• Korean Journal of Agricultural Science
• /
• v.39 no.4
• /
• pp.497-502
• /
• 2012

Since the year 2000, the production and consumption of broccoli have rapidly increased in Korea. And, the average production area and amount were about 1,700 ha and 29,000 ton for the past 5 years. Even with the increase of these cultivation and consumption, more than 95% of the broccoli seeds are currently imported from foreign countries such as Japan and Netherlands. Therefore, development of domestic broccoli varieties is needed to relieve Korean farmers' production cost for broccoli. In this situation, National Institute of Horticultural and Herbal Science (NIHHS) of Korea has tried to develop F1 hybrid varieties from elite lines that were obtained by microspore cultivation method from 2008. As the results, about 850 lines of broccoli were obtained and self-pollinated. Then their ploidy levels of the genome were confirmed to select double haploid (D.H.) lines. And the D.H. lines' horticultural traits were evaluated in open field. After the selection of 17 elite D.H. lines, they were cross-pollinated with a male sterile (MS) line to produce F1 hybrid seeds. After 2 to 3 years field trials of these F1 hybrid varieties at the area of Suwon, Gangneung, and Jeju respectively, two hybrid varieties such as 'Wongyo8011' and 'Wongyo8012' are selected for the application of variety protection. With these 4 years of research, we found that the microspore cultivation method is a powerful tool for the conventional breeding program, especially for the development of various inbred lines and even F1 hybrid varieties in short time.

• Journal of Plant Biotechnology
• /
• v.44 no.1
• /
• pp.27-34
• /
• 2017

Our aim was to find the effective duration and culture conditions for microspore culture in a genetically variant cabbage (Brassica oleraceae L. var. capitata). We discovered that the '$2{\times}NLN$ medium containing $AgNO_3$ 1 mg/l, sucrose 13%' was most efficient in producing the cabbage embryos. The number of induced embryos was higher in $F_2$ or $F_3$ progeny generation than the $F_1$ hybrid cultivar used as plant materials. Thus, we recommend microspore culturing using progeny plants of failed $F_1$ cultivar. The acquisition ratio of embryos and plants derived from microspore was higher in the early flowering period as compared to the late flowering period. When transplanted in the soil, 71.2% plants developed from the early flowering period, compared to 27.0% from the middle period and 1.8% plants from the late period. Thus, we recommend microspore culture using buds collected during the early flowering period.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.5
• /
• pp.411-413
• /
• 2000

The ability of microspores or young pollen grains (male gametophytes) to undergo developmetal switch to embryogenic (sporophytic) pathway exemplifies the concept of totipotency as applied to haploid posmeiotic cells. As a first step pollen is devoid of positional information provided in situ by the intact anther - by isolation and cultivation in vitro in artificial media. This is inevitably accompanied by some degree of stress response in microspore/pollen. It has been shown in both monocots and dicots that intentional stress treatment (mostly starvation or heat shock) greatly stimulates embryo induction rate. Using transgenic sHSP antisense Nicotiana tabacum we show that expression of small heat shock proteins is an integral part of successful embryo and later haploid plant production from pollen grains. Our recently published data show that sHSP chaperone function is optimal in the absence of ATP.