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Phytophagous insect larvae feed on plants containing secondary metabolic products with biological activity against other predatory organisms. Phytophagous insects can use their specialised metabolic systems to covert these secondary metabolic products into compounds with therapeutic properties useful to mankind. Some Asians drink tea decoctions made from phytophagous insect frass which is believed to be effective against inflammatory diseases. However, insects that can convert plant-derived secondary metabolic products into useful human therapeutic agents remain poorly studied. Here, we constructed the TUATinsecta database by integrating publicly plant/insect datasets for the purpose of selecting insect species. Using TUAT-insecta we selected the Asian swallowtail butterfly, Papilio xuthus larvae fed on several species of Rutaceous plants and examined whether the plant-derived secondary metabolites, especially those present in frass, were chemically altered or not. We extracted metabolic products from frass using three organic solvents with different polarities, and evaluated solvent fractions for their cytotoxic effects against several human cell lines. We found that chloroform frass extracts from P. xuthus larvae fed on Poncirus trifoliata leaves contained significant cytotoxic activity. Our findings demonstrate that screening of insect species using the ‘TUATinsecta’ database provides an important pipeline for discovering novel therapeutic agents that might be useful for mankind.

To clarify the response of net photosynthetic rate (Pn), stomatal conductance (gS), transpiration rate (Tr), and leaf intercellular CO2 concentration (Ci) to irradiance on the adaxial and abaxial sides of mature and young strawberry leaves using blue, green, and red light-emitting diodes (LEDs), irradiation from a short distance was investigated using ‘Tochiotome’. Light–photosynthetic response curves of the adaxial side of mature leaves were not different among LED treatments. However, those of the adaxial side of young leaves irradiated with red LEDs were less than those of other LED treatments. Pn of the abaxial side of mature leaves was 42% to 71% of the abaxial side. In young leaves, Pn of the abaxial side was 17% to 68% of the adaxial side. Moreover, light–transpiration response curves were different with LED treatments. Ci and Tr under blue and green LEDs were greater than those under red LEDs. This indicates that blue and green lights affected the stomatal opening. In contrast, red LEDs decreased Ci more than other LED treatments. In addition, reactions of the adaxial side of young leaves under blue and red LEDs were seen not only in ‘Tochiotome’, but also in ‘Sachinoka’ and ‘Eran’, which indicates that the photosynthetic reactions of blue light and red light are common characteristics of the strawberry. Therefore, red LEDs promoted the photochemical reaction and activated the CO2 fixation system. Based on the results of this study of short-distance lighting with LEDs in strawberry production, irradiance of the abaxial side of leaves by blue or green LEDs might improve more assimilates in young leaves compared with red LEDs to increase strawberry yield.

The heat- and drought-sensitive highbush blueberry (Vaccinium corymbosum, section Cyanococcus; hereafter referred to as cor), is one of the main cultivated species of blueberry. In contrast, Vaccinium boninense (bon) and Vaccinium wrightii (wri), in the Bracteata section, are native to subtropical Asia, including Japan. The development of new blueberry cultivars combining the qualities of these species is of considerable interest at present. However, it is difficult to obtain hybrids between species from different sections or with different ploidy levels. Furthermore, our earlier attempt to cross cor with bon and wri did not produce any hybrids ( Miyashita, 2017 ). We hypothesized that the rate of success of interspecific hybridization in Vaccinium is reduced by emasculation, which is commonly performed before pollination. Therefore, the present study aimed to evaluate the crossability between cor and the diploid wild species (bon and wri) and to produce new intersectional hybrids. We made 15 combination crosses between six types of Vaccinium plants, including cor, bon, and wri (five species and an interspecific hybrid), with two crossing methods (emasculation and non-emasculation) for each combination included prior to pollination. The hybridity of the resulting seedlings was identified by polymorphism analysis using simple sequence repeat markers for blueberry. Hybrids were obtained from 10 of the 15 combinations. All these combinations were of the cross type such that both parental section and ploidy level were same, or that either section or ploidy level were different. In seven of the 10 combinations, hybrids were obtained only with the non-emasculation method. However, four combinations of the cross type where both section and ploidy level differed between parents failed to produce any hybrids. These results suggested that intersectional interploid cross type has lower crossability than that of either intersectional or interploid type, and that the non-emasculation method is more effective than the conventional emasculation method to obtain hybrids. However, the non-emasculation crossing did not prevent the production of nonhybrid seedlings, indicating the need to confirm the hybridity of each seedling. Subsequently, six reciprocal cross combinations between cor and the three polyploid or hybrid plants derived from bon and wri were made using the non-emasculation method. This yielded six hybrids from two combinations. To our knowledge, these are the first hybrids derived from cor and two Bracteata species native to subtropical Asia. These hybrids might be useful as breeding materials to enhance heat and drought tolerance in highbush blueberry.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

We investigated the role of heat shock transcription factors (Hsfs) during induction of defense response by heat-shock treatment (HST) in tomato. Leaf disease symptoms were significantly reduced at 12 and 24 h after HST, consistent with upregulation of pathogenesis-related (PR) genes PR1a2 and PR1b1 peaking at 24 h after treatment. These genes were upregulated at the treatment application site, but not in untreated leaves. In contrast to HST, inoculation of the first leaf induced systemic upregulation of acidic PR genes in uninoculated second leaves. Furthermore, heat shock element motifs were found in upstream regions of PR1a2, PR1b1, Chitinase 3, Chitinase 9, Glucanase A, and Glucanase B genes. Upregulation of HsfA2 and HsfB1 peaked at 6 h after HST, 6 h earlier than salicylic acid accumulation. Foliar spray of heat shock protein 90 (Hsp90) inhibitor geldanamycin (GDA) induced PR gene expression comparable to that after HST. PR gene expression and defense response against Pseudomonas syringae pv. tomato (Pst) decreased when combining HST with Hsfs inhibitor KRIBB11. The Hsfs and PR gene expression induced by heat or GDA, together with the suppression of heat shock-induced resistance (HSIR) against Pst by KRIBB11, suggested a direct contribution of Hsfs to HSIR regulation in tomato.

Nondestructive prediction of ingredient contents of farm products is useful to ship and sell the products with guaranteed qualities. Here, near-infrared spectroscopy is used to predict nondestructively total sugar, total organic acid, and total anthocyanin content in each blueberry. The technique is expected to enable the selection of only delicious blueberries from all harvested ones. The near-infrared absorption spectra of blueberries are measured with the diffuse reflectance mode at the positions not on the calyx. The ingredient contents of a blueberry determined by high-performance liquid chromatography are used to construct models to predict the ingredient contents from observed spectra. Partial least squares regression is used for the construction of the models. It is necessary to properly select the pretreatments for the observed spectra and the wavelength regions of the spectra used for analyses. Validations are necessary for the constructed models to confirm that the ingredient contents are predicted with practical accuracies. Here we present a protocol to construct and validate the models for nondestructive prediction of ingredient contents in blueberries by near-infrared spectroscopy.

The purpose of this study was to evaluate the effect of cross direction and cultivars on interspecific hybridization between Vaccinium corymbosum (4x) and Vaccinium virgatum (6x). Totally 99 reciprocal interspecific crosses were made by using ten cultivars of V. corymbosum and five cultivars of V. virgatum. Percent fruit set, number of developed seeds per berry, germination rate and number of seedlings per flower were evaluated. The progeny seedlings were obtained from 65% of all cross combinations, and more than 99% of the seedlings were revealed to be pentaploid hybrids by flow cytometric analysis. In the comparison of crossability between interspecific reciprocal crossing, 4x × 6x crosses showed 2.9 times higher rate of mean fruit set (67%) and 3.3 times higher rate of number of seeds per berry (6.2) than the opposite crosses (6x × 4x). However, the average germination rate (38%) of the 6x × 4x crosses was 1.7 times higher than that of 4x × 6x crosses. Consequently, average number of seedlings per flower (0.96) in 4x × 6x was 3.8 times higher than that in the opposite crosses. According to the number of seedlings per flower significant difference in the crossability was found among the cultivars in V. corymbosum in the reciprocal crosses with V. virgatum, whereas no such significant difference was observed in V. virgatum.

ブルーベリー‘Tifblue’を供試し，土壌が湿潤な状態から葉の光合成速度が著しく低下するまで徐々に乾燥ストレスを与え，その後再び灌水したときの葉の水ポテンシャル，光合成速度，果実肥大の推移を，着果樹と無着果樹とで比較した．土壌含水率の低下に伴い，葉の水ポテンシャルと光合成速度が低下した．葉の水ポテンシャルが約−3.5 MPaで土壌含水率が約8％のとき，果実全てが萎れ，新梢全体が垂れ，葉の光合成はほぼ停止状態であった．着果樹の葉の水ポテンシャルおよび光合成速度の低下は，無着果樹よりも早くおこった．再灌水を行ったところ，乾燥区の葉の水ポテンシャルは再灌水後1日目で高くなったが，対照区と同じ程度までは回復しなかった．再灌水後の乾燥区の光合成速度は対照区の1/2程度であり，着果樹では無着果樹より回復が遅かった．したがって，光合成機能の回復臨界点からの灌水の目安は，葉の水ポテンシャルが−3～−3.5 MPaになる前であること，着果は乾燥ストレスを助長することが分かった．

We detected differences in both onset and progression of visible petal senescence among morning glory cultivars by application of a digital image analysis system. The system is based on semiautomated time-lapse measurement of corolla areas. The system could also be applied to evaluate the effects of ethylene and its inhibitor on visible petal senescence. Both onset and progression of visible petal senescence were accelerated by ethylene treatment in all six cultivars tested. Treatment with aminooxyacetic acid (AOA), an ethylene biosynthesis inhibitor, prolonged time to onset of visible petal senescence in three of the six tested cultivars. In contrast, AOA treatment had no effect on duration of visible petal senescence in any tested cultivars. These data suggested differences among morning glory cultivars in the role of endogenous ethylene in controlling onset of visible petal senescence. In addition, we propose a new application of image analysis to fine quantification of time-lapse changes in the shape of plant organs.

光強度（0～2,000 μmol・m−2・s−1）と温度（15～35℃）に着目し，ファイトトロン内で測定したハイブッシュ種‘Weymouth’とラビットアイ種‘Tifblue’の光合成特性を比較した．両品種の個葉の光合成速度は，温度が高いほど大きくなった．低温条件（15～20℃）における個葉の光合成速度は‘Weymouth’が‘Tifblue’に比べて大きかった．一方，高温条件（25～35℃）におけるそれは品種間で相違がなかったが，‘Weymouth’は‘Tifblue’に比べて蒸散速度が大きく，水利用効率が小さかった．また，ハイブッシュ種‘Blueray’を用い，高温条件で行った実験でも同様の結果が得られた．これらの特性は，ハイブッシュ種が冷涼な気候に適していること，ラビットアイ種が高温，乾燥条件に対する耐性を持つことに関係していると考えられた．また，35℃の高温および1,000 μmol・m−2・s−1以上の光強度の条件で測定した水利用効率の大小は，耐暑性がある個体の選抜の一指標となると考えられた．強光，高温条件では蒸散速度が大きくなるため，夏季の高温時には水分の損失を防ぐために光飽和に達する光強度である1,000 μmol・m−2・s−1を目安に遮光を行うことが有効であることが示唆された．

The most suitable period to reintroduce protocorms of Habenaria radiata that had been gel covered and inoculated with orchid mycorrhizal fungi to a habitat in order to restore the population was investigated. Seed germination rates changed during the sowing season. In October, the germination rate was high except in the dark, but there were no differences in the seed germination rate among different light conditions and dark condition in May the following year. The germination of H. radiata seeds in a habitat started during late March and peaked in late April, then fungal infection of protocorms began. Most of the protocorms were infected with fungi in late May. Protocorms inoculated with orchid mycorrhizal fungi and covered with gel were reintroduced to the habitat between late May and early July. The protocorms reintroduced during late May or mid June showed the best growth.

To establish a model system for alteration of flower color by carotenoid pigments, we modified the carotenoid biosynthesis pathway of Lotus japonicus using overexpression of the crtW gene isolated from marine bacteria Agrobacterium aurantiacum and encoding beta-carotene ketolase (4,4'-beta-oxygenase) for the production of pink to red color ketocarotenoids. The crtW gene with the transit peptide sequence of the pea Rubisco small subunit under the regulation of the CaMV35S promoter was introduced to L. japonicus. In most of the resulting transgenic plants, the color of flower petals changed from original light yellow to deep yellow or orange while otherwise exhibiting normal phenotype. HPLC and TLC analyses revealed that leaves and flower petals of these plants accumulated novel carotenoids, believed to be ketocarotenoids consisting of including astaxanthin, adonixanthin, canthaxanthin and echinenone. Results indicated that modification of the carotenoid biosynthesis pathway is a means of altering flower color in ornamental crops.

自生地で菌根菌接種ゲル被覆サギソウプロトコーム由来の実生個体に形成された球根から翌年も肥大した新球根が形成され，やがて発蕾・開花に至る可能性があるかどうか，また，自生地に生息する菌根菌にはサギソウ球根形成促進効果があるかどうかを検討した． 自生地に植え付けた球根から新たに形成された球根は約2倍に肥大した．サギソウの球根重が150 mg以上に肥大すると，半数が発蕾・開花することから，自生地で菌根菌接種ゲル被覆サギソウプロトコーム由来の実生苗から形成された球根は，5年後に発蕾・開花する可能性があると考えられた．自生地に生息する菌根菌にはサギソウの球根形成を促進する菌株も認められたので，その菌株をゲル被覆サギソウプロトコームに接種して自生地に設置することが望ましいと考えられた．自生地で形成される新球根をさらに肥大させるには，自生地の環境条件も検討する必要がある．

� Background and Aims Induction of dehydration tolerance is a key to achieving high survival rates in cryopreservation of plant specimens. It has been reported previously that two-step preculturing with sucrose effectively increased desiccation tolerance in axillary buds of gentian (Gentiana scabra), which allow the buds to survive cryopreservation. This study is aimed at characterizing each step of this preculturing and to elucidate physiological changes induced during this preculturing. � Methods In standard two-step preculture, excised gentian axillary buds were incubated for 11 d on MS medium with 0� 1 M sucrose at 25 � C (first step: mild osmotic stress was given) and the subsequent incubation on MS medium with 0� 4 M and 0� 7 M sucrose for 1 d each (second step). The levels of abscisic acid (ABA), proline and soluble sugars in gentian buds during the preculture were determined. Effects of various combinations of two-step preculturing and of exogenous ABA and proline were studied. � Key Results During the first preculture step, there was a transient increase in ABA content peaking on day 4, which declined to a background level at the end of the first and second step preculturing. Proline level increased steadily during the first preculture step and increased further in the second preculture step. Incubating buds with medium containing proline, instead of the two-step preculturing, did not allow them to survive desiccation. Incubating buds with ABA instead of 0� 1 M sucrose-preculturing effectively increased desiccation tolerance only when it was followed by the second preculture step. Fluridone, an ABA synthesis inhibitor included in the two-step preculture medium, reduced desiccation tolerance of the buds. The normal first-step preculture increased the levels of soluble sugars 2� 4-fold, especially sucrose and raffinose. Buds treated with the second preculture step had greatly increased sucrose levels. � Conclusions These observations lead to the hypothesis that the first preculture step involves ABA-mediated cellular changes and the second step induces loading of sucrose in the gentian buds.

ユキヤナギSpiraea thunbergii Sieb. ex BlumeとシモツケS. japonica L. fil.との種間雑種を育成し，雑種個体の花芽の発育特性，花器の形態的特性，花色の特性を両親と比較した． 1） 雑種の腋芽の花芽分化は12月中旬から始まり，1月中旬に完了し，2月から花房分化が始まり，4月中旬に開花した．雑種の開花時期は両親の中間で，ユキヤナギよりも遅かったのは花芽形成時期が遅かったことと関係していた． 2） 雑種における雄ずい数，開花時期，1花序あたりの花数，花色，雄ずい長および花柱長は両親の中間的特性を示した．一方，花弁の形，花弁の長さ，花径はユキヤナギに類似し，花の着生状況や花序はシモツケに類似していた． 3） 雑種の全アントシアニン含量はシモツケに比べて少なく，花色は桃色を呈していた．雑種にはシモツケの6つの構成色素（Unknown, Cy3Ga, Cy3G, Cy3Ara, Pg3G, Mv3G）のうち4つのシアニジン系色素（Unknown, Cy3Ga, Cy3G, Cy3Ara）の色素が導入され，Cy3GaとUnknownが主要色素であった．花弁の色相の変化にはPg3GとMv3Gの量が関係していると考えられた．さらに，雑種の花弁は老化すると花色が退化するが，これは主要色素であるCy3Gaの減少が関与していた．よって，Cy3Gaは雑種の主要色素であり，色の濃淡に大きく影響していることが明らかになった．

In vitroにおいてサギソウ球根苗に菌根菌を接種し，菌根菌は球根苗の生育を促進するかどうかを明らかにしようとした．また，それはどのような栄養の吸収によるものであるかを調査した．このことにより，球根苗が形成する新球根の肥大に菌根菌接種は有効かどうかを検討した．1．菌根菌接種は球根苗の生育を促進し，形成される新球根を肥大させることが明らかとなった．2．菌根菌接種が球根苗の生育を促進したのは，菌根菌の作用によりオートミール培地から植物体が炭素化合物を多く吸収したことによると考えられた．3．植物体が吸収した炭素化合物は培地のオートミールが菌根菌によって分解され，根から直接吸収されたものであるか，あるいは菌根菌を経由して吸収されたものであるかは判別できなかった．

サギソウ自生地においてサギソウプロトコームの生存率と生育した個体の球根形成率を高め, 実生育成する方法を検討した.3.5号鉢内の非滅菌用土においてサギソウプロトコームの生存率および球根形成率を高めるには, サギソウプロトコームをゲル被覆し, 菌根菌を接種して一定期間培養した後に非滅菌用土に設置する実生育成法に効果が認められた. 菌根菌接種から設置までの培養日数は14日～42日間が適すると考えられた.そこで, 菌根菌を接種したゲル被覆サギソウプロトコームを菌根菌接種28日後にサギソウ自生地に設置して98日後の生育状況を調査したところ, 菌根菌無接種区では全く生育せず, 菌根菌接種区のみ生育が認められた. とりわけ, 設置したプロトコームの生存率は46.1%となり, 球根形成率も53.0%となった. このことから, 菌根菌接種ゲル被覆サギソウプロトコームによるサギソウの実生育成法は自生地においても高い効果を示すことが明らかとなった.しかし, サギソウ自生地で形成された球根重はかなり小さいことから, 翌年もこの球根から発芽した個体が順調に生育するかどうかをさらに検討する必要がある.

The heritability values of sugar contents in strawberry fruit were estimated from the parent-offspring regression of seven F1 populations, obtained from a common pollen parent 'Toyonoka'. The estimated heritability values for total sugar, hexose (fructose plus glucose) and sucrose contents were 0.568, 1.153 and 0.004, respectively; high additive genetic effects were found in total sugar and hexose contents. Therefore, an optimum method for breeding strawberry cultivars that contain large amounts of sugar and hexose may be to use parental lines with high total sugar and hexose contents, and to select F1 individuals with high sugar contents. The low heritability of sucrose content in this experiment may be attributable to the cultural practices and environmental factors because harvesting strawberry fruits took a long time.

To establish an efficient means of regenerating plantlets via ovule culture from an interspecific cross between Spiraea thunbergii Sieb. ex Blume and S. japonica L. fil., the effects of concentrations of macro-elements in the MS medium and sucrose and the sampling time of ovules were investigated. Survival rates of ovules and normal plants, on the MS medium in which macro-elements were diluted to 1/2 or 1/4 were better than those cultured on standard, undiluted MS medium. The high concentrations of macro-elements increased the rate of blighted plants. Hybrid plantets developed on 1/4 MS medium supplemented with 3% sucrose. Although the frequency of albino plant was not influenced by the concentration of macro-elements in the medium, their rate increased as ovules were cultured in media high in sucrose. When ovules were excised 5 to 22 days after pollination and cultured in 1/4 MS medium supplemented with 3% sucrose, the percentages of normal plants that developed ranged from 1 to 31. When ovules in their differentiation and enlargement stages were excised from 14 to 19 days after pollination and culture, the frequency of normal plants ranged from 25 to 31%. Thus, the success rate of obtaining interspecific hybrids between Spiraea thunbergii Sieb. ex Blume and S. japonica L. fil., was optimum when hybrid ovules were excised from 14 to 19 days after pollination and culture on 1/4 MS medium supplemented with 3% sucrose.

We isolated differentially expressed and dark-responsive genes during flower development and opening in petals of morning glory. Flower opening usually depends on petal expansion and is regulated by both genetic and environmental factors. Flower opening in morning glory (Ipomoea nil) is controlled by the dark/light regime just prior to opening. Opening was normal after 8- or 12-h dark periods but progressed very slowly after a 4-h dark period or in continuous light. Four genes (InXTH1–InXTH4) encoding xyloglucan endotransglucosylase/hydrolases (XTHs) and three genes (InEXPA1–InEXPA3) encoding alpha-expansins (EXPAs) were isolated. The expression patterns of InXTH2, InXTH3, and InXTH4 in petals were closely correlated with the rate of flower opening controlled by the length of the dark period prior to opening, but those of the EXPA genes were not. The expression pattern of InXTH1 gene was closely correlated with petal elongation. Suppression subtractive hybridization was used to isolate dark-responsive genes accompanying flower opening. The expressions of ten isolated genes were associated with the length of the dark period prior to flower opening. One gene was highly homologous to Arabidopsis PSEUDO-RESPONSE REGULATOR7, which is associated with the circadian clock and phytochrome signaling; another to Arabidopsis REVEILLE1, which affects the output of the circadian clock. Other genes were related to light responses, plant hormone effects and signal transduction. The possible roles of these genes in regulation of flower opening are discussed.

Reciprocal crosses between Spiraea thunbergii Sieb. ex Blume. and S. japonica L. fil. were carried out, to incorporate red color to S. thunbergii. In vitro germination rate of the stored pollen, germination of pollen grains on the stigma, growth of the pollen tubes, and the development of ovule were investigated, in addition ovule culture was tried to obtain interspecific hybrids. 1. Since the flowering time of both species differed, pollen grains of both species were stored dry at -30°C, 5°C, and 20°C. Only the pollen of both species stored at -30°C for 360 days remained viable for crossing. 2. Pollen grains of S. japonica, stored at -30°C, germinated well on the stigma of S. thunbergii. The pollen tubes elongated rapidly to the ovary as the developing ovules were observed 10 days after pollination. Stored pollens of S. thunbergii germinated well on the stigma of S. japonica, but whether the pollen tubes reached the ovary it was not confirmed. 3. In the interspecific crosses between S. thunbergii (♀) and S. japonica (♂), enlarged ovules excised 16 days after pollination were cultured in 1/2MS medium containing 30g·liter-1 sucrose and 8g·lite-1 agar. The resulting plantlets seem to be true hybrids between S. thunbergii and S. japonica., based on several morphological characteristics and the RAPD banding patterns which exhibited the same bands as the parents.

Primula obconica Hance secrets primin which causes allergic-dermatitis, and seedling test of primin is important for breeding primin-free cultivars. To be able to select primin-free Primula obconica at their seedling stage, plants grown under different temperature were observed. 1. Primin secretion began in the cotyledonary stage in 'Crystal Apricot' seedlings. 2. When 'Crystal Apricot' seedlings were grown under either low (20/13 °C) or high (30/23 °C) (day/night) temperature, all seedlings secreted primin at the 1st leaf expanding stage under 20/13 °C. Furthermore, the primin secreting percentege of the leaves at lower nodes were consistently high under 20/13 °C. However, the onset of primin secretion was delayed at 30/23 °C, and it ceased earlier at 30/23 °C than it did at 20/13 °C. The percentage of primin-secreting leaves directly below the expanding apical leaf was higher than those of leaves at lower nodes independent of the ambient temperature. 3. The percentage of primin-secreting leaves directly below the expanding apical one in four 'Crystal' cultivars revealed difference among cultivars as to when the secretion began. Primin secreting percentage of all cultivars reached 100% in cotyledon as the first leaf was expanding at 20/13 °C, whereas it was the 4th leaf as the 5th-leaf was expanding at 30/23 °C. In conclusion, our results demonstrate that primin-free plants can be selected at the cotyledon as the first leaf was expanding by growing them at 20/13 °C or at the 4th leaf as the 5th-leaf was expanding at 30/23 °C.

The sugar contents of strawberry fruits extracted by the conventional ethanol method were compared with those extracted with water followed by microwave heating. Sucrose, glucose, fructose and total sugar contents did not differ significantly between the two methods. The time for the water extraction method required approximately half that needed for the conventional ethanol method. Sugar metabolizing enzymes are inactivated by boiling in a microwave oven. In this method, frozen fruits should be chopped, quickly weighed at a low temperature, and the pieces immediately heated in a microwave oven. After strawberry fruits are heated in a microwave oven, they could be processed at a room temperature. Thus, the water extraction method followed by microwave heating is less time consuming but equally accurate for measuring the concentration and composition of soluble sugars in strawberry fruits.

A comparison of the trichome types was made by the Craven test and microscopic observation between primin-secreting and primin-free cultivars of Primula obconica. 1. All cultivars were classified into two groups according to the lengths of trichomes. Group one had trichomes (Fig.1, AaD) whose lengths were 150μm or less, whereas group two was represented by those with trichomes exceeding 1mm (Fig.1, E). Moreover, the trichomes of group one was further classified into four types from the characteristics of the tips, e.g., A : red tip ; B : colorless tip ; C : yellow tip and D : tip with crystallized substance (Fig.1, A, B, C and D, respectively). 2. The trichomes of B, C, and D types were observed both on the primin-secreting and free cultivars but those of A type were observed only on the primin-secreting cultivars. By the Craven test, only the trichome of A type secreted primin at its apex. 3. The distribution density of A type trichome (primin-secreting) was higher on the basal part of the midrib in leaves and on the calyx and peduncle in flower clusters, than in other parts of leaves and flower clusters. Thus, it should be possible to select primin-free plants by avoiding the plants with red tipped trichomes on midrib of young leaves, calyx and peduncle of flower clusters.

Interspecific crosses between Prunus mume cv. Baigo (seed parent) and P. salicina cv. Sordum (pollen parent) were made in 1984 from which four fertile seeds were obtained. When the seeds were planted in a greenhouse in the following spring, three seedlings were obtained. Eventually, the seedlings flowered and set fruits ; they proved to be interspecific hybrids based on peroxidase and esterase isozyme analyses. Morphological characteristics of these seedlings are as follows. Mature leaf : General shape, tip and base form of the leaf and petiole color of the seedlings are similar to 'Baigo' ; 'Sordum' and the seedlings have reniform glands on their leaf base, but 'Baigo' has none. Flower : The flower size of seedlings was intermediate between 'Baigo' and 'Sordum'. 'Baigo' has one flower per flower bud, whereas 'Sordum' has two or three flowers. The hybrid seedlings bear one or two flowers per flower bud and trichomes on the exocarp like 'Baigo', unlike 'Sordum' which has none. The pollen of the seedlings were fertile. Fruit : The shape of matured fruit of 'Baigo' and 'Sordum' is round ; the latter has a slightly mounded tip. Two seedlings segregated to a round fruit and one into an elliptical shape. Flesh color of 'Baigo' is yellow, whereas that of 'Sordum' is red. One seedlings segregated to a red flesh whereas two inherited a light yellow flesh.