The centromere position of each chromosome was identified using the centromere-specific probe pCEN38, as previously described by Islam-Faridi et al. Chromosome Number: 2n = 20. List of genetic markers and their anchored BACs used for integrating linkage and cytogenetic maps. 2n = 10, 20, 30, 40). Data were exported to a spreadsheet (Microsoft Excel) and analyzed. and . The chromosomal location of each BAC was determined by integrating the BACs with the sorghum genetic map (Klein et al., 2000) or by BAC- homologs mapped to sorghum chromosome … 2005b). Seventeen of the 25 species are native to Australia, with the range of some … The arm ratio (average long arm/short arm ratio), total chromosome length (short arm + long arm), and relative chromosome length (length of the individual chromosome/total length of all chromosomes in the genome) were calculated for each chromosome in the complement. Each translocation stock was crossed and backcrossed once to a low-dhur­ rin line of sudangrass. Both belong to the Andropogoneae subfamily. and . At present, there is no suitable answer to this question, but there has been discussion about the evolution of chromosome number. 2002). The 2C DNA content, 2n chromosome number and x = 5 genome size are indicated next to each species. (2002), except as follows. Lengths of arms were determined to orient linkage groups relative to a standard karyotypic layout (short arms at top). BAC clones are positioned on the ideogram according to their positions relative to the centromeres. sorghum (Sorghum bicolor) have the same number of chromo-somes (2n 5 20). Cytogenetically, sorghum is a diploid of 2n = 2x = 20 where 2n is the somatic chromosome number having two complete sets (2x) of chromosomes and a chromosome number of 20. Each letter corresponds to a linkage group (Menz et al. So called ‘bird-resistant, bird-proof or bird-repellent’ sorghums contain condensed tannins, in the nucellar layer and pericarp, that are distasteful to birds and give the crops some protection. 2000). For FISH of the multi-probe cocktail from 17 BAC clones, 50× Cot-1 DNA was added to the probe mixture, which was denatured at 90° for 10 min, chilled on ice, and then annealed for 30 min before application to the slide. For karyotyped images, DAPI-stained chromosomes were measured using Optimas v6.0 (Media Cybernetics, Silver Spring, MD). 2003) and undermine the applicability of each linkage map beyond the respective parental combination. 2003). Anchoring of the sorghum maps to those of rice … The identity of the authors' accession of S. leiocladumwas verified by senior taxonomist Ian Cowie at the Darwin Herbarium. Cytogenetic and genetic analyses showed that sorghum chromosomes are comprised of distal regions of high gene density that exhibit high rates of recombination and large heterochromatic pericentromeric regions characterized by low gene density and low rates of recombination (Kim et al., 2005). In contrast, identification of sorghum chromosomes by simultaneous fluorescence in situ hybridization (FISH) of a landed BAC cocktail was devised to establish a FISH-based karyotypic system for sorghum (Kim et al. HK grew the sorghum plant, carried out the quantification of their sucrose content, and revised the manuscript. 1991), for the purpose of molecular size estimation, it is important to target metaphase, i.e., when molecular density is most uniform along the chromosome long axis and relative lengths most accurately reflect relative molecular size. SK participated in the breeding of the sorghum SIL-05 (line number 89) and provided the seeds. The medial position seen in BTx623 is of interest, but not unique. Figure 1 shows karyotypes of Sorghum species varying in chromosome number and. Although highly repetitive, the genome is more tractable for sequencing than its close relative, Zea mays. However, a temporary constriction occurs in the fifth largest chromosome of a variety of S. bicolor cultivated for silage, in addition to the major constriction in its largest chromosome (Gu et al. The unified nomenclature system for chromosomes and linkage groups of line BTx623 provide a reasonable basis for a genomic nomenclature for S. bicolor in that this line is readily available, highly inbred, and extensively used for genetic, breeding, and genomics research. The first whole genome sequence of a grain sorghum is available, but additional genome sequences are required to study genome-wide … 2000; Cheng et al. and P.E.K.) NOTE: We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail. The results enabled us to align and orientate the linkage maps relative to the 10 chromosome pairs, and to develop nomenclatures for chromosomes and linkage groups that are based on sorghum chromosome size. 1998; Tao et al. 2000; Haussmann et al. 2002; Anderson et al. Karyotype-aided analysis of sorghum chromosome size and DNA content recently allowed the establishment of a unified sorghum chromosome numbering system (K im et al. Main determinant is the karyotype, referring to the number, as well as the size and shape of … S. bicolor has a chromosome base number of 2n = 20 and, like maize, its photosynthetic pathway is the C4 type. LINKAGE mapping of Sorghum has progressed quickly, using diverse mapping populations and markers (Whitkus et al. a.async=true;a.type="text/javascript";b.parentNode.insertBefore(a,b)}, 1); Sorghum bicolor is a widely grown cereal crop, particularly in Africa, ranking 5th in global cereal production. 2002). One species is grown for grain, whil… The stages are based on sorghum structures as they develop over the life of the plant.A sorghum plant has 10 official stages of growth and development, starting with emergence (Stage 0) and ending with physiological maturity of the grain (Stage 9). We developed an integrated “cyto-genomic” map from FISH data on 24 BACs containing linkage markers from across the sorghum genome (Figure 2, Table 2). The centromere for each chromatid was identified by the primary constriction and also by FISH of the centromere-associated sequence pCEN38 (Zwick et al. Chromosome Number of Different Crop Material Agronomy Horticulture Plant Pathology Entemology Plant Breeding Genetics Current Affairs Chromosome number Locality Sorghum × almum Parodi-1 Liu 237 (ILRI 13515) IBSC/US Perennial 2n = 2x = 40 Ethiopia S. × almum-2 Liu 432 (PI 190579) IBSC Argentina S. × drummondii (Nees ex Steud.) All authors read and … Sorghum nitidum is also a perennial diploid with 2n = 10, 20 and is found in Queensland, New Guinea, and … 1992; Fransz et al. 792) for the 21 Sorghum species studied, based upon combined ITS/ndhF sequences. Sorghum bicolor is a drought tolerant C4 grass used for the production of grain, forage, sugar, and lignocellulosic biomass and a genetic model for C4 grasses due to its relatively small genome (approximately 800 Mbp), diploid genetics, diverse germplasm, and colinearity with other C4 grass genomes. Sorghum (Sorghum bicolor) is globally produced as a source of food, feed, fiber and fuel. 1999; Peng et al. Summary statistics for the Sorghum bicolor reference genome. The diploid genome (~730 Mb) has a haploid chromosome number of 10. is five and most polyploid species are autopolyploids. A FISH-based karyotype of S. bicolor inbred line BTx623 was developed, in which chromosomes were ordered and designated according to total length at metaphase, namely SBI-01 (longest) to SBI-10 (shortest). We excluded 74 unlinked SNPs and obtained an initial genetic map with a total of 616 markers on the ten sorghum chromosomes. The number of bases incorporated into the genome, the contiguity of the sequence, and the accuracy of the sequence improved in version 3. Asterisks denote signals from the 17 BACs shown in Figure 1. Seven accessions of S. … Lengths of arms were determined to orient linkage groups relative to a standard karyotypic layout … SBI-01 is morphologically the most distinct chromosome of the sorghum haploid complement. The karyotype of BTx623 is grossly similar to those of other sorghum accessions and cultivars (Magoon and Shambulingappa 1960; Magoon and Ramana 1961; Magoon et al. 2008 ). The short arm is closely related to Brachypodium chromosome 4, sorghum chromosome 8 and rice chromosome 12; the long arm to regions of Brachypodium chromosomes 4 and 1, sorghum chromosomes 1 and 2 and rice chromosomes 9 and 3. The tetraploid S. halepense (2n=40) will hybridize with diploid cultivated sorghum, Sorghumbicolor (L.) Moench (2n=20), and the progeny are usually sterile triploids which may be … The NOR of S. bicolor Combine Kafir 60 is located in the middle of the fifth longest chromosome (Yu et al. Copyright © 2021 by the Genetics Society of America. In this study, PH and FL were not significantly correlated (Table S2), an unexpected finding compared to many other sorghum studies ( Lin et al. As detailed in the methods, we combined SNPs that are within 1cM in genetic distance to construct a genetic map with 381 bins (bin map) with varying SNP numbers in each bin (File S3). Homologous chromosome pairs were identified with the aid of MacProbe v.4.2.3, according to the pattern of signal on each chromosome. 1994; Xu et al. Each trait-associated SNP and annotated genes located within a 50 kb window up and downstream from each trait-associated SNP for each GWAS analysis shown in Figure 5 (d) and (e) and S5 are provided in Additional file S1 . Subscribe via email. However, it is not the diploid chromosome number alone that determines the ability of two parents to readily form a hybrid. Reference (see below) Sign up to receive alert notifications of new articles. Enter multiple addresses on separate lines or separate them with commas. 1964; Bennett and Laurie 1995; Sang and Liang 2000). Some of these species have grown as cereals for human consumption and some in pastures for animals. 2003). Thank you for sharing this Genetics article. Images were taken from an Olympus AX-70 epifluorescence microscope (Olympus America, Melville, NY) equipped with standard filter cubes, a Peltier-cooled monochrome 1.3 megapixel Sensys camera (Photometrics, Tucson, AZ), and MacProbe v.4.2.3 digital imaging system (Applied Imaging, San Jose, CA). Chromosome numbers of the 21 sorghum species studied are listed in Table 2. Populations from the USA and Canada are of Mediterranean origin and are a tetraploid ecotype. Sorghum bicolor has a haploid chromosome number of 10, containing 530 Mb with 33,000 protein-coding genes. number of resistant accessions are present in the temperate-adapted germplasm; other exotic sources of resistance are not currently available for breeding programs. Stiposorghum. The three-letter acronym SBI designates the genus and species, and the two-digit numeric code denotes the chromosome number. 1998, 2000; Boivin et al. Of these common markers included, 251 were selected as bridge markers on the 10 sorghum chromosomes, i.e. 1998; Künzel et al. Sorghum is reflected in the chromosome number of the species belonging to the different subgenera (Figure 1). The 5A genes were used to search for syntenic relationships between grass genomes. One species, Sorghum bicolor, was originally domesticated in Africa and has since spread throughout the globe. Sorghum leiocladumwas reported to have 2n= 20 chromosomes but a new number of 2n= 10 was counted. Relative lengths of chromosomes in FISH-karyotyped metaphase spreads of the elite inbred BTx623 were used to estimate the molecular size of each chromosome and to establish a size-based nomenclature for sorghum chromosomes (SBI-01 … The patterns of signals enable FISH-based recognition of each chromosome pair and associate specific linkage groups with specific chromosomes. Sorghum is a genus of flowering plants in the grass family Poaceae, which includes about 25 species. The characteristics of each of the five pachytene bivalents in the haploid complement and the pachytene accessory chromosome are identified on the basis of total length, arm ratio, and the extent of the heterochromatic region. The mixture was denatured at 90° for 10 min, chilled on ice, and added to the slide. Prior to FISH, chromosomal DNA on slides was denatured at 70° in 100 μl of 70% formamide in 2× SSC on a hot block for 1.5 min followed by dehydration in 70% ethanol at −20° and 85, 95, and 100% ethanol at room temperature, respectively. The two significant SNPs at the end of chromosome 6 are close to a locus for sorghum height identified in a separate sorghum MAGIC population (QTL-6) . A phylogenetic tree based on ITS1, Adh1 and ndhF grouped the species of the genus Sorghum into one distinct monophyletic group, but including two sister lineages, one with x=5, the other with x=10 as basic chromosome numbers. The consistent use of two digits will facilitate data sorting by computers. Chromosome number is a remarkably variable feature of eukaryotic genomes with variations in the somatic chromosome number known to exist at all levels of taxonomic resolution. (1991), respectively, but means of evaluation were lacking and their relationship to molecular markers and genomic resources remains unknown. Bar indicates 1.5 μm for metaphase chromosomes and 50 cM for linkage maps. The genome contains a high level of repeats (61%). Chromosomes are depicted with the shorter arm in the top position. BTx623 contained an exceptionally long pair of chromosomes, SBI-01, eight pairs of metacentric chromosomes closely graded in size, SBI-02, -03, -04, -05, -07, -08, -09, and -10, and one pair of midsized submetacentric chromosomes, SBI-06. (2002). Recognizing the key developmental stages of sorghum can aid in making critical management decisions. Millsp. Lengths of the remaining chromosomes followed a somewhat bimodal distribution, with SBI-02, -03, -04, and -05 constituting the group of longer chromosomes (3.87–3.44 μm) and SBI-06, -07, -08, -09, and -10 constituting the group of shorter ones (3.15–2.97 μm). Rice chromosomes 5 and 10 as well as sorghum chromosomes 1 and 9 were substantially enriched for putative orthologs and outnumbered the remaining chromosomes of the respective genomes. 2002). (2002; data not shown). The diploid genome (~730 Mb) has a haploid chromosome number of 10. Cytogenetically, sorghum is a diploid of 2n = 2x = 20 where 2n is the somatic chromosome number having two complete sets (2x) of chromosomes and a chromosome number of 20. Stiposorghum. The sequenced reads were mapped to the sorghum reference genome 2 assembly (version … 1995 ; Murray et al. Sorghum in different Languages: Cholam ( Tamil ), Jonna ( Telugu ), Searjam ( Malayalam ), ... Large number of varieties/hybrids with higher yield potential than that of local has been released. Cytogenetic maps of sorghum chromosomes 3-7, 9, and 10 were constructed on the basis of the fluorescence in situ hybridization (FISH) of approximately 18-30 BAC probes mapped across each of these chromosomes. In addition, the molecular cytology of three sorghum chromosomes has been analyzed in detail using genetically mapped BAC clones and FISH (I slam-F aridi et al. Assembly. The chromosome number of Saccharum ranges from 2 n = 36 to 170 (D aniels and R oach 1987; J. E. I rvine, unpublished data), while chromosome number of Sorghum ranges from 2 n = 10 to 40 (D oggett and P rasada R ao 1995). The solid line represents the sorghum chromosome. 2002; Bowers et al. ), and the National Science Foundation Plant Genome grants DBI-0077713 (J.E.M. Parasorghum. The lowest haploid. Accession number, life form and origin of 21 Sorghum species analysed for DNA content and chromosome number Herbarium Accession Life Species voucher no.1 form Collection … Sorghum, an ancient old-world cereal grass, is the dietary staple of over 500 million people in more than 30 countries in the tropics and semitropics. Such structural differences between parents can complicate linkage analysis (e.g., see Bowers et al. Here, we used FISH-based karyotyping in concert with analysis of chromosome lengths, arm lengths, and arm ratios to establish a size-based nomenclature for sorghum chromosomes. In addition to its distinctive length (5.11 μm), SBI-01 is one of only two submetacentric pairs and is the only “satellite” chromosome.