Cytoplasmic male sterility system for Brassica species and its use for hybrid seed production in indian oilseed mustard Brassica juncea

A cell of a plant of genus Brassica comprising, in its cytoplasm, a mitochondrial DNA exhibiting the following restriction fragment length polymorphism (RFLP) patterns under hybridization conditions:

• A) a first RFLP pattern, such that when the mitochondrial DNA is digested with EcoRI as restriction enzyme and hybridized to cosmid clone pCos13 (MTCC 5242) containing B. oxyrrhina mitochondrial DNA as probe, the pattern comprises:
• (i) a first restriction fragment length polymorphism band of about 4.0 kb length which is present in CMS genotypes but absent in parent genotypes,
• (ii) a second restriction fragment length polymorphism band of about 3.4 kb length which is present in parent genotypes but absent from CMS genotypes,
• (iii) a third restriction fragment length polymorphism band of about 2.5 kb length which is present in CMS genotypes but absent in parent genotypes, and
• (iv) a fourth restriction fragment length polymorphism band of about 0.7 kb length which is present in CMS genotypes but absent in parent genotypes;
• B) a second RFLP pattern, such that when the mitochondrial DNA is digested with EcoRI as restriction enzyme and hybridized to cosmid clone pCos17 (MTCC 5243) containing B. oxyrrhina mitochondrial DNA as probe, the pattern comprises:
• (i) a first restriction fragment length polymorphism band of about 3.5 kb length which is present in parent genotypes but absent from CMS genotypes, and
• (ii) a second restriction fragment length polymorphism band of about 1.7 kb length which is present in CMS genotypes but absent in parent genotypes;
• and
• C) a third RFLP pattern, such that when the mitochondrial DNA is digested with EcoRI as restriction enzyme and hybridized to cosmid clone pCos42 (MTCC 5244) containing B. oxyrrhina mitochondrial DNA as probe, the pattern comprises:
• (i) a first restriction fragment length polymorphism band of about 4.5 kb length which is present in CMS genotypes but absent in parent genotypes,
• (ii) a second restriction fragment length polymorphism band of about 3.0 kb length which is present in CMS genotypes but absent in parent genotypes, and)
• (iii) a third restriction fragment length polymorphism band of about 2.8 kb length which is present in CMS genotypes but absent in parent genotypes.