Maintainer and restorer identification and conversion of good combiner inbreds into new CMS lines of sunflower (Helianthus annuus L.)

Abstract

Diversification of parental base in any hybrid breeding programme is an important step to sustain the crop. Fifty seven uniform and stable gene pool materials and exotic collection of economic importance of sunflower were crossed with six cytoplasmic male sterile lines of PET-1 background in a Line x Tester fashion to study their maintainer or restorer reaction in a randomized block design in two replications. The inbredGP6-990 acted as restores for all six CMS lines. While inbreds, GP6-217, GP6-219, GP6-351, GP6-400, GP6435, GP6-969, GP6-976, GP6-1153, GP4-363 and GP4-548 were found common maintainers for all six CMS sources. Inbred GP6-212 behaved as restorer for most of the CMS lines but behaved as maintainer for CMS-852A. While, inbred GP6-106 behaved as restorer for CMS-852A and behaved as segregating/partial restorer for CMS-234A, CMS17A, and CMS-7-1A. It showed that these CMS lines have different cytoplasm or are different at molecular levels. Selective inbreds were analyzed for combining ability and ten of the identified good combiner and agronomically superior maintainers were converted into new CMS lines. Newly developed lines, CMS-1001A, CMS-1003A, CMS-1004A, CMS-1006A and CMS-1008A had oil content >36.0% compared to other CMS lines and highest oil content (39.6%) was reported in CMS-1006A coupled with short stature (91.2 cm). These newly developed CMS lines will be utilized in heterosis breeding programme for development of promising hybrids. The identification of new restorers to the good combiner CMS sources assembled should receive priority for hybrid synthesis