Showing papers by "Yoo Gyeong Park published in 2019"

Flowering and Morphogenesis of Kalanchoe in Response to Quality and Intensity of Night Interruption Light.

Abstract: The effects of the quality and intensity of night interruption light (NIL) on the flowering and morphogenesis of kalanchoe (Kalanchoe blossfeldiana) ‘Lipstick’ and ‘Spain’ were investigated. Plants were raised in a closed-type plant factory under 250 μmol·m−2·s−1 PPFD white light emitting diodes (LEDs) with additional light treatments. These treatments were designated long day (LD, 16 h light, 8 h dark), short day (SD, 8 h light, 16 h dark), and SD with a 4 h night interruption (NI). The NIL was constructed from 10 μmol·m−2·s−1 or 20 μmol·m−2·s−1 PPFD blue (NI-B), red (NI-R), white (NI-W), or blue and white (NI-BW) LEDs. In ‘Spain’, the SPAD value, area and thickness of leaves and plant height increased in the NI treatment as compared to the SD treatment. In ‘Lipstick’, most morphogenetic characteristics in the NI treatment showed no significant difference to those in the SD treatment. For both cultivars, plants in SD were significantly shorter than those in other treatments. The flowering of Kalanchoe ‘Lipstick’ was not affected by the NIL quality, while Kalanchoe ‘Spain’ flowered when grown in SD and 10 μmol·m−2·s−1 PPFD NI-B. These results suggest that the NIL quality and intensity affect the morphogenesis and flowering of kalanchoe, and that different cultivars are affected differently. There is a need to further assess the effects of the NIL quality and intensity on the morphogenesis and flowering of short-day plants for practical NIL applications.

Night interruption light quality changes morphogenesis, flowering, and gene expression in Dendranthema grandiflorum

Abstract: We investigated the effects of the quality of light used for interrupting the night period, termed the night interruption light (NIL), on morphogenesis, flowering, and the expression of photoperiodic genes in chrysanthemum (Dendranthema grandiflorum) cultivar ‘Gaya Yellow’, a qualitative short-day (SD) plant. Plants were raised in a closed-type plant factory under white (W) light-emitting diodes (LEDs) providing a light intensity of 180 μmol m−2 s−1 photosynthetic photon flux density, under a condition of long-day (LD, 16 h light/8 h dark), short-day (SD, 10 h light/14 h dark), or SD with a 4-h night interruption (NI) provided by 10 μmol m−2 s−1 PPF green (NI-G), blue (NI-B), red (NI-R), far-red (NI-Fr), or W (NI-W) LEDs. Plants grown in the LD condition were the tallest. The SD, NI-B, and NI-Fr conditions induced flowering. Phytochrome A (phyA) and cryptochrome 1 (cry1) were expressed at high levels in plants in NI-B, NI-Fr, and SD conditions. These results suggest that the NIL quality has significant implications on morphogenesis, flowering, and the expression of photoperiodic genes. Flowering was positively affected by the expression of phyA, cry1, and FLOWERING LOCUS T (FT), whereas it was negatively affected by the expression of phyB and anti-florigenic FT/TFL1 (AFT).

Growth and development of carnation ‘Dreambyul’ plantlets in a temporary immersion system and comparisons with conventional solid culture methods

Abstract: The aim of the current study was to compare the effects of the culture method—conventional solid medium culture and temporary immersion system (TIS)—on the growth and development of carnation ‘Dreambyul’ plantlets. At the same time, different immersion intervals and immersion durations of TIS culture were also tested to find the optimal setting for mass production of high-quality carnation plantlets in vitro. In the first experiment, the results showed that the shoot length, root length, and number of nodes of plantlets cultured in the TIS were highest when the immersion interval was 8 h. Compared with that of plantlets cultured in the conventional solid medium culture, the fresh weight of plantlets cultured in the TIS was at least 3 times greater. The greatest total chlorophyll content, stomata with normal shapes was observed for plantlets grown in the TIS with an 8-h immersion interval. The lowest H2O2 level was recorded in plantlets cultured with the 8-h immersion interval. In the second study, growth traits such as the shoot length, root length, and stem diameter, as well as the number of shoots and roots tended to increase with immersion durations, and reached their peaks when the immersion duration was 90 s. Excessive water accumulation in tissues and a higher incidence of hyperhydricity were observed in plantlets where the immersion duration was 120 and 150 s. These findings suggest that an immersion interval of 8 h, combined with an immersion duration of 90 s, could be the optimal setting for growth and development of carnation ‘Dreambyul’ plantlets cultured in the TIS.

PGR and Its Application Method Affect Number and Length of Runners Produced in ‘Maehyang’ and ‘Sulhyang’ Strawberries

Abstract: Vegetative propagation using runner plants is an important method to expand the cultivation area for the strawberry (Fragaria × ananassa Duch.). However, excessively long runners need an increased total amount of nutrients and energy to receive elongation from mother plants, which may lead to poor growth or reduced output. The use of plant growth regulators (PGRs) is an adoptable way to solve such problems. The objectives of this experiment were to study the effects of PGRs and their application methods on the growth and development of runners, runner plants, and mother plants, and also to find effective ways to control the number and length of runners without harmful side effects. Chlormequat chloride (CCC), 6-benzylaminopurine (BA), and ethephon (ETH) at a concentration of 100 mg·L−1 were applied via three different methods: injection into crowns, medium drench, and foliar spray. The results showed that BA injection into crowns was the most effective combination among all treatments, which prominently shortened the length of runners and increased the number of runners and leaves on a single plant. Furthermore, plants with BA solution injection tended to produce stronger runners with higher fresh and dry weights, without affecting the health states of mother plants. The ETH solution seemed to have toxic effects on plants, by leading many dead leaves and weak runners, and increased activities of antioxidant enzymes. Other than the injection method, the other two application methods of the CCC solution did not significantly affect the growth and development of both cultivars. Runner plants grown for 30 days were not affected by any treatments, and they were in similar conditions. Overall, BA injection into crowns is recommended for controlling the number and length of strawberry runners.

A survey on the graft healing environment of commercial fruit vegetable plug seedling greenhouses in the Republic of Korea

Abstract: Seedling production is the basis of most agricultural, especially horticultural, cultivation and is important for crop cultivation. The quality of seedlings directly affects the quality and yield of crops after transplanting. The scale of seedling production in the Republic of Korea has increased gradually and significantly, and the proportion of grafted seedlings of fruit vegetables has become increasingly important. The quality of grafted vegetable seedlings is valued by farmers more than before; thus, the quality of grafted seedlings of fruit vegetables has become an important area of study. To determine the direction of this research, we surveyed several representative seedling production growers in different provinces of the Republic of Korea. We investigated the graft healing methods used by Korean growers of fruit vegetable plug seedlings, including the light intensity, air temperature, and relative humidity in plug seedling cultivation greenhouses, graft healing tunnels, and closed-type graft healing factories in summer and winter seasons. It was found that the graft healing methods used by different growers varied. There were vast differences in air temperature and relative humidity between graft healing tunnels and closed-type healing factories. In greenhouses, the temperature in winter was low and the light intensity was insufficient, while the temperature in summer was high and relative humidity was too low to be optimal for grafted seedlings. Due to the differences in covering materials, the light spectrum in cultivation greenhouses and the graft healing spaces also varied among growers. In general, there were no standardized production models or environmental conditions for grafted plug seedling cultivation. Therefore, follow-up studies will be needed for the development of the grafted plug seedling industry in Republic of Korea.