• Horticultural Science & Technology
• /
• v.17 no.3
• /
• pp.333-336
• /
• 1999

Current season's shoots on 2-year-old branches of 'Fuji' and 'Jonagold' apple trees were heading back pruned to 5 leaves from early May to mid July at about 12-day intervals. The summer heading back pruning induced regrowth on the pruned shoots with different responses between the two cultivars. Generally, greater regrowth occurred on the pruned shoots of 'Fuji' trees than on those of 'Jonagold', irrespective of the time of the heading cut. The shoots of 'Fuji' trees pruned in late May or in June exhibited greater regrowth compared with those pruned in early May or in July, whereas the summer heading back pruning in June resulted in the greatest regrowth for 'Jonagold'. The heading cut induced terminal flower bud formation on the pruned shoots, the percentage of which was higher in 'Fuji' than in 'Jonagold'. The highest percentages of terminal flower bud formation for 'Fuji' and 'Jonagold' were obtained with the heading cut in late May and in mid June, respectively. Percent flowering of the buds was similar in both cultivars, but percent fruit set was slightly higher in 'Fuji' than in 'Jonagold'. The time of the heading cut did not affect percent fruit set in both cultivars. Our results demonstrate that summer heading back pruning of current season's shoots induces regrowth and terminal flower bud formation therefrom when done at appropriate time, but the specific responses to the heading cut are cultivardependent.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2020.08a
• /
• pp.50-50
• /
• 2020

본 연구는 천궁에 감염된 오이모자이크바이러스(CMV)와 천궁엽맥황화바이러스(CnVYV)의 제거를 위해 항바이러스제인 리바비린 처리 효과를 조사하기 위해 수행되었다. 천궁 기내식물체의 생장점을 절취 후 항바이러스제 농도를 달리한 배지에서 생육을 유도한 후 RT-PCR 방법을 통해 바이러스 검출율을 조사하였다. 리바비린을 40 mg l^-1 농도로 처리하였을 때 바이러스 검출 종 수는 1.1종으로 감소하였다. 또한 동일조건에서 CMV와 CnVYV-2의 검출율은 무처리구 대비 각각 1/5과 1/2 수준으로 감소하였다. 하지만 리바비린 처리에 따른 CnVYV-1의 검출율은 감소하지 않았다. 리바바린 처리 농도에 따른 생존율은 처리구별로 유의적인 차이가 나타나지 않았으나, 40 mg l^-1 리바비린 처리구에서 신초 발생 수와 신초 길이는 무처리구 대비 절반 수준으로 감소하였다. 리바비린 처리를 통해 CMV와 CnVYV-2가 미검출된 23개체를 선발하였으며, 추가적인 바이러스 검정 단계를 거쳐 무병묘 생산에 활용될 것이다.

• Journal of Plant Biotechnology
• /
• v.42 no.4
• /
• pp.396-400
• /
• 2015

To investigate the optimal conditions for shoot organogenesis in Astragalus sinicus L., hypocotyl explants were cultured in Murashige & Skoog's (MS) medium supplemented with 0.1, 1.0, 2.0, or 4.0 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) for 6 weeks. 2,4-D concentration significantly effected morphogenesis: some produced calli with adventitious shoots and roots, some produced calli with adventitious roots, some produced only calli, and some produced deep-brownish calli with roots. The formation of calli with shoots and/or roots was observed at lower levels of 2,4-D, whereas calli without shoots or with deep-brownish roots were formed after treatment with higher levels of 2,4-D. Also, a shoot organogenesis ability of callus clones was observed after treatment with medium with 0.1 or 1.0 mg/L 2,4-D grown in MS medium with combinations of benzyl adenine (BA) and 2,4-D for 4 weeks. Medium with a combination of BA and 2,4-D was effective for shoot formation, whereas root organogenesis from calli decreased. The greatest amount of shoot formation was obtained when calli were cultured in MS medium containing 1.0 mg/L 2,4-D and 0.5 mg/L BA. Upon shoot transfer into 1/2 MS basal medium, plantlets developed, and the plantlets grew well in soil in a greenhouse.

• Horticultural Science & Technology
• /
• v.16 no.4
• /
• pp.520-524
• /
• 1998

This study was carried out to investigate the effect of thidiazuron(TDZ) on callus and shoot primordia formation, to determine the most optimum multiple shoot induction medium, and to obtain the plantlets on solid medium via shoot organogenesis. TDZ 0.01 mg/L in MS medium was most effective on callus formation, and BA 0.1 mg/L was most effective on shoot growth, while TDZ 0.01 mg/L was most effective on callus formation. TDZ 0.001 mg/L was most effective in shoot primordia formation. Shoot tips were cultured with TDZ 0.01 mg/L for 8 weeks and induced callus was transferred to regeneration medium containing TDZ 0.001 mg/L. After 4 weeks induced shoot primordia were resubcultured at growth regulator-free medium for 4 weeks. The induced multiple shoots rooted more efficiently at NAA 1.0, 5.0 mg/L, or IBA 5.0 mg/L.

• Korean journal of applied entomology
• /
• v.58 no.3
• /
• pp.175-182
• /
• 2019

The citrus leafminer, Phyllocnistis citrella (Lepidoptera: Gracillaridae), is an important pest that decreases the productivity of citrus trees by attacking citrus leaves, and especially it causes a severe damage during the young growth stage. In this study, we investigated the distribution of eggs on the leaves of shoots according to the position and the survival rate of this pest in the field condition. The occurrence patterns of P. citrella eggs in citrus orchards were largely affected by the occurrence of shoots. Even if the adults were still being attracted in the pheromone traps, the eggs were not observed on leaves when the growth of shoots was stopped. The density of P. citrella eggs in the citrus shoots peaked at the fifth or sixth leaf from the terminal leaf, and over 90% of the eggs were found in the first to eighth leaves as a whole. In 2015 and 2016, the average survival rate of larvae surviving to pupa was 1.4%, and the rate of survival to adults was 0.2%, indicating that most of them died. Furthermore, we have discussed the management strategy of P. citrella considering the distribution of eggs and the larval survival rate in the citrus shoots.

• Current Research on Agriculture and Life Sciences
• /
• v.32 no.2
• /
• pp.99-103
• /
• 2014

This study investigated the effects of cryopreserving Chrysanthemum morifolium cv. 'White ND' shoot tips for eliminating viroids. As a result, smaller shoot tips (2-3 LP, 1mm) showed a better survival and regrowth than larger shoot tips (4-5 LP, 1.5mm). The most effective vitrification solution for survival and regrowth was PVS3, which induced a high survival rate after 60 minutes of incubation. For a high efficiency, the best pre-treatment condition for vitrification was incubation in 88 mM sucrose for 24 h, 0.3M sucrose for 16 h, 0.5 M sucrose for 6 h, and 0.7 M sucrose for 3 h, in a descending order. The ploidy levels were the same in the mother plants and following cryopreservation, which confirmed the absence of any gene mutation.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.3
• /
• pp.191-195
• /
• 2000

Adventitious shoots were induced from cotyledon and hypocotyl explants of apple hybrid seedlings (P.16$\times$ Malus prunifolia) on MS medium supplement with 2,4-D and various cytokinine (Kn. BA, TDZ) The shoot regeneration from the cotyledon culture was the highest on MS medium supplemented with 1.0 mg/L NAA and 2.0 mg/L BA. Whereas in case of hypocotyl culture, it was the highest on MS medium supplemented with 0.5 mg/L NAA and 0.5 mg/L BA. However, in the MS medium without BA there was no shoot regeneration. Hypocotyl culture seemed to be more effective than cotyledon culture in shoot regeneration. Specially, the top position of the hypocotyl found to be the best explant for shoot induction among the other segments of hypocotyls. Regenerated shoots were rooted on half-stength MS medium with 1.0 mg/L NAA. Above results suggest that Apple hybrid (P.16 $\times$ Malus prunifolia) can be multiplied via cotyledon or hypocotyl culture systems.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.1
• /
• pp.1-6
• /
• 2000

This study was carried out to find the effects of plant growth regulators on callus formation, rooting and shooting from cotyledon explant in oriental me]on. Various combinations of 0.1 mg/L auxins (IAA, NAA) and 0.5, 1.0. 1.5, 2.0 mg/L cytokinins (BA, kinetin, zeatin) were treated to the MS basal medium, respectively. Callus was induced mort effectively as 2,437.0 mg (FW)/explant in MS medium supplemented with 0.1 mg/L NAA and 2.0 mg/L BA, but that was non-embryogenic callus as colored yellow white and broke easily. Root was induced most effectively at a frequency of 98.0% in MS medium supplemented with 0.1 mg/L NAA and 0-5 mg/L kinetin. Shoots formed on cut part of vein at a frequency of 98.0% in MS medium supplemented with 0.1 mg/L IAA and 2.0 mg/L BA, that were multiple shoots. in case of its concentration, BA and lower concentration of IAA and NAA (0.01 and 0.05 mg/L). respectively. shooting ratio was not increased. The result of treatment with BA 0-5 mg/L and IAA 0.1 mg/L, callus induced at a week, and shoot start to form multiple shoots about 3 weeks after inoculation. After 2 times subculture as 2 weeks intervals, divided shoots rooted and developed into intact plantlets at 10 weeks and then that grown normally on pots after acclimatization.

• Korean Journal of Plant Tissue Culture
• /
• v.25 no.1
• /
• pp.63-68
• /
• 1998

Multiple shoots obtained in MS medium suppler with 5.0 mg/L BA though shoot-tip culture. The frequency of vitrified shoot was lower on Bacto-agar medium than on Gelrite as gelling agent. Addition of activated charcoal at concentrations of 0.1~0.3% reduced vitrification and markedly increased shoot growth, and formation and growth of roots, but significantly reduced the number of shoots formed. The ratio of fresh weight to dry weight was decreased by increasing light intensity and agar concentration. Eight-tenths times of macroelement of MS medium was observed to be effective for shoot formation. Addition of IAA effectively promoted shoot formation in both shoot tip and node-bud explants. Supplement of 5.0 mg/L BA, 0.3 mg/L IAA to MS medium was most effective in shoot proliferation on shoot tip and node-bud explants.Multiple shoots obtained in MS medium suppler with 5.0 mg/L BA though shoot-tip culture. The frequency of vitrified shoot was lower on Bacto-agar medium than on Gelrite as gelling agent. Addition of activated charcoal at concentrations of 0.1~0.3% reduced vitrification and markedly increased shoot growth, and formation and growth of roots, but significantly reduced the number of shoots formed. The ratio of fresh weight to dry weight was decreased by increasing light intensity and agar concentration. Eight-tenths times of macroelement of MS medium was observed to be effective for shoot formation. Addition of IAA effectively promoted shoot formation in both shoot tip and node-bud explants. Supplement of 5.0 mg/L BA, 0.3 mg/L IAA to MS medium was most effective in shoot proliferation on shoot tip and node-bud explants.

• Journal of Plant Biotechnology
• /
• v.42 no.1
• /
• pp.49-54
• /
• 2015

Based on the results in this study, here we propose a systematic micropropagation process for 'Gisela 5' that is one of the important dwarfing cherry rootstocks. When the apical tips detached from newly developed shoot in spring season were cultured on the half strength MS media with 0.5 mg/L IBA and 0.5 ~ 1.0 mg/L BA, the cultures scored the highest acquisition rate at 90% for normal shoot with vigorous growth and without hyperhydricity. As next step, the young shoots maintained in vitro well multiplied on the full strength MS medium supplemented with 0.5 mg/L IBA and 0.5 mg/L BA, in which multiplication rate was approximately nine-fold. Given the half strength MS medium containing 2.0 mg/L IBA, each transplanted shoot further developed robust roots. Finally, the plantlets were easily acclimatized in the compost consisted of vermiculite, perlite, and peatmoss in the proportion of 1:1:1. We expect that the results are useful for cherry cultivation and its rootstock production.