• Mycobiology
• /
• v.43 no.1
• /
• pp.87-91
• /
• 2015

Eighteen endophytic fungi with different colony morphologies were isolated from the roots of Nymphoides peltata growing in the Dalsung wetland. The fungal culture filtrates of the endophytic fungi were treated to Waito-c rice seedling to evaluate their plant growth-promoting activities. Culture filtrate of Y2H0002 fungal strain promoted the growth of the Waito-c rice seedlings. This strain was identified on the basis of sequences of the partial internal transcribed spacer region and the partial beta-tubulin gene. Upon chromatographic analysis of the culture filtrate of Y2H0002 strain, the gibberellins (GAs: $GA_1$, $GA_3$, and $GA_4$) were detected and quantified. Molecular and morphological studies identified the Y2H0002 strain as belonging to Aspergillus clavatus. These results indicated that A. clavatus improves the growth of plants and produces various GAs, and may participate in the growth of plants under diverse environmental conditions.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1996.06c
• /
• pp.1021-1030
• /
• 1996

The mechanism of the mulch film cutter assembly designed as an integral part of a rice transplanting device was developed for mulching cultivation of early season culture rice. This mulch film cutter assembly was directly attached to the transplanting device of the rotary type Japanese transplanter. The principle is that the knife cut a planting slit on the polyethylene film while the planting finger immediately plants seedling into the soil through the planting slit. Computer results implied that the knife of the mulch film cutter assembly can make appropriate planting slit on the polyethylene film as the planting finger effectively plants the seedlings into the paddy soil through the same planting slits.

• Korean Journal of Plant Resources
• /
• v.34 no.1
• /
• pp.17-22
• /
• 2021

Plants regenerated from in vitro cultures carry chromosomal variations, especially in long-term culture. Reducing the duration of plant tissue culture is one of the ways to reduce genetic and epigenetic changes. In this study, we reduced the duration of long-term culture and repeat subculture using small bulblets derived from bulb scales in two lily cultivars. The adventitious bulblets derived from bulb-scale tissue were cultured on three different media containing Murashige and Skoog (MS) basal medium supplemented with 1 g/L Charcoal, MS medium containing 0.3 mg/L IAA and 0.4 mg/L BA hormone with or without Charcoal, respectively. About seven weeks later, the number of newly propagated multiple shoots in the two media, A and B media, showed little differentiation. Compared to both media, the number of propagated multiple shoots increased 5-fold in MS medium containing 0.3 mg/L IAA and 0.4 mg/L BA hormone without Charcoal (C medium). The number of propagated multiple shoots ranged from 5 to 6 and 4 to 6 with an average of 5 in TropicalPink and GreenStar cultivars, respectively. The flow cytometric measurements indicated no variation in the ploidy level between control and in vitro propagated plants.

• The Plant Pathology Journal
• /
• v.38 no.1
• /
• pp.33-45
• /
• 2022

To screen antagonistic fungi against plant pathogens, dual culture assay (DCA) and culture filtrate assay (CFA) were performed with unknown soil-born fungi. Among the different fungi isolated and screened from the soil, fungal isolate ANU-301 successfully inhibited growth of different plant pathogenic fungi, Colletotrichum acutatum, Alternaria alternata, and Fusarium oxysporum, in DCA and CFA. Morphological characteristics and rDNA internal transcribed spacer sequence analysis identified ANU-301 as Aspergillus terreus. Inoculation of tomato plants with Fusarium oxysporum f. sp. lycopersici (FOL) induced severe wilting symptom; however, co-inoculation with ANU-301 significantly enhanced resistance of tomato plants against FOL. In addition, culture filtrate (CF) of ANU-301 not only showed bacterial growth inhibition activity against Dickeya chrysanthemi (Dc), but also demonstrated protective effect in potato tuber against soft rot disease. Gas chromatography-tandem mass spectrometry analysis of CF of ANU-301 identified 2,4-bis(1-methyl-1-phenylethyl)-phenol (MPP) as the most abundant compound. MPP inhibited growth of Dc, but not of FOL, in a dose-dependent manner, and protected potato tuber from the soft rot disease induced by Dc. In conclusion, Aspergillus terreus ANU-301 could be used and further tested as a potential biological control agent.

• Journal of Plant Biotechnology
• /
• v.33 no.4
• /
• pp.257-262
• /
• 2006

The paper evaluated the behavior of in vitro culture responses from a diverse set of Indica rice (Oryza sativa L.) genotypes. Significant differences were found in embryogenic callus induction frequency, callus growth and plant regeneration frequency when mature embryos of 11 cultivars, breeding lines and land races were compared. Genotype as well as plant growth regulator influenced the plant regeneration frequency. Callus induction frequency was not correlated with callus growth as well as plant regeneration frequency. The regenerated plants could grow to normal, fertile plants after they were successfully established in soil.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2005.10a
• /
• pp.15-20
• /
• 2005

Locations of silicon accumulation in rice leaves and its possible association with resistance to rice blast were investigated by analytical electron microscopy and atomic force microscopy. A blast-susceptible cultivar, Jinmi, and partially resistant cultivars, Hwaseong and Suwon345, were grown under a hydroponic culture system with modified Yoshida's nutrient solution. Electron-dense silicon layers were frequently found beneath the cuticle in epidermal cell walls of silicon-treated plants. Increasing levels of silicon were detected in the outer regions of epidermal cell walls. Silicon was present mainly in epidermal cell walls, middle lamella, and Intercellular spaces within subepidermal tissues. Furthermore, silicon was prevalent throughout the leaf surface with relatively small deposition on stomatal guard cells in silicon-treated plants. Force-distance curve measurements revealed relative hardness and smaller adhesion force in silicon-treated plants (18.65 uN) than control plants (28.39 uN). Moreover, force modulation microscopy showed higher mean height values of elastic Images In silicon-treated plants(1.26 V) than in control plants (0.44 V), implying the increased leaf hardness by silicon treatment. These results strongly suggest that silicon-induced cell wall fortification of rice leaves may be closely associated with enhanced host resistance to blast.

• Journal of Plant Biology
• /
• v.28 no.1
• /
• pp.45-55
• /
• 1985

Observations on reproduction of Rhodochorton purpureum (Lightfoot) Rosenvinge (Acrochaetiaceae, Rhodophyta) was carried out with plants from Hokkaido, Japan. This species produces no monosporangia both in nature and culture, even though it does tetrasporangia commonly. The plants from Nemuro produce neither sporangia nor gametangia, and thus vegetative reproduction is the only known way to propagate themselves. It is suggested that the vegetative reproduction occurs in nature by fragmentation of vegetative filaments after development of a rhizoid. Several different modes of rhizoid production are described. The plants from Akkeshi and Oshoro (I) produce tetrasporangia that develop into plants producing only tetrasporangia. The plants from Muroran and Oshoro (II) produce tetrasporangia that develop into gametophytes. Gametophytes of R. purpureum from Muroran produce tetrasporangia as well as spermatangia or carpogonia. Such tetrasporangia on gametophytes are presumed to be mitotic.

• Horticultural Science & Technology
• /
• v.28 no.5
• /
• pp.845-849
• /
• 2010

This study was conducted to compare various culture methods and evaluate economic feasibility of each method for mass propagation of new ever-bearing strawberry 'Goha'. Four different methods such as semi-solid culture, solid culture, liquid suspension culture and bioreactor culture were compared. The solid culture and bioreactor culture showed the shortest and longest root length, such as 3.6 cm and 8.3 cm, respectively. Fresh weights of plants cultured in bioreactor were 2,261 mg, which were heavier than those of cultures. Dry weights of plants cultured in bioreactor were the heavier compared to those in other cultures. The number of axillary bud developed in bioreactor was seven, but axillary bud was not developed in other cultures. Production cost through bioreactor culture was calculated to be 303 won per plant which was 542 won less than that of solid culture. As a result, we found that the bioreactor culture was the most cost effective culture method for in vitro mass propagation in new ever-bearing strawberry 'Goha'.

• Journal of Plant Biotechnology
• /
• v.2 no.2
• /
• pp.55-60
• /
• 2000

Experiments initiated 30 years ago to obtain selectable markers have led to a series of studies of Trp biosynthesis and anthranilate synthase (AS) the control enzyme using largely plant tissue cultures since they have experimental properties that can be readily exploited. Enzymological and compound feeding studies provided evidence that AS is the control point in the Trp biosynthesis branch and that altering the AS feedback control by the selection of mutants resistant to the Trp analog 5-methyl-tryptophan (5MT) can lead to the overproduction of this important amino acid. Plants regenerated from these Trp overproducing lines of most species also had high free Trp levels but Nicotiana tabaum (tobacco) plants expressed the feedback altered AS only in cultured cells and not in the regenerated plants. further tests by transient and stable expression of the cloned promoter for the naturally occurring tobacco feedback-insensitive AS, denoted ASA2, confirmed the tissue culture specific nature of the expression control. The 5MT caused by the expression of a feedback-insensitive AS from tobacco has been used to select protoplast fusion hybrids with several species since the resistance is expressed dominantly. Recently the ASA2 gene has been used successfully as a selectable marker to select transformed Astragalus sinicus and Glycine max hairy roots induced by Agrobactetium rhizogenes. These results show that the ASA2y-subunit can interact with the y-subunit of another species to form active feedback-insensitive enzyme that may be useful for selecting transformed cells. Plastid DNA transformation of tobacco has also effectively expressed ASA2 in the compartment in which Trp biosynthesis is localized in the cell.

• Research in Plant Disease
• /
• v.24 no.4
• /
• pp.257-264
• /
• 2018

Hydroponic strawberry culture system is increasing annually. Most of strawberry farmers use mulched bed in hydroponic culture and strawberry plants were transplanted in early September. After transplanting, Fusarium wilt caused by Fusarium oxysporum f. sp. fragariae and twospotted spider mite (TSSM), Tetranychus urticae, can increase their occurrence under high temperature condition. Therefore, we conducted for comparison occurrence of Fusarium wilt and TSSM on mulched with green polyethylene film and non-mulched bed. Occurrence of Fusarium wilt on mulched bed was started from early October and more increase than non-mulched bed. Damage rate of TSSM on mulched bed was shown higher than non-mulched bed. Temperature of substrate in mulched bed increased than non-mulched bed, but relative humidity near plants was decreased. As a result, use of non-mulched bed should be effective for reducing of Fusarium wilt and TSSM on strawberry plants.