• Horticultural Science & Technology
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• v.30 no.4
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• pp.426-431
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• 2012

This study was conducted to establish an efficient screening method for resistant tomato to Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (FOL). The resistance degrees of the six commercial cultivars of tomato to the pathogen were evaluated by dipping roots of the seedlings in spore suspension of five FOL isolates. On the basis of the results, two cultivars (Dotaerangmaster, resistant cultivar to FOL race 1; Supersunload, resistant cultivar to FOL race 2) and two isolates (KACC40043, FOL race 2; TF104, FOL race 3) were selected for system establishment. The disease development of the FOL isolates on the cultivars according to several conditions including root wounding, incubation temperature, inoculum concentration and dipping period of roots in spore suspension was investigated. The resistance of each cultivar to the disease was a race-specific response and hardly affected by the tested conditions except for incubation temperature of $20^{\circ}C$. The optimum temperature for disease development caused by FOL was 25 to $30^{\circ}C$. On the basis of the results, we suggest that an efficient screening method for resistant tomato cultivars to Fusarium wilt is to dip the non-cut roots of tomato seedlings at two-leaf stage in spore suspension of $1{\times}10^7\;conidia{\cdot}mL^{-1}$ for 0.5 hours and transplant the seedling to plastic pot with horticulture nursery media, and then to cultivate the plants in a growth room at $25^{\circ}C$ for 3 weeks with 12 hours light a day.

• Journal of Bio-Environment Control
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• v.12 no.4
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• pp.173-179
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• 2003

This study was established to control the overgrowth of cucumber and tomato plug seedlings by controlling of irradiation timings light intensities of red (R) light. Compared with the control, end-of-day (EOD) timing of R irradiation significantly reduced the seeding heights by 21.3% and 14.2% in cucumber and tomato, respectively. In addition, both plant seedlings treated with R light at EOD timing had the thickest stem diameter. Tomato seedlings treated with R light at EOD showed th highest chlorophyll content and the smallest leaf size. Dry weights of above ground plant tissue in both plant seedlings were significantly reduced by EOD R light treatment. And both plant seedlings treated with EOD treatment had the lowest T/R ratio, and the highest compactness rates. The increased intensities of R light resulted in the shorter plant heights in cucumber and tomato plant seedlings. It also reduced the length of hypocotyls and internodes and the size of leaves in the both seedlings. Elevated R light intensities tended to increase the stem diameter and chlorophyll contents. Dry weights of above ground plant tissue and roots in both plant seedlings were reduced by the elevated R irradiation. Cucumber seedlings treated with 2 and 8 $mol{\cdot}m^{-2}{\cdot}s^{-1}$ and tomato seedlings treated with 8 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ had significantly lower T/R ratio the other treatments tested.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.1
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• pp.8-14
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• 2000

Long term cultivation crops like tomato, capsicum, melon etc. demand much amount of continuous supplying of nutrition during the whole growing periods. It is not easy to cover satisfactorily the nutritional demands for them by splitted top dressings, slow release fertilizer applications and fertigation systems. To overcome these problems, the "CULTAN" (Controlled Uptake Long Term Ammonium Nutrition) Beaker Deposit techniques have been developed and it was put into PVC beaker with the combined nitrogen fertilizer type mixed with the ratio of one-third of ammonium sulfate-N and two-thirds of urea-N, in which nitrogen was loaded on the demanding amount of a tomato plant during the growing period. Gypsum was mixed as a binder, and loamy soil and compost were used as a diffusion regulator. It was placed upside down into root zone of tomato at the transplanting. Tomato roots were spreaded into the Deposit beaker by ammonium ions which attract root growth. The tomato fruit yield and nitrogen uptake by plant were increased by application of $NH_4$-Beaker deposit fertilizer rather than those of common fertilizer treatment. In conclusion, it was able to improve economic and ecological benefits through CULTAN system compared with common fertilization systems. CULTAN system was estimated as a prospective alternative to enhance productivity and minimize nutrient lose. In addition, it shows further developing possibility of CULTAN system by the supplement of micro-nutrients and pesticides in the macro-nutrient beaker deposits.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.172-173
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• 1998

A research collection of Pseudomons solanacearum bacteria, a pathogen causing ‘bacteria wilt’ disease of more than 265 plant species, represented for northern provinces of Vietnam has recently been established and was saved for examination of antifungal activity in their culture fluids. All strains used in this work have been isolated from infected tomato, potato, and groundnut collected from production fields and they express different levels of virulence on their host plants. Cell-free culture fluids of these strains were tested for antifungal activity (to inhibit growth of mycelium and to destroy germination tube of fungal spores) on a number of fungi that either infect or associate with vegetable crops of Solanaceae family (tomato, potato, pepers...), fruit plants (banana), and even well-known by Vietnamese traditional medicine herbal plants belonging to Trifoliatus, Schefflera, Homalomena and Panax genera (Araliaceae family) of which roots are used as a resource of the herbal material. The antifungal activity was found in nearly all strains tested. Result of study on chitin, CMC, tween 80 and casein degradation abilities of the latter suggested that antifungal activity of positively-found strains may be due to their ability of extracelluar chitinase's excretion that destroy fungal cell wall.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.483-487
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• 2001

This study was carried out to investigate the role of attached leaflet on rooting and growth by one nodal cutting in tomato. As cutting sources 4 to 6 nodes could be obtained from one nursery seedling. Medium for cutting was a mixture with perlite plus peat moss (1 : 1, v/v), and each plug capacity was 30mL in the 72 cells-plug tray. Plant height and the number of leaves were significantly increased by attached leaflet cutting in 'Pepe' and 'Coco' cherry tomato. Dry weights of top and root were increased as much as 3 to 15 times in the cutting attached leaflet. Rooting percentage was 93.5% in one node cutting and 86% in the cutting with hypocotyl node part. At 20 to 24 days after nodal cutting, healthy nursery plant could be produced to transplant in field. The nursery plants by nodal cutting (NPNC) showed more fibrous roots and less tap roots than that of seedling. In terms of rooting pattern, NPNC rooted at the whole ground stem part, while rooting of seedling occurred at basal part of hypocotyl.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.84-89
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• 2003

In order to find a chemical agent which is able to modulate the activity of $H^+-ATPase$, microsomal preparation was obtained from the root tissue of tomato plant and the effect of $La^{3+}$ was measured. The activities of plasma and vacuolar membrane $H^+-ATPase$ were analyzed by the inhibited activities using their specific inhibitors, vanadate and $NO_3-$, respectively. $La^{3+}$ inhibited microsomal ATPases in a dose-dependent manner and the inhibitory effect of $La^{3+}$ was suppressed by both vanadate and $NO_3-$, implying that $La^{3+}$ inhibits both plasma and vacuolar membrane $H^+-ATPase$. The Ki. values of $La^{3+}$which inhibit 50% of the activities of plasma and vacuolar membrane $H^+-ATPase$ were 57 and $78\;{\mu}M$, respectively. The $H^+-ATPase$ of the leaky microsomes made by the treatment of Triton X-100 were also inhibited by $La^{3+}$, suggesting that $La^{3+}$ directly inhibits both enzymes. Meanwhile, the inhibitory effect of $La^{3+}$ was decreased by increasing the concentration of ATP, The effect of ATP was also concentration-dependent and 7 mM ATP completely removed the inhibitory effect of $La^{3+}$. These results imply that $La^{3+}$ inhibits both plasma and vacuolar membrane $H^+-ATPases$ by decreasing the binding affinity of ATP and $La^{3+}$ can be used to control the activity or root $H^+-ATPases$.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.365-372
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• 2020

This study was conducted to compare the effects of foliar spray and sub-irrigation of the triazole fungicide diniconazole on the regulation of stem elongation and to investigate the stimulation of root system development during the seedling stage. Comparing the two application approaches, there were significant differences in the leaf area, leaf area ratio (LAR), plant height, compactness, fresh shoot and root production, relative growth rate (RGR), and root to shoot ratio (R/S). At the same application concentration, the sub-irrigation showed a better retarding effect on growth than the foliar spray, because the PGR activity of diniconazole in root absorption was higher than that in shoot absorption. For reaching a target of 20% to 30% inhibition rate of stem length, foliar application concentration of diniconazole exceeded 10, however, only approximately 1 was required in the sub-irrigation application. The root system of tomato seedlings responded strongly to diniconazole application. Total root length, root volume, root average diameter, and the number of root tips increased when diniconazole was sub-irrigation application at 1. A reduction in fine roots (diameter range of 0 to 0.3 mm) and an increase in the roots with a diameter range of 0.3 to 0.6 mm was observed, and this may contribute to the increase in average diameter. The increase in root average diameter may be positive because root penetration increases with root diameter. Our results suggested that sub-irrigation maximized the PGR activity of diniconazole to enhance the retarding effect. And it also possible to enhance the tomato seedling root system by diniconazole stimulating with a lower concentration.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.23-28
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• 2002

This experiment was conducted far the efficient use of plant growth retardants (PGR) for suppression of plug seedling height. 'Seokwang' tomato seeds were soaked in I5 mL solution of daminozide (1,000, 10,000, or 100,000 mg.L-1) or uniconazole (1, 10, or 100 mg.L-1). And then, they were put in $25^{\circ}C$ chamber for one or three days. Seeds were washed in tap waters and were dried in 5$^{\circ}C$ chamber for one day. Dried tomato seeds were sown and seedlings were raised in 288-cell plug trays. Seedlings grown were evaluated at 21 and 38 days after sowing. Treatments of 10 or 100 mg.L-1 uniconazole as compared to the control had significantly suppressed hypocotyl length and seedling height, but fresh and dry weights of roots, emergence, no. of leaves, chlorophyll concentration, dry matter, and T/R ratio were not significant by different among treatments.

• Molecules and Cells
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• v.37 no.2
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• pp.109-117
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• 2014

Microbiota in the niches of the rhizosphere zones can affect plant growth and responses to environmental stress conditions via mutualistic interactions with host plants. Specifically, some beneficial bacteria, collectively referred to as Plant Growth Promoting Rhizobacteria (PGPRs), increase plant biomass and innate immunity potential. Here, we report that Enterobacter sp. EJ01, a bacterium isolated from sea china pink (Dianthus japonicus thunb) in reclaimed land of Gyehwa-do in Korea, improved the vegetative growth and alleviated salt stress in tomato and Arabidopsis. EJ01 was capable of producing 1-aminocy-clopropane-1-carboxylate (ACC) deaminase and also exhibited indole-3-acetic acid (IAA) production. The isolate EJ01 conferred increases in fresh weight, dry weight, and plant height of tomato and Arabidopsis under both normal and high salinity conditions. At the molecular level, short-term treatment with EJ01 increased the expression of salt stress responsive genes such as DREB2b, RD29A, RD29B, and RAB18 in Arabidopsis. The expression of proline biosynthetic genes (i.e. P5CS1 and P5CS2) and of genes related to priming processes (i.e. MPK3 and MPK6) were also up-regulated. In addition, reactive oxygen species scavenging activities were enhanced in tomatoes treated with EJ01 in stressed conditions. GFP-tagged EJ01 displayed colonization in the rhizosphere and endosphere in the roots of Arabidopsis. In conclusion, the newly isolated Enterobacter sp. EJ01 is a likely PGPR and alleviates salt stress in host plants through multiple mechanisms, including the rapid up-regulation of conserved plant salt stress responsive signaling pathways.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.156-161
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• 2006

Overhead and sub-irrigation of deep sea water to tomato seedlings reduced the height as 50% and 58% than control plants. In the same treatment with surface sea water and NaCl water, the reduced rate in tomato seedlings' height were 49% and 56% in overhead irrigation, and 47% and 57% in sub-irrigation, respectively. Most effective method for the inhibition of the growth of the seedling was sub-irrigation method, which supplied water through the roots. No significant difference was observed on fresh weight of the upper part of tomato and cucumber seedlings, though the sub-irrigation reduced the fresh weight than the overhead irrigation. The reduced rate of fresh weight of seedlings by overhead irrigation was by 38% and sub-irrigation by 49% as compared to control. Similarly dry weight of upper and under soil parts of seedlings showed same trend of results thereof as fresh weight. This result can be traced to reduction of growth caused by salts in the water. In stem diameter of seedlings no significant difference was observed between two irrigation methods, even though both deep sea and NaCl water reduced stem diameter, as compared to control water. Overhead irrigation can be chosen by seedling producers because of better seedling quality by using TH ratio. Seedling compactness were not noticed in both the overhead and sub-irrigation. Sub-irrigation was found more effective method far the inhibition of height and compactness of tomato seedlings. Higher the concentration of NaCl, deep sea, and surface sea water, lesser the growth in height, fresh and dry weight, stem diameter, and leaf area was obtained. No significant difference was found, though sub-irrigation suppress the growth of seedlings.