Limits...
Confirming a major QTL and finding additional loci responsible for field resistance to brown spot (Bipolaris oryzae) in rice.

Sato H, Matsumoto K, Ota C, Yamakawa T, Kihara J, Mizobuchi R - Breed. Sci. (2015)

Bottom Line: The major QTL qBSfR11 coincided with qBS11 from the previous study, whereas qBSfR1 and qBSfR4 were new but neither qBS2 nor qBS9 were detected.NILs with qBSfR11 acquired significant field resistance; those with qBSfR1 did not.This confirms the effectiveness of qBSfR11.

View Article: PubMed Central - PubMed

Affiliation: National Agriculture and Food Research Organization, Kyushu Okinawa Agriculture Research Center (NARO/KARC) , 496 Izumi Chikugo, Fukuoka 833-0041 , Japan.

ABSTRACT
Brown spot is a devastating rice disease. Quantitative resistance has been observed in local varieties (e.g., 'Tadukan'), but no economically useful resistant variety has been bred. Using quantitative trait locus (QTL) analysis of recombinant inbred lines (RILs) from 'Tadukan' (resistant) × 'Hinohikari' (susceptible), we previously found three QTLs (qBS2, qBS9, and qBS11) that conferred resistance in seedlings in a greenhouse. To confirm their effect, the parents and later generations of RILs were transplanted into paddy fields where brown spot severely occurred. Three new resistance QTLs (qBSfR1, qBSfR4, and qBSfR11) were detected on chromosomes 1, 4, and 11, respectively. The 'Tadukan' alleles at qBSfR1 and qBSfR11 and the 'Hinohikari' allele at qBSfR4 increased resistance. The major QTL qBSfR11 coincided with qBS11 from the previous study, whereas qBSfR1 and qBSfR4 were new but neither qBS2 nor qBS9 were detected. To verify the qBSfR1 and qBSfR11 'Tadukan' resistance alleles, near-isogenic lines (NILs) with one or both QTLs in a susceptible background ('Koshihikari') were evaluated under field conditions. NILs with qBSfR11 acquired significant field resistance; those with qBSfR1 did not. This confirms the effectiveness of qBSfR11. Genetic markers flanking qBSfR11 will be powerful tools for marker-assisted selection to improve brown spot resistance.

No MeSH data available.


Related in: MedlinePlus

Brown spot lesions observed in the Mie paddy field in 2012. The images were taken 109 days after transplanting. (A) Resistant variety ‘Tadukan’, (B) Susceptible variety ‘Hinohikari’.
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f1-65_170: Brown spot lesions observed in the Mie paddy field in 2012. The images were taken 109 days after transplanting. (A) Resistant variety ‘Tadukan’, (B) Susceptible variety ‘Hinohikari’.

Mentions: Distinct differences in brown spot field resistance were observed between the parental varieties, ‘Tadukan’ and ‘Hinohikari’: the mean disease scores in 2012 and 2013 were 2.2 ± 0.5 and 5.3 ± 0.8, respectively (Fig. 1, 2). The disease score ratings of the RIL populations in 2012 and 2013 were normally distributed, and a certain number of lines exhibited transgressive segregation in both directions, which indicated that the inheritance of field resistance was quantitative (Fig. 2).


Confirming a major QTL and finding additional loci responsible for field resistance to brown spot (Bipolaris oryzae) in rice.

Sato H, Matsumoto K, Ota C, Yamakawa T, Kihara J, Mizobuchi R - Breed. Sci. (2015)

Brown spot lesions observed in the Mie paddy field in 2012. The images were taken 109 days after transplanting. (A) Resistant variety ‘Tadukan’, (B) Susceptible variety ‘Hinohikari’.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4430509&req=5

f1-65_170: Brown spot lesions observed in the Mie paddy field in 2012. The images were taken 109 days after transplanting. (A) Resistant variety ‘Tadukan’, (B) Susceptible variety ‘Hinohikari’.
Mentions: Distinct differences in brown spot field resistance were observed between the parental varieties, ‘Tadukan’ and ‘Hinohikari’: the mean disease scores in 2012 and 2013 were 2.2 ± 0.5 and 5.3 ± 0.8, respectively (Fig. 1, 2). The disease score ratings of the RIL populations in 2012 and 2013 were normally distributed, and a certain number of lines exhibited transgressive segregation in both directions, which indicated that the inheritance of field resistance was quantitative (Fig. 2).

Bottom Line: The major QTL qBSfR11 coincided with qBS11 from the previous study, whereas qBSfR1 and qBSfR4 were new but neither qBS2 nor qBS9 were detected.NILs with qBSfR11 acquired significant field resistance; those with qBSfR1 did not.This confirms the effectiveness of qBSfR11.

View Article: PubMed Central - PubMed

Affiliation: National Agriculture and Food Research Organization, Kyushu Okinawa Agriculture Research Center (NARO/KARC) , 496 Izumi Chikugo, Fukuoka 833-0041 , Japan.

ABSTRACT
Brown spot is a devastating rice disease. Quantitative resistance has been observed in local varieties (e.g., 'Tadukan'), but no economically useful resistant variety has been bred. Using quantitative trait locus (QTL) analysis of recombinant inbred lines (RILs) from 'Tadukan' (resistant) × 'Hinohikari' (susceptible), we previously found three QTLs (qBS2, qBS9, and qBS11) that conferred resistance in seedlings in a greenhouse. To confirm their effect, the parents and later generations of RILs were transplanted into paddy fields where brown spot severely occurred. Three new resistance QTLs (qBSfR1, qBSfR4, and qBSfR11) were detected on chromosomes 1, 4, and 11, respectively. The 'Tadukan' alleles at qBSfR1 and qBSfR11 and the 'Hinohikari' allele at qBSfR4 increased resistance. The major QTL qBSfR11 coincided with qBS11 from the previous study, whereas qBSfR1 and qBSfR4 were new but neither qBS2 nor qBS9 were detected. To verify the qBSfR1 and qBSfR11 'Tadukan' resistance alleles, near-isogenic lines (NILs) with one or both QTLs in a susceptible background ('Koshihikari') were evaluated under field conditions. NILs with qBSfR11 acquired significant field resistance; those with qBSfR1 did not. This confirms the effectiveness of qBSfR11. Genetic markers flanking qBSfR11 will be powerful tools for marker-assisted selection to improve brown spot resistance.

No MeSH data available.


Related in: MedlinePlus