Thinopyrum spp. group 7 chromosome introgressions improve durum wheat response to intense daytime and night-time heat stress at anthesis
Author(s)
DI ROMANA, MARIA LIA
Giovenali, Gloria
Capoccioni, Alessandra
Riccardi, Vinicio
Date Issued
2025
Type
conferenceObject
Abstract
Durum wheat (DW) is a strategic crop in the Mediterranean region, an area increasingly affected
by climate change, where rising day/night (d/n) temperatures threaten yield stability. Enhancing
heat tolerance in DW through the introgression of chromosomal segments from wild wheat
relatives is a promising and validated approach. In this study, four DW–Thinopyrum spp. nearisogenic
recombinant lines (NIRLs) were evaluated for their physiological and agronomic
responses to intense heat stress (IH; 37/27 °C d/n for 3 days) applied at anthesis. The lines
included two primary types (R5+ and R112+), carrying 23%- and 28%-long Th. ponticum 7el1L
segments, respectively, on the 7AL arm, and two secondary recombinants (R69-9/R5+ and R69-
9/R112+), with a Th. elongatum 7EL segment of about 20% arm long, distally inserted within the
described 7el1L segments. Their responses were compared to those of their non-carrier sister
lines (−) and the heat-tolerant cultivar Margherita by measuring 22 morpho-physiological traits
and 9 stress indices. Among the NIRLs, R112+, R69-9/R5+, and R69-9/R112+ showed enhanced
tolerance to IH stress, marked by the maintenance of leaf relative water content, increased
accumulation of proline and soluble sugars in the flag leaf, and preserved photosynthetic
efficiency. Yield performance under IH was stable in these lines (R112+ > R69-9/R5+ > R69-
9/R112+), often matching or exceeding Margherita. R112+ maintained fertility through grain
number retention, while R69-9/R5+ compensated via increased grain weight (+30%). These
results reinforce the value of Thinopyrum wild germplasm in improving DW resilience to extreme
heat, highlighting its utility in breeding programs targeting future climate scenarios.
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