Identification of RFLP markers associated with cytoplasmic male sterility and the survey of cytoplasmic genome variation in Capsicum annuum L

In chile (Capsicum annuum L.), the available knowledge on the behavior of cytoplasmic male sterility (CMS) is relatively limited. Thus, molecular markers that would assist the establishment of CMS based hybrid seed production are not available for breeding purposes. To overcome this gap, and aid the currently employed backcrossing, and testcrossing breeding techniques, identification of molecular markers was targeted in this study.;Similarly, to other plant species, restriction fragment length polymorphism (RFLP) provided an effective tool to identify polymorphic mitochondrial regions that can distinguish individuals regarding their cytoplasm. The nine mitochondrial probe and five restriction enzyme combinations could identify three ( atp9, atp6 and MOC1) polymorphic mitochondrial regions between sterile (S) and normal (N) cytoplasm types that can serve as molecular marker for cytoplasmic comparisons in Capsicum.;The "newly" identified MOC1 (Lycopersicum pennellii) mitochondrial probe was 100% accurate in identifying sterile (S) and normal (N) cytoplasm genotypes through backcrossing, and also aided the study of the CMS related mitochondrial rearrangements in Capsicum. Southern hybridizations with MOC1 could not reveal divergence among the various S-cytoplasm sources of Capsicum annuum indicating that a similar mutation exists for all the tested sterile Capsicum cytoplasm sources. However, some variation was observed within the normal cytoplasm-types.;Based on the MOC1 (Lycopersicum pennellii) sequence information, PCR primers were designed to span the coxII mitochondrial gene region in Capsicum. Study of the MOC1-RFLP marker indicated mitochondrial region showed that the CMS associated rearrangements do not involve the coding region of coxII, but entails its 3' UTR. Besides, homologous region to the MOC1 (Lycopersicum pennellii ) encoding region in chile cannot be amplified. Nevertheless, to increase the MOC1's commercial feasibility (convert into a PCR marker), the Capsicum coxII 3'-flanking region needs to be further studied, so that specific primers can be designed directly from the rearranged mitochondrial region. Because the association of the MOC1 detected polymorphism at DNA level and the expression of sterility is still unknown, the MOC1-RFLP marker remains to be an effective indirect marker for comparing of male sterile and male fertile cytoplasms in Capsicum.