| As high temperature and humidity in the Southwest region at the corn growing season, banded leaf and sheath blight(BLSB) has become a major corn disease in this area, and seriously limited the corn yield and quality. Development and exploitation of genetic resistant varieties is an effective way to control this disease. In this study, the genetic linkage map was constructed with 133 SSR markers based on the recombination inbred lines (RIL), which contains 339 lines derived from the cross of the inbred line R15 (resistant) and the inbred line Ye478 (sensitive). Resistance to BLSB was identificated at Yaan in 2008 and Yaan,Chongqing, Mianyang in 2009 respectively, which was used to analyzing the effects, locus of QTLs related to resistance to BLSB, finding the relationship among resistance to BLSB, plant height and ear height, looking for the "consistency" QTLs and exploring the molecular genetic mechanism for the genetic improvement of maize resistance to BLSB.This study achieved the following results:1.133 pairs of codominant SSR markers were devided into 10 linkage groups by mapmaker-/EXP3.0b software, molecular marker linkage map based on maize recombinant inbred lines was constructed, the total map length was 1658 cM, the average interval distance was 12.56 cM. Compared with the SSR Bin map, all markers on 10 chromosomes arranged in the same order.2.The variance and correlation of lesion height, disease index, ear height and plant height were analized under four environmental conditions.Analysis of variance showed that:In the same environmental conditions every trait value among the different lines were significantly different, this indicated this RILs could be used to study the QTLs related to disease index, lesion height, ear height and plant height; In different environmental conditions the difference of disease index, lesion height, ear height and plant height were all highly significant, therefore, we should look for the "consistency" QTLs of these traits by this RILs. Correlation analysis showed that lesion height was positively correlated with ear height and plant height, the average correlation coefficients were 0.35 and 0.32 respectively. Disease index was positively correlated with lesion height, and negatively with ear height and plant height, the average correlation coefficients were 0.31,-0.74 and-0.57 respectively.3.11 QTLs of resistance to BLSB were detected by composite interval mapping method (LOD>2.0) based on the disease index, they were located on chromosome 2,4,5,8 and 9 respectively, the additive effect aranged from 0.0165 to 0.0545,they could explain the phenotypic variance from 2.81% to 7.29%.Especially, bzqtl-4 and bzqtl-6 could be detected twice and three times respectively.4.7 QTLs of resistance to BLSB were detected by composite interval mapping method (LOD>2.0) based on the lesion height, they were located on chromosome 6,8,9 and 10 respectively, the additive effect aranged from 0.69 to 3.15, they could explain the phenotypic variance from 2.63% to 8.78%. Especially, bbgqtl-4, bbgqtl-5 and bbgqtl-6 could be detected twice, three times and twice respectively.5.11 QTLs related to ear height and 11 QTLs related to plant height were detected by composite interval mapping method (LOD>2.0).Especially, swqtl-3,zgqtl-3 and zgqtl-6 all could be detected twice.6.Compared with zhao maojuns results, we all detected the QTLs related to resistance to BLSB near the SSR markers umc2318,umc2357, bnlg1583 and bnlg1714. Compared the QTLs related to lesion height, disease index, ear height and plant height, we discovered that locations of some QTLs controlling different traits were close to each other or overlaped, this furtherly confirmed the correlation of these traits from the chromosome level.
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