Diplotaxis erucoides-induced cytoplasmic male sterility in Brassica juncea is rescued by the Moricandia arvensis restorer:: genetic and molecular analyses

An alloplasmic cytoplasmic male sterile (CMS) line of Brassica juncea was developed by repeated backcrossing of the sexual hybrid (Diplotaxis erucoides x Brassica rapa) with B. juncea cv. 'Pusa Bold'. The CMS line is comparable to the B. juncea nuclear donor line for all morphological traits except male fertility. Southern and cleaved amplified polymorphic sequence (CAPS) analyses showed that the CMS line carries organellar genomes from the wild species that differ from the organellar genomes of B. juncea. Northern analysis with three mitochondrial gene probes revealed altered atp alpha transcription pattern associated with male sterility. The restorer of CMS (Moricandia arvensis) B. juncea was found to restore male fertility to the new CMS system. The mode of fertility restoration was found to be monogenic and gametophytic. The study identified CAPS markers for the psbB gene that could be useful in quick identification of the erucoides CMS line. Broad similarities and important differences observed at the molecular level between M. arvensis and D. erucoides CMS systems of B. juncea are discussed.