Detection of two quantitative trait loci for resistance to ascochyta blight in an intra-specific cross of chickpea (Cicer arietinum L.): development of SCAR markers associated with resistance |
| |
| Authors: | M Iruela J Rubio F Barro J I Cubero T Millán J Gil |
| |
| Institution: | (1) Dpto. de Mejora y Agronomía, IFAPA, Córdoba, 14080 Córdoba, Spain;(2) Dpto de Agronomia y Mejora Genetica Vegetal, IAS-CSIC, Córdoba, 14080 Córdoba, Spain;(3) Dpto de Genética, ETSIAM, Córdoba, 14080 Córdoba, Spain |
| |
| Abstract: | Two quantitative trait loci (QTLs), (QTLAR1 and QTLAR2) associated with resistance to ascochyta blight, caused by Ascochyta rabiei, have been identified in a recombinant inbred line population derived from a cross of kabuli×desi chickpea. The population
was evaluated in two cropping seasons under field conditions and the QTLs were found to be located in two different linkage
groups (LG4a and LG4b). LG4b was saturated with RAPD markers and four of them associated with resistance were sequenced to
give sequence characterized amplified regions (SCARs) that segregated with QTLAR2. This QTL explained 21% of the total phenotypic variation. However, QTLAR1, located in LG4a, explained around 34% of the total phenotypic variation in reaction to ascochyta blight when scored in the
second cropping season. This LG4a region only includes a few markers, the flower colour locus (B/b), STMS GAA47, a RAPD marker and an inter-simple-sequence-repeat and corresponds with a previously reported QTL. From the
four SCARs tagging QTLAR2, SCAR (SCY17590) was co-dominant, and the other three were dominant. All SCARs segregated in a 1:1 (presence:absence) ratio and the scoring
co-segregated with their respective RAPD markers. QTLAR2 on LG4b was mapped in a highly saturated genomic region covering a genetic distance of 0.8 cM with a cluster of nine markers
(three SCARs, two sequence-tagged microsatellite sites (STMS) and four RAPDs). Two of the four SCARs showed significant alignment
with genes or proteins related to disease resistance in other species and one of them (SCK13603) was sited in the highly saturated region linked to QTLAR2. STMS TA72 and TA146 located in LG4b were described in previous maps where QTL for blight resistance were also localized
in both inter and intraspecific crosses. These findings may improve the precision of molecular breeding for QTLAR2 as they will allow the choice of as much polymorphism as possible in any population and could be the starting point for finding
a candidate resistant gene for ascochyta blight resistance in chickpea. |
| |
| Keywords: | |
| 本文献已被 PubMed SpringerLink 等数据库收录！ |
|
