Molecular-genetic maps for group 1 chromosomes of Triticeae species and their relation to chromosomes in rice and oat

Abstract

Group 1 chromosomes of the Triticeae tribe have been studied extensively because many important genes have been assigned to them. In this paper, chromosome 1 linkage maps of Triticum aestivum, T. tauschii, and T. monococcum are compared with existing barley and rye maps to develop a consensus map for Triticeae species and thus facilitate the mapping of agronomic genes in this tribe. The consensus map that was developed consists of 14 agronomically important genes, 17 DNA markers that were derived from known-function clones, and 76 DNA markers derived from anonymous clones. There are 12 inconsistencies in the order of markers among seven wheat, four barley, and two rye maps. A comparison of the Triticeae group 1 chromosome consensus map with linkage maps of homoeologous chromosomes in rice indicates that the linkage maps for the long arm and the proximal portion of the short arm of group 1 chromosomes are conserved among these species. Similarly, gene order is conserved between Triticeae chromosome 1 and its homoeologous chromosome in oat. The location of the centromere in rice and oat chromosomes is estimated from its position in homoeologous group 1 chromosomes of Triticeae.

Gene evolution at the ends of wheat chromosomes

“…Although the major cereal crop species wheat (Triticum aestivum L.), maize (Zea mays L.), rice (Oryza sativa L.), barley (Hordeum vulgare L.), rye (Secale cereale L.), and sorghum (Sorghum vulgare L.) diverged from a common ancestor Ͼ65 million years ago, they still show a high degree of conservation of gross gene order (1)(2)(3)(4)(5)(6)(7)(8). At the DNA-sequence level, a more complex picture emerges.…”

Four QTLs determine crown rust (Puccinia coronata f. sp. lolii) resistance in a perennial ryegrass (Lolium perenne) population

“…One of Only the left border was calculated as H-TGG-M-CAT-R1 mapped to the distal end of LG1. Table 2 Overview of map positions of heterologous RFLP probes on the rice map (Stephenson, 1999; gramene database), oat map , wheat map, barley map (gramene database; Nelson et al, 1995a, b;Van Deynze et al, 1995a;Gale et al, 1995;Marino et al, 1996) and the ILGI map (Jones et al, 2002a) LG in this study…”

Comparative Genomics of Plant Chromosomes

“…Pioneering efforts in the comparative mapping of maize and sorghum (Hulbert et al, 1990) have been supported by more detailed studies (Whitkus et al, 1992;Berhan et al, 1993;Binelli et al, 1993;Chittenden et al, 1994;Pereira et al, 1994) and supplemented by the comparative organization of maize and rice , wheat and rice (Kurata et al, 1994), and maize, wheat, and rice . A host of investigations additionally encompasses many other cultivated Poaceae, with particular emphasis on the interrelationships among the homeologous chromosome sets of the Triticeae and their relatives (see Naranjo et al, 1987;Chao et al, 1989;Liu and Tsunewaki, 1991;Devos et al, 1992aDevos et al, , 1992bDevos et al, , 1993Devos et al, , 1995Liu et al, 1992;Xie et al, 1993;Namuth et al, 1994;Hohmann et al, 1995;Marino et al, 1996;Mickelson-Young et al, 1995;Nelson et al, 1995aNelson et al, , 1995bNelson et al, , 1995cVan Deynze et al, 1995). Curiously, even in the relatively "conservative" Poaceae, certain lineages appear to be rapidly evolving.…”

“…Most comparative genetic maps continue to be based on a relative paucity of DNA markers, and virtually all are dependent on the availability of DNA polymorphism, which means that only a subset of loci can be mapped. In addition, regardless of how much genomic colinearity may exist between two species, the very fact of speciation means that a certain degree of noncolinearity is likely (see, e.g., Dubcovsky and Dvorak, 1995;Leister et al, 1998).…”