• Food Science and Preservation
• /
• v.18 no.4
• /
• pp.497-501
• /
• 2011

The object of this study was to evaluate the effect of gibberellins (GA) pasting on the bourse shoot, and not just on the fruit characteristics but also on the quality, of Niitaka pear (Pyrus pyryfolia L). The fruit stalk was treated with GA (control, 25mg/fruit stalk) 35 days after reaching full bloom. In the GA-treated tree, the occurrence of abnormal bourse shoot (52.5%) increased, and the spur bud and flower number decreased. The diameter of the GA-paste-treated fruit increased during the pear growth period with GA treatment. The diameter, length, and weight of the GA-paste-treated fruit increased at harvest time, but the hardness was lower than that of the control. The differences in soluble solid, acidity, and fruit color between the control and the GA-paste-treated fruit were not significant. Post-harvest, during the storage period, the hardness of the GA-paste-treated fruit was lower than that of the control, and its weight loss ratio was higher than that of the control on the $60^{th}$ days of storage.

• Korean journal of applied entomology
• /
• v.57 no.3
• /
• pp.221-231
• /
• 2018

The susceptibility of the western flower thrips, Frankliniella occidentalis and garden thrips, Frankliniella intonsa was evaluated using 51 commercial insecticides. 15 kinds of insecticides which showed more than 90% mortality against both thrips, F. occidentalis and F. intonsa was selected. Many active ingredients were misused and abused in commercial mixture formulation insecticides. Since the F. intonsa was more susceptible than F. occidentalis, it was considered that both thrips can be controlled by insecticides that showed insecticidal activity on the F. occidentalis. Lethal time ($LT_{50}$ and $LT_{95}$), systemic toxicity and residual toxicity of selected insecticides were compared. Both chlorpyrifos WP and chlorpyrifos + diflubenzuron WP revealed the fastest toxicity within 2 h ($LT_{95}$), while spinetoram WG revealed the slowest toxicity as 62.3 h ($LT_{95}$). Chlorfenapyr SC showed toxicity at foliar and drenching application while spinetoram WG was toxic only in foliar application. Chlorfenapyr SC showed residual effect at 3, 5, 7, 10, 15 days after treatment and both benfuracarb WG and chlorpyrifos WP showed residual effect at 3 days after treatment. As a result of treatment of selected insecticides for field population of F. occidentalis, the population collected from horticultural crops showed lower susceptibility than the population collected from vegetable crops.

• Journal of Plant Biotechnology
• /
• v.39 no.3
• /
• pp.140-145
• /
• 2012

The flowering locus T (FT) gene, of which expression will be controlled at high temperature by heat shock promoter (it printed as to HSproFT), was introduced into spray-type chrysanthemum (Dendranthema grandiflorum (Ramat.) Kitamura) 2 cultivars ('Pink PangPang' and 'Pink Pride' by co-cultivation with Agrobacterium tumefaciens strain C58C1 harboring pCAMBIA2300 containing the HSproFT gene. After leaf segments of the 2 cultivars were infected with the A. tumafaciens with C58C1 as explants, shoots were regenerated from the explants cultured on the $1^{st}$ selection medium (MS basal salts + 1.0 mg/L BA, 0.5 mg/L IAA + 10 mg/L kanamycin + 0.7% plant agar, pH 5.8). The shoots were transferred into the $2^{nd}$ selection medium (MS basal salts + 1.0 mg/L BA, 0.5 mg/L IAA + 20 mg/L kanamycin + 0.7% plant agar, pH 5.8). One hundred seventeen plantlets from 'Pink PangPang' and 5 ones from 'Pink Pride' were confirmed as transformants by PCR analysis. Twenty six of the transformants and non-transformants were acclimatized and established well in a green house. Eights of 26 transgenic lines showed flower bud 1.7~10 days earlier than nontransgenic plants, and 24 of them flowered 1~6 days earlier than non- transgenic plants. The shape and color of flower of all HSproFT-transgenic lines were not different with those of non- transgenic plants.

• Journal of Korean Society of Forest Science
• /
• v.109 no.4
• /
• pp.512-520
• /
• 2020

We assessed the nectar source potential of a prospective honey plant, Idesia polycarpa, by analyzing nectar volume, free sugar content, and free amino acid content. Idesia polycarpa is a dioecious tree; the males bloom approximately four days earlier than females, and the blooming period is approximately 17 days-from March 14th to March 30th. Upon investigating the patterns of nectar secretion, it was found that male flowers peak on the third day of blooming at 5.0 ± 2.5 μL, and female flowers peak on the second day of blooming, at 1.1 ± 0.4 μL. There was a significant difference between males and females in the total nectar volume (9.7 ± 2.9 μL for males and 1.7 ± 0.5 μL for females) and the dried nectar volume (2.2 ± 0.6 μL for males, 0.8 ± 0.3 μL for females) during the blooming period. The free sugar content of floral nectar was 54.6 ± 15.4 ㎍/μL for males and 20.5 ± 4.9 ㎍/μL for females, and the sugar content per flower was higher in males (170.7 ± 15.4 ㎍) than in females (24.9 ± 5.5 ㎍). Our analysis of the amino acid content showed that 20.4 ± 3.9 mg/L (comprised of 19 amino acids) is produced in male flowers and 3.2 ± 0.1 mg/L (11 amino acids) in female flowers. In the male flower, the main amino acid was glutamine, followed by asparagine and proline, whereas in the female nectar, asparagine was the main amino acid, followed by glutamic acid and glutamine. Idesia polycarpa blooms after the blooming period of a major honey plant, Robinia pseudoacacia, and its nectar volume and nectar characteristics, such as free sugar content and amino acid content, make it a viable honey plant.

• Korean Journal of Agricultural Science
• /
• v.4 no.1
• /
• pp.51-60
• /
• 1977

In order to determine ecological variations of flowering date and yields under the different seasonal cultures, and to select the higher yielding varieties which were adaptable to Korean climate, 100 mungbean cultivars were sown at the interval of 15 days from April 22 to July 21 in 1976. The results obtained are summarized as follows: 1. The number of days required to flowering from seeding were decreased by delaying the seeding date. 2. When accumulated temperature at first flowering from seeding were reached $945-1,126^{\circ}C$, the mungbean cultivars started to flower regardless of seeding dates. Especially, when mungbean was planted around standard planting date, the plants flowered for very short duration. 3. There were highly significant correlations between the number of days from seeding to flowering at each seeding date and standard planting date. 4. Yields per plant were tend to decrease with the delay of seeding date but there were no significant difference between seeding dates. Therefore, it appears that mungbean can be planted for longer period of time compared to other crops such as rice and soybean. 5. Highly significant correlations were found between the number of days of first flowering and yields per plant at most seeding dates. 6. It may be feasible to grow high yielding mungbean cultivars such as CES 140, LM 2100, LM 690, L 576 and LM 689 after harvesting of spring vegetables in May and before planting of fall vegetables.

• Journal of Crop Science and Biotechnology
• /
• v.11 no.3
• /
• pp.199-204
• /
• 2008

Seed dormancy behavior of weed seeds is a critical determinant of their survival rates in a given cropping system as it helps the weeds to evade herbicides and other weeding practices. We investigated the effects of red light, alternating temperature, stratification duration and different doses of nitrogen containing compounds alone or in combination with red light on breaking seed dormancy of Chenopodium album L. The application of red light(80 ${\mu}mols^{-1}m^{-2}$) significantly increased seed germination of C. album in all treatments. Germination rates of 12 h incubated seeds were highest under 20 min of red light irradiation than 1 min, 5 min and 10 min treated seeds. Germination rate was significantly higher at alternating temperatures of $25^{\circ}C\;and\;5^{\circ}C$ for 12 h each with an irradiation of red light(80 ${\mu}mols^{-1}m^{-2}$) for 10 min than other treatments. Stratification period of 15 days significantly stimulated germination percentage of seeds incubated in dark, although 5 days of stratification along with red light application for 10 minutes exhibit similar effects on seeds. Seed germination was also enhanced by nitrogen containing compounds like $NaNO_2,\;KNO_3,\;NH_4Cl\;and\;NH_4NO_3$. We observed that seed germination increased significantly with 25 mM $KNO_3$ and 10 mM $NH_4NO_3$ in dark condition, while $NaNO_2$ and $NH_4Cl$ enhanced seed germination under red light irradiation. It was concluded that red light alone or synergized with alternating temperatures, stratification and nitrogen compounds, especially nitrite and ammonium enhanced seed germination of C. album. Thus, the red light can play a vital role in present and future weed management strategies.

• Korean Journal of Plant Tissue Culture
• /
• v.25 no.2
• /
• pp.135-139
• /
• 1998

Reciprocal interspecific hybrids between N. glauca(2n=24) and N. langsdorffii(2n=18) were obtained by intercrossing. One hundred percent of F$_1$ seeds was produced from intercrossing of N. glauca $\times$ N. langsdorffii, whereas the frequency of F$_1$ hybrid seed formation from N. langsdorffii $\times$ N. glauca was very low. However, all the hybrid seeds were germinated well and then grown to normal plantlets. All the plants of F$_1$ hybrids have chromosome number of interspecific hybrids (2n=21). From observation of morphological characteristic, the structure of petrol, leaf, flower, and the morphology of pollen have characteristics of F1 hybrid. Spontaneous tumors (genetic tumor) were formed from each F$_1$ hybrid; the genetic tumor arose at the reproductive phase when the maternal type of F$_1$ hybrid came from N. glauca, while the genetic tumor arose only after reproductive phase when the maternal type of F$_1$ hybrid came from N. langsdorffii. The genetic tumor actively proliferated on hormone-free medium and produced numerous teratoma shoots. In addition, normal leaf or stem explants of F$_1$ hybrid produced calli on hormone-free medium after 15 days of culture, the calli produced new numerous teratoma shoots after 30 days. The frequency of teratoma shoot formation from rnterspecific hybrid was higher in the N. glauca $\times$ N. langsdorffii than in the N. langsdorffii $\times$ N. glauca. Root development from the teratoma shoots was hardly obtained. Teratoma shoots without roots in vitro can form genetic tumor at the vegetative growth phase after tissue culture.

• Journal of agriculture & life science
• /
• v.43 no.2
• /
• pp.23-30
• /
• 2009

The object of this study was to evaluate the effect of the gibberellin treatment on fruit enlargement and ripening promotion in 'Niitaka' pear(Pyms pynfolia). Fruit weight was similar between $GA_{4+7}$ treatments and the gibberellin-paste control, but fairly increased of fruit weight compared to non-treatment Most effective time for $GA_{4+7}$ treatment to increase diameter and length was on 35 and 40 days after full bloom, respectively. Shape index was similar in all treatments. Fruit enlargement at the period of early growth, $GA_{4+7}$ 2.4% treatment was remarkably effective than $GA_{3}+GA_{4+7}$ 2.7% treatment or non-treatment However at the period of maturity, $GA_{4+7}$ 2.4% treatment and $GA_{3}+GA_{4+7}$ 2.7% treatment showed little differences in fruit enlargement and coloring. In maturing promotion effect, young fruit treated with $GA_{3}+GA_{4+7}$ showed similar fruit coloring to ethephon treatment on 35 days after full bloom, and both of those treatments promoted fruit coloring than non- treatment about 6 days. $GA_{3}+GA_{4+7}$ treatments resulted higher solid content and decreased acidity than non-treatment However, there was no differences in fruit hardness comparing to non-treatment As a result, gibberellin was most effective in fruit enlargement, so as all $GA_{3}+GA_{4+7}$ treatments were more effective on fruit enlargement than ethephon treatment or non-treatment Specifically, when $GA_{3}+GA_{4+7}$ was treated 35days after full bloom of flower, the diameter, the length and the shape of fruit index were best, and fruit coloring was good as well.

• Horticultural Science & Technology
• /
• v.18 no.1
• /
• pp.28-32
• /
• 2000

This study was carried out to investigate the effects of uniconazole treatment on the growth and flowering of potted Chrysanthemum indicum L. for high quality pot plant production. Uniconazole was drenched at 0.05, 0.01, or 0.15 mg a.i./pot at 14 days after planting (DAP) of rooted cuttings. Simultaneously the short-day treatment (SDT) and pinching were adapted. The same amount of uniconazole (0.05 mg a.i./pot) was spilt drenched at once, twice, and three times, respectively, at 1 week interval. Uniconazole markedly reduced plant height, branch length, and stem diameter. Plant height was reduced linearly with increasing uniconazole concentration at 0.05, 0.01, or 0.15 mg a.i./pot up-to 41.6%, 52.5%, and 58.5%, respectively. In 0.05 mg a.i./pot, the number of branches greatly increased and plant height of 22.6 cm was adequate for pot plant. However, higher concentrations (0.10, 0.15 mg a.i.) were not suitable for production of high quality pot plant (17.0, 14.8 cm, respectively). Pinching and SDT decreased the number of days to visible bud, while uniconazole treatments delayed days to visible bud by 5-9 days compared with pinching and SDT. Number of visible buds was highest at 0.05 mg a.i./pot uniconazole treatment. However, flower diameter was decreased by uniconazole treatment, resulting in compact form. Number of stomata was increased by uniconazole treatment. The length of vascular tissues of uniconazole-treated plants ($11.2{\mu}m$) was smaller than that of non-treated plants ($15.0{\mu}m$, and the size of xylem vessel was also decreased. Uniconazole treatment at 0.05 mg a.i./pot at 14 DAP with pinching and SDT were recommended for pot plant production of C. indicum L.

• Horticultural Science & Technology
• /
• v.32 no.1
• /
• pp.60-65
• /
• 2014

This study was conducted to investigate the antimicrobial effect of chlorine dioxide ($ClO_2$) on the vase life of cut rose 'Beast' (Rosa hybrida L.). Postharvest treatments to extend the vase life of cut roses were divided into two: holding solution treatment and pulsing solution treatment. In holding solution treatment, the cut roses were treated with preservative solutions containing tap water (TW, control), distilled water (DW), $ClO_2$ 2, 4, 6, and $8{\mu}L{\cdot}L^{-1}$, and compared with a commercialized antimicrobial compound of 8-HQS $200{\mu}L{\cdot}L^{-1}$. In pulsing solution treatment, cut roses were dipped into the $ClO_2$ solutions of 50, 100, 150, 200, and $250{\mu}L{\cdot}L^{-1}$ for 60 seconds and were placed in DW. The air temperature was $18.4^{\circ}C$, RH 51.5%, and light (photosynthetically active radiation, PAR) $3.6{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ with 12 hour day length. The longest vase life of cut roses was observed in the holding solution with $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ as 13.8 days and pulsing with $200-250{\mu}L{\cdot}L^{-1}$ as 13.5-13.7 days, where vase life were extended four days longer than TW. Whereas, the inclusion of 8-HQS $200{\mu}L{\cdot}L^{-1}$ in vase solution resulted in phytotoxicity. The relative fresh weight and water uptake have similar tendencies. Bacteria inhibition by $ClO_2$ and 8-HQS were very effective. But bacteria at TW and DW treatments on cut flower with stem were detected in $3.7{\times}10^5CFU{\cdot}L^{-1}$ and $6.3{\times}10^5CFU{\cdot}L^{-1}$, respectively (without stem in DW $1.4{\times}10^4CFU{\cdot}L^{-1}$). The $ClO_2$ contents in holding solution of all treatments were scavenged in two-four days after treatment. This study indicated that $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ holding solution treatment and $200-250{\mu}L{\cdot}L^{-1}$ pulsing solution treatment can be applied to extend the postharvest life of cut roses.