Detection of epistatic interaction of two QTLs, <i>gw8.1</i> and <i>gw9.1</i>, underlying grain weight using nearly isogenic lines in rice

Jin, Feng-Xue,Ji, Shi-Dong,Xie, Xiao-Bo,Kang, Ju-Won,Ju, Hong-Guang,Ahn, Sang-Nag Japanese Society of Breeding 2011 Breeding science Vol.61 No.1

<P>Grain weight (GW) is one of the most important targets for grain yield in rice breeding. In previous studies, two quantitative trait loci (QTLs) for GW, <I>gw8.1</I> and <I>gw9.1</I>, have been identified using progeny derived from a cross between the <I>japonica</I> cultivar Hwaseong and <I>Oryza rufipogon </I>(IRGC 105491). To test whether these quantitative trait loci (QTLs) have an epistatic interaction, we developed an F<SUB>2</SUB> population by crossing two nearly isogenic lines (NILs) harboring <I>gw8.1</I> and <I>gw9.1</I>. Simple sequence repeat (SSR) markers tightly linked to the QTLs were used to select F<SUB>3</SUB> QTL-NILs from the F<SUB>2</SUB> population. A two-way ANOVA revealed an epistatic interaction between the two QTLs in the F<SUB>2</SUB> population (<I>P</I> = 0.0084). This interaction was confirmed by an analysis of F<SUB>3</SUB> QTL-NILs indicating that both QTLs are involved in the same genetic mechanism controlling GW. The <I>gw8.1</I> QTL was further mapped between two SSR markers, RM23204 and RM23211, which are 110.1 kb apart. To our knowledge, this is the first report using QTL-NILs to reveal an epistatic interaction between QTLs for GW.</P>

QTL mapping of agronomic traits using an RIL population derived from a cross between temperate <i>japonica </i>cultivars in rice (<i>Oryza sativa</i> L.)

Kwon, Soo-Jin,Cho, Young-Chan,Kwon, Soon-Wook,Oh, Chang-Sik,Suh, Jung-Pil,Shin, Young-Seop,Kim, Yeon-Gyu,Holligan, Dawn,Wessler, Susan R.,Hwang, Hung-Goo,Ahn, Sang-Nag Japanese Society of Breeding 2008 Breeding science Vol.58 No.3

<P>To employ molecular marker-aided selection for developing <I>japonica</I> rice (<I>Oryza sativa</I> L.) cultivars with high yielding potential and good eating quality, we carried out QTL analysis for agronomic and grain traits using 231 recombinant inbred lines (RIL) from a cross between two temperate <I>japonica</I> cultivars, Suweon365 and Chucheongbyeo. A linkage map with 221 loci, including 134 simple sequence repeats (SSRs), 66 amplified fragment length polymorphisms (AFLPs), and 21 miniature inverted repeat transposable elements (MITEs)-anchored markers, was constructed covering 2,227 cM of the twelve rice chromosomes, with an average distance of 11.0 cM between markers. The proportion of polymorphic bands between parents averaged 19.5%, 12.9% and 42.3% for SSRs, AFLPs and MITEs, respectively. Construction of maps without AFLP or MITE markers indicated that expansion of this map is due to the incorporation of AFLP markers, and this result is consistent with previous reports. Twenty-seven QTLs for ten traits were identified over two years, and fourteen were consistently detected in two consecutive years. When the locations of each QTL detected in this study were compared with those in previous QTLs studies, eight QTLs for culm length, spikelets per panicle and, thickness, length and shape of grain, had not been reported in previous mapping studies, indicating potentially novel alleles of <I>japonica</I> rice. Interestingly, a cluster of seven QTLs, including heading date and grain morphology traits, was detected on the long arm of chromosome 7. The markers linked to these QTLs would be valuable in a marker-assisted breeding program for <I>japonica</I> cultivars.</P>

Production of unbolting lines through gamma-ray irradiation mutagenesis in genetically modified herbicide-tolerant <i>Zoysia japonica</i>

Bae, Tae-Woong,Kim, Joonki,Song, In-Ja,Song, Seo-Young,Lim, Pyung-Ok,Song, Pill-Soon,Lee, Hyo-Yeon Japanese Society of Breeding 2009 Breeding science Vol.59 No.1

<P>We have developed a genetically engineered herbicide-tolerant <I>Zoysia</I> grass with potential commercial value. However, the possible flow of genes to wild-type or neighboring plant species raises ecological and commercial concerns, although herbicide-tolerant GM <I>Zoysia</I> grass does not appear to pose a significant risk. One efficient way to prevent transgene escape in GM plants is to control fertility. Thus, we attempted to generate GM <I>Zoysia</I> mutants with defects in the development of reproductive organs, but that can be vegetatively propagated. To induce mutation, a range of γ-rays from 10 to 50 Gy, initially determined to be the optimal dose for inducing mutation, was used to irradiate GM <I>Zoysia</I> during the pollination stage. Notably, nine (4%) lines displayed defects in the floral transition from the vegetative to reproductive phase, while all non-irradiated GM <I>Zoysia</I> grasses developed normally. Under greenhouse conditions (natural light and temperature), these GM <I>Zoysia</I> lines have been vegetatively propagated for four years without forming reproductive structures. This technology could also be applied in other GM plants being cultivated through vegetative propagation, such as creeping bent grass.</P>

Influence of puroindoline genotypes on grain characteristics, physico-chemical properties of flour and end-use quality of Korean wheats

Park, Chul-Soo,Kang, Chon-Sik,Cheong, Young-Keun,Jung, Woosuk,Woo, Sun-Hee Japanese Society of Breeding 2010 Breeding science Vol.60 No.3

<P>Puroindoline genotypes, grain characteristics, physico-chemical properties of flour and end-use qualities of Korean wheat cultivars were evaluated to determine the influence of puroindolines genotypes and to provide on those characteristics. Nine Korean wheat cultivars carried <I>Pina-D1a</I>/<I>Pinb-D1a</I>, fourteen had <I>Pina-D1a</I>/<I>Pinb-D1b</I>, and three had <I>Pina-D1b</I>/<I>Pinb-D1a</I>. <I>Pina-D1b</I>/<I>Pinb-D1a</I> and <I>Pina-D1a</I>/<I>Pinb-D1b</I> genotypes showed significantly higher 1000-kernel weight and hardness index in grain characteristics, higher flour yield, average particle size, ash and protein content, SDS-sedimentation volume, water absorption and mixing time of mixograph, thickness of noodle dough sheet and lower values in lightness of flour and cookie diameter than <I>Pina-D1a</I>/<I>Pinb-D1a</I> genotype. The <I>Pina-D1b</I>/<I>Pinb-D1a</I> genotype showed significantly higher damaged starch content and water retention capacity than other genotypes. Hardness index of grain was positively correlated with flour yield and average particle size of flour. Those parameters were positively correlated with damaged starch, water retention capacity, SDS-sedimentation volume and water absorption of mixograph, and negatively correlated with lightness of wheat flour. In end-use qualities, thickness and lightness of noodle dough sheet and cookie diameter were correlated with hardness index, milling performances and physical properties. However, bread volume and texture of cooked noodles were not influenced by milling performances and physical properties.</P>

A major recessive gene associated with anthracnose resistance to <i>Colletotrichum capsici</i> in chili pepper (<i>Capsicum annuum</i> L.)

Kim, Sang Hoon,Yoon, Jae Bok,Do, Jae Wahng,Park, Hyo Guen Japanese Society of Breeding 2008 Breeding science Vol.58 No.2

<P>Pepper (<I>Capsicum annuum</I> L.) anthracnose, caused by <I>Colletotrichum</I> spp., is an important disease in many Asian countries. Recently, it was found that a local Korean variety, <I>C. annuum</I> ‘Daepoong-cho’, had resistance to <I>C. capsici</I>. Inheritance of resistance to <I>C. capsici</I> was analyzed in segregating populations derived from a cross of ‘Yeoju’ × ‘Daepoong-cho’. An allelism test was carried out in F<SUB>1</SUB> and F<SUB>2</SUB> progenies derived from the cross of ‘Daepoong-cho’ × ‘AR’. ‘AR’ is an anthracnose-resistant breeding line derived from <I>C. chinense</I> Jacq. ‘PBC 932’. Detached mature green fruits were inoculated using the microinjection method. Disease response was evaluated using disease incidence, overall lesion diameter, and true lesion diameter at 7 days after inoculation. The segregation ratios of resistance and susceptibility to <I>C. capsici</I> in F<SUB>2</SUB> and BC<SUB>R</SUB> populations derived from the cross of ‘Yeoju’ × ‘Daepoong-cho’ were fitted to the 1 : 3 and 1 : 1 Mendelian model, respectively. This indicates that the resistance of ‘Daepoong-cho’ to <I>C. capsici</I> is controlled by a single recessive gene. The results of the allelism test indicated that the two resistant lines, ‘Daepoong-cho’ and ‘AR’, possessed the same resistance gene to <I>C. capsici</I>, even though the resistance genes of these two lines originated from different <I>Capsicum</I> species, <I>C. annuum</I> and <I>C. chinense</I>.</P>

BrUGE1 transgenic rice showed improved growth performance with enhanced drought tolerance

Abdula, S. E.,Lee, H. J.,Kim, J.,Niñ,o, M. C.,Jung, Y.-J.,Cho, Y.-C.,Nou, I.,Kang, K.-K.,Cho, Y.-G. JAPANESE SOCIETY OF BREEDING 2016 Breeding science Vol.66 No.2

QTL analysis for eating quality-related traits in an F _2:3 population derived from waxy corn × sweet corn cross

Park, Ki Jin,Sa, Kyu Jin,Koh, Hee-Jong,Lee, Ju Kyong Japanese Society of Breeding 2013 Breeding science Vol.63 No.3

<P>In order to identify quantitative trait loci (QTL) for the eating quality of waxy corn and sweet corn (<I>Zea mays</I> L.), QTL analysis was conducted on an F<SUB>2</SUB> population derived from a cross between a waxy corn inbred line and a sweet corn inbred line. Ten QTLs for pericarp thickness (PER), amylose content (AMY), dextrose content (DEX) and sucrose content (SUC) were found in the 158 F<SUB>2</SUB> families. Among them, four QTLs, qAMY4 (10.43%), qAMY9 (19.33%), qDEX4 (21.31%) and qSUC4 (30.71%), may be considered as major QTLs. Three of these, qAMY4, qDEX4 and qSUC4, were found to be located within a region flanked by two adjacent SSR markers on chromosome 4 (umc1088 and bnlg1265), making this SSR marker pair a useful selection tool for screening the eating quality traits of AMY, DEX and SUC. The QTL for amylose content was found to be located between markers phi027 and umc1634, raising the possibility of its identity being the <I>Wx1</I> gene, which encodes a granule-bound amylose synthase. The new QTLs identified by the present study could serve as useful molecular markers for selecting important eating quality traits in subsequent waxy corn breeding studies.</P>

Effects of allelic variations in starch synthesis-related genes on grain quality traits of Korean nonglutinous rice varieties under different temperature conditions

Mo, Young-Jun,Jeung, Ji-Ung,Shin, Woon-Chul,Kim, Ki-Young,Ye, Changrong,Redoñ,a, Edilberto D.,Kim, Bo-Kyeong Japanese Society of Breeding 2014 Breeding science Vol.64 No.2

<P>Influences of allelic variations in starch synthesis-related genes (SSRGs) on rice grain quality were examined. A total of 187 nonglutinous Korean rice varieties, consisting of 170 <I>Japonica</I> and 17 Tongil-type varieties, were grown in the field and in two greenhouse conditions. The percentages of head rice and chalky grains, amylose content, alkali digestion value, and rapid visco-analysis characteristics were evaluated in the three different environments. Among the 10 previously reported SSRG markers used in this study, seven were polymorphic, and four of those showed subspecies-specific allele distributions. Six out of the seven polymorphic SSRG markers were significantly associated with at least one grain quality trait (<I>R</I><SUP>2</SUP> > 0.1) across the three different environments. However, the association level and significance were markedly lower when the analysis was repeated using only the 170 <I>Japonica</I> varieties. Similarly, the significant associations between SSRG allelic variations and changes in grain quality traits under increased temperature were largely attributable to the biased allele frequency between the two subpopulations. Our results suggest that within Korean <I>Japonica</I> varieties, these 10 major SSRG loci have been highly fixed during breeding history and variations in grain quality traits might be influenced by other genetic factors.</P>

Development and linkage mapping of unigene-derived microsatellite markers in <i>Brassica rapa</i> L.

Ge, Yu,Ramchiary, Nirala,Wang, Tao,Liang, Cui,Wang, Na,Wang, Zhe,Choi, Su-Ryun,Lim, Yong Pyo,Piao, Zhong Yun Japanese Society of Breeding 2011 Breeding science Vol.61 No.2

<P><I>Brassica rapa</I> plants are highly important as vegetables, sources of oilseeds and fodder crop. Here, we developed 450 unigene derived microsatellite (UGMS) markers in <I>B. rapa</I> using unigenes downloaded from the National Center for Biotechnology Information database. Of the 450 UGMS primer pairs, 428 (95.1%) produced repeatable and reliable amplifications of expected size in at least one parental line of <I>B. rapa</I>, and 70 UGMS markers gave 72 polymorphic loci between the two contrasting parental lines. Cross-species transferability analysis of these 70 polymorphic UGMS markers in five other cultivated <I>Brassica</I> species showed varying transferability rates ranging from 82.9% in <I>B. nigra</I> to 97.1% in <I>B. juncea</I> and <I>B. napus</I>, and overall 53 UGMS markers amplified targets in all five species. The <I>B. rapa</I> linkage map was constructed using the 72 UGMS polymorphic loci and 154 previously developed SSRs. The newly developed UGMS markers and linkage map in this study would help in future studies to better understand the organization and evolution of <I>Brassica</I> genomes with respect to unigenes, in addition to mapping, tagging and cloning of economically important trait QTL/gene(s) and marker-assisted breeding in <I>Brassica</I> crops.</P>

Allelic analysis of low molecular weight glutenin subunits using 2-DGE in Korean wheat cultivars

Lee, Jong-Yeol,Jang, You-Ran,Beom, Hye-Rang,Altenbach, Susan B.,Lim, Sun-Hyung,Lee, Choung Keun Japanese Society of Breeding 2017 Breeding science Vol.67 No.4

<P>Two-dimensional gel electrophoresis (2-DGE) was used as a complement to SDS-PAGE to determine the allelic compositions of LMW-GS in 32 Korean wheat cultivars. Protein patterns generated by 2-DGE from each cultivar were compared to patterns from standard wheat cultivars for each allele. At the <I>Glu-A3</I> locus, thirteen <I>c</I>, twelve <I>d</I>, three <I>e</I> (null), two g and two new alleles were identified. At the <I>Glu-B3</I> locus, one <I>b</I>, nineteen <I>d</I>, four <I>h</I>, one <I>i</I> and five <I>ad</I> alleles were identified. At the <I>Glu-D3</I> locus, twenty-three <I>a</I>, four <I>b</I>, four <I>c</I> and one <I>l</I> alleles were identified. When compared to results obtained previously using SDS-PAGE, there were discrepancies in the allelic designations of 10 of 32 cultivars (31%). While SDS-PAGE is a rapid and relatively simple method for assessing LMW-GS composition, the similar mobilities of the proteins makes it difficult to discriminate certain alleles. 2-DGE is a more complicated technique, but provides a more accurate picture of the complement of the LMW-GS in a given cultivar. In addition to providing essential information for wheat breeders, the 2-DGE reference maps generated in this study will make it possible to study the contributions of individual LMW-GS to flour quality.</P>