Evaluation of new inbreds for fertility restoring and maintaining behaviours in two diverse CMS sources of sunflower (Helianthus annuus L.)

Abstract

Eight cytoplasmic male sterile (CMS) lines of sunflower (Helianthus annuus L.) belonging to two differentsources of cytoplasmic male sterility, PET-1 (H. petiolaris) (CMS-852A, CMS-7-1A, CMS-234A, CMS-2A,COSF-1A, COSF-7A and CMS-10A) and CMS I (H. lenticularis) (IMS-852A) were crossed with newly developed20 inbred lines to identify the maintainer or restorer behaviour in Line x Tester fashion and evaluation of test cross progenies was conducted. The presence or absence of pollen in F1 s was recorded in the field whereas pollen fertility was confirmed in the laboratory by acetocarmine staining test. All the inbredswere categorized into complete, partial restorer and maintainer through cytological observation. Twelve inbreds viz., RHAGKVK-1, RHAGKVK-2, AKSFI-49-3, AKSFI-49-4, AKSFI-46-2, HOHAL-37,CSFI-5134,CSFI-5055, CSFI-5133, CSFI-5185, CSFI-5075and Selection-I restored the fertility for most of the PET-1 CMS lines, while CSFI-5033, IB0-50, IB-60, IB-61,IB-67 and IB-101 inbreds maintained sterility. The second CMS line IMS-852A, was maintained by 13 inbredsindicating involvement of different gene(s), while one inbred CSFI-5134 was restored its fertility. Some of theinbreds (AKSFI-49-3 and AKSFI-49-4) were behaved as partial restorers for CMS-10A. The range of fertilityrestoration in different cross combinations was between 46.6 and 99.5 per cent. In the present study 50 to 65 per cent frequency of pollen fertility was reported for PET-1. However, only 5 per cent frequency of pollen fertility was observed for CMS I. From the study it was evident that among the two CMS sources, restorers for CMS I are rather scarce. Efforts should be made to locate restorers for CMS I for its utilization in production of more productive sunflower hybrids