Genetically Characterizing a New Indica Cytoplasmic Male Sterility with Oryza glaberrima Cytoplasm for Its Potential Use in Hybrid Rice Production

Abstract

C ytoplasmic male sterility (CMS) has been widely used for commercial hybrid seed production in a number of cereal crops such as maize (Zea mays L.), sorghum [Sorghum bicolor (L.) Moench], and rice (Perez-Prat and van Lookeren Campagne, 2002). However, large-scale production of hybrids based on a single CMS system could cause disease epidemics. For instance, in 1970 there was an outbreak of Southern corn leaf blight (Helminthosporium maydis Nisikado & Miyake race T) on U.S. maize hybrids produced using Texas-type CMS that carried a mitochondrial gene T-urfl3 with the dual role of causing CMS and disease susceptibility (Levings, 1990). Cytoplasmic diversification for hybrid production has become a priority goal of heterosis breeding especially for monoclinous crops, such as rice, ever since the 1970 incident (Levings, 1990; Dalmacio et al., 1995). Hybrid rice is currently cultivated on more than 16 million ha, which makes up >50% of total rice area in China (Li et al., 2007) and is also being planted commercially in Southern and Southeast Asian countries such as India,

Sustainable hybrid rice cultivation in Italy. A review

“…The cytoplasmic male sterility, a genetic system that maintains male sterility, and a genetic system that restores male fertility are generally accepted as the necessary basics for producing hybrid seed of crops (Huang et al 2013). Hybrids possessing positive traits become potential targets for the transfer of key genes (genes for fertility restoration, cytoplasmic male sterility, photosensitive or thermosensitive male sterility, and wide compatibility) absolutely necessary for the exploitation of heterosis in rice (Shahid et al 2013).…”

“…Risk perception may play a pivotal role in determining the willingness to adopt a new crop or even only a new cultivation technique. In fact, if allocating land to different species or different techniques is a risk-reducing strategy, the riskaverse farmer would broaden the techniques (Harwood et al 1999). In the Italian rice-growing area, where this crop is the prevalent cultivation, farmers tend to increase techniques rather than change species (Stoate et al 2001;Tesio et al 2013).…”

Application of herbicides on parental lines (A clearfield® and R) of hybrid rice at post-flowering stage for production

“…To enable the production of hybrid rice seeds, it is important to have cytoplasmic male sterility, which allows outcrossing between the different plants. It is also vital to have a genetic system that restores male fertility (restorer) (Shahid et al, 2013;Huang et al, 2013;Tesio et al, 2014). The production of hybrid rice seeds requires a system composed of three lines: male-sterile (line A), male-fertile with the ability to maintain sterility of the line A (line B) and another, also male-fertile, with the restoring capacity for fertility in line A (line R).…”

Genomic composition and yield heterosis of the partial inter-specific hybrid rice between Oryza sativa L. and Oryza glaberrima Steud.

“…Quantitative trait loci (QTLs) resistant to biotic or abiotic stresses from O. glaberrima have been identified for the genetic improvement of rice (Jones et al 1997(Jones et al , 1998Haefele et al 2004). Also, a new restorer gene from O. glaberrima has been introduced into the genomic background of O. sativa for pyramiding different restorer genes to breed superior restorer lines for three-line hybrid rice (Huang et al 2013). Studies have been made on the correlation between genetic diversity of parental lines and heterosis of hybrids (Luo et al 1999;Jiang et al 2002;Xu et al 2002;Wang & Lu 2006;Ahmadikhah et al 2008;Zhang et al 2010) and significant correlations between genetic diversity and heterosis have been reported in rice (Jaikishan et al 2010;Jagoz 2011).…”