Gametophytically alloplasmic CMS line of rice (Oryza sativa L.) with variant orfH79 haplotype corresponds to specific fertility restorer

Abstract

For years discovery and identification of the cytoplasmic male sterility (CMS) resource in wild rice is the most intriguing events in breeding field. orfH79, a chimeric gene in mitochondria, has been suggested being the determinant for Honglian CMS in rice. In this report orfH79 gene as molecular marker to screen the wild rice, we found eight accessions with orfH79 gene in the total 42 investigated objects. Sequence analysis revealed that there were a total of nine nucleotide substitutions resulting in the change of nine amino acids in the newly identified orfH79 in wild rice, which further fell into seven haplotypes. In order to investigate the underlying relationship between orfH79 haplotypes and the corresponding fertility restorers, four accessions were selected with different orfH79 haplotype as female parents to hybridize the Honglian maintainer line, Yuetai B. After eight consecutive recurrent backcrosses, four alloplasmic CMS lines with different orfH79 haplotype were developed. Microscopic observation exhibited that their pollen grains were spherical and clear in 1% I(2)-KI solution same as that of Honglian CMS line. Moreover, these four CMS lines displayed various fertility restoring model through test cross, suggesting that each orfH79 haplotye represents a new CMS type and corresponds to their specific Rf allele.

Development of a cytoplasmic male‐sterile line NJCMS4A for hybrid soybean production

“…If the hybrids are male‐fertile, the CMS‐related genes may be different. However, the situation may be more complicated; for example, some isonuclear alloplasmic rice CMS lines contain the same nucleus but different CMS‐related genes in the cytoplasm (Li, Tan, Wang, Wan, & Zhu, ). When the nucleus of a maintainer contains different sterility genes for different cytoplasm sources, the CMS‐related genes in the cytoplasm may be different despite the fertility of the hybrids being the same.…”

“…The second strategy is to use CMS maintainers as a nuclear background to test a group of female parents to seek other male-sterile cytoplasm sources. Some reports had proven that new male-sterile cytoplasm sources could be discovered effectively in this way (Zhao & Gai, 2006 However, the situation may be more complicated; for example, some isonuclear alloplasmic rice CMS lines contain the same nucleus but different CMS-related genes in the cytoplasm (Li, Tan, Wang, Wan, & Zhu, 2008). When the nucleus of a maintainer contains different sterility genes for different cytoplasm sources, the CMS-related genes in the cytoplasm may be different despite the fertility of the hybrids being the same.…”

Male Sterility-Inducing Mitochondrial Genomes: How Do They Differ?

“…2) (Iwabuchi et al, 1993;Akagi et al, 1994). Later, homologous sequences have been found in other sources of rice CMS (Li et al, 2008;Itabashi et al, 2009). Interestingly, trans-taxonomic homology has also been observed between orf79 and orf107 (Fig.…”

The Ogura sterility-inducing protein forms a large complex without interfering with the oxidative phosphorylation components in rapeseed mitochondria

“…Although sterility genes from different systems do not share homology (with three exceptions discussed in Budar and Berthomé (2007) and a case recently reported by Li et al (2008)), they do display some similar characteristics. Most sterility genes originate from the high recombination activity of plant mitochondrial genomes, are co-transcribed with normal mitochondrial genes encoding respiratory complex subunits, and also encode small proteins, most of which contain a hydrophobic domain (reviewed in Hanson and Bentolila 2004).…”