QTL Analysis Of Resistance To Asian Corn Borer In Maize

Maize is a one of the most important crops which can be used as food, forage and the raw material of industry. It is of strategic importance to the development of agriculture and even national economy. Maize production in China has been seriously affected by corn borer, especially Asian corn borer (Ostrinia furnacalis., ACB). Breeding for corn borer resistance should be a priority in reducing the damage of this pest. Genetics analysis for the resistance to the pest is the base of improving the resistant germplasm and enhancing the efficiency of breeding.QTL analysis on the resistance to Asian corn borer were carried out in this study, using AFLP and SSR markers and two F2:3 populations derived from the cross of H21 (resistant) Mol7(susceptible) and Zi330(susceptible) K.36(resistant). The major results and conclusions are described as follows.1. In Population H21 Mol7, nine QTL were detected for resistance to ACB, which were localized on chromosome 1,4,5,8 and 10. These QTL showed predominantly overdominance, subsequently dominance or partial dominance gene action. These QTL explained 7.7-51.8% of the phenotypic variance. Five were from the resistant parent H21, four were from the susceptible parent Mo 17 in all Alleles contributing enhanced resistance.2. In Population ZJ330XK36, eight QTL were detected for resistance to ACB, which were localized on chromosome 1,2,3,4,5,8 and 9. These QTL showed overdominance, dominance, partial dominance and additive gene action. These QTL explained 8.8-49.6% of the phenotypic variance. Seven were from the resistant parent K36, only one was from the susceptible parent Zi330 in all Alleles contributing enhanced resistance.3. QTL detected in chromosome bins 1.02/03 and 8.03/04 were in common between the H21 X Mo 17 population and the ZJ330XK36 population.4. The QTL in chromosome bin 4.01/02 was located in the region of bxl gene that is required for synthesis of DIMBOA. The result suggested DIMBOA is one of the bases ofantibiosis resistance to ACB. QTL in our study in chromosome bins 5.04 and 8.05 were located in similar bins as QTL for leaf toughness and leaf protein content. The result suggested that the mechanism of resistance to ACB closely correlate with tolerance to damage.5. The QTL for resistance in our study at chromosome bins 1.02/03, 8.03/04, 4.05, 2.02/03, 5.07 and 9.03 were in similar bins as QTL for resistance to European corn borer (ECB) in ECB studies. These results suggested that the mechanism of resistance to ACB was similar to ECB.