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Rachis brittleness in a hybrid–parent barley ( Hordeum vulgare ) breeding germplasm with different combinations at the non‐brittle rachis genes
Author(s) -
FernándezCalleja Miriam,
Casas Ana M.,
PérezTorres Antonio,
Gracia Maria Pilar,
Igartua Ernesto
Publication year - 2020
Publication title -
plant breeding
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.583
H-Index - 71
eISSN - 1439-0523
pISSN - 0179-9541
DOI - 10.1111/pbr.12776
Subject(s) - biology , hybrid , germplasm , hordeum vulgare , brittleness , agronomy , rachis , poaceae , gene , genetics , botany , materials science , composite material
Two dominant, closely linked and complementary genes, Btr1 and Btr2, control rachis brittleness in barley. Recessive mutations in any of these genes turn the fragile rachis (brittle) into a tough rachis phenotype (non‐brittle). The cross of parents with alternative mutations in the btr genes leads to a brittle F 1 hybrid that presents grain retention problems. We evaluated rachis fragility through a mechanical test and under natural conditions, in F 1 crosses with different compositions at the btr genes. Brittleness was significantly higher in Btr1btr1Btr2btr2 crosses compared to hybrids and inbred parents carrying one of the mutations ( btr1btr1Btr2Btr2 / Btr1Btr1btr2btr2 ). This fact could jeopardize the efficient harvest of hybrids bearing alternative mutations, reducing the choice of possible crosses for hybrid barley breeding and hindering the exploitation of potential heterotic patterns. Furthermore, non‐brittle hybrids showed higher brittleness than inbreds, suggesting the presence of other dominant factors affecting the trait. In conclusion, this work encourages a deeper study of the genetic control of the rachis brittleness trait and urges the consideration of rachis tenacity as a target for hybrid barley breeding.