Crossability ofTriticum urartuandTriticum monococcumWheats, Homoeologous Recombination, and Description of a Panel of Interspecific Introgression Lines

Abstract

Triticum monococcum (genome Am) and T. urartu (genome Au) are diploid wheats, with the first having been domesticated in the Neolithic Era and the second being a wild species. In a germplasm collection, rare wild T. urartu lines with the presence of T. monococcum alleles were found. This stimulated our interest to develop interspecific introgression lines of T. urartu in T. monococcum, a breeding tool currently implemented in several crop species. Moreover, the experiments reported were designed to reveal the existence in nature of Am/Au intermediate forms and to clarify whether the two species are at least marginally sexually compatible. From hand-made interspecific crosses, almost-sterile F1 plants were obtained when the seed-bearing parent was T. monococcum. A high degree of fertility was, however, evident in some advanced generations, particularly when T. urartu donors were molecularly more related to T. monococcum. Analysis of the marker populations demonstrated chromosome pairing and recombination in F1 hybrid plants. Forty-six introgression lines were developed using a line of T. monococcum with several positive agronomic traits as a recurrent parent. Microsatellite markers were tested on Au and Am genomes, ordered in a T. monococcum molecular map, and used to characterize the exotic DNA fragments present in each introgression line. In a test based on 28 interspecific introgression lines, the existence of genetic variation associated with T. urartu chromosome fragments was proven for the seed content of carotenoids, lutein, β-cryptoxanthin, and zinc. The molecular state of available introgression lines is summarized.

Comparison of gene expression profiles and responses to zinc chloride among inter- and intraspecific hybrids with growth abnormalities in wheat and its relatives

“…Thus, post-zygotic reproductive isolation via the Ned1-Ned2 interaction is incomplete between the two wild diploid wheat species. However, other types of reproductive isolation additively underlie the two wild diploid wheat species (Fricano et al 2014;Johnson and Dhaliwal 1976;Yamagishi 1987). For example, when ssp.…”

“…Many of the F 1 seeds from T. urartu crossed with pollens of T. monococcum ssp. aegilopoides failed to germinate, as reported previously (Yamagishi 1987;Fricano et al 2014); some plants that germinated were used for phenotyping and RNA extraction.…”

Molecular diversity and landscape genomics of the crop wild relative Triticum urartu across the Fertile Crescent

“…The outgroup samples may be contributed by ex situ erroneous taxonomic assignment or by hybridization events. Triticum urartu can cross with T. monococcum , producing fertile progeny (Baum and Bailey, ; Fricano et al ., ; Nasernakhaei et al ., ), and the diversity of these samples may indeed reflect such occurrence in our collection. Previous studies considering smaller collections and using less advanced molecular markers have already reported high variability among T. urartu natural accessions (Castagna et al ., ; Mizumoto et al ., ; Wang et al ., ); however, this is the first time that a genomic approach has been used to characterize a collection representative of the whole geographic distribution of T. urartu .…”

“…The availability of a draft genome sequence for T. urartu (Ling et al ., ) and of the high‐quality genome sequence of related species such as wild emmer (2 n = 2 x = 28; genome AABB) (Avni et al ., ), opens the possibility of extensively characterizing the genetic diversity of T. urartu , propelling its incorporation into wheat breeding pipelines. Alleles from T. urartu may be then transferred to cultivated wheat, either by biotechnology approaches, amphiploid production (Ahmed et al ., ) or by direct hybridization with polyploid (Qiu et al ., ) and diploid wheat (Fricano et al ., ). Recently, T. urartu alleles were expressed in cultivated wheat to complement their homeologs, providing enhanced functionality (Gao et al ., ).…”

A molecular genetic research of the Triticum sinskajae A. Filat. et Kurk. by RAPD analysis and by comparing the nucleotide sequences of the variable intergenic region of the petN-trnC-GCA chloroplast genome and intron of the histone H3.2 gene

“…В целом t. boeoticum, t. monococcum и t. sinskajae, вероятнее всего, являются близкородственными вида-ми диплоидных пшениц, тогда как t. urartu довольно существенно отличается от них, и в литературе име-ются тому подтверждения, хотя изначально этот вид считался подвидом t. boeoticum ssp. thaoudar [16]. Например, авторы исследования дефенсинов дипло-идных пшениц указывают на то, что t. urartu ближе к полиплоидным пшеницам, чем к t. monococcum и t. boeoticum [17].…”