I have brinjal line have trait for wilt resistant that identified by phenotypic data, than I go for cross them with wilt susceptible line, generate F1 and F2, BC1 BC2. based on chai square test and I know this a recessive resistant gene. but now want to know that trait governed by how many gene? how to know pattern of inheritance that gene? or any other method to prove and validate these trait is recessive resistant. finally after know about all genetics which breeding method I should preferred to integrate this trait in promising variety.
Note: I am convectional breeder so want more suggestion on convectional method and also i appreciate advance molecular breeding based suggestion, thank you ...
You have rightly elaborated about the crossing of susceptible genotypes with resistant ones, and raising different generations namely F1, F1, F2, BC1, BC2. Further validation/testing of a large number of observations using the chi-square test for expected segregation ratio in F2, BC1 and BC2 is the right approach to determine whether the resistance is due to recessive or dominant genes. The chi-square-based approach is used only when the reaction is clear cut categorized into resistance or susceptibility i.e. resistance is governed by one or few genes. In every case, the expected segregation ratio (mono-hybrid, di-hybrid, trihybrid, tetra-hybrids ratio) is tested using chi-square and accordingly number of genes is determined. In case resistance is governed by many genes and in fact quantitative in nature, then the generation means analysis is used to determine the gene action and their interaction in conferring different gradients of resistance or susceptibility. All these approaches are based on field-based data. Molecular markers can also be used to determine the segregation in the referred segregating generation if markers are linked with QTL/gene.
Dear @Vekariya Rajesh For detailed genetic analysis, you should have 2-3 wilt resistant lines and equivalent number of wilt susceptible lines. Typically such lines should have distinct pedigree. In addition to what you have narrated, also make resistant to resistant and susceptible to susceptible crosses in order to rule out many a possibility. By analysing your phenotypic data, you can detect only such number of genes for which selected parents will differ. For the rest, I endorse what has been mentioned by @Narendra Kumar Singh.
Omics approaches may help you. whole transcriptomics may revel the regulation and expression of transcripts.
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