritional status of a tree.

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Somatic hybrids between southern type Chinese cabbage (Brassica campestris L. pekinen-sis group 'Kenshin') and the common cabbage (B. oleracea L. var. capitata 'Yoshin') were produced by means of cell fusion with polyethyleneglycol. Among 61 plants regenerated, 31 were judged as hybrids by their morphology, whereas 29 were calssified as the cabbage type and 1 was Chinese cabbage. The initial protoplast culture medium containing 1 mg-liter^-1 2, 4-D gave a higher frequency of hybrids than did media at higher 2, 4-D concentrations. No substantial differences could be observed between the growth regulator conditions set for cal-lus and regeneration cultures. Shoots of the hybrid type grew slower than did those of cab-bage type plants on regeneration media. Somatic hybrids showed intermediate characteristics of both parents with respect to leaf morphology and phosphoglucomutase isozyme bands. The regenerated Chinese cabbage plant and most of the hybrids flowered within 60 days after transplantation, whereas cabbage plants took longer to flower or they never bolted. Somat-ic hybrids generally had larger petals than did the parental species.

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Protoplasts, isolated from cotyledons of aseptically germinated seeds of the melon 'Charen-tais', were used to investigate the effects of hormones and osmotic conditions on cell divi-sion and plantlet regeneration.
1. Division of protoplasts occurred at a high frequency during the initial incubation peri-od on the modified MS medium (200 mg•liter^-1 NH₄NO₃ and 1% sucrose) containing a wide range of 2, 4-D concentrations. Protoplast division was continuous in a medium containing 0.05 mg•liter^-1 2, 4-D and 0.5 mg•liter^-1 BA even as the protoplasts mature and formed cell walls.
2. Three osmotic conditions; mannitol only and an equimolor conc. of mannitol and sucrose and that of mannitol and glucose were used to clarify the role of the osmoticum on the shoot regeneration from calli. No obvious difference among the three osmotic conditions was ob-served in the frequency of cell division at initial culture and in callus formation. The callus grown in a medium containing mannitol and glucose differentiated shoots at the highest fre-quency among the media tested.
3. More shoots were regenerated in a MS medium containing 0.5 mg•liter^-1 GA₃ and 2 mg•liter^-1 BA than were formed with a combination of GA3 and zeatin. The GA₃ com-bined with cytokinins promoted more shoots formation from calli than did the IAA-cytokinin combinations.
The following protocol for shoot regeneration of melon was quite efficient: a) Culture the protoplasts in the modified MS medium supplemented with 0.05 mg•liter^-1 2, 4-D, 0.5 mg•liter^-1 BA, 0.2 M mannitol and 0.2 M glucose. b) Transfer the callus grown in the above medium to regeneration medium supplemented with 2 mg•liter^-1 BA and 0.5 mg•liter^-1GA₃. On the average, three shoots per callus were regenerated.
Many regenerated shoots may appear abnormal and will not elongate normally, in which case, transplant the explant intact onto a MS medium containing 0.1 mg•liter^-1 BA and 0.2 mg-liter^-1 GA₃. Subculture the explant several times to promote elongation of the shoots. Finally, subculture the elongated shoot on MS agar medium with 1 mg•liter^-1 NAA for 24 hr and then transfer it to one without any hormone. The treated shoot will regener-ate roots and grow into a normal plant.

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To breed an improved 'Morioka-16' which is resistant to Alternaria black spot, caused by Alternaria alternate strawberry pathotype, culture-caused mutagenesis was used. Calliclones induced by shoot apex culture of cv. Morioka-16 were inoculated with the pathogen by three screening methods.
Using one of these methods, three plants resistant to the disease were successfully selected from 1196 calliclones which had been inoculated with the pathogen.
These three mutants were named 'M16-AR 1', 'M16-AR 2' and 'M16-AR 3' and their plant and fruit characters were examined. No differences between cv. Morioka-16 and the three mutants were found in terms of plant height, leaf number, flowering time, harvesting time, yield, and fruit characters.

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The influence of reduction of solar radiation by a concrete structure on the growth of komatsuna (Brassica campestris L. rapifera group) was studied. Five plots were laid out on the west side of the wall (5.3 m tall, and oriented 18° west of magnetic north). The distances of plots 1, 2, 3, 4 and 5 from the wall were 0, 1.5, 3.0, 4.5 and 6.0 m, respectively.
1. In control plot without shading, mean daily photon flux density, mean soil temperature and air temperature in early summer, 1989 (Exp. 1) were 29.1 mol•m^-2, 21.2°C and 21.3°C, respectively, whereas in autumn, 1989 (Exp. 2), they were 21.6 mol•m^-2 (74% compared with Exp. 1), 17.5°C (3.7°C lower) and 16.9°C (4.4°C lower), respectively.
2. In Exp. 1, the total photon flux density (TPFD) of the control during the growth period was 756.1 mol•m^-2, those of plots 1, 2, 3 and 5 under shading were 60, 72, 76 and 97% compared with the control, respectively. The dry weight (DW) of the control plants 26 days after emergence was 1.97 g, those of plots 1, 2, 3, 4 and 5 were 53, 60, 79, 76 and 94% of the control, respectively. In Exp. 2, the TPFD and DW of control plants 25 days after emergence were 539.7 mol•m^-2 and 0.77 g, respectively; the % reduction in DW of plants in the shade plots with respect to the control was similar to that in Exp. 1.
3. In both experiments, a linear relation (y = -0.08+1.06x; r = 0.92) existed between relative values of TPFD (x) and DW (y) about 2 weeks after emergence. Using this equation, we will be able to predict the degree of reduction of dry matter production of komatsuna under shaded conditions provided the reduction in solar radiation caused by the structure can be estimated.
4. The relationship between relative values of TPFD and top dry weight or leaf area was similar to that between TPFD and total dry weight. The influence of reduction of solar radiation on partioning ratio of dry matter and thickness of leaf was not statistically apparent.

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Effects of sowing time, soil temperatures, and shading with cheesecloth on the internal browning in roots of Japanese radish and relationship between the disorder and the polyphenol concentration and oxidase activity were investigated.
1. The occurrence of internal browning differed greatly with sowing dates; it was maximum in the late June sowing, and less in earlier and later sowings, no symptom appeared when seeds were sown after 15 August. The higher the air temperature and the more the amount of insolation during the late stage of growth, the more serious was the internal browning in the roots. The internal browning was also severe when the soil temperatures were high during the late stage of growth. The incidence of internal browning decreased when the plants were shaded with cheesecloth.
2. The polyphenol concentration and the polyphenol oxidase activity in the roots were higher in plants growing while high soil temperatures prevailed. Hence, the incidence of internal browning was positively correlated with both the polyphenol concentration and the polyphenol oxidase activity in the roots.

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Gene analysis of the disease-resistant selections, 'M16-AR 1', 'M16-AR 2' and 'M16-AR3' was made. These calliclones were derived by culturing the shoot apices of 'Morioka-16' which is susceptible to Alternaria alternata strawberry pathotype. The analysis is based on the results of disease reactions of their progenies from selfing (S₁) and hybrid crosses (F₁)with 'Morioka-16' and with 'Hokowase', a recessive homozygote with respect to the susceptible gene. The following results were obtained:
S₁ progenies of each line showed resistance to the pathogen. F₁ progenies of reciprocal crosses between 'M16-AR 1, 2 or 3' × 'Morioka-16' (heterozygous in relation to the susceptible gene) and between 'M16-AR 1, 2 or 3' × 'Hokowase' (homozygous recessive in relation to the susceptible gene) resulted in the following segregation ratios of susceptibility (S) and resistance (R) to the pathogen.
'M16-AR 1, 2 or 3' × 'Morioka-16' and vice versa l (S) : 1 (R)
'M16-AR 1, 2 or 3' × 'Hokowase' and vice versa 0 (S) : 1 (R)
The results described above suggest that the genotype of each of the three lines exhibited variation from the genotype of 'Morioka-16', namely, heterozygote to recessive homozygote with respect to the susceptible gene.

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pollination, were investigated for genetic variations in flowering time, petal length and width, pistil length, and silique length and width. These reproductive characteristics of the strains were compared with those of ten other vegetables belong to Brassica campestris L.
1. There was a significant variation among the Sugukina strains for flowering time with the maximum difference being 15 days.
2. No significant difference was observed for flower size, whereas silique length and width varied significantly among strains with high heritabilities between two successive generations (rank correlations of 0.93 and 0.83, respectively). These results demonstrate that genetic heterogeneity exists among Sugukina strains for flowering time and silique size. Compared with other vegetables of the same species, the Sugukina strains tended to have larger flowers and siliqua.

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In the Japanese radish cv. Gensuke, hollowing of the root has generally been regarded as peculiar to summer-sown crops. Hollowing starts as the intercellular air spaces in the stele near the pith begin to coalesce. The intercellular air spaces are formed among large parenchymatous cells, but these cells are unable to divide fast enough to prevent the formation of a central cavity, a phenomenon associated with high soil temperature during root growth. In general, cell division and enlargement become restricted when cells begin to lignify. Taking these facts into consideration, the present investigation was carried out to elucidate how lignification of xylem parenchymatous cells surrounding the intercellular air space is related to the occurrence of hollowing.
Weights of radish leaves and roots were much smaller when plants are grown under high soil temperature than when temperatures are low or moderate. The parenchymatous cells surrounding the intercellular air space show a positive red reaction to phloroglucinol-HCl reagent when the plants are grown under high soil temperature, while cells surrounding the air space are colorless in the plants grown under low and moderate soil temperatures. The rate of plant growth was significantly faster in the early sown plot than in the late sown plot. The average soil temperature in the early sown plot was as much as 6° to 12°C higher than it was in the late sown plot. Large hollow cavities were found to be more numerous in roots from the early sown plot. In roots from the early sown plot large projecting cells were seldom observed inside the air space owing to the active lignification of cells on the surface of the hollow space; but in roots from the late sown plot large unlignified cells projected into the hollow zone. In examining 60-day-old roots, the surface cells of the hollows were found to vary from large, brownish ones to small, whitish parenchymatous ones. The brownish tissues of the hollow stained intensely red with phloroglucinol-HC1, reagent whereas the whitish tissues turned slightly pink with the same reagent.
We conclude from these results that: 1) the intercellular air spaces often coalesce into longitudinal hollow pockets in roots grown under high soil temperature, and 2) that active lignification of the cells lining the hollow space stops cells division and this prevents cells from intruding into the hollow. Conversely, lignification seldom occurs in cells of the central stele when roots are not heat-stressed; and because the parenchymatous cells continue to proliferate rapidly, the intercellular air spaces remain small and do not coalesce into a large hollow cavity.

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Etiolated taro (Colocasia esculenta Schott) stem cultured under dark were used to study callus formation and plant regeneration. Aseptic plantlets derived from shoot apices of 'Eguimo', Ishikawa-wase' and Tatsugashira' corms were used as explants.
1. Etiolated stems were obtained by culturing them under dark condition on MS medium supplemented with 0.2 mg•liter^-1 NAA (Table 1) ; their elongation was not promoted by a supplement of 1.0 mg•liter^-1 of GAliter₃.
2. The longest stem was obtained from Ishikawa-wase', followed by that of 'Eguimo' and then 'Yatsugashira' (Table 2).
3. Friable callus was obtained from etiolated stem segments on MS medium supplemented with 2 mg•liter^-1 2, 4-D and 2ip (Table 3), whereas protocorm-like structure developed on a medium containing 0.2 to 2.0 mg•liter^-1 NAA plus 2 mg•liter^-1 BA or 2ip.
4. Shoots were regenerated from a protocorm-like structure by transferring to MS medium (Table 4) or from callus by subculturing them on MS medium containing 2 mg•liter^-1 BA (Table 5). These shoots formed roots after being transferred to a basal MS medium.

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This paper deals with the phylogenies of section Camellia of Chinese origin using a floweranthocyanin as a chemical marker.
Wild forms of camellias, C. semiserrata Chi and C. chekiangoleosa Hu, were characterized by the presence of pigments with lower Rf-values on two-dimensional thin layer chromatograms (TLC-plate). Of these pigments, both species contained exclusively or mainly spot 1, a mixture of cyanidin-3-glucoside and 3-galactoside. In addition, the latter C. chekiangoleosa contained a relatively large amount of cyanidin-3-galactoside within spot 1, which is associated with C. japonica subsp. rusticana (Honda) Kitamura, and the former C. semiserrata contained extremely small amount of this pigment.
On the other hand, C. polyodonta How contained some individuals with the saluenensisspecific higher Rf pigments together with main lower Rf pigments.
From the standpoints of these pigmentations, the manner of pigment-inheritance previously reported and the geographic distribution of the species in and around China, section Camellia may be arranged in the following two phylogenetic sequences; 1) from C. saluenensis Stapf ex Bean or its allied species to C. polyodonta and 2) from C. polyodonta or its primitive forms through C. semiserrata and/or C. chekiangoleosa to the groups of C. japonica Linn.
Consequently, as the species extended north-eastwards from the so-called centre of origin, the anthocyanins became chemically simpler, since the genes favouring their production are recessive to those favouring the production of more complex anthocyanins.

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The involvement of abscisic acid (ABA) in inhibition of germination of rose achenes was studied and a method for removing ABA was established. Intact achenes of Rosa hybrida L., cv. Inspiration never germinated at 25°C under continuous irradiation with white light, whereas seeds excised from the achenes readily germinated. Seed germination was inhibited when seeds were incubated together with previously removed pericarps. The amounts of ABA released into water from these achenes, seeds, and seeds plus pericarps during the incubation were quantified by enzyme-linked immunosorbent assay (ELISA). The higher level of ABA, detected in the sample with the lower germination percentage, indicated that ABA, localized in the pericarps, inhibited the germination. Achenes of Rosa multillora Thunb. were placed on a polystyrol foam tray which had many small holes and the tray was floated in a beaker of distilled water so that the achenes were steeped in water with sufficient aeration. This procedure improved the seed germination, probably through leaching ABA from the pericarps. The germination percentage was markedly increased when activated charcoal was added to the water. The effect of the leaching was greater at 5°C than at 25°C.

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To elucidate the basis of chromosome variations in the Japanese garden chrysanthemum, the present study was carried out using natural sports in flower colour.
1. Of 297 chrysanthemum cultivars examined, we found the frequency of sports to be low and varied slightly among the flowering forms. The average mutation frequency within this select group was 10.8%; it ranged from 5.2 to 15.7%.
2. Thirty-two sports and 25 parental cultivars of Japanese chrysanthemums were surveyed for chromosome number variations. The chromosome numbers in 5 out of 32 sports (15.6%) differed from the parents by plus or minus one chromosome.
3. Several clonal strains of 'Kii-amaga-hara' and their parental cultivar 'Amaga-hara' from which they originated as sports were subjected to karyotype analysis as related to satellite chromosome variations. The chromosome numbers varied little in the sport or parental plants, whereas the karyotype constitutions differed considerably among them. These results indicate that structural changes in chromosomes may have occurred in the sports.
4. Four clonal strains of 'Kii-shuho-no-chikara' and five of its parental cultivar 'Shuho-no-chikara' were examined for the variations in chromosome numbers and certain morphological or ecological characteristics. Four parental strains (80% of those examined) had the same chromosome number (2n=54) as the original clone but in the two mutant strains (50% of those examined), the chromosome number was 52. As one might expect, the loss of two chromosomes by the strains resulted in considerable differences in several characteristics as compared with the original clone.
5. Our analysis confirms that the appearance of sports is attributable to chromosome variations in the garden chrysanthemums. However, the frequency of these sports depends on the particular cultivar of chrysanthemum.

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Pollen grains of Lilium species, cultivars and hybrids were stored at 4°C and tested for their viability by in vitro pollen germination and in vivo seed formation. Gelatin capsules were superior to paraffin paper pockets as receptacles to retain the germination capacity of pollen grains of L. X 'Enchantment'; 6065% relative humidities (RH) were found to be optimum for their storage. Pollen grains of 12 Lilium plants were enclosed in gelatin capsules and stored in desiccators with 6065% RH at 4°C for periods of 9 to 12 months. Eight of them retained the germination capacity in vitro, but the rate of germination and the length of pollen tubes varied with Lilium species and cultivars. Stored pollen grains of L. maculatum and L. auratum formed as many seeds as freshly harvested pollen. Pollen grains of other Lilium plants germinated well in vitro, but they produced only a few seeds per pod. These results revealed that stored pollen grains may have the in vitro germination capacity, but only those from a few species and cultivars have the ability to produce seed.

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To overcome self-incompatibility of Tulipa gesneriana L., the effects of manipulating the flowering time under forcing condition, pollination after the excision of the stigma (intrastylar pollination), and the immersion of stigma in hot water (40° to 50°C) were tested. Five cultivars were self-pollinated between February and April under forcing and in open cultures.
1. Four cultivars set self-seeds under forcing culture, whereas none set in the open. This result indicates that forcing early flowering reduces self-incompatibility.
2. When self-pollination was performed on the cut surface of a style from which the stigma was excised, self-incompatibility was partially overcome in that 8 to 81 seeds per ovary were set in each of five cultivars.
3. When stigmas were immersed in 50°C water for 1 to 3 min just before self-pollination, self-incompatibility was overcome slightly.
These are practical techniques of obtaining selfed progenies in a tulip breeding program.

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To elucidate the karyomorphological character and mechanism of the appearance of aneuploidy in garden chrysanthemums, karyotype analysis was made by using 17 cultivars and one strain of chrysanthemum which differ in use, flower size, and flower type.
1. Size and shape of chromosomes. 1) The longest chromosome in each cultivar was 3.95.8 μm (av. 4.9 μm) and the shortest was 1.73.3 μm (av. 2.6μm). 2) The shape was classified into four types by the position of centromere; medium (m), sub-median (sm), subterminal (st), and terminal (t). Since the morphological variation of chromosomes was narrow, it was difficult to detect an indicator chromosome. 3) One to seven satellite chromosomes per chromosome set were observed in 77.8% of given cultivars; usually one to four and rarely were there five to seven.
2. As for the position of centromere, most chromosomes were the m type, followed by sm, st, and t types. A possible relationship between the frequency of occurrence of the m type chromosomes and use or flower size of garden chrysanthemum was recognizable in some cases. The karyotype component of garden chrysanthemums showed obvious hybridity in all cultivars.
3. Judging from the above results, the heterozygous karyotype seems to be closely related to the occurrence of aneuploidy in garden chrysanthemums. Moreover, the genomic makeup of the aneuploidy differed among the cultivars of garden chrysanthemum.

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To derive a forcing schedule of Gypsophila paniculata L. with three flushes per year, the effects of chilling exposure and BA application on the flowering were investigated, using 'Red Sea' and 'Bristol Fairy' selections.
1. To force the 1st flush in November, a foliar spray of 100300 ppm BA was effective in advancing flowering time in 'Bristol Fairy'. Although the percentage of bloom in 'Bristol Fairy' line 13 gradually decreased as the time of final pinching was delayed, all plants treated with BA before 30 September bloomed. However, advanced flowering was accompanied by flower malformation. Cut flowers from BA-treated plants were shorter and smaller in volume than were those of BA-untreated plants.
2. Exposure of rooted cuttings to 2°C for 40 or 55 days before planting reduced the number of days to bloom and improved cut flower quality of the 1st flush. When rooted cuttings previously exposed to chilling for 40 days were planted on 15 September and sprayed with 100 ppm BA on 30 September, their flowers had sufficient length and volume; they were ready to be harvest between mid- and late November.
3. Exposure to natural chilling for more than 50 days (800 hr below 10°C) after the 1st flush was required for vigorous shoot regrowth in line 09. Application of 300 ppm BA in combination with natural chilling promoted the flowering, so that the 2nd flush was harvested in mid-April. The 3rd flush was harvested from late June to early July, about 1 month later than when natural flowering would occur.
On the basis of these data, a forcing schedule or system with three flushes per year was derived through: a) selection of vegetative lines with less chilling requirements, such as 'Red Sea', 'Bristol Fairy' lines 09 and 13; b) by exposing these selections to appropriate chilling period, and c) timely administration of foliar sprays of BA.

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Both water-soluble oxalic acid and water-insoluble calcium oxalate are usually found in spinach leaves. In this study, spinach was cultivated in a standard solution culture containing 0.67, 25, 50 ppm CaCl₂. The plant weight and height and oxalate contents per plant and per unit weight were determined during the growing cycle. The activities of enzymes related to the biogenesis and degradation of oxalates in the leaves were compared during the growing season.
1. The increase in the weight of the spinach was proportional to the amount of Ca in solution (Fig. 2).
2. The amount of oxalate accumulated by the plant was a function of the Ca solution in the nutrient culture; a large fraction of the oxalate was in the insoluble form (Fig. 3).
3. A small amount of oxalate was exuded by the roots into the external medium. These results suggest that the formation of the water-insoluble Ca oxalate is a defense mechanism to protect the plant from a harmful buildup of soluble oxalic acid.
4. That biogenetic oxalate-enzymes, e. g., glyoxylate oxidase and oxaloacetase, and an oxalate degrading enzyme, oxalate decarboxylase, are present in spinach leaves was confirmed.
Oxalate might be biosynthesized and degraded by the action of these enzymes; the accumulation of oxalate in the plant tissues is attributed to the shift in equilibrium in favor of biosynthesis rather than degradation.

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Experimental model glass chambers and a large apparatus to handle about ten tons of fruit at a time were constructed to study the removal of astringency from persimmon fruits (Diospyros kaki Thunb. cv. Hiratanenashi) by using ethanol and carbon dioxide together or alone.
Results with glass chambers revealed that astringency was removed slightly faster because more ethanol and acetaldehyde accumulated in the fruit flesh when the treatment combined ethanol and carbon dioxide rather than with either reagent alone. The loss of astringency was almost entirely due to the effects of carbon dioxide. When fruits were treated with either ethanol or carbon dioxide before the other reagent was used, the loss of astringency was mainly due to the effects of carbon dioxide. Flesh firmness decreased slightly during treatment more so in fruits treated with both reagents than in those treated with carbon dioxide alone.
Our results with large apparatus showed that the removal of astringency was again mainly due to the effects of carbon dioxide and the rate of flesh softening was somewhat hastened when ethanol was added before the carbon dioxide treatment, as was observed with small glass chambers.

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To develop a nondestructive sugar analyzer for intact peaches, the potential of the near infrared (NIR) method with fiber optics in interactance mode was evaluated. In 'Shimizu Hakuto', a white peach cultivar, there were clear differences among the NIR second derivative spectra of high, medium, and low Brix values in the wavelength region around 906 nm. This wavelength was assigned to sucrose and selected as first calibration wavelength. The highest multiple correlation coefficient of 0.97 was obtained in the linear regression equation that included four optical terms of d²log(1/R) at 906, 878, 870 and 889 nm, while a standard error of calibration (SEC) was 0.48°Brix. A bias-corrected standard error of prediction (SEP) was 0.50°Brix with a bias of 0.01°Brix, suggesting that the MR method is sufficiently accurate to determine sugar content in intact peaches to be practical.

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The effect of environmental gas conditions on the occurrence of off-odor or off-taste in stored Satsuma mandarin fruits was investigated. The fruit was hermetically packaged in polyethylene bags with or without the inclusion of ethylene or CO₂ gas, and with or without the inclusion of their absorbents. The samples were then stored at 20°, 8°, or 1°C. The control fruits were stored in perforated bags.
1. The organoleptic tests of fruits after storage in perforated bags revealed that off-odor occurred after 15 days at 20°C and after 1 month at 8°C.
2. The concentration of dimethyl sulfide (DMS), the causal compound of off-odor, in the central cavity of the fruits increased sharply after 15 days storage at 20°C in all treatments. At 8°C, the concentration increased gradually when the fruit packed in perforated bag or in bags with CO₂ absorbent. At 1°C, DMS level remained very low in all treatments.
3. In bags containing CO₂ absorbent, the low CO₂ concentration resulted in a greater DMS accumulation at 20°C and 8°C than it did at 1°C. Ethylene absorbent (KMnO4 type) decreased the DMS concentration at 20°C because it also absorbed DMS.
4. Fruit decay and off-taste of the juice developed rapidly at all temperatures when 100% CO₂ was introduced in bags at the beginning of storage. Inclusion of 1, 000 ppm ethylene at the beginning of storage also promoted the production of off-taste and decay. In other treatments, the off-taste developed gradually. The ethanol concentration in the juice increased markedly in CO₂ and ethylene-treated fruit.

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To establish a physiological basis for storage and transport of the Chinese pear 'Yali', (Pyrus ussuriensis Maxim. var. sinensis Kikuchi), the occurrence of chilling injury and storage life of fruit stored at 0°, 5°, 10°, and 20°C were investigated. Inhibitory effects of temperature-conditioning prior to low temperature storage on chilling injury were also studied; the mechanism of conditioning-effect is discussed.
1. Browning and water-soaked appearance of flesh, which seemed to be symptoms of chilling injury, were observed in the fruit stored at 0° or 5°C, but not at 10° and 20°C. After an extended storage, browning of the core occurred at all temperatures, indicating to be a different symptom from that of chilling injury.
2. The rates of respiration and ethylene production in the fruit decreased with the lowering of storage temperature. The rates of respiration in the fruit transferred to 20° from 5°C recovered at the level of the fruit stored throughout the experiment at 20°C. However, respiration rates of fruit injured by the low temperature treatment and then transferred to 20°C were higher than that of the control.
3. The electrolyte leakage from flesh discs increased with the occurrence of chilling injury and continued to increase with the development of the injury symptoms.
4. The occurrence of chilling injury in fruits stored at 5°C was inhibited by various temperature-conditioning lasting more than three weeks. As stepwise cooling and delayed storage both inhibited the occurrence of chilling injury, the mechanisms of conditioning effects seem to depend on aging rather than on cold-acclimatization of the fruit.
5. The fruit stored at 5°C after an appropriate temperature-conditioning retained good eating quality even after 5 months of storage.

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