A fertile amphiploid between diploid wheat (Triticum tauschii) and crested wheatgrass (Agropyron cristatum)

Abstract

Alloploidy, one of the most efficient evolutionary mechanisms in nature, has not been extensively exploited in plant breeding programmes. Many genomic combinations remain to be created by plant breeders, to be used directly as new crops or indirectly to widen the genetic basis of crops. The Triticeae tribe, to which wheat belongs, is among the botanical groups in which this strategy has been successfully explored. However, there remain valuable genomic combinations that have not been obtained at the diploid level. The Agropyron complex (wheat-grasses) has recently been the focus of attention for interspecific hybridization, but intergeneric hybrids or amphiploids with wheat have not been reported at the diploid level. Here we report synthesis of a tetraploid amphiploid between Triticum tauschii and Agropyron cristatum by crossing two tetraploid accessions. Using total genome in situ hybridization (GISH) staining on metaphase I pollen mother cells, data on allosyndetic and autosyndetic chromosome pairing have been obtained. These data support the view that the A. cristatum tetraploid parent used in the synthesis of the amphiploid has a segmental alloploidy nature.

Production and identification of wheat-Agropyron cristatum 6P translocation lines

“…Allosyndetic associations between wheat and A. cristatum are rare [23,[36][37][38]; consequently, homoeologous pairing between wheat and A. cristatum chromosomes rarely takes place even when induced with a Ph-system [39]. Translocations induced by tissue culture are very technical and troublesome because they require a long period to obtain regenerative plants [40].…”

Morphological, yield, cytological and molecular characterization of a bread wheat X tritordeum F1 hybrid

“…This process could induce genetic effects like structural heterosis, which can result in bigger size and wide adaptation of the resulting polyploid species (Fernández-Escobar and Martín 1985;Stoinova 1994;Martín et al 1999).…”

“…Martín et al (1999) used the genomic in situ hybridization (GISH) technique in combination with morphological and RAPD analyses for characterization of the amphiploid Agropyrum cristatum and its parents. Carvalho et al (2005) used ISSR markers to characterize three different hybrid combinations.…”

“…Interspecific hybridization has been used by plant breeders in order to interchange genetic material between different plant species or to produce new species (see Gupta and Priyadarshan 1982;Fedak 1992;Martín et al 1999). In the tribe Triticeae of family Poaceae, different hybrid combinations of Triticum, Hordeum and Secale have been produced (LimaBrito et al 1996;Martin et al 1996).…”

Specific Variation in Shoot Growth and Root Traits Under Waterlogging Conditions of The Seedlings of Tribe Triticeae including Mizutakamoji (Agropyron Humidum)

“…A. humidum might be useful to increase the waterlogging tolerance of wheat and barley and to create new crops with high adaptability to waterlogging. Fatih (1983), Martin et al (1999) and Soliman et al (2001) reported fertile amphiploids between wheat and another species of genus Agropyron, such as A. cristatum and A. intermedium. Khan (2000) also reported the recombination of chromosomes between wheat and A. intermedium.…”