Estimation Of Introgression Lines Based On Maize Inbred Line NX110 And QTL Analysis Of The Traits Associated To Drought Toleration

Introgression lines(ILs)in maize,as a permanent mapping population,were developed using advanced-backcross and marker-assisted selection,which is a novel and ideal materials for genetic analysis of quantitative trait locus(QTLs).there, Comparing with the traditional population,were more advantages in the maize ILs,such as:1)There were clear genetic background and relatively steady genetic base in ILs,which were widely used to analyze the interaction among QTLs or between Environment and QTL;2)Single segment introgression lines or near isogenic lines can be further developed from ILs,which makes great progress in the improvement of the accuracy and sensitivity of QTL mapping and identification;3)In addition,genetic effects of QTLs can be exactly analyzed and study on the interaction of QTL and environment or among QTL by using the ILs.In this study,the introgression lines(ILs)were developed using BS110(Nongxi 110)as the recurrent parent and 60 elite inbred lines as donor,through 3～4 cycles advanced backcross and 1～2 cycle self-cross.The foreground and background of the introgression populations,combined with phenotypic selection,were selected by SSR marker in backcross BC3F2 generation.The results were as follows:1,the polymorphism of the SSR markers,came from http://www.maizegdb.org/, were screened between donors and recurrent parent nongxi 110.The 94 pair polymorphic primers were detected using PAGE.The polymorphic loci were used for foreground selection and background selection.2,The foreground selection was performed using 94 SSR loci and PAGE among the introgression population including 92 individual.The results showed that there were 672 segments introgressed in maize inbred line Nongxi 110.At the same time,the background detection was carried on using 58 SSR locus among the introgression lines. The results indicated that the genetic background was identical to Nongxi 110 excluding the remained fragment,and the recoverage range from the minimal recoverage 94.26% to the maximal recoverage was 100%;the average rate was 98.14%.3,The genetic analysis of the introgression lines was carried out by the popular biosofeware GGT 3.x among the 92 population.The results showed that the average length of the introgressed segment was 91.10 cM,varying from 6.8 to 342.86 cM.Total length was 3643.92 cM with coverage of 43.96%of chromosomes in NX 110-IL.4,The QTLs for five agronomic traits related drought tolerance were elementarily identified using Windows QTL IciMapping v1.0 according to the criteria-LOD>2.0. The results showed that there were the total 13 QTLs detected among the five agronomic characters of the introgression lines including 4 QTLs for hundred kernel weight,3 QTLs for ear height,2 QTLs for ear length,1 QTL for ear diameter,3 QTLs for ASI.