Articles

Identification of quantitative trait loci for resistance to Curvularia leaf spot of maize


Abstract


Resistance of maize to Curvularia leaf spot (CLS), a severe foliar disease in hot and humid maize growing areas, is quantitative in nature. The F2:3 families derived from the cross between the resistant Shen137 and susceptible Huangzao4 inbred lines, were used to detect QTL conferring resistance to CLS. Four QTL were detected on chromosomes 1, 3, 8, and 10, and could totally explain 38.8% of the total phenotypic variation. Another F2 population consisting of 63 highly resistant and 59 highly susceptible plants, selected from 822 F2 plants, was also subjected to QTL analysis for CLS resistance. Four QTL were found on four chromosomes 1, 4, 9, and 10, which accounted for 45.7% of the total phenotypic variation. Interestingly, a major resistance QTL, qCLS10.4, on chromosomal bin10.04 was consistently detected in both populations. Apart from additive effect, dominant effect also exerted significant influence on resistance to CLS. Therefore, breeders should avoid an early generation selection of resistant individuals in breeding program.

Keywords

maize; Curvularia leaf spot; QTL; selective genotyping

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