Genetic Genome-wide Analysis Of Maize S-CMS Unstable Fertility Restoration Based On QTL Mapping

The maize is very important grain crop. A cost-competitive and satisfactory technique was used to produce maize hybrid seed with development and research of CMS maize inbred line as female parent because the manual teaseling is eliminated. Three types of male-sterile cytoplasm in maize, designated as T, C and S, can be dassified by the specific nuclear genes that suppress the mal-sterity effects of these cytoplasm and restore male-sterlity effects of these cytoplasm and restore pollen fertilily. S-cytoplasm has more sub-types among T.C.S. It is conditioned by the interaction of the cytoplasm mitochondria genome and nudear gene of main effective restore of fertility gene Rf3 and other minor genes The interaction of major and minor gene and function of minor genes nave not been understand very clear up to now. All of the linkage analyses reported so far have been based only on marker from chromosome2 long arm and have not provided DNA marker data for assessing the possibility that additional hybrid sterility loci may occur in other pants of the genome It is therefore necessary to adopt genome-wide approach to determine whether or not loci that may significantly influence the effects of restore fertilily on S type CMS are indeed present in the genome moreover, the precise map location of the Rf3 locus is still not close ,because of difficulties experience in previous studies in using small number segregating population.The study in this paper was undertaken to assess the presence of additional loci for restore fertilily in F2 backcross [ (M017cms-S XYe107) X Mo17] and F2 intercross of [M017cms SX Ye 107].We also determined the precise map of RD locus with the SSRs marker ,and using SSRs marker to analysis the genetic reason of F2 sterile plants in F2 population and to analysis and research variable fertility of restoring S- type Mol7cms-S under diffferent nuclear genetic background and generations The main results are asfollow:1 The relation among the emerge of anther ,open of anthter and ratio of pollen starch -filled were studied and A new suggestion to identify instability of male fertility of CMS was made.2 The fertility of 15 crosses from Mol7cms-S intercross inbred lines were investigated. The results show that there are different effect minor genes in the inbred lines.The starch-filled pollen ratio from 8 different populations from F1, BC1 and F2 generations was mainly controlled by one major gene ,while modified by minor genes by X2test ,and there is significantly difference between generations of crosses by F-test, The fertility was decreasing with increasing number of generation.3 A DNA marker genetic linkage map was constructed using 123 BC1 plants and 63 F2 plants The map, constituting of RFLP ,SSR ,Inter-SSR and RAPD marker loci, spanned a lotal of 1730.29 cM. The linear order of the markers in the map on the chromosomes was in agreement with UMC RFLP map in 2000.4 Genome-wide QTL analysis detected 3 QTLs conferting signifycant effects on BC1 hybrid fertility on search-filled pollen ratio. The major locus on chromosome 2 with the previously indentific RD locus, It is very important that there are four high peaks within Msumc1525 and MRAopQ7-2. The minor locus on chromosome 9 located between MraopK16-1 and MraopJ4-l and chromosome 6 between MSbnlg1139 and MraopI10-2. These 3 QTLs individually explained 95.3%, 10.4%, 9.2%. 6 main QTLs was located on 3 chromosomes using 125 AFLP and 15 SSR marker genetics map constructed with 63 F2 plants.5 Using SSR marker and mapping analysis we showed that RD locus is located an estimated 2.29 cM distal to the MSumc1525 marker locus and 8.9 cM promixal to MSumc1230 locus with three populations.6 With SSRs to assess F2 nonrestoring plants genotype we made sure that the ware truly hybrid, but abort pollen. Wide-genome QTLs analysis of F2 generation detected 2 main QTLs reducing fertility function.7 According to study results we make out the model about major restore gene and minor independent action each other and interaction within...