Multi-environment QTL analyses for drought-related traits in a recombinant inbred population of chickpea (Cicer arietinum L.).

A recombinant inbred line (RIL) population, comprising 181 lines derived from ILC588 × ILC3279, was evaluated in 10 environments across three locations with different moisture gradients. A drought resistance score (DRS) and three phenology traits-plant height (PLHT), days to flowering (DFLR), and days to maturity (MAT)-were recorded along with seven yield-related traits-grain yield (GY), biological yield (BY), harvest index (HI), the number of pods/3 plants (Pod), percentage of empty pods (%Epod), 100 seed weight (100 sw), and seed number/3 plants (SN). Two RILs (152, 162) showed the best GYs and DRSs under stressed and non-stressed environments. The quantitative trait loci (QTLs) analyses detected 93 significant QTLs (LOD ≥ 2.0) across the genome × environment interactions. The highest phenotypic variation (>24 %) was explained by the QTLDFLR in Terbol-11. Four common possible pleiotropic QTLs on LG3 and LG4 were identified as associated with DFLR, DRS, GY, MAT, HI, SN, and Pod. No significant epistatic interactions were found between these QTLs and the other markers. However, the QTL for DRS was detected as a conserved QTL in three late planting environments. The markers H6C-07 (on LG3) and H5G01 (on LG4) were associated with QTLs for many traits in all environments studied except two. The allele 'A' of marker H6C07 (from the tolerant parent ILC588) explained 80 % of the yield increase under late planting and 29.8 % of that under dry environments. Concentrating on LG3 and LG4 in molecular breeding programs for drought could speed up improvement for these traits.

A genetic linkage map of Lens sp. based on microsatellite and AFLP markers and the localization of fusarium vascular wilt resistance.

Microsatellites have currently become the markers of choice for molecular mapping and marker-assisted selection for key traits such as disease resistance in many crop species. We report here on the mapping of microsatellites which had been identified from a genomic library of lentil (Lens culinaris Medik.). The majority of microsatellite-bearing clones contained imperfect di-nucleotide repeats. A total of 41 microsatellite and 45 amplified fragment length polymorphism (AFLP) markers were mapped on 86 recombinant inbred lines derived from the cross ILL 5588 x L 692-16-1(s), which had been previously used for the construction of a random amplified polymorphic DNA and AFLP linkage map. Since ILL 5588 was resistant to fusarium vascular wilt caused by the fungus Fusarium oxysporum Shlecht. Emend. Snyder & Hansen f.sp. lentis Vasud. & Srini., the recombinant inbreds were segregating for this character. The resulting map contained 283 markers covering about 751 cM, with an average marker distance of 2.6 cM. The fusarium vascular wilt resistance was localized on linkage group 6, and this resistance gene was flanked by microsatellite marker SSR59-2B and AFLP marker p17m30710 at distances of 8.0 cM and 3.5 cM, respectively. These markers are the most closely linked ones known to date for this agronomically important Fw gene. Using the information obtained in this investigation, the development and mapping of microsatellite markers in the existing map of lentil could be substantially increased, thereby providing the possibility for the future localization of various loci of agronomic interest.