1.

論文(リポジトリ)

論文(リポジトリ)
仲村, 一郎 ; 東江, 栄 ; 村山, 盛一 ; 飛田, 哲 ; 柳原, 誠司 ; 川満, 芳信 ; 本村, 恵二 ; Nakamura, Ichiro ; Agarie, Sakae ; Murayama, Seiichi ; Tobita, Satoshi ; Yanagihara, Seiji ; Kawamitu, Yoshinobu ; Motomura, Keiji
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.1-7,  2004-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3560
概要: 本研究では,NaCl処理後の葉身の陽イオン音量(K^+, Ca^<2+>),及び適合溶質(プロリン,スクロース)音量を測定し,O.latifoliaの浸透圧調節能力について検討した.得られた結果は以下の通りである.1) NaCl 処理後のに音量は,O.latifoliaで最も高かったことから,O.latifokiaはK^+の関与する反応,すなわち液胞の浸透圧の維持や気孔開閉の調節能が高いことが示唆された.2)K^+/Na^+比と耐塩性の強弱との間に規則性は見出せなかった.3) Ca^<2+>/Na^+比と耐塩性の強弱との間に関連性は見出せなかった.4) NaCl存在下のプロリン音量は,耐塩性種の方で大きかった.また,耐塩性の高い種においてはプロリン音量と浸透ポテンシャルとの間に高い負の相関関係が認められ,浸透調節に対するプロリンの関与が示唆された.5)膨圧と水ポテンシャルの関係から,O.latifoliaは塩ストレス条件下で膨圧を維持することが明らかとなった.<br />To elucidate the mechanisms of salt tolerance in wild rice Oryza latifolia Desv., we have tested the ability of osmotic adjustment by comparing its content of cation (K+ and Ca^<2+>) and compatible solute (proline and sucrose) in the leaves with those of salt-sensitive wild rice Oryza rufipogon, check varieties of cultivated rice (O. sativa L.), SR26B (salt-tolerance) and IR28 (salt-susceptible). When the plants were water-cultured with 6dSm^<-1> (50mM) and 12dSm^<-1> (113mM) NaCl for 30 days, the content of K^+ and Ca^<2+> were highest in the leaves of O. latifolia among the species, suggesting that this species has higher capacity of the physiological functions regulated by K^+ and Ca^<2+>, such as osmotic adjustment in vacuole, stomatal regulation and maintaining plasmamembrane structure. However, there was no correlation between the degree of salt tolerance estimated by dry matter production and the ratio of cation contents such as K^+/Na^+ or Ca^<2+>/Na^+ in the leaves. These indices of salt tolerance were the lowest in O. latifolia due to large amounts of Na^+ in the leaves of this species. Proline contents in the salt stress-leaves were higher in the salt tolerant cultivar SR26B and O. latifolia. There was the negative significant correlation between free proline content and osmotic potential in the salt tolerant species, indicating that proline participates in osmotic adjustment in the salt tolerant species. The correlation of turgor pressure and water potential showed that O. latifolia maintained turgor pressure under the salt-stress condition. 続きを見る
2.

論文(リポジトリ)

論文(リポジトリ)
Pham, Cuong Van ; Murayama, Seiichi ; Ishimine, Yukio ; Kawamitsu, Yoshinobu ; Motomura, Keiji ; Tsuzuki, Eiji
出版情報: Plant Production Science.  7  pp.22-29,  2004-03.  The Crop Science Society of Japan — 日本作物学会
URL: http://hdl.handle.net/20.500.12000/4872
概要: The thermo-sensitive genie male sterile (TGMS) T29^S line was sterile when exposed to daily mean temperatures of 24.1℃ o r above during the critical stage (from 15 to 11 days before heading). It was completely sterile for both pollen and spikelet when the plant headed from June 16 to November 7 in Okinawa, because the temperature exceeded 24.1℃. The heterosis of the F_1 hybrids between the T29^S line and seven indica cultivars was examined. Most of the F_1 hybrids showed positive heterosis over the male parent for grain yield per plant and the number of spikelets per panicle, and one of them manifested heterosis for grain yield over a F_1 hybrid from a cytoplasmic male sterile (CMS) line. Dry matter accumulation per plant at the panicle initiation stage in most F_1 hybrids was higher than that in the respective male parent or mid-parent, and it was correlated with a larger number of tillers and leaf area per plant. All F_1 hybrids produced a larger number of panicles per plant than their respective male parent. Positive heterosis over the male parent for the number of filled grains per panicle, 1000-grain weight and harvest index was obtained in several F_1 hybrids. A positive correlation was found between grain yield and the dry matter accumulation per plant in F_1 hybrids. Both the larger number of panicles per plant and the larger number of spikelets per panicle were more important for the positive heterosis for grain yield in F_1 hybrids rather than the higher 1000-grain weight. Among the yield attributes, a larger number of filled grains per panicle mainly contributed to a higher grain yield of F_1 hybrids. 続きを見る
3.

論文(リポジトリ)

論文(リポジトリ)
本村, 恵二 ; 石嶺, 行男 ; 諸見里, 善一 ; 村山, 盛一 ; Motomura, Keiji ; Ishimine, Yukio ; Moromizato, Zenichi ; Murayama, Seiichi
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.35-40,  2003-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3593
概要: 細胞質雄性不稔性を用いたイネのヘテロシス育種においては、中国の海南島で発見されたWA細胞質が主に用いられている。しかしこの様な特定の細胞質のみを用いた限定的な利用では遺伝的脆弱性が心配される。その解決のためには、多くの雄性不稔細胞質を発見・ 同定し、遺伝分析を行って優良素材を探索する必要がある。著者等はその点の研究を進めており、今回次のような研究を行った。Oryza rufipogonのK18系統を1回親母本にし、栽培イネ品種、台中65号を反復親父本に用いて8回の連続戻交雑を行って、雄性不稔系統RT18Aを得た。同系統の花粉は球形であるが正常花粉に比べて小さく、また正常花粉が染色液で濃紫色になるのに対して同花粉は薄い褐色を示した。これらの花粉は活性を持たず、したがって種子稔性も完全不稔であった。この花粉退化の様式は既に報告したRT61C系統のそれと似ており、同系統の稔性回復遺伝子を用いてRT18Aの雄性不稔性の遺伝分析を行い、併せてRT18A系統の細胞質の同定を試みた。両系統および台中65号を材料に用いて交雑実験を行い、以下の結果を得た。稔性は細胞質と核内の稔性回復遺伝子との相互作用により支配されていた。すなわち、正常細胞質(mfc)のもとでは稔性回復遺伝子(Rf^1_1-rf)の優劣に関係なく、花粉が正常に発育し、受精が行われるため種子稔性も正常であった。雄性不稔細胞質(msc_1)のもとでは、Rf^1_1遺伝子を持つ花粉は正常であるが、rf遺伝子をもつ花粉は途中で発育を停止し不稔となった。そのため雄性不稔細胞質のもとでは遺伝子型により花粉および種子稔性が異なった。(msc_1)Rf^1_1Rf^1_1では花粉は球形で濃染し正常であり、種子稔性も正常であった。(msc_1)Rf^1_1rfではRf^1_1花粉は正常であるがrf花粉は不稔であった。種子稔性は、(msc_1)rfrf個体以外は高かった。(msc_1)Rf^1_1rf個体の自殖後代では、不稔個体が生ぜず、配偶体支配型の花粉不稔を示すことがわかった。以上の結果はRT61Cに見られた雄性不稔および稔性回復の遺伝に酷似しており、RT18Aの細胞質はRT61Cのそれと同一の可能性が高かった。しかし、確実な同定のためには他の複数の稔性回復遺伝子との間で示される稔性反応を調べる必要がある。<br />The usage of limited cytoplasm of crpos is genetically vulnerable. It may cause outbreak of diseases and insects, which attack a particular cytoplasm preferentially. Therefore, it is necessary to develop other sources of cytoplasmic male sterility. In this paper, the inheritance of male sterility and fertility restoration induced by the interaction between cytoplasm and a nuclear gene in rice line will be reported. To develop isogenic lines, K18, a line of Oryza rufipogon, was used as the initial female parent, followed by successive backcrosses to Taichung 65 as the recurrent male parent. In B C_8F_1 generation the male sterile line was developed and designated as RT18A. The line had sterile pollen so that spikelets were also revealed to be sterile. On the other hand, RT61C was also developed by the successive backcross method. It was found that the line carried both male sterile cytoplasm (cms_1) and restoring gene (Rf^1_1) derived from K61C. To clarify inheritance of cytoplasmic male sterility and identify cytoplasm in RT18A, crossing tests were carried out, and the following results on inheritance of cytoplasmic male sterility and restoration fertility were obtained. Fertility was conditioned by the interaction between a pair of nuclear restoring genes, Rf^1_1 and rf, and the male sterile cytoplasm, msc_1. Pollen grains with the Rf^1_1 gene displayed normal development under the msc_1 cytoplasm, while pollen grains with the rf gene degenerated under this cytoplasm. Therefore, the degree of pollen and spikelet fertility in the msc_1 plants varied with the genotype. In pollen fertility, (msc_1)Rf^1_1Rf^1_1 plants showed complete fertility; (msc_i)Rf^1_1rf plants 50% fertility-normal pollen grains and degenerated ones; and (msc_1)rfrf plants complete sterility. In spikelet fertility, both (msc_1)Rf^1_1Rf^1_1 and (msc_1)Rf^1_1rf plants showed a high degree of fertility, while the (msc_1)rfrf plants showed complete sterility. In contrast, in the plants with the male fertile cytoplasm of Taichung 65, mfc, pollen grains developed normally and displayed an equal opportunity of fertilization regardless of their genotype. Pollen grains with the rf gene of the (msc_1)Rf^1_1rf plants could not be used for fertilization and this type of pollen abortion was gametophytic. This mode of inheritance was the same as that observed in RT61C. The abortion of sterile pollen grains also started at an earlier stage of pollen development as RT61A, i. e. the grains were smaller and less stained. It was considered that this stage of pollen degeneration was controlled by the characteristics of cytoplasm. Therefore, cytoplasm of RT18A must be the same as that of RT61A, i. e. msc_1. However, for positive identifiction the more detailed examinations are needed with the use of other restoring lines. 続きを見る
4.

論文(リポジトリ)

論文(リポジトリ)
Ishimine, Yoshito ; Hossain, Md. Amzad ; Ishimine, Yukio ; Murayama, Seiichi
出版情報: Plant Production Science.  6  pp.83-89,  2003-03.  The Crop Science Society of Japan — 日本作物学会
URL: http://hdl.handle.net/20.500.12000/4871
概要: Effects of planting depth on emergence, growth, development and yield of turmeric (Curcuma longa L.) in dark red soil (Shimajiri Mahji) were evaluated in Okinawa, Japan. Turmeric planted at the depths of 8, 12 and 16 cm emerged earlier and more evenly than that planted at a shallower depth in both glasshouse and field experiments. Weed growth was unaffected by the planting depth of turmeric until 50-60 days after planting (DAP), but affected thereafter due to mutual shading with the canopy. Weed biomass at 90-140 DAP was significantly smaller in the fields where turmeric was planted at the depths of 8, 12 and 16 cm than in the field where it was planted at a shallower depth. The turmeric rhizome (yield) developed earlier when planted at 8, 12 and 16 cm depths than at 4 cm. In a glasshouse study, shoot biomass and yield of turmeric were significantly greater when planted at the depths of 4, 8 and 12 cm than that of 2 cm. In field experiments, they were also significantly greater when planting depth was 8 or 12 cm than 4 cm. Even in turmeric planted at a 16 cm depth shoot dry weight and yield were greater than that planted at a 4 cm depth, but it was comparatively difficult to harvest rhizomes in this field. About 30% of turmeric in the field planted at a 4 cm depth was uprooted by a typhoon, but not at the depths of 8, 12 and 16 cm. The over all results suggested that rhizomes of turmeric should be planted at a depth of 8 to 12 cm in dark red soil for a higher yield and lower weed competition. 続きを見る
5.

論文(リポジトリ)

論文(リポジトリ)
川満, 芳信 ; 重久, 利枝子 ; 福澤, 康典 ; 村山, 盛一 ; Kawamitsu, Yoshinobu ; Shigehisa, Rieko ; Fukuzawa, Yasunori ; Murayama, Seiichi
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.1-14,  2002-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3616
概要: CAM植物であるパインアップルのCO_2収支量を増大させるためには明期の気孔を更に開孔させる必要があると考え,気孔開閉を制限している要因を検討した.1.暗期を短縮してCO_2固定を抑制してもリンゴ酸蓄積量は対照区とほぼ同じであった.暗期にお けるリンゴ蓄積量とPhase-3の長さ,明期におけるリンゴ酸の消失と気孔開孔(ガス交換の開始)には関係は無く,Phase-4において葉内CO_2濃度が低下しても気孔は開かなかった.2.暗期短縮やCO_2-free air処理はリンゴ酸蓄積量を減少させたが,Phase-4の気孔開孔は著しく阻害された.3.葉のリンゴ酸含量が増加すると水ポテンシャルおよび浸透ポテンシャルは低下した.4.暗期を短縮した長日条件にすると明期のCO_2吸収は増加し,総CO_2収支量は僅かに増加した.更に明期が長くなると,C_3回路よりもリンゴ酸を精製するC,ジカルボン酸回路が活発に働き,総CO_2収支量の増加は期待できなかった.<br />In crassulacean acid metabolism (CAM) plants, the CO_2 balance is dependent on the malic acid accumulated in the dark period. Due to the CAM pathways in pineapple, the light use efficiency is low. It is, therefore, necessary to open the stomata further during light period in order to increase the total CO_2 balance. The present paper described that the effects of dark period length and CO_2 free air at Phase 1, stopping the nocturnal CO_3 fixation, on the diurnal changes in gas exchange rate and leaf conductance in pineapple plants. Outlines of the result are as follows ; The malic acid accumulation was almost equal to the control, even if the dark period was shortened. There was no relation between the malic acid accumulation in the dark period and the Phase-3 length and elimination of malic acid and stomatal opening in the light period (e. g. the beginning of the gas exchange at late afternoon). That is to say, the stomatal opening did not occur at Phase 4 even if the low internal CO_2 concentration ocuurred. Dark period shortening and CO_2-free air treatment increased the stomatal conductance in dark period and decreased the malic acid accumulation, resulting the inhibition of stomatal opening at Phase 4. Leaf water potential and osmotic potential decreased when the malic acid content increased. The CO_2 uptake in light period incerased under the long day conditions, however, the totalCO_2 balance slightly increased. If the light period extended more, C_4 cycle which forms the malic acid becomes active in Phase 4 and the increased CO_2 balance could not be expected. 続きを見る
6.

論文(リポジトリ)

論文(リポジトリ)
Nakamura, Ichiro ; Murayama, Seiichi ; Tobita, Satoshi ; Ba Bong, Bui ; Yanagihara, Seiji ; Ishimine, Yukio ; Kawamitsu, Yoshinobu
出版情報: Plant Production Science.  5  pp.305-310,  2002-12.  The Crop Science Society of Japan — 日本作物学会
URL: http://hdl.handle.net/20.500.12000/4870
概要: The physiological responses of wild Oryza species (Oryza latifolia Desv., a salt-tolerant species and O. rufipogon Griff., a salt-susceptible species) to salinity stress were investigated by comparing with check varieties of cultivated rice (O. sativa L.), SR26B (salt-tolerant) and IR28 (salt-susceptible). As the Nacl concentration of water culture solution was raised to 12 dS m^<-1> (about 113mM), leaf Na^+ content per dry matter in wild Oryza species increased from 4 to 17 times as compared with the control (no NaCl treatment), whereas the accumulation was lower in cultivated rice varieties. The increased concentration of leaf Na^+ resulted in the decrease in leaf water potential (Ψ_w) in all rice species, although the degree of decline in photosynthetic rate was different among the varieties. It was notable that the photosynthetic rate was almost constant in O. latifolia though Ψ_w decreased to - 2.0 MPa with the increased NaCl concentration in the water culture solution. A significant negative correlation between free-proline content and osmotic potential (Ψ_s) of leaf blade was found in both salt tolerant entries, SR26B and O. latifolia. In spite of higher leaf Na^+ storage, the survival rate of O. latifolia was higher than that of SR26B, indicating that the mechanism of salt tolerance in O. latifolia may be different from that in SR26B. 続きを見る
7.

論文(リポジトリ)

論文(リポジトリ)
川満, 芳信 ; 大城, 常明 ; 村山, 盛一 ; Kawamitsu, Yoshinobu ; Oshiro, Tsuneaki ; Murayama, Seiichi
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.39-52,  2001-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3642
概要: CAM植物は, 炭素固定能力が低く, また, 1日のCO_2収支量は暗期に蓄積されるリンゴ酸含量に依存し, 太陽エネルギー利用効率は低い。本報では, パインアップルを明期に開孔させ光エネルギー利用効率を高めるため, 暗期の有無や温度変化を制 御して検討した。結果の概要は以下の通りである。1) 通常の日長条件下では, ガス交換速度は温度の変化に関係なく, 4つのPhaseを有する典型的なCAM型を示した。連続明期条件下に曝した場合, ガス交換速度および気孔伝導度は日変化を維持した。明期と暗期で温度変化を与えた場合, リンゴ酸含量は低下した。2) 暗期のある条件下での明期暗期温度差はガス交換速度の日変化やCO_2収支量に影響を与えた。また, リンゴ酸含量の蓄積や脱炭酸過程に温度は影響を与えた。3) 気孔伝導度とガス交換速度との関係をプロットしたところ, Phase 1とPhase 4でそれぞれ傾きの異なる回帰直線が得られた。回帰直線の傾きはCO_2固定酵素の違いを反映し, 連続明期下におけるCO_2固定酵素の特定が可能であった。以上より, 気孔は暗期の存在, 温度変化によって影響を受け, また, リンゴ酸の増減によってコントロールされていると考えられ, 明期に気孔を開かせる条件として明期暗期の温度差が無くリンゴ酸の蓄積を抑制する方法で達成できると予想される。<br />In CAM plants, CO_2 balance is dependent on malic acid content accumulated in the dark period, consequently the light use efficiency is low. In this paper, in order to increase the light use efficiency in pineapple plants, the diurnal changes in gas exchange parameters were examined under such conditions without dark period and of controlling temperature change. Outlines of the result are as follows; Under the control conditions, the diurnal courses in gas exchange rate showed CAM type with four phases regardless of the change of temperature. Under the continued light period, gas exchange rate and stomatal conductance showed daily variation when temperature change was given in the transient from light to dark period. In addition, the malic acid content was decreased when the temperature changed. Light and dark period temperature gradient under the normal conditions with the dark period affected the diurnal changes in gas exchange rate and CO_2 balance. Moreover, it was recognized that the temperature shift affected storage and decarboxylation process of the malic acid content. The slope of the regression line between stomatal conductance and gas exchange rate at Phase-1 and Phase-4 was significantly different, suggesting the difference in the CO_2 fixing enzymes. Base on the hypothesis, the enzyme under the continued light period could be speculated. From the present study, stomata is affected by the existence of dark period and temperature change, and it seems to be controlled by the increase and decrease of malic acid content. 続きを見る
8.

論文(リポジトリ)

論文(リポジトリ)
本村, 恵二 ; 石嶺, 行男 ; 村山, 盛一 ; 比嘉, 照夫 ; 呉屋, 昭 ; 友寄, 哲夫 ; Motomura, Keiji ; Ishimine, Yukio ; Murayama, Seiichi ; Higa, Teruo ; Goya, Akira ; Tomoyose, Tetsuo
出版情報: 熱帯農業 = Japanese Journal of Tropical Agriculture.  45  pp.202-208,  2001-09-01.  日本熱帯農業学会 — Japanese Society for Tropical Agriculture (JSTA)
URL: http://hdl.handle.net/20.500.12000/5009
概要: Oryza rufipogonの1系統K98を一回母本に栽培イネの台中65号で8回の連続戻し交雑をし, その後自殖をくり返して核置換系統RT98Cを育成した.同育成系統は正常な花粉および種子稔性をもつが, 台中65号との交雑後代においては不 稔個体を生ずる場合があった.そこで稔性に関する遺伝実験を行った結果, 次の結論を導くことができた.稔性は細胞質と核内の1座性の稔性回復遺伝子(Rf-rf)により支配されており, また配偶体支配型であった.ただし, 雌性配偶子は細胞質や稔性回復遺伝子の種類に関わらず常に正常稔性を示しており, 稔性支配を受けるのは雄性配偶子のみであった.すなわち, RT98Cの細胞質は雄性不稔細胞質(msc)であり, この中ではRf遺伝子をもつ花粉は正常に発育するが, rf遺伝子をもつ花粉は退化して受精機能をもたなかった.一方, 台中65号の細胞質は正常な細胞質(mfc)であり, この中ではRfをもつ花粉もrfをもつ花粉も正常に発育した.ヘテロ個体(msc)Rfrf個体を自殖させた場合, 全て種子稔個体となり種子不稔個体が全く現れなかったことから, 稔性は配偶体支配型であることが認められた.なお, ヨード・ヨードカリ液での花粉の染色具合, あるいは花粉の大きさなどは接合体の遺伝子型に関係なく正常花粉も退化花粉もほぼ同様であり, 区別できなかった.<br />Through successive backcrosses, the cytoplasm and nuclear fertility restorer gene of K98,a line of Oryza rufipogon, were introduced into Taichung 65,O. sativa, and a nuclear-substituted line, RT98C, was developed. This line showed a high degree of spikelet fertility, but it produced fertile and sterile plants in the cross with Taichung 65. To analyze the mode of inheritance of the fertility, crossing tests were carried out, and the following results were obtained. Pollen fertility was controlled by the interaction of the cytoplasm and the single restorer fertility gene (Rf-rf), but the function of the embryosac was not affected by the cytoplasm and restorer fertility gene. That is, all the pollen grains in the cytoplasm of Taichung 65 were normal regardless of the dominance or recessiveness of the restorer fertility gene they carried. On the other hand, the pollen grains carrying the Rf gene in the cytoplasm of RT98C were normal, while the pollen grains carrying the rf gene in this cytoplasm became sterile. The normal cytoplasm of Taichung 65 was designated as (mfc) and the sterile cytoplasm of RT98C as (msc). When the (msc) Rfrf plants were selfed, in all the resulting plants, spikelet fertility was restored, and no sterile plants were observed, suggesting that the pollen grains carrying the rf gene were not viable. Thus, the male sterility and fertility restoration in this line were controlled by the genotype of the gamete itself but not by that of the zygote, indicating the presence of a gametophytic control of fertility. Only in the (msc) rfrf plants spikelet fertility was not restored, while in the plants with all the other genotypes, viz. (msc) RfRf, (msc) Rfrf, (mfc) RfRf, (mfc) Rfrf and (mfc) rfrf, spikelet fertility was restored, resulting in a high degree of spikelet fertility. Although pollen grains carrying rf in (msc) degenerated regardless of the plant genotype (Rfrf or rfrf), they all stained well in a I_2KI solution and showed a normal size. 続きを見る
9.

論文(リポジトリ)

論文(リポジトリ)
Sarker, Mohammad Abu Zaman ; Murayama, Seiichi ; Ishimine, Yukio ; Tsuzuki, Eiji
出版情報: Plant Production Science.  4  pp.196-201,  2001-09.  The Crop Science Society of Japan — 日本作物学会
URL: http://hdl.handle.net/20.500.12000/4868
概要: A pot experiment was conducted to study photosynthetic rate in terms of carbon dioxide exchange rate (CER), chlorophyll meter reading (SPAD value) and specific leaf area (SLA) of 12 F_1 hybrids from crosses between japonica and indica rice and their parents, and to estimate the heterosis in F_1 hybrids at active tillering, flowering and dough ripe stages. In all F_1 hybrids and parent cultivars, CER was high at the active tillering stage with a small heterosis value. A positive heterosis for this trait was found at the flowering stage. The magnitude of heterosis for CER depended on the cross combinations. Although a positive heterosis for SPAD value was found at the active tillering stage, there was no correlation between heterosis for SPAD value and that for CER at the flowering stage, at which heterosis for CER was positive. Heterosis for SLA was high at the active tillering stage and gradually decreased thereafter. Heterosis for CER might be dependent not only on negative heterosis for SLA but also on other photosynthetic factors such as N content, soluble protein content and Rubisco activity. 続きを見る
10.

論文(リポジトリ)

論文(リポジトリ)
Sarker, Mohammad Abu Zaman ; Murayama, Seiichi ; Ishimine, Yukio ; Nakamura, Ichiro
出版情報: Plant Production Science.  4  pp.202-209,  2001-09.  The Crop Science Society of Japan — 日本作物学会
URL: http://hdl.handle.net/20.500.12000/4869
概要: A pot experiment was conducted to investigate the heterosis for morphological characters and to examine the relationship among some characters at active tillering, flowering and dough ripe stages of 12 F_1 hybrids from crosses between japonica and indica rice. Heterosis for plant height, number of tillers, green leaf area and dry matter accumulation per plant was positive at all stages. The intensity of heterosis was higher at the active tillering stage for number of tillers, leaf area and dry matter accumulation per plant. A significant positive relationship was found between tiller number and leaf area per plant at active tillering and flowering stages. Significant positive relationships between leaf area and dry matter accumulation, and between tiller number and dry matter accumulation per plant were observed at all stages. A significant positive relationship was found between leaf area per plant at an early stage and dry matter accumulation per plant at a later stage, suggesting that early development of leaf area is an important factor for higher dry matter accumulation in F_1 hybrids. Although heterosis for percent dead leaf blade was positive at the flowering stage due to early leaf senescence in some F_1 hybrids, a larger leaf area was also found in F_1 hybrids at this stage and leaves of F_1 hybrids remained green longer compared to parent cultivars up to the dough ripe stage. 続きを見る