Cytoplasmic Genetic Male Sterility in Plants – a Molecular Perspective

Male sterility is defined as the failure of plants to produce functional anthers, pollen, or male gametes. First documentation of male sterility came in 1763 when Kölreuter observed anther abortion within species and specific hybrids. It is more prevalent than female sterility, probably because, male sporophyte and gametophyte less protected from environment than ovule and embryo sac. Male sterility is easy to detect because a large number of pollen are produced and could be easily studied. It can also be easily assayed through staining technique (carmine, lactophenol or iodine); while detection of female sterility requires crossing. Male sterility has propagation potential in nature since it can still set seed and is important for crop breeding, while female sterility does not. Male sterility can be aroused spontaneously via mutations in nuclear and/or cytoplasmic genes.