Search

Archaeological excavations led by Yung-jo Lee and Jong-yoon Woo were carried out twice at the Sorori paleolithic site, Cheongju, in the Republic of Korea, at the upper stream of the Geumgang river, the Miho riverside. A total of 127 rice seeds were excavated, including 18 ancient rice and 109 Quasi-rice, in 1998 and 2001. At the first excavation, eleven short japonica-type ancient rice and one slender smooth ancient rice with two kinds of Quasi-rice were excavated. The average length of the 11 short rice grains obtained from the first and second excavation was 7.19 mm and the average width was 3.08 mm, respectively. The Quasi-rice are apparently different from the rice and do not have bi-peak protuberances on their glume surface. At the second excavation, six short ancient rice chaffs and some Quasi-rice 2 were found. These short-grained ancient rice were comparable to the ancient rice that were excavated at the Illsan Neolithic site. Geologists and radiologists confirmed that the peat layer in which the rice found was older than 15,000 years. In this study, the morphological characteristics, crushing, and DNA band patterns related to the genetic polymorphism of rice grains in Cheongju Sorori were compared and analyzed for genetic similarities and differences with wild rice, weed rice, and modern rice. The morphological, ecological, and physiological variations in rice grains excavated from the Sorori site were presumed to denote the origin of rice domestication in Korea. It is also suggested that the results of the DNA sequencing of excavated rice are very important clues in estimating the origin of the early domestication of rice. [ABSTRACT FROM AUTHOR]

Amaranth is a nutritionally valuable crop, as it contains phenolic acids and flavonoids, yielding diverse plant secondary metabolites (PSMs) like phytosterol, tocopherols, and carotenoids. This study explored the variations in the contents of seventeen polyphenolic compounds within the leaves of one hundred twenty Amaranthus accessions representing nine Amaranthus species. The investigation entailed the analysis of phenolic content across nine Amaranthus species, specifically A. hypochondriacus, A. cruentus, A. caudatus, A. tricolor, A. dubius, A. blitum, A. crispus, A. hybridus, and A. viridis, utilizing ultra performance liquid chromatography with photodiode array detection (UPLC-PDA). The results revealed significant differences in polyphenolic compounds among accessions in which rutin content was predominant in all Amaranthus species in both 2018 and 2019. Among the nine Amaranthus species, the rutin content ranged from 95.72 ± 199.17 μg g−1 (A. dubius) to 1485.09 ± 679.51 μg g−1 (A. viridis) in 2018 and from 821.59 ± 709.95 μg g−1 (A. tricolor) to 3166.52 ± 1317.38 μg g−1 (A. hypochondriacus) in 2019. Correlation analysis revealed, significant positive correlations between rutin and kaempferol-3-O-β-rutinoside (r = 0.93), benzoic acid and ferulic acid (r = 0.76), and benzoic acid and kaempferol-3-O-β-rutinoside (r = 0.76), whereas gallic acid showed consistently negative correlations with each of the 16 phenolic compounds. Wide variations were identified among accessions and between plants grown in the two years. The nine species and one hundred twenty Amaranthus accessions were clustered into six groups based on their seventeen phenolic compounds in each year. These findings contribute to expanding our understanding of the phytochemical traits of accessions within nine Amaranthus species, which serve as valuable resources for Amaranthus component breeding and functional material development. [ABSTRACT FROM AUTHOR]

A large number of expressed sequence tags (ESTs) in public databases have provided an opportunity for the systematic development of simple sequence repeat (SSR) markers. EST-SSRs derived from conserved coding sequences show considerable cross-species transferability in related species. In the present study, we assessed the utility of cereal EST-SSRs in ryegrass (Lolium spp.). A total of 165 cereal EST-SSRs were tested; a high rate of transferability (57%) and polymorphism (67% of functional EST-SSRs) was demonstrated between cereals and ryegrass. A total of 46 segregating loci derived from 37 EST-SSRs were mapped on an existing ryegrass genetic map. The mapped loci were uniformly distributed across all seven linkage groups without significant clustering at the distal regions of linkage groups. Sequences of ryegrass amplicons generated by randomly selected 16 EST-SSRs were aligned with reference sequences of cereal EST-SSRs. The SSR motifs and repeat lengths of the cereal EST-SSR markers were different from the majority of ryegrass amplicons. Furthermore, a majority of EST-SSRs amplified different flanking sequences of SSRs in ryegrass than the original cereal sequences. Our results suggest that the high degree of cereal EST-SSR transferability to ryegrass can be a useful enhancement to the molecular database of PCR-based markers but sequence analysis is essential before transferring genetic information using comparative mapping. Key words: Lolium, Poaceae, polymorphism, SSR marker, transferability, comparative mapping. La presence d'un grand nombre d'etiquettes de genes exprimes (EST) au sein des banques de sequences publiques ont permis de developper systematiquement des marqueurs microsatellites (SSR). Les EST-SSR derives de regions codantes conservees presentent une transportabilite importante aupres d'especes apparentees. Dans le present travail, les auteurs ont explore l'interet des EST-SSR developpes chez les cereales pour emploi chez le ray-grass (Lolium spp.). Un ensemble de 165 EST-SSR a ete teste. Des fortes proportions de transportabilite (57 %) et de polymorphisme (67% des EST-SSR fonctionnels) ont ete observees entre les cereales et le ray-grass. Au total, 47 locus en segregation, reveles a l'aide de 37 EST-SSR, ont ete positionnes sur une carte genetique du ray-grass. Les locus etaient egalement distribues sur les sept groupes de liaison sans groupement significatif aux extremites distales des groupes de liaison. Les sequences des amplicons obtenus chez le ray-grass a l'aide de 16 EST-SSR pris au hasard ont ete alignees avec les sequences de reference des EST-SSR chez les cereales. Les motifs et le degre de repetition des SSR chez les cereales etaient differents de ceux observes chez le ray-grass dans la majorite des cas. De plus, une majorite des regions amplifiees bordant les EST-SSR etaient differentes chez le ray-grass. Ces resultats suggerent que la grande transportabilite des EST-SSR chez le raygrass contribue a ameliorer la base de donnees moleculaires sur les marqueurs de type PCR mais que l'analyse des sequences est essentielle en vue de l'utilisation de l'information genetique pour de la cartographie comparee. Mots-cles : Lolium, poacees, polymorphisme, marqueur SSR, transportabilite, cartographie comparee. [Traduit par la Redaction], Introduction During the last two decades, a large number of expressed sequence tags (ESTs) have been generated in several cereal crop species. This information is an excellent resource for molecular [...]

Wild soybean (Glycine soja Sieb. and Zucc.) is an important source of genetic variation for introducing useful traits into cultivated soybeans [Glycine max (L.) Merr.]. Little is known about genetic diversity within South Korean wild soybeans and how they differ genetically from other G. soja lines originating from other regions. Forty-six simple sequence repeat markers covering the 20 soybean linkage groups were used to estimate genetic diversity among 274 wild soybean accessions from South Korea (210), China (34), Japan (25), and eastern Russia (5) and three cultivated checks. Glycine soja populations from South Korea, China, and Japan all had high genetic diversity with indexes of 0.849, 0.818, and 0.804, respectively. Cluster analyses grouped the 274 accessions into three genetic groups. Cluster I and II consisted of 85 accessions, with 79 of 85 from Korea, only one from China, and five from Japan. Cluster III contained 192 of the 274 G. soja accessions. Nearly all of the accessions from China and Japan, all from Russia, and 131 of 210 from South Korea were assigned to Group III. However, there was no difference between populations for genetic diversity for South Korea and China. Although it is a very small country, South Korea is a major center of diversity for wild soybeans and potentially a source of useful genes not found in other parts of the world.

Abstract: Tef (Eragrostis tef (Zucc.) Trotter) is the most important cereal crop in Ethiopia; however, there is very little DNA sequence information available for this species. Expressed sequence tags (ESTs) [...]

The density and utility of the molecular genetic linkage map of cultivated sunflower (Helianthus annuus L.) has been greatly increased by the development and mapping of several hundred simple sequence repeat (SSR) markers. Of 1089 public SSR markers described thus far, 408 have been mapped in a recombinant inbred line (RIL) mapping population (RHA280 x RHA801). The goal of the present research was to increase the density of the sunflower map by constructing a new RIL map (PHA x PHB) based on SSRs, adding loci for newly developed SSR markers to the RHA280 x RHA801 RIL map, and integrating the restriction fragment length polymorphism (RFLP) and SSR maps of sunflower. The latter was accomplished by adding 120 SSR marker loci to a backbone of 80 RFLP marker loci on the HA370 x HA372 [F.sub.2] map. The map spanned 1275.4 centimorgans (cM) and had a mean density of 6.3 cM per locus. The PHA x PHB SSR map was constructed from 264 SSR marker loci, spanned 1199.4 cM, and had a mean density of 4.5 cM per locus. The RHA280 x RHA801 map was constructed by adding 118 new SSR and insertion-deletion (INDEL) marker loci to 459 previously mapped SSR marker loci. The 577-locus map spanned 1423.0 cM and bad a mean density of 2.5 cM per locus. The three maps were constructed from 1044 DNA marker loci (701 unique SSR and 89 unique RFLP or INDEL marker loci) and supply a dense genomewide framework of sequence-based DNA markers for molecular breeding and genomics research in sunflower., THE FIRST MOLECULAR GENETIC LINKAGE MAPS Of cultivated sunflower were developed by means of RFLP (Berry et al., 1995, 1996, 1997; Gentzbittel et al., 1995, 1999; Jan et al., 1998) [...]

Abstract Background Tef [Eragrostis tef (Zucc.) Trotter] is the major cereal crop in Ethiopia. Tef is an allotetraploid with a base chromosome number of 10 (2n = 4× = 40) and a genome size of 730 Mbp. The goal of this study was to identify agronomically important quantitative trait loci (QTL) using recombinant inbred lines (RIL) derived from an inter-specific cross between E. tef and E. pilosa (30-5). Results Twenty-two yield-related and morphological traits were assessed across eight different locations in Ethiopia during the growing seasons of 1999 and 2000. Using composite interval mapping and a linkage map incorporating 192 loci, 99 QTLs were identified on 15 of the 21 linkage groups for 19 traits. Twelve QTLs on nine linkage groups were identified for grain yield. Clusters of more than five QTLs for various traits were identified on seven linkage groups. The largest cluster (10 QTLs) was identified on linkage group 8; eight of these QTLs were for yield or yield components, suggesting linkage or pleotrophic effects of loci. There were 15 two-way interactions of loci to detect potential epistasis identified and 75% of the interactions were derived from yield and shoot biomass. Thirty-one percent of the QTLs were observed in multiple environments; two yield QTLs were consistent across all agro-ecology zones. For 29.3% of the QTLs, the alleles from E. pilosa (30-5) had a beneficial effect. Conclusion The extensive QTL data generated for tef in this study will provide a basis for initiating molecular breeding to improve agronomic traits in this staple food crop for the people of Ethiopia.

Abstract Background Earlier comparative maps between the genomes of rice (Oryza sativa L.), barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) were linkage maps based on cDNA-RFLP markers. The low number of polymorphic RFLP markers has limited the development of dense genetic maps in wheat and the number of available anchor points in comparative maps. Higher density comparative maps using PCR-based anchor markers are necessary to better estimate the conservation of colinearity among cereal genomes. The purposes of this study were to characterize the proportion of transcribed DNA sequences containing simple sequence repeats (SSR or microsatellites) by length and motif for wheat, barley and rice and to determine in-silico rice genome locations for primer sets developed for wheat and barley Expressed Sequence Tags. Results The proportions of SSR types (di-, tri-, tetra-, and penta-nucleotide repeats) and motifs varied with the length of the SSRs within and among the three species, with trinucleotide SSRs being the most frequent. Distributions of genomic microsatellites (gSSRs), EST-derived microsatellites (EST-SSRs), and transcribed regions in the contiguous sequence of rice chromosome 1 were highly correlated. More than 13,000 primer pairs were developed for use by the cereal research community as potential markers in wheat, barley and rice. Conclusion Trinucleotide SSRs were the most common type in each of the species; however, the relative proportions of SSR types and motifs differed among rice, wheat, and barley. Genomic microsatellites were found to be primarily located in gene-rich regions of the rice genome. Microsatellite markers derived from the use of non-redundant EST-SSRs are an economic and efficient alternative to RFLP for comparative mapping in cereals.

Corn starch serves as food, feed, and a raw material for industrial use. Starch makes up most of the biomass of the corn hybrid and is the most important and main yield component in corn breeding programs. Starch is composed of two polymers, branched amylopectin and linear amylose, which normally constitute about 75% and 25% of the corn starch, respectively. Breeding for corn starch quality has become economically beneficial because of the development of niche markets for specialty grains. In addition, due to the increased demands of biofuel production, corn ethanol production is receiving more attention. Consequently, improving starch quantity has become one of the most important breeding objectives. This review will summarize the use of corn starch, and the genetics and breeding of grain quality and quantity for industrial applications. [ABSTRACT FROM AUTHOR]