|LIU, ZHAO - North Dakota State University|
|CAI, XIWEN - North Dakota State University|
Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/2014
Publication Date: 12/1/2014
Citation: Liu, Z., Cai, X., Seiler, G.J., Jan, C.C. 2014. Interspecific amphiploid-derived alloplasmic male sterility with defective anthers, narrow disk florets, and small ray flowers in sunflower. Plant Breeding. 133(6):742-747. DOI:10.1111/PBR.12216.
Interpretive Summary: Cytoplasmic male sterility (CMS) is the maternally inherited inability to produce functional pollen. Nuclear fertility restoration genes (Rf) in fertility restorer lines overcome the effects of the CMS and consequently produce a male-fertile phenotype. CMS has been reported in over 150 species. The CMS generated from intraspecific or interspecific crosses is termed alloplasmic, which has the nucleus from one species and the cytoplasm from another. The CMS/Rf system is important for hybrid sunflower (Helianthus annuus L.) seed production. A single alloplasmic CMS, PET-1, and Rf1 gene is used exclusively for commercial hybrid sunflower seed production.
Technical Abstract: The cytoplasmic male-sterility (CMS)/fertility-restoration system is important for hybrid sunflower (Helianthus annuus L.) seed production. Two novel alloplasmic CMSs, designated CMS GRO1 and CMS MAX3 with defective anthers, narrow disk florets with no swollen corolla, and short, narrow ray flowers, were observed in BC4F1 progenies of the amphiploids (AMPs) H. grosseserratus/P 21 and H. maximiliani/P 21 (2n=68) with HA 410. Among seven interspecific AMPs and 19 cultivated lines, only AMP H. cusickii/P 21 and HA 410 failed to restore male-fertility. Segregation of CMS, male-fertile plants, and plants with reduced male-fertility was observed both in the testcross progenies of a six line half-diallel cross of F1’s with CMS MAX3, and in an F2 population of CMS GRO1 x RHA 274. Male-fertility restoration was controlled by at least two dominant genes. Detailed analysis of the mitochondrial genes may provide insight into the differences between these two CMSs and other CMS lines. The new CMSs will facilitate the studies of the interaction between cytoplasmic and nuclear genes, and also provide unique ornamental flower types.