Marker-aided selection of QTLs for drought tolerance in rice
Drought is an increasingly important constraint limiting rice world production. Drought tolerance, however, is a complex character resulting from many interacting component traits that QTL mapping studies have shown to be quantitative. To demonstrate the efficiency of marker-aided selection (MAS) to manipulate QTLs, two examples of selection based on markers only are described. The first study aimed at introgressing alleles for root depth. QTL detection had already been conducted in the appropriate background and the MAS step was therefore implemented directly. The interesting alleles were coming from Azucena, a deep-rooted variety, and IR64, the target for introgression, was used as the recurrent parent in 3 cycles of marker-assisted backcrosses. Several QTLs were manipulated at once. BC3F2 progenies were genotyped to select plants with Azucena alleles at the QTLs and assess the return to the recurrent parent. The phenotypic evaluation of BC3F3 families showed that the introgressed QTLs were expressed in the recipient background. It also highlighted the importance of the initial QTL analysis methods. In standard breeding programs, however, specific QTL detection results are seldom available. The advanced backcross QTL analysis method allows the simultaneous discovery and transfer of interesting QTLs from an unadapted donor to an elite variety. We used this method to transfer QTLs for osmotic adjustment, an important component of true tolerance, from IR62266, an indica donor, to IR60080-46A, a japonica elite line. BC3F3 plants were produced and QTL analysis of osmotic adjustment was conducted to determine the best plants to cross to construct improved near-isogenic lines. (Texte intégral)
| Main Authors: | , , , , , , , |
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| Format: | conference_item biblioteca |
| Language: | eng |
| Published: |
Scherago International
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| Subjects: | F30 - Génétique et amélioration des plantes, Oryza, résistance à la sécheresse, sélection, technique analytique, http://aims.fao.org/aos/agrovoc/c_5435, http://aims.fao.org/aos/agrovoc/c_2392, http://aims.fao.org/aos/agrovoc/c_6951, http://aims.fao.org/aos/agrovoc/c_1513, |
| Online Access: | http://agritrop.cirad.fr/487400/ |
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