• Title/Summary/Keyword: Endosperm removal

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Rapid in vitro Germination of Zygotic Embryos via Endosperm Removal in Eleutherococcus senticosus

  • You Xiang-Ling;Choi Yong-Eui;Yi Jae-Seon
    • Journal of Plant Biotechnology
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    • v.7 no.1
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    • pp.75-80
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    • 2005
  • Eleutherococcus senticosus (also called Acanthopanax senticosus), belonging to Araliaceae family, has been used as an important medicinal woody plant. Mature seeds of Eleutherococcus senticosus have rudimentary (extremely immature) zygotic embryos and require a long-term stratification for about 18 months to induce germination. Here, through the methods of endosperm removal and other exogenous treatments, we investigated the factors for inducing rudimentary embryos by in vitro culture, Rudimentary zygotic embryos in seeds were at globular to heart-shaped stage at about $250{\mu}m$ in length just after harvest of fruits. When the seeds without testa were cultured on 1/2 MS (Murashige and Skoog 1962) medium, they did not germinate regardless of medium and sucrose concentrations but the removal of endosperm tissue markedly stimulated the growth of rudimentary zygotic embryos. The embryo reached ear-lier maturation, once when the endosperm surrounding the rudimentary embryos was removed. Rudimentary zygotic embryos developed cotyledons within 3 weeks of culture after endosperm emoval. However, post-mature zygotic embryos failed to germinate though they were morphologically normal, indicating another dormancy of embryos. $GA_3\;(2.0\;\cal{mg/L})$ and/or charcoal ($0.2\%$) treatment rapidly enhanced the germination of zygotic embryos. These results suggest that E. senticosus seeds have double dormancy; i. e. morphological rudimentary dormancy influenced by surrounding endosperm and physiological dormancy after post-maturation of zygotic embryos. Based on the above findings, we established the rapid germination of rudimentary zygotic embryos by in vitro culture of excised seeds with endosperm removal and $GA_3$ treatment.

Seedcoat removal and seed germination in Helianthus tuberosus L. (종피제거와 돼지감자종자의 발아)

  • 임근발
    • Korean Journal of Plant Resources
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    • v.3 no.1
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    • pp.31-40
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    • 1990
  • Pericarp and seedcoat removal treatments were tested to determine their effectiveness in the hard-to-germinate botanical seeds of jerusalem artichoke. Fresh seed of five Helianthus tuberosus L.varieties were (A)untreated (B)water soaked overnight (C) soaked overnight followed by renoval of pericarp or (D) soaked overnight followed by renoval of pericarp and seedcoat. The results indicate that treatments which removed the pericarp and seedcoat were the very effective, giving germination of over 90%. A considerable increase in germination did not follow only the peri-carp removal treatments. The factors inhibitory to germination of fresh jerusalem artichoke seed is associated withthe seedcoat. The removal treatment of pericarp and seed-cost is recommended despite its complexity because it givesa high germination percentage and varies least from varietyto variety. Heliarthus tuberosus L., a biomass potential crop, is a member of the family compositae. The genus Helianthushas provided man with two food plants, the sunflower (H.annus) and the jerusalem artichoke or topinambour (H. tube-rosus) . (3) The jerusalem artichoke grown for its tubers, has always been an extremely minor crop, but it is stillgrown in many places as a food for man or livestock and forthe production of alcohoL. Though tubers are used for pro-pagation jerusalem artichoke also flower and produce seedin head-like in florescences. Flowers are developed acro-petaLly on flattened receptacles such that outermost flowers are oldest. Each of these epigynous flowers may develop an achene-type fruit in which outer layers of the overy wallpersist, while inner layers become disorganized. Insidethe ovary wall of mature fruit, there is a papery seedcoat, probably composed of compact cells from endosperm, integu-ments, and nucellus.In general, the efforts to improving this crop havebeen hampered by the hard-to-germinate botanical seed.Seeds did not germinate for at least IL months after harvest.Fresh seeds of some varieties require one year more to gar-minate. (5) Since the time factor between generations isof concern in a prospective breeding program of jerusalemartichoke , these observations led to investigation of thenature of delayed seed germination in jerusalem artichokeas a biomass potential crop.

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Contents of $\beta$-Glucan in Various Cereals and Its Functional Properties

  • Whang, Key
    • Preventive Nutrition and Food Science
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    • v.3 no.4
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    • pp.382-386
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    • 1998
  • A soluble dietary fiber, $\beta$-glucan, contained in oat and barley has nutritional benefits such as hypocholesterolemic effects and influences blood glucose regulation. The contents of $\beta$-glucan in both cereals range from 3 to 7% with the exception of a certain barley genotype which contains up to 16% $\beta$-glucan. $\beta$-Glucan is distributed mainly in the cell walls of endosperm and the distal (bran) portion of kernel. Various procedures have been developed for increasing the extraction yield of $\beta$-glucan. Oat gum prepared with weak alkali extractionand alcohol proecipitation following protein removal usually contains 80% $\beta$-glucan.The most commonly used method for $\beta$-glucan quantitiation is an enzymatic procedure combining lichenase plus $\beta$-glucosidase followed by measuring the amount of glucos released by glucose oxidase-peroxidase treatment. The increase in foam-and emulsion-stabilizing capacity of $\beta$-glucan is due to the increase in viscosity of the aqueous phase. Therefore, $\beta$-glucan shows great potentials as a thickener and a stabilizer.

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Utilization of Korean Maizes in Prodction of Alkaline Processed Snack Foods

  • Lee, Jae-Kwon
    • Preventive Nutrition and Food Science
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    • v.2 no.1
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    • pp.11-16
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    • 1997
  • Alkaline cooking and processing properties of domestic maize were evaluated by comparing to those of imported control maize(Asgrow 404). Domestric maize varieties were hydrated more rapidly and had lower dry matter losses during alkaline cooking than control maize due to softer endosperm texture and incomplete removal of pericarps. Domestic maize varieties produced masas with proper handling properties when nixtamals had 50~52% moisture. However, masas produced from domestic maizes were puffed dur-ing baking and frying process due to the release of more free starch granules in the masa than control masa. Tortilla chips prepared from domestic maizes absorbed more oil during frying and had slightly higher water content with darker color than tortilla chips prepared from control maize. Among the domestic maize hybrids, KS42/Fla2BT113 had more acceptable kernel characteristics of tortilla chips than other varieties.

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Disinfection of Fusarium-infected Rice Seeds by Prochloraz and Gaseous Chlorine Dioxide

  • Jeon, Young-ah;Lee, Young-yi;Lee, Ho-sun;Sung, Jung-sook;Lee, Seokyoung
    • 한국균학회소식:학술대회논문집
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    • 2014.10a
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    • pp.25-25
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    • 2014
  • Three species of Fusarium, F. fujikuroi, F. verticillioides and F. proliferatum, are known to be associated with bakanae disease of rice [1, 2]. F. fujikuroi infects rice flowers and survive in endosperm and embryo of the seeds. Infected seed is an important source of primary inoculum of pathogens [3]. Seeds of rice (Oryza sativa cv. Boramchan) collected from bakanae-infected field were found to be 96% infected with Fusarium sp., 52% with F. fujikuroi, 42% with F. verticillioides, and 12% with F. proliferatum as determined by incubation method and species-specific PCR assays. F. fujikuroi was detected at lemma/palea, endosperm and embryo whereas F. verticillioides and F. proliferatum were recovered only from lemma/palea by means of component plating test. Seed disinfection methods have been developed to control bakanae disease and prochloraz has been most widely used for rice seeds. Two chemicals formulated with prochloraz (PC 1) and prochloraz + hexaconazole (PC 2) that inhibit biosynthesis of ergosterol strongly reduced the incidence of Fusarium spp. on selective media to 4.7% and 2.0%, respectively. Disease symptoms of rice seedlings in nursery soil were alleviated by chemical treatment; seedlings with elongated leaves or wide angle between leaf and stem were strikingly reduced from 15.6 to 3.2% (PC 1) and 0 (PC 2), stem rots were reduced from 56.9 to 26.2% (PC 1) and 32.1% (PC 2), and normal seedling increased from 0.4 to 13.3% (PC 2). Prochloraz has some disadvantages and risks such as the occurrence of tolerant pathogens [4] and effects on the sterol synthesis in animals and humans [5]. For these reasons, it is necessary to develop new disinfection method that do not induce fungal tolerance and are safe to humans and animals. Chlorine dioxide ($ClO_2$), that is less toxic, produces no harmful byproducts, and has high oxidizing power, has been reported to be effective at disinfection of several phytopathogenic fungi including Colletotrichum spp. and Alternaria spp. [6]. Gaseous $ClO_2$ applied to rice seeds at a concentration of 20 ppm strongly suppressed mycelial growth of Fusarium fujikuroi, F. verticillioides and F. proliferatum. The incidence of Fusarium spp. in dry seed with 8.7% seed moisture content (SMC) tended to decrease as the concentration of $ClO_2$ increased from 20 to 40 ppm. Applying 40 ppm $ClO_2$ at 90% relative humidity, incidence was reduced to 5.3% and resulted in significant reduction of disease symptoms on MS media. In nursery soil, stem rot was reduced from 56.9 to 15.4% and the number of normal seedlings increased from 0.4 to 25.5%. With water-soaked seeds (33.1% SMC) holding moisture in the endosperm and embryo, the effectiveness of disinfection using $ClO_2$ increased, even when treated with only 20 ppm for four hours. This suggests that moisture was a key element for action of $ClO_2$. Removal of the palea and lemma from seeds significantly decreased the incidence of Fusarium spp. to 3.0%. Seed germination appeared to decrease slightly by water-soaking at $30^{\circ}C$ because of increased SMC and by physical damage of embryos from hulling. These results indicate that the use of gaseous $ClO_2$ was effective as a means to disinfect rice seeds infected with Fusarium spp. and that moisture around the pathogens in the seed was an important factor for the action of $ClO_2$. Further investigations should be conducted to ascertain the best conditions for complete disinfection of Fusarium spp. that infect deep site of rice seeds.

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Survey on the Chitinolytic Activity from Some Plants for the Industrial Utilization (공업적 이용을 위한 식물성 키틴분해효소의 탐색)

  • Han, Beom-Ku;Lee, Woo-Jin;You, Tak;Park, In-Ho;Jo, Do-Hyun
    • Applied Biological Chemistry
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    • v.39 no.6
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    • pp.466-471
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    • 1996
  • The survey on the chitinolytic activity of some plants was performed for the purpose of obtaining some reliable and inexpensive sources of chitinase. Rice, soybean for sprouting, kiwi fruit, almond and crude papain were investigated. Rice bran, seed coat of the soybean and the pericarp of kiwi fruit showed a considerable activity, while the bean after the removal of the seed coat, the mixture of rice integument and endosperm, polished rice, and defatted soybean powder didn't have any detectable activity. These crude enzymes have shown to contain both endo- and exochitinase activity. The effects of pH and temperature on the enzyme activity were variable. Furthermore we have observed the chitosanolytic activity from these enzyme Preparations. The rice bran had the highest activity in the enzymatic degradation of chitosan, and seed coat of soybean and the pericarp of kiwi fruit followed. On the basis of the fact that crude papain was not only commercially available but also the most potent in the endochitinase activity and the lowest in the exochitinase activity, we could conclude that crude papain was considered as the most suitable source of the chitinase among plants studied in this paper. In addition, rice bran was worth further investigation from the point of utilizing agricultural by-product.

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