• The Plant Pathology Journal
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• v.31 no.4
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• pp.441-445
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• 2015

Carrot (Dacus carota var. sativus) is one of the top-ten most economically important vegetable crops produced worldwide, and the root-knot nematodes, Meloidogyne spp., are one of the most important pests in the carrot. In Korea, M. hapla and M. incognita are presumed to be the major root-knot nematodes distributing mostly in open carrot fields and greenhouses, respectively. In our study, currently-developed and commercial carrot cultivars and the parental lines were examined for their pathological responses to M. incognita and M. hapla 7 weeks after inoculation with about 1,000 second-stage juveniles (J2) of the nematodes. All the carrot cultivars and lines showed susceptible responses to both nematodes with the gall index (GI) of 2.4-4.4, which were always higher on the carrot plants infected with M. incognita than M. hapla. Gall sizes were remarkably larger with more serious reduction of the root growths in the plants infected with M. incognita than M. hapla, suggesting the carrot lines examined in our study were more susceptible to the former than the latter. In the infection sites of the root tissues, giant cells were more extensively formed, occupying larger stellar regions with the prominent destruction of adjacent xylem vessels by M. incognita than M. hapla. All of these results suggest M. incognita affect more seriously on the carrot plants that are grown in greenhouses, compared to M. hapla that has a major distribution in open carrot fields, which would be used for determining cropping systems based on target nematode species, their damage and pathological characteristics.

• Journal of Life Science
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• v.10 no.1
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• pp.7-13
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• 2000

The purpose of this study was to investigate whether the extracts of Daucus carota L. could lead to a beneficial outcomes on serum lipid and antioxidative enzyme activity in ovariectomized rats. Sprague-Dawley rats were randomly assigned to one control and three diet groups; carrot seed, carrot root and estrogen after ovariectomy operation. Experimental diets were fed for 8 weeks. The GOT activity was decreased in the carrot extracts treated group than in the control group. The carrot seed extracts treated group showed the lowest SOD and catalase activities compare to other groups. Serum total cholesterol and LDL cholesterol decreased in the carrot seed extracts group than in the control group. From these results, it suggest that carrot seed extracts positively influenced on serum lipid and antioxidative enzyme activity.

• Research in Plant Disease
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• v.20 no.2
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• pp.129-131
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• 2014

In February 2014, gray mold rotting symptoms were observed in carrots in cold storage at Gangneung, Gangwon province, Korea. The typical symptom of gray mold rot showed abundant blackish gray mycelia and conidia was observed on the infected root. The pathogen was isolated from infected root and cultured on PDA for further fungal morphological observation and confirming its pathogenicity according to Koch's postulates. Results of morphological data, pathogenicity test and rDNA internal transcribed spacer (ITS 1 and 4) sequence showed that the postharvest gray mold rot of carrot was caused by Botyrtis cinerea. This is the first report of postharvest gray mold rot on carrot in Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.89-93
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• 1997

To determine the optimum levels of soil phosphorus and potassium for the carrot growth and to investigate the relationship between the quality of carrot root and, P and K contents in soil, carrot was planted in $1m^2$ bottomless pot with five levels of P and K. Maximum root weight was harvested in the plots with 425mg/kg of available P as $P_2O_5$ and $0.72cmol^+/kg$ of exchangeable potassium as K in soil at carrot shoot elongation stage. The concentrations of P and K in harvested carrot root were high in the plots with 359-396 mg/kg of available $P_2O_5$ and $0.79-0.87cmol^+/kg$ of exchangeable K. Sugar content in carrot root increased to available $P_2O_5$ 284 mg/kg in soil and it decreased as soil potassium increased.

• KSBB Journal
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• v.6 no.2
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• pp.195-199
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• 1991

The effects or polyamines on growth, anthocyanin contents and $\beta$-glucan synthetase(GSII) activity in carrot hairy root were studied. Growth of hairy root was stimulated somewhat when each polyamine concentration was treated, especially addition of 1mM spermidine resulted in about 20% increase. On the whole, the axial diameter of hairy root was increased in response to increase in concentration of polyamine. On the other hand, GSII activity was stimulated in response to increase in concentration of polyamine, especially addition of 1mM spermine resulted in about 100% increase of activity. Therefore increased activity of GSII stimulated growth and thickness of hairy root. Anthocyanin contents were not affected by the polyammine.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.617-621
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• 2002

In order to optimize the carrot hairy root culture for SOD production, a fed-batch culture of hairy roots was performed in a bioreactor. Maximum SOD activity was obtained when the hairy roots were transferred to the MS medium containing 110 g/1 concentration of sucrose. By controlling the sucrose concentration (70 g/1 sucrose for growth and 110 g/1 sucrose far production, respectively) In a two-stage fed-batch culture, 29 g/1 of the hairy roots was obtained based on the final dry mass. The volumetrically determined SOD activity and productivity in the fed-batch culture were about 6 times higher than those from the flask culture containing sucrose at 30 g/1 concentration.

• The Plant Pathology Journal
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• v.33 no.1
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• pp.66-74
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• 2017

This study was conducted to examine infectivity (penetration and gall and egg-mass formations) of the root-knot nematodes, Meloidogyne incognita and M. hapla, on carrots grown in soil conditions of 5 different soil textures consisting of bed-soil (b) and sand (s) mixtures (b-s mixtures) at the ratios of 10:0, 7:3, 5:5, 3:7, and 0:10. For M. incognita, the nematode penetration rates in b-s of 0:10 (100% sand) were significantly higher than in the other b-s mixtures, more greatly at 2 and 5 days after inoculation than at 10 DAI, while no significant differences in the penetration rates were mostly shown for M. hapla at the above DAI. However, for both nematodes, gall and egg-mass formations were remarkably increased in the b-s mixture of 0:10, compared to the other b-s mixtures, which is coincided with the general aspects of severe nematode infestations in sandy soils. This suggests the increased gall and egg-mass formations of M. incognita should be derived from the increased penetration rates in the sandy soil conditions, which provide a sufficient aeration due to coarse soil nature for the nematodes, leading to their mobility increased for the enhanced root penetration. For M. hapla, it is suggested that the sandy soil conditions affect positively on the healthy plant growth with little accumulation of the inhibitory materials and sufficient aeration, enhancing the nematode growth and feeding activities. All of these aspects provide information reliable for the development screening techniques efficient for the evaluation of the nematode resistance in the breeding programs.

• KSBB Journal
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• v.4 no.2
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• pp.94-98
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• 1989

In vitro attachment experiments of bacteria to surface of host plant cell were carried out using C14 labeled cells of A. rhizogenes strain A4 and carrot protoplasts isolated from suspension culture of cells. Protoplasts were cocultivated with A. rhizogenes at various times after their isolation. Attachment kinetics showed that adherence of bacteria to protoplasts attained a maximum level within 120mins of co-cultivation. Maximum attachment occured at pH 6.0 and 24-35$^{\circ}C$. Bacterial attachment was observed at botg carrot cells with and without primary cell wall. The inhibition of transformation on the carrot root discs by A. rhizogenes was observed when non-related strain and heat inactivated bacterial strain cells were pretreated.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.155-159
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• 1992

This study was carried out to know the effects of two kinds of peper mill sludge manure compost(SMC-1 and SMC-2) on the growth and chemical comments of carrot(Daucus carota L.) : SMC-1 contained 18% of swine manure and 8 % of sawdust on a fresh weight basis and SMC-2 contained swine manure without sawdust a third of the total weight of the manure and S-0(control) was treated with chemical fertilizer only, S-1 and S-2 was with SMC-1 and SMC-2 respectively, in addition to the chemical fertilizer. Carrot treated with S-1 and S-2 showed the increasing tendency of fresh weight per root and fresh yield of carrot per unit area than control(S-0), and the contents of nitrogen(N), phosporus(P), potassium(K) and calcium(Ca) in carrot grown on SMC treatments were higher than those on control(S-0), The S-2 treatment tended to increase values of the fresh weight of live leaves, root diameter, fresh weight per root and fresh yield of carrot per unit area than S-1 treatment. The contents in carrot were higher in the order of K>Ca, N. P>Mg, and the contents of aluminium, zinc, copper and chromium were below the level of toxicity for plant growth, and the contents of cadmium and lead were negligible. From the results obtained, it can be said that SMC application showed favorable effects on the growth of carrot when compared to control(S-0), and with the SMC treatments SMC-2 aplication was favorable.

• Horticultural Science & Technology
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• v.18 no.6
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• pp.802-807
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• 2000

This study was conducted to propagate the arbuscular mycorrhizal fungi in vitro using the hairy root of carrot transformed by Agrobacterium rhizogenes with Ri t-DNA. Mycorrhizal spores and roots in sudangrass plants were wet-sieved, surface-sterilized and inoculated onto the hairy root of carrot on the Modified Strullu & Romand (MSR) medium. The mycorrhizal spores of Glomus sp. propagated in vitro for 12 weeks was about $50{\mu}m$, and the shapes of spores were round or elliptic. Spores were formed mainly at the middle of the hyphae. Number of mycorrhizal spores propagated using dual culture of the transformed carrot roots and the mycorrhizal inoculum for 12 weeks were about 1,200 per plates.