Kimchi cabbage (known as Chinese cabbage) is major vegetable in Korea. An inbred line of ‘Wonkyo20038ho’, was developed by the National Institute of Horticultural & Herbal Science, RDA in Republic of Korea. The microspore culture was carried out using ‘Chunhuigohangwang’ which was introduced from China in 2002. Among 3 DH inbred lines, ‘Wonkyo20038ho’ inbred line was finally selected after field exhibition in 2009. The horticultural traits of ‘Wonkyo20038ho’ inbred line; half-open head, white inner leaf colour, and dark green outer leaf colour. The average (for four years) head weight was 2025.3g, and head width and height were 15.8cm and 32.4cm, respectively. Head shape was narrow elliptic and degree of overlapping leaf was medium. Numbers of outer and internal leaves were 14.1 and 49.8, respectively. Harvest maturity was mid-late maturing type and average of seed yield for five years was 926 seeds. In addition, ‘Wonkyo20038ho’ inbred line is suitable for salad in that it possessed few trichome and narrow elliptic head shape.
자포니카 초다수성 품종으로 다수성에 관여하는 형질 특성 이 다른 드래찬과 보람찬을 이용하여 이삭과 수량 관련 형질 의 다양성이 증대된 약배양 유래 집단을 육성하고 다수성 계 통을 선발하였다. 163개로 구성된 약배양 유래 집단과 선발 된 다수성 13계통의 이삭 및 수량 관련 형질을 상관분석, 주 성분분석 및 경로계수 분석을 통해 분석하였다. 이삭 관련 형 질 중 2차 지경 착생립수가 1차 지경 착생립수에 비해 수당립 수와 높은 정의 상관관계를 나타냈으며 수당립수가 증가하는 쪽으로 기여도가 컸다. 형질들의 수량에 기여하는 정도를 보 면 집단에서는 수당립수가 선발 계통에서는 수수가 수량성 증진에 기여도가 가장 컸다. 수수는 집단과 선발 계통에서 모 두 등숙률과 정의 상관을 나타냈다. 선발 계통에서 수수 증가 에 의한 등숙률의 향상과 단위면적당 립수의 증가로 인한 수 량성 향상이 수당립수 증가에 의한 향상 효과보다 컸다. 13개 선발 계통 중 AC60, AC152, AC156, AC161 계통은 모부본 인 드래찬(481 kg/10a)과 보람찬(559 kg/10a) 보다 높은 수 량성을 나타냈다. 드래찬은 수수가 적고 수당립수가 많은 소 얼 수중형을 나타냈으며 보람찬은 수수가 많고 등숙률이 높 은 수수형에 가까웠다. 선발된 다수성 계통들은 모부본의 중 간 형태의 형질 특성을 나타내며 개선된 잠재 수량성을 가지 고 있다. 이들 우량 계통들은 자포니카 다수성 품종 개발을 위해 활용될 수 있을 것이다.
Improving rice high-quality potential is to suffice the food demand of the rapid decreasing consumption, and is a major breeding target recently. We calculated the alkali digestion value (ADV), used to indirectly measure gelatinization temperature, to evaluate the quality of cooked rice in 2013 and 2014. The ADV score of frequency distribution was higher milled rice than brown rice. In total, nine different quantitative trait loci (QTLs) were found on chromosomes1, 3, 5, 6 and 8 in 2013 and 2014. Also, chromosome 5, 8 were detected over two years. The polymorphism using RM223, RM3530, and RM18130 markers can be used to select lines that have a good trait for breeding of high-quality rice. We conclude that selected molecular markers from this QTL analysis could be exploited in future rice quality.
Glucosinolates (GLS) are secondary metabolites commonly occurring in Brassica crops and more than 130 different GLS have been reported in diverse plants. Recent studies have indicated that isothiocyanate (ITC) derived from GLS by hydrolysis had a potential for anticancer activity against several rumor cells on human. In addition, it was found that glucoraphenin (GRE) and glucoraphasatin (GRH) were abundant and differently regulated in radish plant, depending upon organs and developmental stages. Microspores isolated from flower buds of radish were cultured in vitro to obtain doubled haploid (DH; but homozygous) lines in a short time period. The present study was conducted to determine the concentration of GRE and GRH, an immediate precursor of ITC from DH lines of radish plant. Total 41 DH lines were selected based on flow cytometry analysis. The seeds, obtained by bud pollination from the DH lines, were planted and 3-weeks-old young seedlings were used for the major aliphatic GLS analysis. Amounts of GRH were highly variable from the DH lines ranging from 2.3 to 31.5 mg·g-1 dry weight (DW). The donor plant (DP) contained 18.4 mg·g-1 DW. It was noticed that there were 6-fold differences in the amounts of GRE between the highest and lowest DH lines. Among 41 lines tested, 14 DH lines of radish plant were significantly reduced in the amount of sum of GRH and GRE compared those of the donor plant (P<0.05), whereas only three lines increased. The results obtained in the present study will lend to select genotypes with low and high GLS contents of radish plant. In addition, those DH lines will aid to elucidate a biosynthetic pathway of the aliphatic GLS in radish plant, which remain for the most part unsolved.
Maize breeding is mainly divided by two steps; line development and hybrid selection. Line development is very important procedure to make good hybrids and this line development in Korea is fully depend upon conventional methods like pedigree selection, back-cross, etc. For development of pure line, we have to do self-pollination for at least seven cycles. This line development system is tedious, labor-intensive, and time-consuming procedure. Doubled Haploid technology for maize is a new system to develop inbred lines within short period and many maize research institutes in foreign advanced countries have been actively using this technology. Using Doubled Haploid technology, we can greatly reduce the period of line development and strengthen maize research ability in Korea. Key requisite for Doubled Haploid breeding is possession of inducer lines which can produce haploid when source population is crossed with them. Maize Research Institute in Gangwon Province secures the right of using inducer lines and is trying to introduce Doubled Haploid breeding in Korea. Doubled Haploid breeding system is as follows; crossing between population and inducer, separation haploid seeds from F1 seeds, chromosome doubling, doubled plant management, self-pollination, seed multiplication, and assessment. We expect our breeding capacity will be progressed by introduction of Doubled Haploid technology. When this technology comes to combine with marker assisted selection, we can increase competitiveness against global institutes.
For genetic mapping studies, biparental segregating populations are often useful, however recombination is limited, giving rise to large genomic regions under QTL, and one can only study alelles present in both parents. In Wageninegn UR, a core collection is being developed representing all Brassica rapa morphotypes and geographic origins. As most B. rapa accessions are heterozygous and heterogeneous, we started a project to fix the collection through microspore culture. The resulting Diversity Fixed Foundation Set will be an interesting resource for association mapping studies, which have as advantage that they present the allelec variation present in the collection, and for mapping studies recombination is increased. Nineteen accessions of eight subspecies of Brassica rapa were used for microspore culture to developdoubled haploid lines. Eight morphotypes were represented: 3 Chinese cabbage, 2 Chinese turnip cabbage, 3 Pak choi, 5 Turnip, 3 Broccolleto, 1 Mizuna, 1 Komatsuna and 1 Turnip greenfrom the 19acessions examined, embryos were obtained for 13, representing six subspecies (Komatsuna and Turnip Green had no response). The embryo yields differed significantly between these 13 accessions. We regenerated normal plants from 10 accessions that survived more than 4 weeks in the soil using microspore culture. Nine accessions flowered after 4 weeks vernalization at 5℃ and seeds were harvested from 5 accessions. From a Mizuna, we obtained 3791 seeds from one plant and total 7318 seeds were harvested from 5 accessions representing 4 subspecies(Chinese cabbage, Chinese turnip cabbage, Pak choi, Mizuna). At present, we carry out experiment for obtain more seeds and induce embryos from the other plant materials.
Demand for high quality rice has always been a major factor in the international rice marketing. In the present study, doubled haploid (DH) population derived from anther culture of a Tongil/japonica hybrid was used for genetic analysis of rice grain quality. The average values of DH lines for grain weight, grain length and the ratio of grain length to width were near the mid-parent value. More than 40% DH lines showed transgressive segregation for grain weight, length, amylose and lipid content, but less than 10% DH lines observed on ratio of length to width and grain thickness were transgressive segregation. Correlation analysis between appearance qualities and physicochemical characters indicated that grain width and grain thickness both significantly and negatively correlated to protein and lipid content. A highly significant negative correlation between protein content and amylose content was observed.
Somaclonal variation was observed in the field on doubled haploid plants derived from single pollen of a rice cultivar "Hwaseongbyeo". The variations of seven quantitative traits including plant height and one qualitative trait (pubescence) in 436 lines (R2 generation) were analyzed. The number of lines which fell beyond the boundaries of the 95% confidence intervals of the check variety, Hwaseongbyeo was checked for each quantitative trait, and of those fertility showed the highest variation frequency (85.6%), followed by plant height (77.5%), flag leaf length (66.5%), grains per panicle (42.2%), days to heading (34.5%), panicle length (30.7%) and panicles per hill (22.7%). And the variations of quantitative traits except days to flowering appeared to move in the negative direction compared to "Hwaseongbyeo". Variability within lines was also observed for quantitative and qualitative traits. Twenty-nine R2 lines (7%) segregated for pubescence and 130 R2 lines (30%) showed variation with regard to fertility. This suggests that mutations usually occur before diploidization. Twenty-nine R2 lines representing a wide spectrum of variation were chosen for RAPD analysis. The number of lines showing DNA polymorphism compared to Hwaseongbyeo ranged 0 from to 10 according to the primer used and this seems to indicate that specific loci have highly mutable genomic site.utable genomic site.