Development and evaluation of chromosome segment substitution lines (CSSLs) carrying chromosome segments derived from <i>Oryza rufipogon</i> in the genetic background of <i>Oryza sativa</i> L.

Abstract

The wild relatives of rice (Oryza sativa L.) are useful sources of alleles that have evolved to adapt in diverse environments around the world. Oryza rufipogon, the known progenitor of the cultivated rice, harbors genes that have been lost in cultivated varieties through domestication or evolution. This makes O. rufipogon an ideal source of value-added traits that can be utilized to improve the existing rice cultivars. To explore the potential of the rice progenitor as a genetic resource for improving O. sativa, 33 chromosome segment substitution lines (CSSLs) of O. rufipogon (W0106) in the background of the elite japonica cultivar Koshihikari were developed and evaluated for several agronomic traits. Over 90% of the entire genome was introgressed from the donor parent into the CSSLs. A total of 99 putative QTLs were detected, of which 15 were identified as major effective QTLs that have significantly large effects on the traits examined. Among the 15 major effective QTLs, a QTL on chromosome 10 showed a remarkable positive effect on the number of grains per panicle. Comparison of the putative QTLs identified in this study and previous studies indicated a wide genetic diversity between O. rufipogon accessions.

Genetic mechanisms of abiotic stress tolerance that translate to crop yield stability

“…For example, certain stress tolerances of maize can be enhanced by the identification, characterization and ultimate introgression of teosinte traits 30,31,138 , with the same paradigm applicable to other cereals 132,76,77 , soybean 139 , tomato 140 , potato 131 and the cornucopia of secondary crops. In some cases, key adaptation loci can be introduced into a related species via segmental translocations 141 , as demonstrated with a rye-wheat translocation that enhances root biomass and provides drought resilience in wheat 45 .…”

Development of chromosome segment substitution lines (CSSLs) of Oryza longistaminata A. Chev. & Röhr in the background of the elite japonica rice cultivar, Taichung 65 and their evaluation for yield traits

“…The uniform genetic background of CSSLs allows the identification by association of putative QTLs controlling valuable traits from the wild species. As such, simple but robust statistical analysis such as Dunnett's and boxplot analysis are sufficient in detecting putative effective QTLs (Shim et al 2010Furuta et al 2014). Successful introgression of alleles from wild species into the genome of cultivated rice expands the range of genetic variation available for rice improvement.…”

Identification of rice chromosome segment substitution line Z322-1-10 and mapping QTLs for agronomic traits from the F3population

“…Thus, the use of CSSLs can simplify the study of complex genetic traits (Furuta et al 2014). Once the CSSL libraries are developed in the genetic background of an elite cultivar, the best performing CSSLs may be released as new cultivars.…”

“…Chromosome segment substitution lines (CSSLs) can be used both for QTL mapping and for new cultivar development as female lines due to the unique feature of uniform genetic background (Furuta et al 2014). Therefore, development of CSSLs is a useful step to improve breeding programs (Zamir 2001).…”