Field-based screening identifies resistance to Sunn pest (Eurygaster integriceps) feeding at vegetative stage in elite wheat genotypes

Abstract

Sunn pest (Eurygaster integriceps Puton) is currently widely distributed in West and Central Asia and Eastern Europe, but has not been found in Australia, Western Europe or North America. Climate warming is known to promote the expansion of its range of distribution, and it is expected that the insect could spread into new territories. Varieties of wheat (Triticum aestivum) carrying resistance remain an important component of managing the biosecurity risk of any potential incursion. Previous studies have identified sources of Sunn pest resistance in wheat, but there is little information on the genes that confer the resistance. This research used field-based, artificial infestation cages to evaluate 204 elite wheat varieties for Sunn pest resistance, at Terbol, Lebanon. A significant (P < 0.001) difference in resistance was observed among the wheat germplasm, with 19 varieties rated as resistant to moderately resistant and 17 as highly susceptible. Three of the elite varieties showed very little damage, a status similar to that of the resistant check, ICBW-209273. In parallel, the research carried out a genome-wide scan with single-nucleotide polymorphism (SNP) markers to identify chromosome regions and putative genes associated with resistance. Association mapping identified SNP markers with significant associations on chromosomes 2D, 4B and 5B. When these markers were projected onto the wheat population sequencing-based (POPSEQ) reference map, they tended to map close to the location of wheat height-reducing genes. The phenotypic variation explained by the identified markers ranged from 7% to 11%, and collectively, they explained 23.9% of the variation or 45% of the generalised heritability. Marker-trait association was confirmed in two independent, doubled-haploid wheat populations, derived from crosses involving wheat landraces from Afghanistan, where Sunn pest is recognised as an endemic problem. In the two wheat populations, the analyses validated the strong association between wsnp_BF483640B_Ta_2_2 and resistance to Sunn pest damage at the vegetative stage. This study demonstrates existence of genetic resistance to Sunn pest feeding at the vegetative stage in elite wheat germplasm. The study also identified and validated SNP markers that could be useful tools for transfer of resistance into new wheat cultivars.

Unravelling the Complex Genetics of Karnal Bunt (Tilletia indica) Resistance in Common Wheat (Triticum aestivum) by Genetic Linkage and Genome-Wide Association Analyses

“…Results from genetic linkage and association mapping are often not identical (Lou et al 2015; Albert et al 2016; Li et al 2016), but they are complementary, that is, results from genome-wide association studies often confirm previously detected QTL (Waugh et al 2010; Raman et al 2010; Mulki et al 2012; Emebiri et al 2017). In the current study, the results from GWA mapping validated the consensus regions on chromosomes 3B and 4B identified from the bi-parent populations (Figure 5), but also identified novel loci for Karnal bunt resistance.…”

Вплив Пошкодження Зерна Пшениці Озимої Клопом Шкідлива Черепашка (Eurygaster Integriceps Put.) На Її Врожайність Та Якість Зерна

“…Клоп щороку атакує близько 150 млн га полів у світі [14]. Пшениця, пошкоджена клопами, містить ферменти, які розщеплюють білки клейковини, викликають швидке розслаблення тіста [15-16], що призводить до виробництва хліба невідповідного за формою та текстурою [17][18][19] зі значними фінансовими втратами.…”