Golden SusPtrit: a genetically well transformable barley line for studies on the resistance to rust fungi

Abstract

Therefore, a doubled haploid (DH) mapping population (n = 122) was created by crossing SusPtrit with Golden Promise to develop a 'Golden SusPtrit', i.e., a barley line combining SusPtrit's high susceptibility to non-adapted rust fungi with the high amenability of Golden Promise for transformation. We identified nine genomic regions occupied by resistance quantitative trait loci (QTls) against four non-adapted rust fungi and P. hordei isolate 1.2.1 (Ph.1.2.1). Four DHs were selected for an Agrobacterium-mediated transformation efficiency test. They were among the 12 DH lines most susceptible to the tested nonadapted rust fungi. The most efficiently transformed DH line was SG062n (11-17 transformants per 100 immature embryos). The level of non-adapted rust infection on SG062n is either similar to or higher than the level of infection on SusPtrit. Against Ph.1.2.1, the latency period conferred by SG062n is as short as that conferred by SusPtrit. SG062n, designated 'Golden SusPtrit', will be a valuable experimental line that could replace SusPtrit in nonhost and partial resistance studies, especially for stable transformation using candidate genes that may be involved in rustresistance mechanisms.

Genomic regions responsible for amenability to Agrobacterium-mediated transformation in barley

“…suggested that a region close to TFA2 on chromosome 2H, of the line SG062N, may affect transformation efficiency. The locations of TFA6 and TFA8 also correspond with regions previously reported by Yeo et al 5. Mano et al 6,.…”

“…reported that barley cultivar ‘Lenins’ has higher regeneration ability compared to some other cultivars, but that trait alone is not enough for efficient transformation. Yeo et al 5. suggested that a region close to TFA2 on chromosome 2H, of the line SG062N, may affect transformation efficiency.…”

“…Analysis of functional alleles generally requires development of a genetic substitution line of the target allele from the donor into ‘Golden Promise’ via multiple generations of back-crossing. Recently Yeo et al 5. developed a new barley line ‘Golden SusPtrit’ (SG062N) that combines the transformation ability of ‘Golden Promise’ with the high susceptibility to rust disease inherited from ‘SusPtrit’, to develop a line of barley amenable for functional studies of non-host and partial resistance to fungal rust.…”

“…The enhanced rate of Agrobacterium -mediated transformation in this recombined line suggested the existence of genetic factors responsible for the transformation efficiency of ‘Golden Promise’. That study also compared the genomic differences between a transformation-susceptible line (SG062N) and an insusceptible line (SG133N) in the same double haploid (DH) mapping population, to predict the genomic regions responsible for Agrobacterium -mediated transformation in ‘Golden Promise’5.…”

Mapping genes in barley for resistance to Puccinia coronata from couch grass and to P. striiformis from brome, wheat and barley

“…In particular, the experimental research line SusPtrit (Atienza et al 2004), which has been developed to have extraordinarily high susceptibility to heterologous rust fungi, proved to be instrumental in elucidating the inheritance of nonhost resistance. Mapping populations were developed with SusPtrit using the regular, immune, cvs Vada, Cebada Capa and Golden Promise as resistant parents (Jafary et al 2006(Jafary et al , 2008Yeo et al 2014).…”