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Cheongju, South Korea

Anderson N.O.,University of Minnesota | Won M.-K.,Crop Research Division | Kim D.-C.,Floriculture Research Center
HortScience | Year: 2016

Global warming has created increased nighttime temperatures both in field and greenhouse production of chrysanthemums during flower bud initiation (FBI) and development, causing heat delay or complete cessation of flowering. Integration of breeding and selection for heat delay insensitivity (HDI) has become imperative for greenhouse (cut, potted types) and must be accomplished on a genotypic basis, similar to winterhardiness. This is a breeding objective in the joint garden chrysanthemum breeding project between the Chungnam Provincial Agricultural Research and Extension Services and the University of Minnesota. The objectives of this research were to test 10 genotypes (cultivars, seedlings) from both breeding programs when grown in lowtemperature (LT) and high-temperature (HT) short-day (SD) and long-day (LD) conditions (four environments: LTSD, LTLD, HTSD, and HTLD); determine the extent of heat delay and HDI for visible bud date (VBD), flowering, and other phenotypic traits; evaluate relative injury (RI) and cell membrane thermostability (CMT), and to select future parents with lowered RI values, higher CMT, shorter heat-induced flowering delay, and/or HDI. ‘Magic Ball’ and ‘Minnwhite’ had the shortest plant height in HTLD and HTSD, whereas ‘Geumbangul’ had stability for height in all treatments. Lowest long day leaf numbers (LDLN) occurred under LTSD in seven genotypes. However, both ʻGeumbangulʼ and ‘Magic Ball’ had complete stability for LDLN across all environments. Sigmoid curves for RI% and temperature were found for all genotypes and environments with R2 = 0.79–0.89. Only ‘Mellow Moonʼ had stability or equal VBDs in HTSD, LTSD, and LTLD conditions. This is the first-ever report of stability for VBD across inductive and noninductive HT/LT treatments. Only ʻCenterpiece’ flowered in all environments and also had 0 day of heat for VBD in LT and 1 day of heat delay in HT, as well as three others (Mn. Sel’n. 01-210-43, ‘Autumn Fireʼ, and ‘Geumbangul’). Few had linear regressions with positive slopes for heat-induced VBD or flowering delay regressed with RI%; most had no slope (R2 ≈ 0.0) for all treatments (ʻCenterpieceʼ, Mn. Sel’n. 01- 210-43), whereas others were negative (ʻMammoth™ Dark Bronze Daisyʼ, Flw LTLD– LTSD). Surprisingly, one linear regression had a slope of R2 = 1.0 (‘Geumbangul’, Flw LTLD–LTSD). These responses are all novel in chrysanthemums. Selecting the best parents in both breeding programs to maximize stability of all traits across these four environments with minimal crossing and selection across generations could be accomplished by stacking parental traits. A crossing scheme involving just three parents is proposed to incorporate stability for all traits in just a few generations. © 2016, American Society for Horticultural Science. All rights reserved. Source

Huh Y.S.,Horticultural Research Division | Lee J.K.,Horticultural Research Division | Kim I.J.,Crop Research Division | Kang B.G.,Horticultural Research Division | Lee K.Y.,Crop Research Division
Journal of Plant Biotechnology | Year: 2015

Interest and great demand for blueberry (Vaccinium corymbosum) have increased, as V. corymbosum is now one of the most economically important crops in Korea. It is expected that blueberry production and the area planted for cultivation will increase consistently in the years ahead because of high profitability and the consumer's demand for healthy ingredients. Effective mass production of blueberry is urgently needed for commercial cultivation establishment, but a main limitation is lack of a propagation system that produces a disease-free plant material for commercial plantation. A large amount of research has focused entirely on developing tissue culture techniques for blueberry propagation. However, controlling fungal and bacterial contamination of woody plant material is extremely difficult. Our study was conducted to investigate the effect of biocide addition during the in vitro culture of blueberry on plantlet growth and contamination occurrence. Four biocides, including Plant Preservative Mixture (PPM™), vancomycin, nystatin and penicillin G, were used in varying concentrations during the in vitro propagation of blueberry. When nystatin was added into the medium at low concentrations, the overall growth of blueberry plantlets was retarded. Addition of vancomycin and penicillin G in high concentrations decreased contamination but induced plantlet mortality. On the other hand, when 1ml/L PPM™ was added, the growth characteristics of blueberry plantlets did not significantly differ from non-treatment (control), and the contamination occurrence rate was very low. From these results, we found that the addition of the appropriate biocide could provide an effective method to reduce contamination in the culture process, thereby raising in vitro production efficiency. © Korean Society for Plant Biotechnology. Source

Singh R.D.,Crop Research Division | Shivani,Crop Research Division | Khan A.R.,Crop Research Division | Chandra N.,Crop Research Division
Archives of Agronomy and Soil Science | Year: 2012

An experiment was conducted at ICAR Research Complex for Eastern Region, Research Farm, Sabajpura, Patna (longitude 85°13′N and 1atitude 25°37′E), Bihar, India for four consecutive years 2004-05 to 2007-08 to develop a diversified cropping system for an irrigated ecosystem in Bihar by introducing pulse/oilseed/vegetables as a second or third crop in 10 rice-based cropping systems. Four crop cycles have been completed for all the cropping systems. During all years of the experiment there were significant variations among the cropping systems. Maximum paddy yield equivalent was recorded in rice-tomato-bottle gourd (40.44 t ha-1) followed by rice-potato-onion (28.47 t ha-1), rice-coriander-lady's fingers (26.79 t ha-1), rice-carrot-cowpea (24.59 t ha-1) and rice-mustard-tomato (24.44 t ha-1). A higher value for the diversification index (DI) represents a higher level of crop diversification. It is evident from the results, that DI varies from 0.299 on a medium-sized farm to 0.903 on a small farm, with an average DI value of 0.643 among all farm categories. A survey revealed that the average DI value for small-scale farmers was highest (0.741) compared with the medium- (0.591) and large-scale (0.626) categories, and the differences were negligible. This seems reinforce the view that the smaller the farm, the higher the level of crop diversification. © 2012 Copyright Taylor and Francis Group, LLC. Source

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