Identification of Rice Accessions Having Cold Tolerance at the Seedling Stage and Development of Novel Genotypic Assays for Predicting Cold Tolerance

Abstract

Rice is susceptible to cold stress at the seedling stage, which can delay growth and decrease yield. We evaluated 187 rice accessions for cold tolerance at the seedling stage and developed genotypic assays for three markers. All japonica (20/20) and 20/140 indica accessions were highly cold tolerant. Two SNP markers specific for COLD1 and LOC_Os10g34840 were practical to use by normal agarose gel. The SNP marker specific for COLD1 was highly specific for predicting cold tolerance. However, the sensitivity of this marker was low as several cold-tolerant indica accessions lacked the cold-tolerant allele. The LOC_Os10g34840 marker was slightly more sensitive than the COLD1 marker for predicting highly cold-tolerant accessions. An insertion/deletion variant in the NAC6 gene was identified as a novel cold tolerance marker. The NAC6 marker predicted more highly cold-tolerant accessions compared with the other two markers. The SNP marker specific for LOC_Os10g34840 and the NAC6 marker were present in several tested subgroups, suggesting their wide effects and distribution. The three markers combined predicted the most highly cold-tolerant accessions, indicating that the marker combination is superior for applications such as marker-assisted breeding. The cold-tolerant accessions and the genotypic marker assays will be useful for future rice breeding.

The Molecular Mechanism of Cold-Stress Tolerance: Cold Responsive Genes and Their Mechanisms in Rice (Oryza sativa L.)

“…In this respect, the genome of Kongyu 131 has been modified by the transfer of a tiny chromosomal segment (~800 kb) from the rice indica variety to enhance its ecological adaptability and allow its cultivation in regions of low latitude [ 110 ]. An effective breeding program focused on the development of rice varieties with cold tolerance has involved the assessment of multiple rice accessions for their ability to tolerate cold at various developmental stages [ 111 ]. By employing genotypic assays targeting specific markers such as COLD1 and NAC6, researchers were able to identify accessions with strong cold tolerance and find new markers that accurately predict cold tolerance.…”

Insights on the enhancement of chilling tolerance in Rice through over-expression and knock-out studies of OsRBCS3

“… 2 Chilling stress affects rice growth and development, photosynthesis, the antioxidant system, hormone balance and other physiological processes, resulting in adverse consequences such as rice growth retardation, chlorosis, malformation, spikelet sterility and yield reduction. 3 , 4 The booting stage is the most sensitive stage of rice growth to chilling stress, which causes male sterility, anther cracking, pollen viability decline, pollination and fertilization disorders. 5 , 6 Heilongjiang province is the northernmost region of China.…”