Identification of Cold‐Tolerant Breeding Lines by Quantitative Trait Loci Associated with Cold Tolerance in Rice

Abstract

Low temperature or cold stress is one of the major abiotic stresses limiting rice (Oryza sativa L.) production and productivity in the temperate rice growing regions as well as in tropical high lands worldwide. Low temperature at the reproductive stage causes high sterility and decreases production. In this study, we assessed recombinant inbred lines (RILs) that possessed cold‐tolerance genes and/or quantitative trait loci (QTL) from the donor line IR66160‐121‐4‐4‐2 in the genetic background of a cold‐sensitive japonica cultivar, Geumobyeo. The selected 15 RILs with QTL for cold tolerance were phenotyped for three main agronomic traits—culm length (CL), days to heading (DTH), and spikelet fertility (SF)—which were most affected during cold stress. The RILs with cold‐tolerant and cold‐sensitive parents were evaluated under cold‐water (18–19°C) irrigation in the field and cold‐air temperature (17–18°C) in the temperature‐controlled greenhouse. The RILs showed significant differences in these traits compared to the cold‐sensitive parent. Traits CL and DTH exhibited positive correlation with SF in the selected breeding lines. The SF of the selected breeding lines was higher (51–81%) than that of the cold‐sensitive parent, Geumobyeo (7%). Our results confirmed that cold tolerance was associated with SF but the traits CL and DTH were differently associated with cold tolerance. The cold‐tolerant breeding lines selected in this study had at least one of the three QTL associated with cold tolerance. The breeding lines confirmed to have cold tolerance are useful to breed cold‐tolerant cultivars and increase our understanding of the mechanism of cold tolerance in rice.

Overexpression of an alternative oxidase gene, OsAOX1a, improves cold tolerance in Oryza sativa L.

“…Cold exposure at the seedling and subsequent vegetative growth stages can lead to poor germination, yellowing leaves, and growth retardation (de Los Reyes et al, 2013). Unpredictable chilling snaps at the reproductive stage causes heading delay and high sterility, resulting in severe yield losses (Jena et al, 2012). Therefore, in rice breeding, screening for cold tolerance gene(s) is particularly important to deal with the current increase in occasional extreme weather events.…”

The Photosynthetic Characteristics in Chaling Common Wild Rice (Oryza rufipogon Griff.) under the Cold Stress

“…Most of its varieties, especially those of widely grown indica varieties and indica hybrids, are sensitive to cold stress. Cold stress can seriously influence rice grain quality or reduce yield in high-latitude or high-altitude regions of China, Japan, Korea, and other parts of the world (Jena et al, 2012). So enhancing the cold tolerance of rice cultivars is desired in order to alleviate the impact of cold stress on them.…”

<i>Oryza</i> Wild Species: An Alternative for Rice Breeding under Abiotic Stress Conditions

“…Regarding the agronomic features, the subspecies Indica presents absence of awns, easy threshing, plants of light green color, large number of tilers and sensitivity to low temperatures. On the other hand, genotypes of the japonica subspecies present awns, tolerance to threshing, plants with dark green color, smaller number of tillers and tolerance to low temperatures, being the subspecies that represents 80% of the world's production [36]. Genotypes from Indic germplasm have spread throughout flooded regions of tropical lowlands of South and Southeast Asia, and China.…”