Comparative mapping of Andropogoneae: Saccharum L. (sugarcane) and its relation to sorghum and maize

Abstract

Comparative genetic maps of Papuan Saccharum officinarum L. (2n ‫؍‬ 80) and S. robustum (2n ‫؍‬ 80) were constructed by using single-dose DNA markers (SDMs). SDM-framework maps of S. officinarum and S. robustum were compared with genetic maps of sorghum and maize by way of anchor restriction fragment length polymorphism probes. The resulting comparisons showed striking colinearity between the sorghum and Saccharum genomes. There were no differences in marker order between S. officinarum and sorghum. Furthermore, there were no alterations in SDM order between S. officinarum and S. robustum. The S. officinarum and S. robustum maps also were compared with the map of the polysomic octoploid S. spontaneum 'SES 208' (2n ‫؍‬ 64, x ‫؍‬ 8), thus permitting relations to homology groups (''chromosomes'') of S. spontaneum to be studied. Investigation of transmission genetics in S. officinarum and S. robustum confirmed preliminary results that showed incomplete polysomy in these species. Because of incomplete polysomy, multipledose markers could not be mapped for lack of a genetic model for their segregation. To coalesce S. officinarum and S. robustum linkage groups into homology groups (composed of homologous pairing partners), they were compared with sorghum (2n ‫؍‬ 20), which functioned as a synthetic diploid. Groupings suggested by comparative mapping were found to be highly concordant with groupings based on highly polymorphic restriction fragment length polymorphism probes detecting multiple SDMs. The resulting comparative maps serve as bridges to allow information from one Andropogoneae to be used by another, for breeding, ecology, evolution, and molecular biology.

Diploid/Polyploid Syntenic Shuttle Mapping and Haplotype-Specific Chromosome Walking Toward a Rust Resistance Gene (Bru1) in Highly Polyploid Sugarcane (2n ∼ 12x ∼ 115)

“…This implies that only single-dose markers [i.e., markers present on only one of the hom(oe)ologous haplotypes] can be used for high-resolution mapping. Our strategy for helping to rapidly saturate a given target area was to use bulk segregant analysis while also benefiting from the good syntenic relationships between sugarcane and two model diploid Poaceae species, sorghum and rice (Grivet et al 1994;Dufour et al 1997;Glaszmann et al 1997;Guimaraes et al 1997;Ming et al 1998;Jannoo et al 2007), which are estimated to have diverged from sugarcane 8 and 50 MYA, respectively (Wolfe et al 1989;Jannoo et al 2007). Genetic maps, physical maps, and/or genome sequence data from these two species were tapped to select loci potentially present in the target area.…”

Plant genomics and agriculture: From model organisms to crops, the role of data mining for gene discovery

“…Sorghum, maize and sugarcane belong the Andropogoneae tribe and the genome of sorghum is the smallest of the three. Comparison of maize, sugarcane and sorghum, revealed that maize is an ancient tetraploid while sugarcane is a polyploid (Guimaraes et al 1997). Furthermore a simple organization of the comparative mapping suggested a high degree of conservation of genic regions and duplicated structure in these polypoid species, while sorghum standing between these two food crops (Draye, 2001).…”

The Fruits of Tropical Plant Genomics

“…The closest relative of sugarcane is sorghum-the two grasses are thought to have diverged from a common ancestor as little as five million years ago [1] and some genotypes can still be crossed to one another [43]. Sorghum and sugarcane genomes share more extensive genome-wide colinearity, and fewer chromosomal rearrangements [47,65,107], than either share with any other known grass. The finding that many regions of the sorghum genome correspond to four or more homologous regions of sugarcane suggests that in the short period since their divergence from a common ancestor, sugarcane has been through at least two whole genome duplications [107].…”