岡山大学農学部Acta Medica Okayama2186-77551012012閉鎖型植物工場における連続光の利用（第4報）連続光下における植物の生理学的変化ならびに障害誘発の概念4964ENNaokiHataMasaharuMasudaKenjiMurakamiAkioKobayashiPhysiological changes and concept of injury induction occurring under continuous light are comprehensively reviewed. Continuous light usually reduces photosynthetic rate, which may relate to changes in transpiration and leaf necrosis caused by reactive oxygen species. Other factors apart from photosynthesis may also affect leaf injuries occurring under continuous light. Continuous light sometimes increases carbohydrate and some secondary metabolite contents.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551012012‘ファースト’雄性不稔突然変異体 (T -4) を種子親とした軟果皮中玉トマトF(1) 系統 (MS-II) の特性1924ENJunkoToyaMasaharuMasudaKenjiMurakamiBreeding for a soft pericarp in medium-sized tomato fruit was conducted by crossing the male sterile mutant (T-4) of the large-fruited 'First' and a small-fruited pure line with a soft pericarp (S). Pericarp characteristics of the F(1) hybrid (named MS-II) were compared with the parents and two similar medium-fruited tomato cultivars, 'Red ore' and 'Frutica'. Pericarp firmness in MS-II was lower as compared with that of both T-4 and S. Differences in pericarp firmness among MS-II, 'Red ore' and 'Frutica' were dependent on truss. In the first truss, MS-II developed fruits with a softer pericarp than 'Red ore', but with a firmer pericarp than 'Frutica'. In the second and third trusses, pericarp firmness of the fruit in MS-II tended to be lower than those of the other two cultivars. The thickness of the exocarp cuticle in MS-II was lower than that in 'Red ore', but was no different to that in 'Frutica'. Thus genotypic differences in pericarp firmness among MS-II, 'Red ore' and 'Frutica' seem to be derived from differences in the degree of cutin development in the epidermal perimeter. A thinner cuticle can explain pericarp softness in the fruits above the second truss in MS-II.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551012012盛夏期における防根給水ひもを用いたメロン砂栽培の可能性1318ENMasakiKawaharaMasaharuMasudaEffects of liquid fertilizer (LF) and controlled-release fertilizer (CRF) on growth and fruit enlargement of netted melon in 6L sand medium were investigated in a cultivation method using root-proof capillary wicks in mid-summer. Average of maximum and minimum root-zone temperatures was
34.8°Cand 26.9°C, respectively. Wilted symptoms appeared very often in 5 out of 8 plants at 2 weeks after transplanting in CRF with a high electric conductivity (EC) of medium solution. In contrast, such symptoms were not found at all in LF with a lower EC. In LF, average fruit weight was 2.3Kg and fruit Brix was 14.4, and non-wilted plants in CRF also showed the same levels as LF in weight and Brix of fruits. These results indicated the possibility of sand culture for melon in mid-summer with LF or a modified fertilizer combination design of CRF.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-0254 1002011ネットメロンの防根給水ひも栽培における肥効調節型肥料の適用915ENMasakiKawaharaSayoMurakamiMasaharuMasudaUse of controlled-release fertilizer in limited amount of soil and sand medium for netted melon cultivation using a root-proof capillary wick was investigated. The first experiment consisted of 3 lots of soil medium. 1) 3L medium used throughout the cultivation period (A); 2) 6L medium used throughout the cultivation period (B); 3) 3L used until pollination stage, then a partitioning board removed to increase the growth medium to 6L (C). Average of one fruit weight was 1.4 kg in A and B, but only 1.2 kg in C. Brix° value was 13.1 in A, 13.6 in B and 13.4 in C, respectively. The stem diameter at the time of pollination was largest in B in which there was fruit cracking that was also observed in C, but not in A. The root dry weight was highest in A. These results indicate that the restricted medium of 3L presents a potential for good fruit production. The second experiment consisted of 4 lots with 3L medium each: 1) soil and fertilizer medium as in experiment 1; 2) sand and fertilizer medium as in lot 1); 3) sand and slower release fertilizer; 4) sand and half of fertilizer at planting and an additional fertilizer bag placed on the wick at time of pollination. Although cracking fruits occurred 75% in 3) and 37.5% in 4), there was no cracking of fruits in 1) and 2), in which fruit weight in the latter was 1.5kg and brix° value of 14.5 was obtained. These results indicate that controlled-release fertilizer is useful for fruit production
of netted melon in sand medium of 3L with a high potential for reuse.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-0254 9912010トマトの防根給水ひも栽培における肥効調節型肥料と根域拡張に伴う「紐」の適用4347ENMasaharuMasudaYukiFujiiTakafumiKinoshitaThis study was conducted to investigate the effects of controlled-release fertilizers and wick addition to the root-zone on plant growth and yield of medium-fruit sized tomato up to the 18(th) truss in long-term forcing culture. The set-up consisted of a box partitioned by a board into two halves, named box 1 and box 2. Box 1 contained 2.8 ℓ of growth medium (soil : bark : perlite : peat=2 : 2 : 1 : 1). Plant was grown in box 1 with a capillary wick, and at flowering of the 8(th) truss, the partition was removed and box 2 filled with 2.8 ℓ of the medium. There were two treatments, with or without capillary wick in box 2, namely, single wick (S) and double wicks (D). Plant height was greater in D than S in January, and the difference increased gradually thereafter. Flowering time of 18(th) truss in D was 10 days earlier and decapitated shoot weight was twice that of S. Fruit yield per plant was 8 kg in S and 9 kg in D with similar value of Brix and titratable acidity. There was no difference between S and D in dry root weight (7g/plant) or in xylem exudates (8ml/h), while in S in April plant growth was inferior, leaf color yellow greenish and fruit colour uneven towards the end of growth of plants. Xylem sap analysis showed that NO(3)-N was 10 me/ℓ in S and 6 me/ℓ in D. This concentration is weaker than that of Enshi standard nutrient solution generally used in hydroponics. These results suggest that application of controlled-release fertilizers and wick addition to box 2 with root-zone extended was effective for plant growth performance and fruit yield.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-0254 9812009大玉トマトの防根給水ひも栽培における生育途中の根域拡張と「ひも」適用が果実生産に及ぼす影響2329ENAyukiMorishigeMasaharuMasudaKenjiMurakamiThis study was conducted to investigate the possibility to use capillary wick system in large-fruited tomato production. The first experiment in the autumn-winter season of 2006 was carried out to investigate
the effects of the amount of substrate on growth and yield of tomato. Treatments involved growing large-fruited tomato in one box (2.8ℓ/plant) continuously, or adding substrate at flowering of the 7th truss in a 2nd box (5.6ℓ/plant). Fruit yield was higher when the root-zone was extended with double the substrate volume. The second experiment in spring-summer season of 2007 was aimed at improving growth and yield of tomato by extension of root-zone and addition of wick. Tomato plants were either grown in one box with one wick continuously, or with addition of substrate in a 2nd box at flowering of the 4th truss. Additionally, one more wick was inserted into 50% of the 2nd boxes. Half of the plants were grown in two boxes with one wick, and the other half with two wicks. Higher yield was obtained from the plants grown in two boxes with two wicks, suggesting that fruit yield was increased by increasing water transport through wick addition coupled with root-zone extension. Plant growth and fruit yield of large-fruited tomato was stable without blossom-end rot when root-zone was extended and half strength of Ohtsuka-A nutrient solution supplied through the capillary wick system. There was, however, a slight sign of physiological disorder at the leaf margins similar to potassium deficiency.No potential conflict of interest relevant to this article was reported.園芸学会Acta Medica Okayama0013-76267612007Partial Fertility Restoration as Affected by Night Temperature in a Season-dependent Male-sterile Mutant Tomato, Lycopersicon esculentum Mill4146ENMasaharuMasudaKenjiKatoKenjiMurakamiHiroshiNakamuraThis study was conducted to investigate the influence of night temperature on the restoration of fertility in a season-dependent male-sterile tomato mutant (T-4). Plants were grown in greenhouses, in which minimum and maximum temperatures were set at 10℃ and 28℃ by heating and ventilation, respectively. Flowers were hand-pollinated and the fruit-set, seed-set, and number of seeds were examined. The rate of fruit-set was high and did not differ much from October to February; almost all fruits formed in October had self-fertile seeds, but 80% of the fruits from November to February were parthenocarpic. The rate of fruit-set dropped from 70% in March to below 10% in May. During this period, most of the fruits were seeded, though fruit-set was low. The number of seeds per seeded fruit varied with the season, being as high as 50 seeds in October, 1-2 seeds per fruit between November and March, and 1-20 seeds per fruit between April and June. A low night temperature of 12℃ did not affect fruit-set but resulted in a better seed-set than a high night temperature of 18℃ in the greenhouse. Further, pollination of the plants in phytochambers also resulted in a better fruit- and seed-set at 12℃ than 24℃. In all cases, the influence of low temperature was more pronounced in autumn than in spring. Fruit-set was 70% at 12℃ and 46% at 24℃. Of these fruits, 50% at 12℃ and 10% at 24℃ were seeded. It was inferred that partial fertility restoration in T-4 can be achieved by manipulation of night temperatures. The female organ was shown to be normal, functional, and compatible with wild-type pollen. From these results, the potential of the male-sterile T-4 mutant for use in a two line hybrid-seed production system was apparent.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-0254 9712008｢毛管給水ひも」によるトマト栽培の可能性について4954ENMasaharuMasudaShokoFukumotoThis research was conducted to investigate any potential problems that may be encountered while
using capillary wick irrigation system. Medium-fruited tomato plants were cultivated in spring up to the
10th truss.
In the first experiment, a 1/5,000a wagner pot was used, and small openings were made 5mm or
50mm from the bottom of the pots. Capillary wicks, 4 cm in width and 45 cm in length were inserted
into the slits and aligned to the pot’s inner wall perpendicularly to the soil surface. The other end of the
wick was dipped in half or full strength Ohtsuka-A nutrient solution. The wick was covered with water
permeable root-barrier material to prevent root penetration into wick. This resulted in good growth and
relatively high yield. Without covering, roots grew vigorously into the wicks and 1 month after transplanting
extended to the reservoir solution. Removal of root overgrowth caused wilting in some of the
plants. This symptom was more pronounced where the wick insertion points were 50 mm from the base.
Root contexture was observed in non-covered and imperfectly covered wicks. These results indicate that
it is important to make a wick with a perfect covering for stable plant growth and fruit yield.
In the second experiment, the capacity of 2 cm or 4 cm wide with and single or double layers of capillary
wicks to transport water to the plant root-zone was examined. Some of the plants wilted in the 2 cm
single layer, while no differences were observed in other treatments. Furthermore, a high percentage of
blossom-end rot was recorded in all treatments. In response to water uptake by the plants, the nutrient
solution was supplied daily depending on the decrease of water in the reservoir, in order to maintain the
water level fluctuation within a 3 cm range. This fluctuation may account for the blossom-end rot
prevalence observed, probably due to water-stress imposed on the plants by unstable water level in the reservoir.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-02548411995メロン‘ハネデュー’の主枝節上における両性花の発現及び着生果実の形質に及ぼすエセフォンの影響1723ENYasumasaIkedaSyojiNanbaMasaharuMasudaThe effects of ethephon on the sex expression of flowers,and subsequent fruit quality of 'Honey Dew'melon were investigated.Ethphon induced many bisexual flowers on the primary shoot in the concentration of 100 or 200mg･ℓ-1
applied at the 8true-leaf expanded stage.The concentration of 200mg･ℓ-1 caused undeveloped and aborted flower buds,and the plant hight decreased with shoter internode.When enthphon treatment was repeated in the concentration of 100mg･ℓ-1,the number of bisexual flowers decreased;replicated treatment reduced both bisexual and flowers.In plants treated with 100mg･ℓ-1 at the 2,4 or 8 true-leaf expanded stages,many bisexual flowers occurred at the 6th to 9th,11th to 22nd and 16th to 25th nodes of the primary shoot,respectively.The fruits set on the primary shoot by ethephon treatment increased in the ratio of longitudinal diameter to cross.Ethephon-induced fruits decreased slightly in sugar content and the flesh was softer than those of the control.These results suggested that single treatment of ethephon was recommended in the concentration of 100mg･ℓ-1 at the 4-6 true-leaf expanded stage for induction of bisexual flowers on the 15th to 20th nodes of the primary shoot.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-02548711998トマトの果柄に処理した45Caの果実への移動149154ENMotofumiNomuraHiroshiHasegawaMasaharuMasudaMovement of calcium (45Ca) from the peduncle to fruit of tomato during the days and night was investigated. Further, the effects of additional NaCl to the culture solution on the water potential in plants and 45Ca movement to fruit were also examined. The activity of 45Ca on a dry weight basis in the peduncle was higher during the day than at night, however, in calyx and fruit the 45Ca activity was similar both during the day and night. Import of 45Ca into the leaves from the peduncle was not different between the day and the night. Additional NaCl to the culture solution resulted in a greater water saturation deficit (WSD) of the immature leaves just below the 2nd and 3rd trusses, unlike with the mature leaves below the 1st truss where the WSD did not decrease with NaCl treatment. On the oher hand, the activity of 45Ca in the peduncle and calyx was not different between the NaCl treatment and the control. However, the activity in the distal part of the fruits was lower with, NaCl treament than in the control. These results suggested that the high WSD effectively decreased the import of calcium into fruits from the peduncle. It seems that the import of 45Ca into fruit not only dependent on the conductive tissues but also a possible driving force in xylem water flow, and that NaCl interferes with movement of calcium in the fruits.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-02548811999Partial Inhibition of Pollen Degradation by Gibberellic Acid Mutants Derived from cv. First (Lycopersion esculentum Mill.)5763ENYouhuiMaKeiSakataMasaharuMasudaThe young flower buds in three male sterile mutants derived from cv.First were treated with gibberellins to determine whether pollen degradation could be inhibited.Microscopic observations of acetocarmine preparations revealed that the application of gibberellins inhibitde pollen degragation for all tested mutants of Fms-1,Fms2 and Fms-3 in which their breakdown in microsporogenesis occurs at microspore stage,during meiosis and at tetrad formation ,respectively.The optimum concentration and treatment time were 10mg/1 and 6-12days before flowering,GA7 proved to be preferable to GA3 for pollen fertility restoration.With the elingation of stameans by gibberellin application,viable pollens appeared frequeitly in Fms-2 mutant,being over 200grains on a 0.5mm
equatorial section of anthers in the best case,as compared to the other mutants.Bioassay using dwafrice seedilings showe that the Fms-2 plants had lower levels of gibberellin in their anthers compared with normal ones.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-02549512006Mutagenesis in Gynomonoecious Spinach (Spinacia oleracea L.) Plants and Selection of Low Oxalate Variants2128ENNaokiHataKenjiMurakamiYuichiYoshidaMasaharuMasudaAtsushiTanakaNaoyaShikazonoYoshihiroHaseThis study was conducted to evalute mutagenesis in gynomonoecious spinach (Spinacia oleracea L.) plants for inducing low oxalate variants.Gamma-ray and ion beams of 220 MeV12C5+ and 50MeV 4He2+ ware used as mutagen in seed irradiation. Optimum dosages for irradiation were determined to be about 100Gy, 15-20Gy and 150-200Gy in gamma-ray, 12C5+ and 4He2+, respectively. In M2 generation, there was one line segregating albino seedlings, one line segregating xantha seedlings and two lines segregating dioesious spinach. To save on labor and time for analysis, selection of low oxalate variants in M2generation was conducted by a two-step selebtion which consisted of the first snalysis of bulked leaves from 2 plants as one specimen followed by the second analysis of selected individual plants. In the first analysis of 813 specimens, we selected 13 specimens as low and 9 specimens as high in oxalate content. In the second analysus, there was consistency in the distribution of low and high oxalate content corresponding to the first screening, indicating that selebtion of low oxalate variants could be achived by this two-step selebtion with half the labor and time for analysis as compares to non-bulked method. There were no clear differences in distribution of oxalate content between M3progenies of plants selected as low or high oxalate content, suggesting that the low oxalate content in plants isolated in M2generation was not of a genetic origin. From these results, it seems to be necessary to explore a variant with obvious deviation from the bontinuous variation of oxalate content in the M 2 generation.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-02547811991NFT水耕トマトの長期栽培における果実収量と品質に及ぼす台木の影響1725ENMasaharuMasudaShujiFurusawa最近,トマトの養液栽培においても地下部病害の発生が見られるようになって来た.これを回避する方法の一つは土栽培と同様に病害抵抗性台木に接ぎ木することである.本研究は台木KNVF-R3とLS-89に接ぎ木し長期栽培したトマトについて,残存培養液の濃度変化および果実収量と品質を調査し,NFT水耕における接ぎ木の意義について考察したものである. 当初の培養温のNO3-N,P,K,Ca,Mgはそれぞれ園試標準濃度の16,4,8,8,4me/lに設定し,水と養分を補給する時に当初のEC2.4mS/cmに調整して栽培したところ,いずれの台木とも定植2か月後の12月末まではNO3-N,Ca,Mg濃度は極めて安定で,それ以降は徐々に上昇した.一方,PとKは定植後より徐々に低下する傾向を示し2月下旬の第3段果房収穫時には残存培養液中にほとんど存在しなかった.EC値が非常に高くなったためこの生育段階からEC1.2mS/cmに低めて栽培したが,数週間後に一時的に中位葉の葉縁が黄色となるK欠の典型的症状が認められた. 果実の可溶性固形物(Brix°)はいずれの台木も果房段位が上がるにつれて増加した.滴定酸度は中段果房まで除々に低下し,それより上段で再び上昇する傾向を示した.台木問では,可溶性固形物,滴定酸度とも2,3の果房を除いてKNVF-R3台が最も高かった.土栽培では一般に病害抵抗性台木に接ぎ木されると,特に果実の可溶性固形物含量が低下し食味が劣るとされるがNFT水耕ではそのような事は無く,接ぎ木はとりわけ長期栽培における病害回避の点で意味を持つものと考えられた。No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-02547711991アスパラガス側芽培養でのアンシミドールによる発根及び多芽体形成915ENSachikoMatsubaraSeijiMasudaKenjiMurakamiKazuhisaTakahashiSatoshiIshikuraアスパラガス側芽培養での発根促進と多芽体形成のための培地条件を検討した.供試材料として‘メリーワシントン500W’の播種後15-20日令植物の側芽を用いた.側芽を5μM ancymidolと5% ショ糖添加MS培地で2月間培養したところ,生存個体の90% が発根した.一方,3.9〜39μM ancymido1と3% ショ糖添加MS培地で2月間培養後に多芽体が形成した11.7μM ancymidolでは生存個体の70% と最も高率に形成し,それからは12.7本の苗条が伸長したが,そのうちの一部分は水浸状であった.正常な植物体は,0.5〜10μM ancymidolと5% ショ糖を添加したMS培地で2月間培養することにより得られ,特に5〜10μMancymidol添加により植え付け外植体の約70%が正常個体となった.また,5〜50μM ancymidolと5% ショ糖を添加したMS培地で2月間培養すると多芽体の形成が見られ,それらをMS培地に移植することにより苗条の伸長が見られた。No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-02547511990ネット型メロン‘アールスフェボリット’の2,4-Dによる単為結果誘導ならびに果実の肥大と糖蓄積の様相1521ENMasaharuMasudaHirohumiNagaoSachikoMatsubaraネット型メロン‘アールスフェボリット’の単為結果誘導ならびに果実の肥大と糖蓄積に及ぼす植物ホルモンの効果について検討した.開花時に花柱を切除し,その切口に合成オーキシンの2,4-D,NAA,CPAを処理した.単為結果誘導には100mg/lの2,4-Dが最も効果が高く,かつ果実の肥大も交配果のそれに近い様相を呈した.しかし,成熟果実のBrix値や糖含有率は交配果に比べて低く,ネット密度は粗く貫入抵抗は大きくなった. 一方,花柱を切除せず柱頭に2,4-Dを10μl処理すると,果実にはネット密度の粗さやBrix値の低下が見られず,交配果のそれに極めて近いものとなった.この場合,2,4-D処理果の有胚種子率は約30%,交配果のそれは85%で,有胚種子の多少が必ずしもBrix値や糖含有率に影響を及ぼすものではないと考えられた。No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-02547511990ニンニクのウイルス・フリー株の生産性及び花床培養による増殖913ENSachikoMatsubaraDzenChenMasaharuMasudaKenjiMurakamiニンニクの茎頂培養によるウィルスフリー株の育成を試み,フリー株と罹病株の球の生産性の比較を行った.またフリー株の増殖を目的とした花床培養を試みた.生産性の比較:茎頂培養により育成したウィルスフリー株からの球根と,罹病株からの球根を,圃場に植え付け翌年6月に掘り上げて球の収量を比較した.フリー株の球重は罹病株に比較して1.4倍,球数は1.2倍となった.抽台茎上の花床に形成された珠芽も多かった.花床培養:花床を8分割して培養したところ,NAAを添加したMS基本培地に植え付けた区で正常な苗条が再生し,特に0.1mg・l-1NAA添加区で苗条の再生数が多く,それらをホルモン無添加培地に移植することにより球となった.1花床から約40球が再生された。No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-02547411989キュウリ葉におけるマグネシウムの欠乏症と移動の難易714ENMasaharuMasudaキュウリはマグネシウム欠乏症の発生し易い野菜のひとつである.本報告は主として葉におけるマグネシウム含有量の変化並びに移動の難易について検討したものである. 1.培養液の養分除去8日目における成分含有量の減少率は,葉においてP=K>全N>Mg=Ca,根において全N=K>P=Mg>Caとなり,葉のマグネシウムとカルシウム及び根のカルシウムはほとんど変化しなかった. 2.培養液の養分を除去し1か月後に葉分析を行った結果,有果区の葉は摘果区に比べマグネシウムおよびカリの含有率は低く,カルシウムの含有率は高かった.一方,1葉当たりのマグネシウム含有量は有果区に挽いても処理開始時よりわずかに増加し,カリ含有量はわずかに減少した. 3.培養液のマグネシウムを除去し葉に硫酸マグネシウムを散布した結果,散布葉のみが緑色を保ち,その上下節葉はネクロシスを呈した.さらに,散布を葉の一部に限定すると,その部分のみで緑色が保たれた.散布部位におけるマグネシウムの形態別含有率は水溶性アルコール可溶性,および不溶性のいずれも無散布部位より高かったが,とくに水溶性と不溶性マグネシウムにおいて顕著であった. 4.以上の結果,キュウリ葉におけるマグネシウムの移動は容易ではなく,特に,散布したマグネシウムはほとんど移動しないと考えられた。No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-02547411989In vitro Rooting of Male and Female Asparagus Derived from Apices and Lateral Bud Explants15ENSachikoMatsubaraMasaharuMasudaKazuhisaTakahashiTreatments to promote in vitro rooting of shoots derived from apices and lateral buds of male and female asparagus plants were studied. Effects of phytohormones, NAA and BA, IBA and Rootone (0.4% α-naphthylacetoamide) were evaluated. Apices and lateral buds placed on MS basal medium +0.3mg･l-1NAA and 0.1mg･ I-1lBA as a root-initiation medium for 0, 2 , 3 and 4 weeks followed by transfer to MS basal medium indicated that two or three weeks treatment was the most effective on rooting of mlale lateral buds and female apices. Apices and lateral buds were also placed on MS medium containing 0. 0.01, 0.1, 1,0 and 10.0mg･l-1 of IBA. Seventy % of male lateral shoots rooted on MS medium +1 mgl-1IBA, but it was ineffective for female shoots. Rootone was the most effective on rootin of lateral shoots, irrespective of sexes, but ineffective on apical shoots.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama0474-02549412005トマト‘ファースト’種子へのイオンビーム照射によって誘発された短節茎突然変異体の生育肥大特性と遺伝様式2529ENMasaharuMasudaToshihikoYuasaKenjiMurakamiTomato(Lycopersicon esculentum L.) cv. 'First' mutants with short internodes grew vigorously. The number of leaves slightly increased and the shape of the leaves was similar to wild type. In inflorescence morphology, the number of flowers increased and the length of peduncle and pedicel were shorter. In fruit characteristics, weight per fruit, total yield, sugar and acid contents were similar to wild type. But a lot of malformed fruit set was observed in the mutant line, due to the number of locules and short length of the peduncle and pedisel. The segregation ratio of the short internodes character fitted 3:1 of normal:short ,hence it was considered to be contralled by a single pair of recessive genes. Allelism with alresdy known dwart gene was examined by crossing with 'Alisa Craig', which had a symbolized dwart gene, br or bu. Thereby, it was revealed that bu and short internodes gene ware in the same gene locus. This mutant line has no negative effect on plant growth and fruit yield, but was unsuitable for use as fresh fruit by reason of malformed fruits. These results indicated the possibility of breeding of a new cultivar with bu gene derived from 'First'. Since the mutant with short internodes is derived from 'First', which is already a commercial variety with excellent characteristics, raising a new commercial variety with short internodes trait may not take a long time.No potential conflict of interest relevant to this article was reported.