Wild barley: a source of genes for crop improvement in the 21st century?

Abstract

The development of new barleys tolerant of abiotic and biotic stresses is an essential part of the continued improvement of the crop. The domestication of barley, as in many crops, resulted in a marked truncation of the genetical variation present in wild populations. This process is significant to agronomists and scientists because a lack of allelic variation will prevent the development of adapted cultivars and hinder the investigation of the genetic mechanisms underlying performance. Wild barley would be a useful source of new genetic variation for abiotic stress tolerance if surveys identify appropriate genetic variation and the development of marker-assisted selection allows efficient manipulation in cultivar development. There are many wild barley collections from all areas of its natural distribution, but the largest are derived from the Mediterranean region. The results of a range of assays designed to explore abiotic stress tolerance in barley are reported in this paper. The assays included; sodium chloride uptake in wild barley and a mapping population, effects for delta 13C and plant dry weight in wheat aneuploids, effects of photoperiod and vernalization in wild barley, and measurements of root length in wild barley given drought and nitrogen starvation treatments in hydroponic culture. There are examples of the use of wild barley in breeding programmes, for example, as a source of new disease resistance genes, but the further exploration of the differences between wild barley and cultivars is hampered by the lack of good genetic maps. In parallel to the need for genetic studies there is also a need for the development of good physiological models of crop responses to the environment. Given these tools, wild barley offers the prospect of a 'goldmine' of untapped genetic reserves.

Can barley (Hordeum vulgare L. s.l.) adapt to fast climate changes? A controlled selection experiment

“…To what extent the apparent genetic variation in barley will translate into tolerance to the prevailing abiotic stress under climate change is yet unexplored. If not present in the present crop cultivars, this highly requested environmental tolerance might be found in the landraces or cross compatible wild relatives (Ellis et al 2000;Newton et al 2010). In a long term monitoring program Nevo et al (2012) for example found that natural climate stress created profound adaptive changes in wild barley (Hordeum spontaneum K. Koch).…”

<b>Identification of QTL underlying agronomic, morphological and physiological traits in barley under rainfed conditions using SNP markers

“…The introgression of genomic segments from wild to cultivated barley has been a useful procedure for increasing the genetic variation of traits that contribute to drought tolerance (Lakew et al, 2011). However, only 40% of wild barley alleles are represented in cultivated barley (Ellis et al, 2000).…”

Path analysis of genotype × environment interaction in wheat-barley disomic addition lines

“…Disomic addition lines, in which a single pair of chromosomes from a related species is added to the full chromosome complement of the recipient, can be used to identify chromosomes carrying the genes controlling adaptation and phenotypic stability, and form the starting point for gene transfer and the genetic improvement of genotypic stability (Ellis et al, 2000;Farshadfar, 2008).…”