QTL detection for drought tolerance in composite maize populations

Abstract

The most significant QTLs for leaf ABA and root characteristics are shown to be on chromosomes 1 (bin 1.06) and 2 (bin 2.04). Assuming that the same QTLs could be present in different genotypes, the objective of this work was to ascertain if the QTLs with major effect detected i n one genotype could be detected in a different genetic background with different molecular markers of that chromosome region. Also, bulk segregant analysis (BSA) of 10 tolerant and 10 susceptible to drought maize populations was performed in order to confirm the potential of this approach in informative marker identification. Probes umc1601, umc1776, bnlg2248, dupSSR27 and bnlg2246 detected allele frequency differences between tolerant and susceptible populations of over 14%. It was also shown that BSA can identify informative molecular markers, although marker analysis of individual plants is necessary for final conclusion about linkage of the marker and the trait of interest.

Najznačajniji QTL-ovi za sadržaj ABA u listu i neke karakteristike korenovog sistema se, prema podacima iz literature, nalaze na hromozomima 1 (bin 1.06) i 2 (bin 2.04). Pretpostavljajući da isti QTL-ovi mogu biti prisutni u različitim genotipovima, cilj ovog rada je bio da se utvrdi da li QTL-vi sa major efektom u jednom genotipu mogu biti detektovani u različitim genetičkim okruženjima, koristeći molekularne markers datog hromozomskog regiona. Takođe, analiza grupnih uzoraka 10 tolerantnih i 10 osetljivih populacija na sušu je urađena da bi se proverila ispravnost ovog pristupa u identifikaciji informativnih markera. Probama umc1601, umc1776, bnlg2248, dupSSR27 i bnlg2246 detektovana je razlika u frekvenciji alela između tolerantnih i osetljivih populacija veća od 14%, što ukazuje na moguću povezanost markera i svojstva od interesa, mada je za konačan zaključak neophodno uraditi analizu pojedinačnih biljaka grupnih uzoraka.