Identification of male sterile cytoplasm in safflower

Vrijendra Singh, M. K. Galande, S. R. Deshmukh, M. B. Deshpande and N. Nimbkar

Abstract

The program for development of cytoplasmic-genetic male sterility in safflower at this Institute has been carried out for the last 4-5 years by following the conventional method of cytoplasmic male sterility development i.e. by transferring the nuclear genotype of the cultivated species into the cytoplasm of a wild relative.  While looking at all possible avenues for developing cytoplasmic male sterility (CMS) in safflower, a male sterile plant having rudimentary anthers was noticed in a F₃ population of an interspecific cross.  The male sterile plant was maintained by pollination with the fertile sib counterpart as well as with other genotypes of fertile nature.  The seeds of each cross obtained from the male sterile plant were sown separately to know the nature of genes that existed in the pollinator parents.  The observations on the nature of plants in the crosses exhibited the presence of both sterile and fertile plants.  The male sterile plants of each cross were crossed separately with their fertile sibs as well as with several diverse genotypes. The resultant progenies raised in summer 2000 exhibited restoration of fertility in four crosses out of 81 evaluated during the season.  The rest of the progenies segregated into sterile and fertile plants. Efforts are underway to confirm the restoration of fertility of the sterile cytoplasm and to identify the maintainer gene for the same.

 The development of the CMS system in safflower would speed up the process of commercialization of safflower hybrids, which is already in progress using the genetic male sterility based hybrids.

 Key words: Cytoplasmic male sterility, nuclear genotype, interspecific, restorer, maintainer, hybrids