Validation of markers linked to late leaf spot and rust resistance, and selection of superior genotypes among diverse recombinant inbred lines and backcross lines in peanut (Arachis hypogaea L.)

Recombinant inbred lines (RILs) from four populations involving cultivated varieties, and backcross lines from three populations involving cultivated varieties and synthetic tetraploids (developed from wild diploids) were employed for validating late leaf spot (LLS) and rust resistance-linked markers and identifying superior genotypes in peanut. GM2009, GM2301, GM2079, GM1536, GM1954 and IPAHM103 markers showed significant association with rust resistance. They were successfully validated in a new RIL (TG 19 × GPBD 4) and two backcross (DH 86 × ISATGR 278-18 and DH 86 × ISATGR 5) populations. GM1954, GM1009 and GM1573 markers showed significant association with LLS resistance. TAG 19 × GPBD 4 and ICGS 76 × ISATGR 278-18 populations showed strong co-segregation of LLS-linked markers with the phenotype. From these genetic resources, six superior genotypes were identified. RIL 78-1 was resistant to LLS and rust, and recorded 30 % more pod yield than GPBD 4 (control). It also had higher kernel yield and oil yield along with higher oleate and linoleate content over GPBD 4. These genetic and genomic resources could be useful in breeding for LLS and rust resistance in peanut