• Title/Summary/Keyword: ripening stage

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Agronomical Studies on the Thermal Conditions for Double Cropping of Rice (수도이기작재배 가능성에 대한 기상적 조사연구 - 적산온도를 중심으로 -)

  • Kang-Sae Lee;Jong-Kyu Hwang
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.14
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    • pp.53-64
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    • 1973
  • The studies reported herein were conducted to investigate the effect of thermal conditions in double-cropping of rice. The accumulated daily mean and minimum air temperatures, for the period of the last 30 years, were examined at the 10 different meteorogical stations which are located in the southern part of Korea. The results obtained could be summarized as follows: 1. The first cropping. a. It seemed to be free from any frost-damage of rice at the seeding stage at Yeosu, Pusan and Cheju. However, it was found that there were some dangers of frost damage for about 30 to 40 day at Iri, Chonju and Kwangju, for 18 to 28 days at Daeku and Ulsan, and for 4 to 14 days at Mokpo and Pohang, respectively. b. The early critical transplanting date seemed to be from middle to late-April in the first cropping. As compared with the ordinary lowland seedlings, the semi-protected and upland ones could be planted 5 and 10 days earlier, respectively. c. The early critical heading date was about late-June and there were some low-temperature damages for 8 to 25 days at young-ear formation stage of rice plant, depending upon location. d. The early critical ripening date (the early critical transplanting date of the 2nd cropping) was from late-July to early-August. It took about 32 to 39 days in ripening. There was a tendency of SS${\fallingdotseq}$SL$15^{\circ}C$ (${\theta}$15) and the minimum of $10^{\circ}C$ (${\theta}$10), the ten locations could be devided into two ripening groups of ${\theta}$15>${\theta}$10 and ${\theta}$15<${\theta}$10. c. The late critical ripening date was around October 9 at Iri, Chonju, Kwangju and Daeku and around October 28 at Mokpo, Yeosu, Pusan and eheju. Three to four days were more required for a complete ripening of rice, as compared with the above dates. d. There was an overlap of about 12 to 42 days between the first and second cropping when early-maturing varieties requiring an accumulated mean air temperature of $1, 550^{\circ}C$, from transplanting to heading, were grown. Therefore, some varieties which could head with an accumulated daily mean air temperature of 1, 000 to $1, 200^{\circ}C$, should be either developed or some new cultural technology be established in order to have a successful double cropping in rice.

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Structural Changes and Histochemical Study of Endosperm on Panax ginseng C.A. Meyer during Embryo Development (인삼(Panax ginseng C.A. Meyer) 종자의 배발달에 따른 배유의 구조변화 및 조직화학적 연구)

  • 유성철;김유갑
    • Journal of Ginseng Research
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    • v.16 no.1
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    • pp.37-43
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    • 1992
  • Structural changes of the endosperm of Panax ginseng C.A. Meyer from fertilization to germination were investigated by light microscope. The endosperm of the ginseng seed is cellular type. Since endosperm cells adjacent embryo continuously breakdown and disappear with the elongation of embryo, the real of endosperm is gradually decreased. As the anatropous ovules of immature seed with green seed coat developes more and more, ovary cells adjacent ovary cavity become abundant by the periclinal division, their size is decreased, hypotrophy of cell wall discern, and they are gradually differentiated in seed coat. Though embryo responds strongly to basic dye at the stage of completion of endosperm formation, tissue of endosperm responds to acidic dye positively Cell wall of embryo and endosperm are composed of primary cell wall not lignified. Endosperm cells adjacent embryo begin to breakdown in the endosperm tissue of indehiscent seed before the beginning of the after-ripening. Dehiscent seed of which seed coat is opened through after-ripening represent the form as a seedling in the result of embryo developments with the formation of organs; radicle, cotyledon, plumule. Umbilifom layer represents strong positive response to the toluidine blue and the basic function. Umbiliform layer that endosperm cells breakdown and disappear is observed clearly at the periphery of the embryo cotylemon, while slightly at the periphery of the radicle.

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Changes in the Enzyme Activities, Pectins and Structure of Persimmon Fruit during Softening (감과실의 연화중 효소활성, 펙틴 및 조직의 변화)

  • 신승렬;문광덕;이광희;김광수
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.5
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    • pp.611-616
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    • 1993
  • This study was carried out to investigate change in the polygalacturonase and ${\beta}-galactosidase$ activities, pectins, cell wall structure of persimmon fruit during ripening and softening. Polygalacturonase and ${\beta}-galactosidase$ activities were not detected at turning stage. However polygalacturonase activities of mature and soft persimmon fruits were 55.01 and 206.70units/100g-fresh weight(fr. wt.), respectively. ${\beta}-Galactosidase$ activities of mature and soft persimmon fruits were 21.79 and 380.23unit/100g-fr. wt. respectively. The contents of total and insoluble pectins increased during maturation but decreased during softening. The content of water-soluble pectin increased during maturation and softening. The intercellular space was in larged during ripening, and middle lamella was degraded in mature persimmon fruit, and the cells of soft persimmon fruit were separated each other.

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Phyllosticta musarum Infection-Induced Defences Suppress Anthracnose Disease Caused by Colletotrichum musae in Banana Fruits cv 'Embul'

  • Abayasekara, C.L.;Adikaram, N.K.B.;Wanigasekara, U.W.N.P.;Bandara, B.M.R.
    • The Plant Pathology Journal
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    • v.29 no.1
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    • pp.77-86
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    • 2013
  • Anthracnose development by Colletotrichum musae was observed to be significantly less in the fruits of the banana cultivar 'Embul' (Mysore, AAB) infected with Phyllosticta musarum than in fruits without such infections. Anthracnose disease originates from quiescent C. musae infections in the immature fruit. P. musarum incites minute, scattered spots, referred to as freckles, in the superficial tissues of immature banana peel which do not expand during maturation or ripening. P. musarum does not appear to have a direct suppressive effect on C. musae as conidia of C. musae germinate on both freckled and non-freckled fruit forming quiescent infections. Our investigations have shown that P. musarum infection induced several defence responses in fruit including the accumulation of five phytoalexins, upregulation of chitinase and ${\beta}$-1,3-glucanase, phenylalanine ammonia lyase (PAL) activity and cell wall lignification. $^1H$ and $^{13}C$ NMR spectral data of one purified phytoalexin compared closely with 4'-hydroxyanigorufone. Some of the P. musarum-induced defences that retained during ripening, restrict C. musae development at the ripe stage. This paper examines the potential of P. musarum-induced defences, in the control of anthracnose, the most destructive postharvest disease in banana.

Altered Fine Structure of Amylopectin Is Induced by Exogenous Gibberellin During Rice Grain Ripening

  • Kim, Sang-Kuk;Park, Shin-Young;Lee, Sang-Chul;Lee, In-Jung
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.6
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    • pp.523-526
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    • 2006
  • When $GA_{4}$ was applied to heading stage, it was examined to understand the change of plant hormones and starch during grain filling and ripening. Exogenous gibberellin caused a dramatic decrease in endogenous ABA content. Endogenous $GA_{4}$ content in both superior and inferior part was more promoted in $GA_{4}-treated$ rice grain than in the control. $GA_{1}$ content of an inferior part was not detected in the control and $GA_{4}-treated$ rice otherwise $GA_{4}$ was detected in all grain parts. Ripened grain rate in $GA_{4}-treated$ rice grain was lower than that of the control plant. Amylopectin from $GA_{4}-treated$ grain contained more very short chains with degree of polymerization (DP) between 4 and 8 than amylopectin from the control plant. It suggests strongly that fine structure of rice endosperm may be changed by exogenously applied $GA_{4}$ in rice plants.

Microstructural Evolution of Electromagnetically Stirred Al alloy Billet During Isothermal Reheating at the Solid-liquid State (전자기 교반한 알루미늄합금 빌렛의 재가열시 고액공존구역에서의 조직변화)

  • Lee, Dock-Young
    • Journal of Korea Foundry Society
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    • v.28 no.3
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    • pp.129-135
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    • 2008
  • The reheating stage of electromagnetically stirred Al billet is a critical factor in the thixoforming process. When reheated to the solid-liquid state, the microstructure evolves to a more globular and more homogeneous structure by a coarsening mechanism, the kinetics depending on the initial microstructure. Microstructural evolution has been characterized by conventional parameters (mean size of particle and shape factor) as a function of holding time in the solid-liquid state. The aim of this study is to report experimental results concerning microstructural evolution in the solid-liquid state of electromagnetically stirred Al billet. The material was elaborated in the form of continuously cast bars solidified with electromagnetic stirring to degenerate the dendritic structure. The choice of the reheating conditions is determined by a dendritic ripening and coalescence mechanism, involving variations of both the shape and size of the particles. The reheating time has to be long enough to allow a minimum degree of spheroidizing, but has to be limited as much as possible in order to avoid excessive ripening. The optimum microstructure was obtained at the reheating temperature of near $584^{\circ}C$ and the holding time of 5 min. The only means of combining high productivity with good casting quality was to use feedstock billets whose microstructure showed rapid transformation characteristics.

The Effect of Split Dressing on Grain Ripening in Rice Plant (수도에 대한 삼요소분시가 등숙율에 미치는 영향)

  • Choon-Johong Ro
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.19
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    • pp.25-31
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    • 1975
  • In order to increase the rate of ripening during the grain-forming stage the partial dressing was introduced with the ordinary dressing comparatively. Two different rice varieties, Bong-kwang(early) and Nong-kwang (moderate), grown at the fine sand alluvial soil of River, Han Kimpo, were investigated. To evaluate the photosynthetic ability of these treatments assimilation rate of Carbon-14 was effectively carried out with the active leaves of rice at the maturing stage, and the inorganic constituents of leaves, stem, leaf sheath and grain were analyzed. All the data on the photosynthetic ability, inorganic constituent and yield determining were discussed with the point of continual phloem translocation between those plant organs.

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Studies on the Growth and Nutrient Uptake of Flag Leaf and Chaff of Rice Plant in Cold Injury Location II. Influence of Different Transplanting Date on Nutrient Uptake of Flag Leaf and Chaff of Rice Plant (냉해지대의 수도생육과 임,불임 인각의 양분흡수에 관한 연구 제2보 재배시기 이동이 수도지엽과 인각의 양분흡수에 미치는 영향)

  • Kim, Y.J.;Choi, S.I.;Ra, J.S.;Lee, J.H.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.27 no.3
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    • pp.206-217
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    • 1982
  • This experiment was conducted to study about nutrient absorption of flag leaf and chaff of rice plant different transplanting date with elevations. Heading stage was delayed by destructive cold temperature or late transplanting. Plant analyses revealed that above poor plants also had higher total nitrogen content, but ower silicate in the flag leaf and sterile chaff. Total nitrogen and silica contents to accumulated in flag leaf between yield was significant high correlation. The chaff of late transplanting and sterility was high total nitrogen. Relationship between silicate absorption and total nitrogen of chaff was significant high correlation. Ripening temperature after heading stage was influenced total nitrogen of chaff. Phosphate, potassium, calssium and silicate contents of chaff increased hight ripening temperature but total nitrogen decreased. Therefore, inorganic element contents of chaff was closely connected with grain sterility.

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Effect of High Temperature and Water Management on Agronomic Characters in Rice (고온 및 고온기 물관리방법이 수도생육에 미치는 영향)

  • 이승필;김상경;이광석;최대웅;이상철
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.35 no.3
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    • pp.195-200
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    • 1990
  • These experiments were conducted to determine the effect of high temperature and water managements on growth and yield of rice. Shoot dry weight and percent of fresh roots were decreased when rice plant was exposed to high temperature, and also high temperature treatment decreased yield components of rice through spikelet number at meiotic, filled grain ratio and percent of fertility at heading, and 1,000 grain weight at ripening stage. Nitragen content of the rice varities was decreased by high temperature treatment regardless different growth stage, although Si content increased. Grain yield of rice varieties significantly decreased due to high temperature when rice plants were treated at heading stage followed by ripening stage. meiotic, young panicle initiation, maximum tillering and tillering stage in order. Effect of the continual submerging on temperature increased by 1.1$^{\circ}C$ at daytime and by 3.7$^{\circ}C$ at nighttime, but flowing water irrigation which can maintain optimum temperature reduced plant height and increased dry weight and percent of fresh roots. Flowing water irrigation showed higher yield by 4-8% compared to continual submerging method through increment of yield components such as spikelet number, filled grain ratio and 1,000-grain weight.

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Studies on the organic acids metabolism in chlorella cells. (Chlorella의 유기산대사에 관한 연구)

  • Chin, Pyung;Lee, Yung-Nok
    • Korean Journal of Microbiology
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    • v.3 no.2
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    • pp.15-21
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    • 1965
  • Using the synchronous culture method and the manometric technique, changes in respiratory activities, utilization of some organic acids (succinate, malate, lactate and acetate etc.) and its effect on glucose metabolism in Chlorella cells at different growing stages were measured. 1) Endogenous respiration of the cells was not active at growing stage and was almost constant throughout the early ripening, maturing and division stages. 2) Lactate was utilized as respiratory substrate better than other organic acids tested. Exogenous respiration of glucose was most active at growing and maturing stages and was decreased strikingly at division stage. 3) Succinate and citrate inhibited endogenous and glucose respiration of the cells throughout the all life cycle. 4) Malate and acetate were utilized in the cells at early growing and division stages better, and malate enhanced the glucose respiration while in case of acetate it was depressed. 5) Calcium ion inhibited not only permeability of respiratory substrate but endogenous respiration itself.

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