Extremely high temperatures resulting from climate change have become a major challenge for increasing rice production.Therefore,our objective was to develop heat-tolerant aromatic rice varieties using the pedigree me...Extremely high temperatures resulting from climate change have become a major challenge for increasing rice production.Therefore,our objective was to develop heat-tolerant aromatic rice varieties using the pedigree method,focusing on selecting for seed-setting ability under extremely high temperatures along with the use of single nucleotide polymorphism/insertion and deletion(SNP/InDel)markers to improve aromatic properties and grain quality.Furthermore,the QTL-seq approach was utilized to identify QTLs for seed-setting rate in an F2 population subjected to heat stress.The candidate QTL regions were then aligned to confirm SNPs/InDels in synonymous F7 candidate heat-tolerant lines.The results revealed that four promising lines,namely 84-7-1-9,84-7-1-10,159-3-3-1,and 159-3-3-10,were classified as heat-tolerant with low amylose content.In addition,lines 84-7-1-9 and 84-7-1-10 were identified as aromatic rice encompassing the aroma gene(badh2).Regarding the QTL-seq results,the qSF2.1 region ranged from 311051 to 3929422 bp on chromosome 2,was identified based on the highest contrasting SNP index between the heat-susceptible and tolerant bulks.The candidate genes within this region include two genes related to heat shock proteins,three genes associated with pollen fertility,and four genes involved in heat stress and other abiotic stress responses.These genes are proposed as potential candidates for heat tolerance and could serve as targets in rice breeding programs aimed at enhancing heat tolerance.展开更多
A total of 10 000 M4 individuals in Jao Hom Nil (JHN) mutant population was treated with high temperature (40 ℃ to 45 ℃) during the day time (6 h) from the booting to the harvesting stages, and ambient temperature (...A total of 10 000 M4 individuals in Jao Hom Nil (JHN) mutant population was treated with high temperature (40 ℃ to 45 ℃) during the day time (6 h) from the booting to the harvesting stages, and ambient temperature (33 ℃ to 35℃) was used as the control. The results of screening and yield trials found that the mutant line M9962 had a high spikelet fertility of 78% under heat stress. In addition, the other mutant lines, including M3181 and M7988, had a spikelet fertility of approximately 70%. However, the JHN wild type, Sin Lek, RD15 and RD33 had very low spikelet fertility of 34%, 14%, 9% and 4%, respectively. The lower spikelet fertility at an elevated temperature resulted in a dramatic decrease of filled grain and contributed to a loss in 100-grain weight. M9962 is a potential genetic stock for use in a heat tolerance breeding programme. In addition, spikelet fertility at high temperature was representative of heat tolerance and can be used as a screening trait for heat tolerance during the reproductive phase on a large scale.展开更多
Seed-setting rate, yield components and grain quality traits of 169 accessions from an exotic rice germplasm were tested under high temperatures from 40 oC to 45 oC for 6 h during the daytime at the vegetative and rep...Seed-setting rate, yield components and grain quality traits of 169 accessions from an exotic rice germplasm were tested under high temperatures from 40 oC to 45 oC for 6 h during the daytime at the vegetative and reproductive stages, respectively. The results showed that heat stress significantly decreased the seed-setting rate of all the accessions, but the heat stress effects varied among accessions. Based on the decreases in seed-setting rate at high temperatures, N22 was the most tolerant, followed by AUS17, M9962, SONALEE and AUS16. Moreover, the reductions in seed-setting rate and yield under heat stress were more serious at the vegetative stage （45 d before heading） than at the booting stage （15 d before heading）. In addition, heat stress also affected grain quality, especially by conferring chalkiness to most of the accessions, but SONALEE did not change much. The heat-tolerant accessions identified here and the phenotype protocols developed could be used in future genetic studies and breeding programmes focused on heat tolerance.展开更多
Paw San Hmwe （PSM） rice has been cultivated in many areas of Myanmar for a long time. Strong aroma, good taste and its elongation during cooking are the key characteristics of PSM rice. Thirty-one PSM accessions wer...Paw San Hmwe （PSM） rice has been cultivated in many areas of Myanmar for a long time. Strong aroma, good taste and its elongation during cooking are the key characteristics of PSM rice. Thirty-one PSM accessions were genotypically characterized, and their physical grain and cooking quality traits were studied. We used specific gene markers associated with aroma, apparent amylose content （AAC） and alkali spreading value to determine the alleles carried by different PSM accessions. The results revealed that six PSM accessions （PSM10, PSM12, PSM13, PSM21, PSM22 and PSM30） had a 3-bp insertion in Os2AP gene. Gel consistency （GC） allele was predominant among the PSM accessions for gelatinization temperature （GT）, however, the phenotype observed was between low and intermediate GT because of the combination of the GC allele with the presence of low GT allele at heterozygous state from the other loci of the SSIla gene. Intermediate to high AAC was observed among the PSM accessions corresponding to the haplotype identified for the single nucleotide polymorphism G/T and the （Cm）n repeat in the Wx gene. The characterization and grouping data of PSM accessions posted benefits to Myanmar seed banks, and our results will help in maintaining the integrity of PSM rice variety.展开更多
Breeding program strategies to develop novel short grain white rice varieties such as japonica(short grain)that introgress biotic stress resistance and high grain quality have been developed usingindica rice(Pin Kaset...Breeding program strategies to develop novel short grain white rice varieties such as japonica(short grain)that introgress biotic stress resistance and high grain quality have been developed usingindica rice(Pin Kaset+4 and Riceberry)for applications in japonica rice(Kashihikari)improvement.Fourbreeding lines showing promising agronomic performance with short grain and low amylose content(<20%)were obtained.In addition,sensory testing of these breeding lines showed high scores thatsimilar to Kashihikari.Two promising lines,KP48-1-5and KP48-1-9,which possessed a combination offour genes resistance to different biotic stresses(Bph3+TPS+Xa21+Pi-ta)and four genes for grainquality(G83+SSlla+w+badh2),were deveiaped using marker-assisted selection(MAS)with thepedigree method.The current study clearly illustrated the successful use of MAS in combining resistanceto multiple biotic stresses while maintaining a high yield potential and preferred grain quality.Moreover,the results indicated that this breeding program,which includes crossing temperate japonica with indica,can create novel short grain rice varieties adapted to a trapical environment like the japonica type.展开更多
基金Agricultural Research Development Agency in Thailand for financing the study and the provision of this research.
文摘Extremely high temperatures resulting from climate change have become a major challenge for increasing rice production.Therefore,our objective was to develop heat-tolerant aromatic rice varieties using the pedigree method,focusing on selecting for seed-setting ability under extremely high temperatures along with the use of single nucleotide polymorphism/insertion and deletion(SNP/InDel)markers to improve aromatic properties and grain quality.Furthermore,the QTL-seq approach was utilized to identify QTLs for seed-setting rate in an F2 population subjected to heat stress.The candidate QTL regions were then aligned to confirm SNPs/InDels in synonymous F7 candidate heat-tolerant lines.The results revealed that four promising lines,namely 84-7-1-9,84-7-1-10,159-3-3-1,and 159-3-3-10,were classified as heat-tolerant with low amylose content.In addition,lines 84-7-1-9 and 84-7-1-10 were identified as aromatic rice encompassing the aroma gene(badh2).Regarding the QTL-seq results,the qSF2.1 region ranged from 311051 to 3929422 bp on chromosome 2,was identified based on the highest contrasting SNP index between the heat-susceptible and tolerant bulks.The candidate genes within this region include two genes related to heat shock proteins,three genes associated with pollen fertility,and four genes involved in heat stress and other abiotic stress responses.These genes are proposed as potential candidates for heat tolerance and could serve as targets in rice breeding programs aimed at enhancing heat tolerance.
基金supported by the Agriculture Research Development Agency and the Office of the Higher Education Commission for the Strategic Scholarships Fellowships Frontier Research Networks of Thailand
文摘A total of 10 000 M4 individuals in Jao Hom Nil (JHN) mutant population was treated with high temperature (40 ℃ to 45 ℃) during the day time (6 h) from the booting to the harvesting stages, and ambient temperature (33 ℃ to 35℃) was used as the control. The results of screening and yield trials found that the mutant line M9962 had a high spikelet fertility of 78% under heat stress. In addition, the other mutant lines, including M3181 and M7988, had a spikelet fertility of approximately 70%. However, the JHN wild type, Sin Lek, RD15 and RD33 had very low spikelet fertility of 34%, 14%, 9% and 4%, respectively. The lower spikelet fertility at an elevated temperature resulted in a dramatic decrease of filled grain and contributed to a loss in 100-grain weight. M9962 is a potential genetic stock for use in a heat tolerance breeding programme. In addition, spikelet fertility at high temperature was representative of heat tolerance and can be used as a screening trait for heat tolerance during the reproductive phase on a large scale.
基金supported by the Agriculture Research Development Agency of Thailandthe Office of the Higher Education Commission of Thailand for the Strategic Scholarships Fellowships Frontier Research Networks for financially supporting
文摘Seed-setting rate, yield components and grain quality traits of 169 accessions from an exotic rice germplasm were tested under high temperatures from 40 oC to 45 oC for 6 h during the daytime at the vegetative and reproductive stages, respectively. The results showed that heat stress significantly decreased the seed-setting rate of all the accessions, but the heat stress effects varied among accessions. Based on the decreases in seed-setting rate at high temperatures, N22 was the most tolerant, followed by AUS17, M9962, SONALEE and AUS16. Moreover, the reductions in seed-setting rate and yield under heat stress were more serious at the vegetative stage （45 d before heading） than at the booting stage （15 d before heading）. In addition, heat stress also affected grain quality, especially by conferring chalkiness to most of the accessions, but SONALEE did not change much. The heat-tolerant accessions identified here and the phenotype protocols developed could be used in future genetic studies and breeding programmes focused on heat tolerance.
基金supported by the National Center for Genetic Engineering and Biotechnology,Thailand (Grant No.P1020028)Generation Challenge Program,Mexico (Grant No.P0900835)
文摘Paw San Hmwe （PSM） rice has been cultivated in many areas of Myanmar for a long time. Strong aroma, good taste and its elongation during cooking are the key characteristics of PSM rice. Thirty-one PSM accessions were genotypically characterized, and their physical grain and cooking quality traits were studied. We used specific gene markers associated with aroma, apparent amylose content （AAC） and alkali spreading value to determine the alleles carried by different PSM accessions. The results revealed that six PSM accessions （PSM10, PSM12, PSM13, PSM21, PSM22 and PSM30） had a 3-bp insertion in Os2AP gene. Gel consistency （GC） allele was predominant among the PSM accessions for gelatinization temperature （GT）, however, the phenotype observed was between low and intermediate GT because of the combination of the GC allele with the presence of low GT allele at heterozygous state from the other loci of the SSIla gene. Intermediate to high AAC was observed among the PSM accessions corresponding to the haplotype identified for the single nucleotide polymorphism G/T and the （Cm）n repeat in the Wx gene. The characterization and grouping data of PSM accessions posted benefits to Myanmar seed banks, and our results will help in maintaining the integrity of PSM rice variety.
基金supported by the Tana Group International Co.Ltd.,Thailand(2015-2019).
文摘Breeding program strategies to develop novel short grain white rice varieties such as japonica(short grain)that introgress biotic stress resistance and high grain quality have been developed usingindica rice(Pin Kaset+4 and Riceberry)for applications in japonica rice(Kashihikari)improvement.Fourbreeding lines showing promising agronomic performance with short grain and low amylose content(<20%)were obtained.In addition,sensory testing of these breeding lines showed high scores thatsimilar to Kashihikari.Two promising lines,KP48-1-5and KP48-1-9,which possessed a combination offour genes resistance to different biotic stresses(Bph3+TPS+Xa21+Pi-ta)and four genes for grainquality(G83+SSlla+w+badh2),were deveiaped using marker-assisted selection(MAS)with thepedigree method.The current study clearly illustrated the successful use of MAS in combining resistanceto multiple biotic stresses while maintaining a high yield potential and preferred grain quality.Moreover,the results indicated that this breeding program,which includes crossing temperate japonica with indica,can create novel short grain rice varieties adapted to a trapical environment like the japonica type.
