Banishing barberry: The history of Berberis vulgaris prevalence and wheat stem rust incidence across Britain

Abstract

Wheat stem rust, caused by the fungal pathogen Puccinia graminis f. sp. tritici (Pgt), is a notoriously damaging disease of wheat and barley (Figure 1). Today, stem rust occurs in most major wheat-growing regions worldwide, and western Europe is currently experiencing a resurgence in infections after many decades of absence (Lewis et al., 2018; Saunders et al., 2019). Stem rust has threatened crop production throughout history, with the earliest archaeological evidence of its spores having been identified close to the centre of the area where cereal cultivation first began, on Neolithic potsherds from

Analysis of wild plant pathogen populations reveals a signal of adaptation in genes evolving for survival in agriculture in the beet rust pathogen (Uromyces beticola)

“…However, many agronomically important rusts also have an alternate host which is used by the fungus to enter its sexual phase (27). In the case of the wheat rusts, hundreds of years before a causative link was established, superstition drove the removal of its alternative host, Berberis, from cereal growing regions (21). U. beticola reproduces on wild sea beet and, the permanent proximate availability this host offers a (post hoc) explanation as to why we have not observed divergence of karyon (reduced heterozygosity) in U. beticola.…”

“…In most cases, the sexual phase of the life cycle occurs on a different host plant, termed heteroecious (as opposed to autoecious). In the case of wheat stem rust this alternate host is barberry which has been associated with increased rust virulence in Europe and the US for hundreds of years (21).…”

The Evolving Battle Between Yellow Rust and Wheat: Implications for Global Food Security

“…tritici (causal agent of stem rust). Historically this resulted in efforts to eradicate Berberis species in many European and North American countries (Barnes et al 2020). However, it was not until 2010 that Berberis species were formally con rmed to support development of Pst pycnia and aecia (Jin et al 2010).…”

The threat to global food security from wheat rust: ethical and historical issues in fighting crop diseases and preserving genetic diversity

“…Many of the great famines of the eighteenth and nineteenth centuries, with death tolls in the millions, began with outbreaks of pathogens that attacked staple crops (Alfani & O'Grada 2019). Rust fungi (taxonomized under the order Pucciniales) attack cereals, and have been devastating to wheat cultivation for millenia (Barnes et al 2020). Since the Green Revolution, crop losses to rust have been greatly reduced through campaigns to breed resistant varieties, the development of fungicides, and, earlier in the twentieth century, the removal of barberry shrubs from wheat-growing regions (barberry plays a role in some rust fungi life cycles).…”

“…The first concerted efforts to breed wheat that would be immune to wheat rust date back to the early 1800s, after virulent attacks of wheat rust in Australia (Johnson 2010: 4). By the twentieth century, when the life-cycle of stem rust was understood to include barberry shrubs as a second host, large state-sponsored campaigns to eradicate barberry trees were undertaken in Europe and America (Barnes et al 2020;Peterson 2018). During the twentieth century, more than 500 million barberry bushes were destroyed in North America; but globally, wheat production during these decades was regularly punctuated by devastating losses from wheat rust (Ehrenberg 2010).…”