Quantitative trait locus (QTL) mapping is a highly effective approach for studying genetically complex forms of plant shattering. With QTLs mapping, the shattering loci can be described. SSR marker is based on the imformation of Simple Sequence Repeat and easy to analyze using PCR and has high reproducibility. For analyzing QTLs associated with shattering, we selected 219 SSR markers from 254 SSR markers and used them for implementing Mapmaker(Ver. 3.0) and Mapchart(Ver. 2.2). Mapmaker help to calculate distances between each markers and Mapchart is a program for drawing Genetic map. This Genetic map of rice (Oryza sativa L.) covering 2082.4 cM with 9.5 cM between makers in the Kosambi function has been constructed using 120 F1 DH plants from a single cross between the indica variety Chungchung and the japonica variety Nagdong.

This study was carried out to gain the basic informations about botanical characteristics of plant type and properties related to table quality for developing the new colored waxy corn hybrid. Materials used were produced by our laboratory in 2007 and their major traits were evaluated fro two years(2008 to 2009) at Corn Breeding Farm of Coll. of Agri. & Life in CNU. Items surveyed were major agricultural characteristics including ear length and traits related to edible. Botanical characteristics as a plant type and ear pattern of the developed waxy corn hybrids showed large ranges among them; stem height of CNU08H-h39 among used hybrids was the highest as 235.7cm, while CNUH08-15 was the lowest. Ear height of Daehackchal Gold 1 was the highest as 83.7cm and that of CNU08H-15 was the lowest among used hybrids. Ear length of CNU08H-h121 among used hybrids was the longest as 23.1cm, while that of CNU08H-71 was the smallest as 12.7cm. Kernel sugar content of the used hybrids appeared to be 16.1 to 13.0Brix(%). Especially, CNU08H-15, CNU08H-35 and CNU08H-h39 hybrids were highly appeared as 15 above. Pericarp thickness of check hybrid, Yeonongchal, was thicker as 46.0㎛, while that of CNU08H-39 compared to other hybrids showed the thinnest as 23.0㎛. From this study, we could obtain several superior colored hybrids with thinner pericarp and high sugar contents like CNU 08-39 and CNU 08-h121 hybrids. Accordingly, these hybrids will be apply as new developed variety through confirmed trials.

Barley Yellow Mosaic Virus (BaYMV) caused significant reduction in barley yield and is difficult to control due to alive parasitic soil-borne fungus, Palmyra gamines that transmits the, virus. Previous studies have indicated that a virus-free soil could be infested by using virus-contaminated farming machineneries and implements. For the further confirmation of this finding, different proportions of BaYMV-infested soil were mixed into virus free soil. Three barley varieties (Hordum vulgarae, cv "Olbori", "Baegdong" and "Sacheon 6") were sown in pots treated with different rate of P. graminis-infested soil ranging from 0% to 100% in October 20, 2001. Results showed that BaYMV infection increased as the rate of infested soil increased. Initial symptoms were observed in a pots treated with 10% infested soil in all the 3 varieties of barley. "Olbori" had about 5% infection in 20% infested soil and about 10% infection in 40% or 50% infested soil and about 20% infection in 60% infested soil. In "Baegdong", the trend of BYMV occurrence was similar with "Olbori" but the time of severe infection was earlier than "Olbori". BaYMV infection in "Sacheon 6" was even earlier than "Baegdong" with much more severe symptoms than "Baegdong". The growth rate of barley was affected by about 19-22% when grown in 20% infested soil. As the rate of BaYMV infested soil increased the heading date was delayed but the maturing date was early in "Olbori" and "Sacheon 6". Also, reduction rate of culm length in 3 varieties increased with increase of infested soil content. However, "Olbori" showed the highest reduction. "Sacheon 6", have been characterized with long spike length, however was significantly reduced as the infested soil increased. On the other hand, spike length of "Olbori" was not significantly affected despite of increased of infested soil. The reduction rate of 1000 kernel weight was higher in large kernel size cultivar "Sacheon 6" and "Olbori" than small kernel size "Baegdong" as increase of BaYMV-infested soil content.

A population ofrecombinant inbred lines derived from a cross between Ilpumbyeo, a blast-susceptibleyopowca cultivarofhigh eating-quality and high yield potential, and GL33, a blast-resistance/apowca weedy rice was used to identifv QTLs affect-ing importan

This experiment was conducted to investigate the variation of nitrogen(N) uptake efficiency and their relationships withciency and partitioning parameters as physiological N use efficiency [PNUE], agronomic N use efficiency [ANUE], apparentrecovery [AR],

Three rice cultivars, Namweonbyeo (early maturing), Hwaseongbyeo (medium maturing) and Dongjinbyeo (medium-late maturing) were trans-planted with 3 different seedling ages to investigate their growth habits and to improve the cultural method in paddy fields in the southern plain area of the Honam region in 1993. The 10-day old seedlings had more vigorous elongation of plant height and higher tillering ability but lower effective tiller rate, when compared with 35-day or 40-day old seedlings. Leaf area index and top dry weight were lower in 10-day old seedlings up to 40 days after transplanting but thereafter, were not different among seedlings ages. CGR was later in 10-day old seedlings, up to 30 days after transplanting, but in 30 to 40 days after transplanting, it was reversed. RGR was the highest in infant seedlings to 40 days after trans-planting, while in 50 days after transplanting, it was reversed. Panicle number and spikelet number per square meter were the highest in 40-day old seedlings, next highest in 35-day old seedlings and the lowest and in adult seedlings up to 40 days after transplanting, while spikelet number per panicle was vice versa. Milled rice yield did not vary significantly by seedling ages, but among the varieties, it was less in Hwaseongbyeo compared with Naweonbyeo and Dongjnbyeo.