1Indian Institute of Vegetable Research, Varanasi-221 005
Deptt. of Mycology and Plant Pathology, Banaras Hindu University, Varanasi-221 005
Online published on 20 May, 2016.
Cytoplasmic male sterility systems (CMS) have been useful in the production of hybrid seed in a number of crops. The Texas or T-cytoplasmic male sterile line (cms-T) system was used extensively in the 1960s to eliminate the need for hand detasseling in hybrid maize production. As a consequence of the 1970 epidemic of southern corn leaf blight cms-T is no longer widely used commercially. However it has been developed as a model system to study the genetic and molecular mechanisms underlying male sterility and fertility restoration. Male sterility in T-cytoplasm maize results from the action of aT-cytoplasm specific mitochondrial gene, T-urf13. Full (or partial) fertility restoration of T-cytoplasm maize is mediated by the Rf2 nuclear restorer in combination with one of the three restorers: Rf1, Rf8, or Rf*. Rf2 encodes a protein highly similar to mitochondrial aldehyde dehydrogenases; Rf1, Rf8 and Rf* each mediate discrete T-urf13 mitochondrial transcript processing events. AFLP bulk segregant analysis has been used to identify DNA markers closely linked to the Rf8 locus. These tools provide a foundation, for determining mechanisms of nuclear-directed mitochondrial RNA processing and fertility restoration.
