Quantitative trait loci for yield and morphological traits in maize under drought stress

Abstract

Drought is one of the most important factors contributing to crop yield loss. In order to develop maize varieties with drought tolerance, it is necessary to explore the genetic basis. Mapping quantitative trait loci (QTL) that control the yield and associate agronomic traits is one way of understanding drought genetics. QTLs associated with grain yield (GY), leaf width (LW3, LW4) plant height (PH), ear height (EH), leaf number (NL), tassel branch number (TBN) and tassel length (TL) were studied with composite interval mapping. A total of 43 QTLs were detected, distributed on all chromosomes, except chromosome 9. Phenotypic variability determined for the identified QTLs for all the traits was in the range from 20.99 to 87.24%. Mapping analysis identified genomic regions associated with two traits in a manner that was consistent with phenotypic correlation among traits, supporting either pleiotropy or tight linkage among QTLs.

Suša je jedan od najznačajnijih faktora koji utiče na smanjenje prinosa. Mapiranje lokusa za kvantitativna svojstva (QTL) koja kontrolišu prinos i vezane agronomske osobine daju uvid u genetičku osnovu odgovora biljke na stres suše i omogućavaju stvaranje tolerantnih genotipova. Lokusi za kvantitativna svojstva vezani za prinos, širinu lista, visinu biljke, visinu biljke do klipa, broj listova, broj grana metlice i dužinu metlice identifikovani su primenom composite interval mapping metode. Detektovano je ukupno 43 QTL-a, na svim izuzev na 9 hromozomu. Fenotipska varijabilnost za ova svojstva bila je u opsegu od 20.99 to 87.24%. Identifikovani su genomski regioni vezani za dva ili više svojstva, i istovremeno je kod njih detektovana visoka fenotipska korelacija, što ukazuje na postojanje plejotropnih ili epistatičkih interakcija između QTL-ova.