Pentaploid Wheat Hybrids: Applications, Characterisation, and Challenges

Abstract

Interspecific hybridisation between hexaploid and tetraploid wheat species leads to the development of F1 pentaploid hybrids with unique chromosomal constitutions. Pentaploid hybrids derived from bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum spp. durum Desf.) crosses can improve the genetic background of either parent by transferring traits of interest. The genetic variability derived from bread and durum wheat and transferred into pentaploid hybrids has the potential to improve disease resistance, abiotic tolerance, and grain quality, and to enhance agronomic characters. Nonetheless, pentaploid wheat hybrids have not been fully exploited in breeding programs aimed at improving crops. There are several potential barriers for efficient pentaploid wheat production, such as low pollen compatibility, poor seed set, failed seedling establishment, and frequent sterility in F1 hybrids. However, most of the barriers can be overcome by careful selection of the parental genotypes and by employing the higher ploidy level genotype as the maternal parent. In this review, we summarize the current research on pentaploid wheat hybrids and analyze the advantages and pitfalls of current methods used to assess pentaploid-derived lines. Furthermore, we discuss current and potential applications in commercial breeding programs and future directions for research into pentaploid wheat.

Inheritance and Genetic Mapping of the Reduced Height (Rht18) Gene in Wheat

“…Three of the originally-sown plants did not grow to maturity. This is expected as sterility is often associated with the incompatibility among the tetraploid and hexaploid crosses [ 20 , 21 ]. The F 2 population had a height distribution skewed towards the parent Icaro ( Figure 1 ).…”

The Use of Pentaploid Crosses for the Introgression of Amblyopyrum muticum and D-Genome Chromosome Segments Into Durum Wheat

“…In crosses involving parents of different ploidy levels, it has been shown that using the higher ploidy level genotype as the maternal parent is generally more successful in producing viable F 1 progeny (Ramsey and Schemske, 1998; Kalous et al, 2015). In pentaploid wheat crosses, the hexaploid parent is usually used as the female parent (Padmanaban et al, 2017a; Padmanaban et al, 2017b) and thus, the hexaploid WMI lines were used here as the female parent. Viable F 1 seeds were obtained with both durum wheat parents, Om Rabi 5 and Karim.…”

Molecular breeding technologies and strategies for rust resistance in wheat (Triticum aestivum) for sustained food security

“…Transfer of R genes from wild species by classical breeding is time-consuming (often more than 10 years), and often associated with linkage drag. In addition, crosses between wild species and wheat can be complicated due to differences in ploidy level (Padmanaban et al, 2017). The native R genes, including their native promoters and terminators, could be used for transformation of commercially cultivated varieties.…”