Global warming poses a threat to rice production.Breeding heat-tolerant rice is an effective and economical approach to address this challenge.African rice is a valuable genetic resource for developing heat-tolerant c...Global warming poses a threat to rice production.Breeding heat-tolerant rice is an effective and economical approach to address this challenge.African rice is a valuable genetic resource for developing heat-tolerant crops due to its intricate mechanism for adapting to high temperatures.Oryza longistaminata,a widely distributed wild rice species in Africa,may harbor an even richer gene pool for heat tolerance,which remains untapped.In this study,we identified three heat tolerance QTLs from O.longistaminata at the seedling stage,including novel heat tolerance loci qTT4 and qTT5.Our findings demonstrated that the O.longistaminata alleles for these two QTLs can enhance the heat tolerance of rice seedlings.Remarkably,qTT5 was mapped to a region spanning approximately 287.2 kb,which contains 46 expressing genes.Through the analysis of Gene Ontology and expression differences under heat induction,we identified four candidate genes.Our results lay the foundation for discovering heat tolerance genes underlying O.longistaminata and developing new genetic resources for heat-tolerant rice breeding.展开更多
As a natural genetic reservoir, wild rice contains many favorable alleles and mutations conferring high yield and resistance to biotic and abiotic stresses. However, there are few reports describing favorable genes or...As a natural genetic reservoir, wild rice contains many favorable alleles and mutations conferring high yield and resistance to biotic and abiotic stresses. However, there are few reports describing favorable genes or QTL from the AA genome wild rice O. longistaminata, which is characterized by tall and robust habit and long tassels and anthers and shows high potential for use in cultivated rice improvement. We constructed a stable BC_(2)F_(20) backcross inbred line(BIL) population of 152 lines from the cross of 9311 × O.longistaminat. Some BILs showed large panicles, large seeds, and strong resistance to rice false smut, bacterial leaf blight, rice blast spot, and brown planthopper. Genomic resequencing showed that the 152 BILs covered about 99.6% of the O. longistaminata genome. QTL mapping with 2432 bin markers revealed 13QTL associated with seven yield traits and eight with resistance to brown planthopper and to four diseases. Of these QTL, 12 for grain yield and 11 for pest and disease resistance are novel in Oryza species.A large-panicle NIL1880 line containing QTL qPB8.1 showed a nearly 50% increase in spikelet number and27.5% in grain yield compared to the recurrent parent 9311. These findings support the potential value of O. longistaminata for cultivated rice improvement.展开更多
Plant microRNAs(miRNAs)play important roles in biological processes such as development and stress responses.Although the diverse functions of miRNAs in model organisms have been well studied,their function in wild ri...Plant microRNAs(miRNAs)play important roles in biological processes such as development and stress responses.Although the diverse functions of miRNAs in model organisms have been well studied,their function in wild rice is poorly understood.In this study,high-throughput small RNA sequencing was performed to characterize tissue-specific transcriptomes in Oryza longistaminata.A total of 603 miRNAs,380 known rice miRNAs,72 conserved plant miRNAs,and151 predicted novel miRNAs were identified as being expressed in aerial shoots and rhizomes.Additionally,99 and 79 miRNAs were expressed exclusively or differentially,respectively,in the two tissues,and 144 potential targets were predicted for the differentially expressed miRNAs in the rhizomes.Functional annotation of these targets suggested that transcription factors,including squamosa promoter binding proteins and auxin response factors,function in rhizome growth and development.The expression levels of several miRNAs and target genes in the rhizomes were quantified by RT-PCR,and the results indicated the existence of complex regulatory mechanisms between the miRNAs and their targets.Eight target cleavage sites were verified by RNA ligase-mediated rapid 5′end amplification.These results provide valuable information on the composition,expression and function of miRNAs in O.longistaminata,and will aid in understanding the molecular mechanisms of rhizome development.展开更多
Photosynthetic efficiency,a key trait that determines yield potential in rice,is quantitatively regulated by multiple genes.Utilization of valuable genetic resources hidden in wild rice is an effective way to improve ...Photosynthetic efficiency,a key trait that determines yield potential in rice,is quantitatively regulated by multiple genes.Utilization of valuable genetic resources hidden in wild rice is an effective way to improve rice photosynthesis and yield potential.In this study,152 backcross inbred lines derived from wild rice Oryza longistaminata were explored for QTL mapping of photosynthetic rate(Pn)and biomass(BM)in natural fields.Five novel QTLs for Pn and seven QTLs for BM or daily biomass(DBM)derived from O.longistaminata were identified.One of these QTLs,qPn8.1,could significantly improve Pn and was located in a 68-kb region containing only 11 candidate genes.Meanwhile,qBM1.1 and qDBM1.1 for BM and DBM on chromosome 1 were overlapped with qPn1.1 for Pn from 9311,and could affect both Pn and BM in natural fields.These QTLs identified in O.longistaminata may provide a novel alternative to explore new genes and resources for yield potentiality,highlighting the important role of wild rice in rice breeding programs.展开更多
The African rice midge, Orseolia oryzivora H. & G., is an important insect pest in Burkina Faso. Our study was conducted from 2017 to 2019 in three irrigated rice schemes including Banzon, Karfiguéla and Vall...The African rice midge, Orseolia oryzivora H. & G., is an important insect pest in Burkina Faso. Our study was conducted from 2017 to 2019 in three irrigated rice schemes including Banzon, Karfiguéla and Vallée du Kou in Western Burkina Faso. The objective of this study was to investigate the ecology of the insect pest. In each rice scheme, four plots of 500 m2 each, spread 50 m apart were randomly selected in farmers’ fields and used for the study. In each plot, a light trap was implemented along one of the diagonals of the plot. Each light trap consisted of a yellow plastic round bowl containing soapy water almost at half the bowl and a torch. The bowl had a capacity of 4.5 l, a diameter of 28 cm and a height of 10.5 cm. The torch had 3 batteries of 1.5 V each, 30 cm long and 1 cm diameter. The torches were lit every night at 6 pm and off at 6 am. Four hundred tillers were collected per month from the cultivated rice and from each of the alternative hosts of the rice midge in order to evaluate the monthly gall count, pre-imaginal populations and parasitism associated with O. oryzivora and its cousin, O. bonzii that is hosted by Paspalum scrobiculatum. The number of O. oryzivora’s adults caught in the light traps was higher during the wet season than the dry season. The level of larval parasitism ranged from 6.16% (Banzon) to 14.29% (Vallée du Kou). The highest level of pupal parasitism (13.73%) was recorded in Vallée du Kou. The damage of O. oryzivora was observed on the wild rice species, O. longistaminata in all three sites. The highest levels of parasitism associated with O. bonzii were recorded in Karfiguéla (20.08% and 25.21% for larval parasitism and pupal parasitism, respectively). These findings are useful in the development of a sustainable control strategy of O. oryzivora.展开更多
基金partly granted from the National Natural Science Foundation of China(Grant No.U20A2023)the Joint Open Competitive Project of the Yazhou Bay Laboratory and the China National Seed Company Limitedhe Hubei Hongshan Laboratory,China(Grant No.2021hszd010)。
文摘Global warming poses a threat to rice production.Breeding heat-tolerant rice is an effective and economical approach to address this challenge.African rice is a valuable genetic resource for developing heat-tolerant crops due to its intricate mechanism for adapting to high temperatures.Oryza longistaminata,a widely distributed wild rice species in Africa,may harbor an even richer gene pool for heat tolerance,which remains untapped.In this study,we identified three heat tolerance QTLs from O.longistaminata at the seedling stage,including novel heat tolerance loci qTT4 and qTT5.Our findings demonstrated that the O.longistaminata alleles for these two QTLs can enhance the heat tolerance of rice seedlings.Remarkably,qTT5 was mapped to a region spanning approximately 287.2 kb,which contains 46 expressing genes.Through the analysis of Gene Ontology and expression differences under heat induction,we identified four candidate genes.Our results lay the foundation for discovering heat tolerance genes underlying O.longistaminata and developing new genetic resources for heat-tolerant rice breeding.
基金partly granted from the National Natural Science Foundation of China(U20A2023, 31870322)the Creative Research Groups of the Natural Science Foundation of Hubei Province,China (2020CFA009)the Hubei Hongshan Laboratory (2021hszd010)。
文摘As a natural genetic reservoir, wild rice contains many favorable alleles and mutations conferring high yield and resistance to biotic and abiotic stresses. However, there are few reports describing favorable genes or QTL from the AA genome wild rice O. longistaminata, which is characterized by tall and robust habit and long tassels and anthers and shows high potential for use in cultivated rice improvement. We constructed a stable BC_(2)F_(20) backcross inbred line(BIL) population of 152 lines from the cross of 9311 × O.longistaminat. Some BILs showed large panicles, large seeds, and strong resistance to rice false smut, bacterial leaf blight, rice blast spot, and brown planthopper. Genomic resequencing showed that the 152 BILs covered about 99.6% of the O. longistaminata genome. QTL mapping with 2432 bin markers revealed 13QTL associated with seven yield traits and eight with resistance to brown planthopper and to four diseases. Of these QTL, 12 for grain yield and 11 for pest and disease resistance are novel in Oryza species.A large-panicle NIL1880 line containing QTL qPB8.1 showed a nearly 50% increase in spikelet number and27.5% in grain yield compared to the recurrent parent 9311. These findings support the potential value of O. longistaminata for cultivated rice improvement.
基金supported by the National Natural Science Foundation of China(31271694 and U1302264)
文摘Plant microRNAs(miRNAs)play important roles in biological processes such as development and stress responses.Although the diverse functions of miRNAs in model organisms have been well studied,their function in wild rice is poorly understood.In this study,high-throughput small RNA sequencing was performed to characterize tissue-specific transcriptomes in Oryza longistaminata.A total of 603 miRNAs,380 known rice miRNAs,72 conserved plant miRNAs,and151 predicted novel miRNAs were identified as being expressed in aerial shoots and rhizomes.Additionally,99 and 79 miRNAs were expressed exclusively or differentially,respectively,in the two tissues,and 144 potential targets were predicted for the differentially expressed miRNAs in the rhizomes.Functional annotation of these targets suggested that transcription factors,including squamosa promoter binding proteins and auxin response factors,function in rhizome growth and development.The expression levels of several miRNAs and target genes in the rhizomes were quantified by RT-PCR,and the results indicated the existence of complex regulatory mechanisms between the miRNAs and their targets.Eight target cleavage sites were verified by RNA ligase-mediated rapid 5′end amplification.These results provide valuable information on the composition,expression and function of miRNAs in O.longistaminata,and will aid in understanding the molecular mechanisms of rhizome development.
基金partly granted from the National Natural Science Foundation of China (Grant Nos. U20A2023 and 32172074)the Creative Research Groups of the Natural Science Foundation of Hubei Province,China (Grant No. 2020CFA009)the earmarked fund for China Agriculture Research System (Grant No. CARS-01-08)
文摘Photosynthetic efficiency,a key trait that determines yield potential in rice,is quantitatively regulated by multiple genes.Utilization of valuable genetic resources hidden in wild rice is an effective way to improve rice photosynthesis and yield potential.In this study,152 backcross inbred lines derived from wild rice Oryza longistaminata were explored for QTL mapping of photosynthetic rate(Pn)and biomass(BM)in natural fields.Five novel QTLs for Pn and seven QTLs for BM or daily biomass(DBM)derived from O.longistaminata were identified.One of these QTLs,qPn8.1,could significantly improve Pn and was located in a 68-kb region containing only 11 candidate genes.Meanwhile,qBM1.1 and qDBM1.1 for BM and DBM on chromosome 1 were overlapped with qPn1.1 for Pn from 9311,and could affect both Pn and BM in natural fields.These QTLs identified in O.longistaminata may provide a novel alternative to explore new genes and resources for yield potentiality,highlighting the important role of wild rice in rice breeding programs.
文摘The African rice midge, Orseolia oryzivora H. & G., is an important insect pest in Burkina Faso. Our study was conducted from 2017 to 2019 in three irrigated rice schemes including Banzon, Karfiguéla and Vallée du Kou in Western Burkina Faso. The objective of this study was to investigate the ecology of the insect pest. In each rice scheme, four plots of 500 m2 each, spread 50 m apart were randomly selected in farmers’ fields and used for the study. In each plot, a light trap was implemented along one of the diagonals of the plot. Each light trap consisted of a yellow plastic round bowl containing soapy water almost at half the bowl and a torch. The bowl had a capacity of 4.5 l, a diameter of 28 cm and a height of 10.5 cm. The torch had 3 batteries of 1.5 V each, 30 cm long and 1 cm diameter. The torches were lit every night at 6 pm and off at 6 am. Four hundred tillers were collected per month from the cultivated rice and from each of the alternative hosts of the rice midge in order to evaluate the monthly gall count, pre-imaginal populations and parasitism associated with O. oryzivora and its cousin, O. bonzii that is hosted by Paspalum scrobiculatum. The number of O. oryzivora’s adults caught in the light traps was higher during the wet season than the dry season. The level of larval parasitism ranged from 6.16% (Banzon) to 14.29% (Vallée du Kou). The highest level of pupal parasitism (13.73%) was recorded in Vallée du Kou. The damage of O. oryzivora was observed on the wild rice species, O. longistaminata in all three sites. The highest levels of parasitism associated with O. bonzii were recorded in Karfiguéla (20.08% and 25.21% for larval parasitism and pupal parasitism, respectively). These findings are useful in the development of a sustainable control strategy of O. oryzivora.
