Fertility Restoration of the Sorghum A3 Male-Sterile Cytoplasm through a Sporophytic Mechanism Derived from Sudangrass

Authors

Hoang V. Tang, University of Florida
Jeffrey F. Pedersen, University of Nebraska-LincolnFollow
Christine D. Chase, University of FloridaFollow
Daryl R. Pring, University of Florida

Document Type

Article

Date of this Version

2007

Citation

Published in Crop Sci. 47:943–950 (2007).

Comments

U.S. Government Work

Abstract

Fertility restoration of sorghum [Sorghum bicolor (L.) Moench] lines carrying the IS1112C (A3 group) male-sterile cytoplasm has been documented as a two-gene gametophytic mechanism involving complementary action of restoring alleles designated Rf3 and Rf4, as derived from IS1112C. Fertility restoration capability has also been reported from sudangrass (S. bicolor subsp. drummondii) populations. We describe characteristics of a fertility restoration system derived from sudangrass, in which male-sterile individuals were observed at high frequency in backcross and F₂-F₃ segregating populations. Segregation analyses were consistent with a sporophytic restoration system involving two complementary genes. Pollen iodine staining in fertile progeny indicated that the restorers were not efficacious, and fertility was decreased in progeny of backcrosses. Silencing of restoring alleles through paramutation might be operative in these examples. Sudangrass-derived fertility restoration did not involve enhanced transcript processing of the chimeric mitochondrial open reading frame orf107. Thus male sterility induced by the A3 cytoplasm can be restored through different mechanisms.