Studies On Rolled Leaf QTL And Non-Mendelian SSR Segregation In Rice

Hidden roll leaf diversities in the recombinant inbred lines(RILs)from MH63 and 02428 have been mined in the 3 environment.The favourate alleles associated with roll leaf have been detected by GWAS using an 1129 gerplasms panel from 3K rice.MH63,3027 derived from MH63,and Teqing(TQ)which is a high yielding indica variety from China,Gaozi(GZ)and Aizi(AZ)which are the same purple plant but different plant height,Dhan4 and Swarna both came from India were developed some reciprocal cross combinations,respectively.To expore the relationship between unexpected loci and segregation distortion,and simulate the law of the non-Mendelian inheritance,the SSR genotype from F1 to F3 were scanned.MH63 as recurrent parent and 3027 as donar were used to develop a set near-isogenic lines.With SSR makers tracking from BC2F1 to BC3F4 and BC4F2,the effects of unexpected loci on the phenotype were analysised,and the diversity of populations by unexpected loci was declared.The main results are shown as follow:1.Joint mapping and allelic mining of the rolled leaf trait in rice.Rolled leaf has long been considered as one of the key components for the plant architecture.A total of seven main-effect loci were identified to be underlying the transgressive segregation of progenies from parents with minor differences.Five of them were known and two(qRl7b and qRl9b)were newly reported.Many favorable elelle and the donors were identified from an 1129 germplasms panel with 27,921 SNP.By increasing makers for one of favorable elelle,at least 3 sub-regions with the averaged gene effects of 3.5%and a range from 2.4%to 4.1%for LRI were found.The representative SNPs for the favorable alleles mined at the reliable QTL such as qRl4,qRl5,qRl6,qRl7a and qRl9a would be useful in the future molecular designed breeding for rice ideal plant type by joint mapping.2.Non-Mendelian law based on test cross combinations and SSR makersMH63,3027 with 97.56%genome of MH63 and five test parents(Teqing,Gaozi,Aizi,Dhan4,Swama)were developped some reciprocal cross combinations,and 74,80,76,83,87 SSR makers were detected the corresponding F1?F3 genotype,respectively.Lots of unexpected bands,which most bands were concentrated upon some individual or some locus,were found in F1 generations except TQ/3027.Furthermore,there were always some recurrent unexpected loci without the effect of cytoplasm and background in the corresponding F1 combinations.The unexpected individuals were also found in F2 from F1 with the whole standard heterozygous genome,but the its propotion got much lower than F1.Even if F2 displayed some single or cluster segregation distortion(SD)phenomeno,some recurrent SD loci were detected in the different of cytoplasm and background.By loss of heterozygosity(LOH)loci and revert of heterozygosity(ROH)loci in F3 from F2 without unexpected bands corresponding with the F2 recurrent SD loci and F1 recurrent unexpected loci,we speculated some relationship among them three.3.Non-Mendelian law based on NILs and SSR makersMH63 as recurrent parent and 3027 as donar have been used to develop a set near-isogenic lines.Some non-polymorphic AA_SSR and polymorphic AB_SSR makers between biparent were tracked from BC2F1 to BC3F4 and BC4F2.Then,the SSR unexpected bands effects on the phenotype were anlysised.Some AA_SSRs were shown some polymorphism in BC2F1,and most of this unexpected polymorphism may inherit BC3F1 stability,and few happened to the new SSR unexpected bands.Five groups BC3F2 were derived from two BC3F1 individuals with whole recurrent parental genome as control groupand three BC3F1 individuals with unexpected bands as test groups.With detecting BC3F2 genotype by increasing AA_SSR,unexpected bands almost in the genome-wide which were concentrating upon some individual or some locus were found in the test groups.Contrastively,there were not unexpected bands in the control groups.It confirmed that the unexpected bands were corresponded with microsatellite instability(MSI)from human tumor tissue which SSR motif just variatied based on sequencing results.Clearly,MSI is aspontaneous phenomenon and effected on phenotype after excluding PCR factor with two genotype methods in five groups BC3F3 from BC3F2 selfing and BC4F1 from BC3F2 backcrossing.As following,plant heigh(PH)and heading date(HD)in BC3F4 and BC4F2 were investigated.Four QTLs effected PH and four QTLs effected HD were detected.Among them,six QTL were detected by AA SSR.This study has the important implication for rice breeding with preliminarily revealing MSI in the cross between indica rices and needs the further study to mine the deeper mechanism.