Data from: Globally-deployed sorghum aphid resistance gene RMES1 is vulnerable to biotype shifts but being bolstered by RMES2

Durable host plant resistance (HPR) to insect pests is critical for
sustainable agriculture. Natural variation exists for aphid HPR in sorghum
(Sorghum bicolor) but the genetic architecture and phenotype have not been
clarified for most sources. To assess the threat of a sorghum aphid
(Melanaphis sorghi) biotype shift, we characterized the phenotype of
Resistance to Melanaphis sorghi 1 (RMES1) and contributing HPR
architecture in globally-admixed populations selected under severe aphid
infestation in Haiti. We developed and sequenced RMES1 near-isogenic lines
and found RMES1 reduces sorghum aphid fecundity but not bird cherry-oat
aphid (Rhopalosiphum padi) fecundity, suggesting a discriminant HPR
response typical of gene-for-gene interaction. Analyzing whole-genome
resequencing of a global diversity panel, we found resistant alleles at a
second gene, RMES2, were more frequent than RMES1 resistant alleles in
landraces and historic breeding lines. RMES2 contributes early and
mid-season aphid resistance in a segregating F2 population, however, RMES1
was only significant with mid-season fitness. In a fixed population with
high aphid resistance, RMES1 and RMES2 were selected for demonstrating a
lack of significant antagonistic pleiotropy. Associations with resistance
co-located with cyanogenic glucoside biosynthesis genes support additional
HPR sources. Globally, therefore, a vulnerable HPR source (RMES1) is
bolstered by a second common source of resistance in breeding programs
(RMES2) which may be staving off a biotype shift.