Identification of stable restorers for diverse cytoplasmic source in Sorghum [Sorghum bicolor (L.) Moench.]

In sorghum [Sorghum bicolor (L.) Moench.], milo is the lone source of cytoplasmic male sterility (CMS) extensively used in production of commercial hybrids. The hazards of such a narrow cytoplasmic base are apparent and consequently new diverse sources like A₂, A₃, A₄, maldandi, VZM and G₁ were identified. However, the commercial exploitation of these sources has not been possible because of the difficulty in fertility restoration on these sources. The present study was, therefore, undertaken to test different sorghum germplasm lines for their fertility restoration/maintenance on maldandi and milo cytoplasm. Twenty-five diverse accession were selected from minicore collection and crossed with two male sterile lines viz., 104A (milo) and M 31-2A (maldandi). The resulting F₁s were classified as fertility restorers and maintainers based on seed set on bagged ear heads. The restoration studies indicated that 2 lines on maldandi and 6 on milo cytoplasm showed strong fertility restoration (> 90 % seed set).