Chromosomal regions associated with thein vitroculture response of wheat (Triticum aestivumL.) microspores

Abstract

Generation of doubled haploid plants is a powerful tool in breeding, as homozygous individuals will be obtained directly from hybrids. However, genotype variability in regeneration efficiency of most European wheat (Triticum aestivum L.) varieties has limited its use in wheat. This study intended to identify quantitative trait loci (QTLs) for green plantlet regeneration from wheat microspore cultures. A QTL analysis using DArT markers was conducted based on a bi-parental F 3 population, derived from a cross between the varieties Svilena and Jensen, which displayed markedly different capacity for plantlet regeneration. Two QTLs on chromosome 1B and 7B explained 53% of the variation in green plantlet regeneration. Furthermore, a collection of 94 European wheat varieties was genotyped and phenotyped. The microspore response level was low among western and northern European wheat varieties, and the positive QTLs found in the bi-parental population were rare in the variety collection. Identification of the two QTLs enables introduction of high regeneration efficiency into wheat germplasm. Moreover, our results proved that the efficient regeneration observed for one variety could be crossed into modern winter wheat.

Inheritance patterns of the response to in vitro doubled haploid induction in perennial ryegrass (Lolium perenne L.)

“…Additionally, variation in the inheritance patterns between the populations indicates the presence of different numbers of distinct alleles in their paircross parents (Madsen et al 1995;Torp et al 2001;Nielsen et al 2015). For example, non-androgenic parent P133 may harbour superior alleles for microspore embryogenesis and plant regeneration compared to P10.…”

“…Additionally, the absence of a correlation between QTL explaining variation in green plant production with embryo formation or plant regeneration was reported in wheat (Torp et al 2001;Nielsen et al 2015). Several other possibilities may be considered instead; for example, dominant control of green plant production by several genes, alleles for which are contributed solely by the androgenic parents (Tuvesson et al 1989;Opsahl-Ferstad et al 1994b), or complementation of recessive beneficial alleles present in a heterozygous state within the non-androgenic parents (Madsen et al 1995).…”

“…Nevertheless, it was soon realized that high androgenic capacity in perennial ryegrass is not only strongly genotype-dependent, but, similar to wheat, also a rare trait in breeding germplasm (Olesen et al 1988;Bante et al 1990;Madsen et al 1995;Nielsen et al 2015). In addition to improved induction protocols, introgression of androgenic capacity was therefore deemed a prerequisite for the implementation of DH production in perennial ryegrass breeding programs (Halberg et al 1990).…”

“…For example, a recent genome-wide association study (GWAS) in wheat found two QTL on chromosomes 1B and 7B that explained 53% of the variation in green plant production (Nielsen et al 2015). Similarly, genes on chromosome 4A seem to be responsible for total and green plant production in triticale (×Triticosecale Wittm.)…”

High Frequency of Doubled Haploid Plant Production in Spelt Wheat

“…The other methods for DH plant production are AC and isolated microspore culture. AC is frequently used in breeding and applied research of common wheat (Lantos et al, 2013;Castillo et al, 2015, Nielsen et al, 2015, while published reports of in vitro androgenesis induction are limited in spelt wheat. Takács et al (1994) reported on the androgenesis induction in AC of a spelt wheat genotype, in which the number of responsive anthers was 6.4%.…”