Detection of QTLs for cold tolerance of rice cultivar ‘Kuchum’ and effect of QTL pyramiding

• Published in: Theoretical and applied genetics Vol. 129; no. 3; pp. 631 - 640
• Main Authors: Endo, Takashi, Chiba, Bunya, Wagatsuma, Kensuke, Saeki, Kenichi, Ando, Tsuyu, Shomura, Ayahiko, Mizubayashi, Tatsumi, Ueda, Tadamasa, Yamamoto, Toshio, Nishio, Takeshi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-03-2016; Springer; Springer Nature B.V
• Subjects: Adaptation, Physiological - genetics; Agricultural production; Agriculture; Alleles; Biochemistry; Biomedical and Life Sciences; Biotechnology; Breeding; Cold; Cold Temperature; Crosses, Genetic; Cultivars; Fertility; Genetic aspects; Genetic Markers; Genotype; Life Sciences; Observations; Original Article; Oryza - genetics; Plant Biochemistry; Plant Breeding/Biotechnology; Plant Genetics and Genomics; Quantitative Trait Loci; Rice; Water treatment; Japan; INW, Japan; Cold Stress; Pyramid; Cold Tolerance; Culm Length; Seed Fertility
• DOI: 10.1007/s00122-015-2654-2
• EISSN: 1432-2242
• ISSN: 0040-5752

KEY MESSAGE : A QTL for cold tolerance at the booting stage of rice cultivar ‘Kuchum’ was detected and delimited into a 1.36 Mb region, and a cold-tolerant line was developed by QTL pyramiding. Low temperature in summer causes pollen sterility in rice, resulting in a serious loss of yield. The second most widely grown rice cultivar in Japan, ‘Hitomebore’, has been developed as a cultivar highly tolerant to low temperature at the booting stage. However, even ‘Hitomebore’ exhibits sterility at a temperature lower than 18.5 °C. Further improvement of cold tolerance of rice is required. In the present study, QTLs for cold tolerance in a Bhutanese rice variety, ‘Kuchum’, were analyzed using backcrossed progenies and a major QTL, named qCT-4, was detected on chromosome 4. Evaluating cold tolerance of seven types of near isogenic lines having ‘Kuchum’ alleles around qCT-4 with a ‘Hitomebore’ genetic background, qCT-4 was delimited to a region of ca. 1.36 Mb between DNA markers 9_1 and 10_13. Homozygous ‘Kuchum’ alleles at qCT-4 showed an effect of increasing seed fertility by ca. 10 % under cold-water treatment. Near isogenic lines of ‘Hitomebore’ having ‘Silewah’ alleles of Ctb1 and Ctb2 and a ‘Hokkai PL9’ allele of qCTB8 did not exhibit higher cold tolerance than that of ‘Hitomebore’. On the other hand, a qLTB3 allele derived from a Chinese cultivar ‘Lijiangxintuanheigu’ increased cold tolerance of ‘Hitomebore’, and pyramiding of the qCT-4 allele and the qLTB3 allele further increased seed fertility under cold-water treatment. Since NILs of ‘Hitomebore’ with the ‘Kuchum’ allele of qCT-4 were highly similar to ‘Hitomebore’ in other agronomic traits, the qCT-4 allele is considered to be useful for developing a cold-tolerant cultivar.