Genomic Approaches for Dissecting Complex Traits Related to Quality Production of Range Grasses

Tropical grasses have been widely used as warm-season forage grasses in the warm temperate zone since the early 20th century because of their high yields; they have also been used as perennial forages in their native tropical areas. Increasing demand for animal production sparked by economic development in tropical countries is requiring breeders to improve native forage grasses in these countries. Considerable efforts have been made to breed accessions with improved characteristics and to develop new cultivars. However, cross-breeding is not common, owing to a lack of genetic information and to complexities related to polyploidy, high sterility rates, outcrossing, and apomixis. Nevertheless, several of the difficulties are being resolved by advanced research using molecular genetic tools, involving linkage analysis for the inheritance of genes for traits with major effects, such as apomixis. However, additional improvement is required for forage grasses with complex major traits that are controlled by multiple minor genes, such as forage yield, nutrient uptake, and sterility. In these cases, molecular tools can be combined with simple measurements of plant physical or morphological traits to support breeding. In addition, combining molecular tools with conventional breeding methods could lead to effective selection of promising breeding resources

Perturbative Approach to the Gravitational Lensing by a Non-spherically Distorted Compact Object

We investigate the gravitational lens effect caused by a non-spherically distorted compact object. The non-spherical property of the gravitational potential is modeled by a quadrupole moment. Under the assumption that the quadrupole contribution is small, we solve perturbatively the lens equation and obtain the image positions and the amplification factors. We show that the separation angle of two major images is only slightly changed by the existence of the quadrupole contribution, whereas the difference of the amplification factors may be significantly modified. Our results indicate that even a tiny non-spherical distortion of the lens potential may cause significant amount of flux anomalies in the lensed images.Comment: 10 pages, version accepted for publication in PT

A New Candidate Cultivar of Brachiaria Grass \u27Br-203\u27 Developed with Apomixis Marker Assisted Selection, through a Collaborative Breeding Activity of Thailand and Japan

Brachiaria grass (Brachiaria spp.) is one of most important tropical forage grass which belongs to family Poaceae, subfamily Panicoideae, tribe Paniceae, genus Brachiaria. Brachiaria grass has attracted attention because of a leading ‘Green Revolution’ over tens of millions of hectares in the Central Brazilian Cerrado in the 1970s. Breeding programs for Brachiaria grass have been conducted mainly by the International Center for Tropical Agriculture (CIAT) and the Brazilian Agricultural Research Corporation (EMBRAPA). Careful and effective recurrent selection of tetraploid sexual lines for vigor, growth habit, leafiness, and spittlebug resistance have spawned several successful hybrid cultivars: ‘Mulato’, ‘Mulato II’, and ‘Caiman’ (Miles et al., 2004). Research activities on tetraploid sexual lines of Brachiaria spp. (Ishigaki et al., 2010) have been also continued in tropical and subtropical Japan and Southeast Asia. Our recent breeding program for Brachiaria spp. has also got underway in the tropical monsoon region, particularly areas of Indo-China. Marker-assisted selection (MAS) for breeding population has been previously done with some important crops and forages. Apomixis is one of important trait for breeding, which can lead eternal asexual propagation through seed. Previous report (Ebina et al., 2005) revealed that the apomixis co-segregated marker could assist breeding selection. In this paper, we report a new candidate cultivar ‘Br-203’ bracharia grass crossed with a sexual maternal tetraploid parent of ‘Miyaokikoku’ and an apomixis paternal tetraploid parent of ‘Mulato’. After pre-selection by MAS for apomixis trait in Japan, effective and compact breeding populations have been transferred to Department of Livestock Development (DLD) Thailand. Major agronomical traits selections have been successfully performed in Thailand. The result shows the combination of MAS and conventional breeding method is a powerful and effective way of breeding of a new apomixis bracharia grass cultivar

青森県民の健康寿命アップ対策としての「心疾患10年リスク」の活用について(青森県の健康寿命アップと保健大学の取り組み, 第2回青森県立保健大学学術研究集会)

publisher青森市国立情報学研究所の「学術雑誌公開支援事業」により電子化されました

Complete Chloroplast Genomes of Erianthus arundinaceus and Miscanthus sinensis: Comparative Genomics and Evolution of the Saccharum Complex.

The genera Erianthus and Miscanthus, both members of the Saccharum complex, are of interest as potential resources for sugarcane improvement and as bioenergy crops. Recent studies have mainly focused on the conservation and use of wild accessions of these genera as breeding materials. However, the sequence data are limited, which hampers the studies of phylogenetic relationships, population structure, and evolution of these grasses. Here, we determined the complete chloroplast genome sequences of Erianthus arundinaceus and Miscanthus sinensis by using 454 GS FLX pyrosequencing and Sanger sequencing. Alignment of the E. arundinaceus and M. sinensis chloroplast genome sequences with the known sequence of Saccharum officinarum demonstrated a high degree of conservation in gene content and order. Using the data sets of 76 chloroplast protein-coding genes, we performed phylogenetic analysis in 40 taxa including E. arundinaceus and M. sinensis. Our results show that S. officinarum is more closely related to M. sinensis than to E. arundinaceus. We estimated that E. arundinaceus diverged from the subtribe Sorghinae before the divergence of Sorghum bicolor and the common ancestor of S. officinarum and M. sinensis. This is the first report of the phylogenetic and evolutionary relationships inferred from maternally inherited variation in the Saccharum complex. Our study provides an important framework for understanding the phylogenetic relatedness of the economically important genera Erianthus, Miscanthus, and Saccharum

Divergence times of the PACMAD clade.

<p>A Bayesian relaxed-clock approach based on 76 concatenated protein-coding chloroplast genes was used to estimate divergence times.</p

Microsatellites in <i>Erianthus arundinaceus</i> and <i>Miscanthus sinensis</i> chloroplast genomes.

<p>Microsatellites in <i>Erianthus arundinaceus</i> and <i>Miscanthus sinensis</i> chloroplast genomes.</p

Alignment of whole chloroplast genome sequences from four Panicoideae species.

<p>Chloroplast genomes were aligned by using the mVISTA program with the <i>Zea mays</i> sequence as a reference. The <i>X</i>- and <i>Y</i>-scales indicate the coordinates within cp genomes and the percentage of identity (50%–100%), respectively. Genome regions (exons, introns, and conserved non-coding sequences) are color-coded. Gray arrows indicate the direction of transcription of each gene. The genes encoding transfer RNAs (<i>trn</i>) are indicated under gray arrows using the single-letter amino acid code (e.g., K: <i>trn</i>K).</p

Chloroplast genome maps of <i>Erianthus arundinaceus</i> and <i>Miscanthus sinensis</i>.

<p>The genes of different functional groups are indicated in different colors. Genes on the inside and outside of the maps are transcribed clockwise and counter-clockwise, respectively. The thick lines on the inner circles indicate inverted repeats (IRa and IRb), which separate the genomes into the small single-copy (SSC) and large single-copy (LSC) regions.</p