In sunflower, single source of cytoplasm PET-1 has been exploited extensively for hybrid seed production so far. There is a need to diversify the cytoplasmic base to safeguard sunflower crop from future biotic and abiotic threats, if the cytoplasm becomes susceptible. In the present study diverse cytoplasmic male sterile lines based on CMS PEF, CMS I and PET-1 were utilized to study the nature and extent of genetic differences, breeding value of these sources and to utilize them in heterosis breeding programmes. Along with traditional cytoplasmic source PET-1, other sources
