“Gene pyramiding” via ingegneria cromosomica di geni di resistenza a fusariosi e ruggini trasferiti in frumento tenero e duro da specie selvatiche del genere Thinopyrum
Author(s)
Forte, Paola
Date Issued
June 11, 2013
Type
Doctoral Thesis
Abstract
Favoured by climatic changes, Fusarium Head Blight (FHB), a serious worldwide wheat disease, has become also a threat in unusual distribution areas. Therefore, new resistant and adapted varieties are needed, capable of maintaining their yield capacity and grain quality. The
transfer of alien chromosomes or fragments of them in the genome of wheat, defined as “chromosomal engineering”, is an improvement strategy which, combined with the use of advanced selection systems, allows to access and exploit genes derived from wild wheat relatives in breeding programs. Through this strategy, a gene/QTL for FHB resistance (FHBres7el2), present in the wild Thinopyrum ponticum accession that contains el2 chromatin, has been transferred from a bread wheat line (7DS.7el2L) to bread (7DS.7DL/7el1L) and durum wheat (7AS.7AL/7el1L) genotypes, already carrying other useful genes, i.e. Lr19+Sr25+Yp, previously transferred from a different (el1) Th. ponticum accession. Similarly, even another gene/QTL of FHB resistance (FHBres7E), present in a species of the same genus, the Thinopyrum elongatum, has been object of another transfer from a bread wheat line, CS7E(7D), to bread wheat (7DS.7DL/7el1L) genotypes, always in association with genes Lr19 + Yp + Sr25. In this thesis, with the help of molecular markers and in situ hybridization (GISH) techniques, the cross progeny of such lines were characterized and selected. Although with a different frequency, pyramiding of the Th. ponticum genes (el1 + el2) has been achieved in both bread and durum wheat; while the pyramiding of the Th. ponticum and Th. elongatum genes (el1 + E) has been achieved in the bread wheat. Also, to assess the FHBres efficacy in both species most of the bread (7DS.7DL-7el17el2L) and durum (7AS.7AL-7el17el2L) wheat recombinants were subjected to infection with Fusarium spp. The selected lines, carrying the novel el1 (Lr19+Sr25+Yp) + el2 (FHBres) combination, showed in all cases a significant reduction (60-70%) of the susceptibility to Fusarium Head Blight.
Additional information
Dottorato di ricerca in Biotecnologie vegetali
Subjects
File(s)![Thumbnail Image]()
Name
pforte_tesid.pdf
Size
2.53 MB
Format
Adobe PDF
Checksum (MD5)
0c735c5993973106a21919e41d277227