Application of molecular markers in bulk segragant analysis of yield in maize (Zea mays L) synthetic populations

Abstract

Chromosome regions which carry potential QTLs for high grain yield in two synthetic maize populations - B73xMol7 and LlxMol7, were identified by bulk segregant analysis (BSA). Yield was evaluated on F2 testcross families in field trials using a Nested design. Based on yield data, p3 families with the corresponding highest and lowest testcross yields were selected for BSA. Genome analysis of F3 families was carried out with 58 RFLP markers. Allele frequency differences were detected at four RFLP loci n chromosomes 1, 2, 6 and 10 (B73xMol7), i.e. four RFLP loci on chromosomes 1, 2, 6 and 9 (LlxMo17). Only one region, at chromosome 6, was identified in both populations, but with two different RFLP markers. In B73xMol7 it was umc65 and in LlxMol7 umc2l RFLP marker. Bulk segregant analysis was shown to be a quick and informative method for identification of chromosome regions which determine high yield expression in maize, i.e. for identification of RFLP markers closely linked to potential genes involved in expression of the trait.

Identifikacija hromozomskih regiona potencijalnih nosioca QTL uključenih u ekspresiju visokog prinosa zrna kukuruza kod dve sintetičke populacije B73xMol7 i LlxMol7, urađena je analizom grupnih uzoraka. Prinos je određen na familijama test-ukrštanja F2 biljaka u poljskim ogledima, po Nested dizajnu. Na osnovu podataka o prinosu odabrane su F3 familije sa najvećim i najmanjim prinosom odgovarajućih familija test-ukrštanja. Analiza genoma visoko i nisko prinosnih grupnih uzoraka F3 familija je urađena pomoću 58 RFLP markera. Na osnovu razlika u frekvenciji alela identifikovana su četiri RFLP lokusa na hromozomima l, 2, 6 i 10 (B73xMol7), odnosno četiri RFLP lokusa na hromozomima l, 2, 6 i 9 (LlxMol7). Samo je jedan region, na hromozomu 6 identifikovan u oba ukrštanja, ali sa dva različita markera - umc65 u B73xMol7 i umc21 u LlxMol7. Analiza grupnih uzoraka se pokazala kao brza i informativna metoda u identifikaciji hromozomskih regiona koji determinišu ispoljavanje visokog prinosa kod kukuruza, tj. u identifikaciji RFLP markera blisko vezanih za potencijalne gene uključene u ekspresiju ove osobine.