A double mutant with streaked leaf and abnormal floret was found and temporarily named streaked leaf and floral organ number mutant （st-fon）. For this mutant, besides white streak appeared on culm, leaves and panicl...A double mutant with streaked leaf and abnormal floret was found and temporarily named streaked leaf and floral organ number mutant （st-fon）. For this mutant, besides white streak appeared on culm, leaves and panicles, the number of floral organs increased and florets cracked. The extreme phenotype was that several small florets grew from one floret or branch rachis in small florets extended and developed into panicles. By using transmission electron microscope to observe the ultrastructure of white histocytes of leaves at the seedling stage, the white tissues which showed abnormal plastids, lamellas and thylakoids could not develop into normal chloroplast, and the development of chloroplast was blocked at the early growth stage of plastid. Scanning electron microscope and paraffin section were also used to observe the development of floral organs, and the results indicated that the development of floral meristem was out of order and unlimited, whereas in the twisty leaves, vascular bundle sheath cells grew excessively, or some bubbly cells increased. Genetic analyses carried out by means of cross and backcross with four normal-leaf-color materials revealed that the mutant is of cytoplasm inheritance.展开更多
Bacterial leaf streak （BLS） of rice, caused by Xanthomonas oryzae pv. oryzicola （Xoc） is a worldwide destructive disease. Development of resistant varieties is considered to be one of the most effective and eco-fr...Bacterial leaf streak （BLS） of rice, caused by Xanthomonas oryzae pv. oryzicola （Xoc） is a worldwide destructive disease. Development of resistant varieties is considered to be one of the most effective and eco-friendly ways to control the disease. However, only a few genes/QTLs having resistance to BLS have been identified in rice until now. In the present study, we have identified and primarily mapped a BLS-resistance gene, blsl, from a rice line DP3, derived from the wild rice species Oryza rufipogon Griff. A BC2F2 （9311/DP3//9311） population was constructed to map BLS-resistance gene in the rice line DP3. The segregation of the resistant and susceptible plants in BCzFz in 1：3 ratio （Z2=0.009, Z20 05,1=3.84, P〉0.05）, suggested that a recessive gene confers BLS resistance in DP3. In bulked segregant analysis （BSA）, two SSR markers RM8116 and RM584 were identified to be polymorphic in resistant and susceptible DNA bulks. For further mapping the resistance gene, six polymorphic markers around the target region were applied to analyze the genotypes of the BC2F2 individuals. As a result, the BLS-resistant gene, designated as blsl, was mapped in a 4.0-cM region flanked by RM587 and RM510 on chromosome 6.展开更多
β-Glucosidase belongs to the glycoside hydrolase I family,which is widely present in multiple species and responds to various biotic and abiotic stresses.In rice,whetherβ-glucosidase is involved in the interaction b...β-Glucosidase belongs to the glycoside hydrolase I family,which is widely present in multiple species and responds to various biotic and abiotic stresses.In rice,whetherβ-glucosidase is involved in the interaction between plants and microorganisms is not clear.In this study,we found that the expression of several genes encodingβ-glucosidases,including OsBGLU19 and OsBGLU23,were upregulated after inoculation with Xanthomonas oryzae pv.oryzicola(Xoc)and downregulated after inoculation with X.oryzae pv.oryzae(Xoo).The respective insertion mutants of OsBGLU19 and OsBGLU23,bglu19 and bglu23,were more susceptible to Xoc infection.The expression of OsAOS2,a key gene in the jasmonic acid signal pathway,was dramatically downregulated after inoculation with Xoc in the bglu19 and bglu23 mutants.Simultaneously,the expression of downstream disease resistance-related genes,such as OsPR1a,OsPR5 and a key transcription factors OsWRKY72 were obviously downregulated.The resistance mediated by OsBGLU19 and OsBGLU23 to bacterial leaf streak is related to disease resistance-related genes above mentioned.展开更多
[ Objectives] Rice materials with broad-spectrum resistance against several pathogenic strains of Xanthomans oryzae pv. Oryzicola （Xooc） at multiple growth stages were screened, in order to provide reliable resistan...[ Objectives] Rice materials with broad-spectrum resistance against several pathogenic strains of Xanthomans oryzae pv. Oryzicola （Xooc） at multiple growth stages were screened, in order to provide reliable resistance sources for variety breeding against rice bacterial leaf streak. [ Methods] A total of 1 100 rice lines with rich genetic background were offered as selective objects, and highly susceptible cultivar Jingang 30 was used as the control. Inoculation was carried out with five strong pathogenic strains of Xooc through acupuncture method at various growth stages for resistance identification. [ Results] Fourteen disease-resistant materials were obtained through preliminary screening, accounting for 1.27% of the total materials. Nine materials moderately resistant to bacterial leaf streak were obtained via secondary screening, accounting for 0.82% of the total materials. Besides, three of them （ RL6, RL9 and RLL4） were resistant to a number of pathogenic strains of Xooc at three growth stages. In particular, RL16 presented broad-spectrum resistance to multi-strains with high resistance levels. Six of them （ RI2, RIA, RIS, RL8, RL11 and RL12） were resistant to single strain at single growth stage. [ Conclusions] The obtained three materials have broad-spectrum resistance to bacterial leaf streak at multiple growth stages, which can be served as an important source to cultivate disease-resistant rice varieties. RL6 maintains high broad-spectrum resistance at all growth stages, which can be used as a prior resistance source for rice variety breeding. Six materials obtained with resistance against bacterial leaf streak at particular growth stages can be used as candidate resistance sources.展开更多
Rxol cloned from maize is a non-host gene resistant to bacterial leaf streak of rice. pCAMBIA1305-1 with Rxo1 was digested with Sca I and NgoM IV and the double right-border binary vector pMNDRBBin6 was digested with ...Rxol cloned from maize is a non-host gene resistant to bacterial leaf streak of rice. pCAMBIA1305-1 with Rxo1 was digested with Sca I and NgoM IV and the double right-border binary vector pMNDRBBin6 was digested with Hpa I and Xma I. pMNDRBBin6 carrying the gene Rxo1 was acquired by ligation of blunt-end and cohesive end. The results of PCR, restriction enzyme analysis and sequencing indicated that the Rxo1 gene had been cloned into pMNDRBBin6. This double right-border binary vector, named as pMNDRBBin6-Rxol, will play a role in breeding marker-free plants resistant to bacterial leaf streak of rice by genetic transformation.展开更多
To understand virus infection situation of integrated demonstration and regional test sugarcane varieties in national sugarcane system in Guilin City,Guangxi Province,leaf samples with or without symptoms were collect...To understand virus infection situation of integrated demonstration and regional test sugarcane varieties in national sugarcane system in Guilin City,Guangxi Province,leaf samples with or without symptoms were collected from 37 sugarcane varieties,and five kinds of viruses were detected by RT-PCR with specific primers,including Sugarcane yellow leaf virus( SCYLV),Sugarcane streak mosaic virus( SCSMV),Sorghum mosaic virus( SrM V),Sugarcane mosaic virus( SCMV) and Sugarcane bacilliform virus( SCBV). The results showed that SCYLV was detected from four sugarcane varieties,and the detection rate was10. 81%; SCSMV was detected from five sugarcane varieties,and the detection rate was 13. 51%; SrM V was detected from four sugarcane varieties,and the detection rate was 10. 81%; SCMV had not been found; SCBV was detected from 27 sugarcane varieties,and the detection rate was 72. 9%. Additionally,mixed infection of different viruses was widespread,and the total mixed infection rate was 21. 62%. Thus,integrated demonstration and regional test sugarcane varieties in national sugarcane system in Guilin City had been seriously infected by viruses,and mixed infection of different viruses was common. The paper will provide a reference for breeding and popularization of antiviral sugarcane varieties.展开更多
基金supported by the Foundation Program,Innovative Team Development Plan of the Ministry of Education,China(Grant No.IRT0453)the Financial Gene Engineering Excellent Article Foundation Program of Sichuan Province,China(Grant No.2011LWJJ-005)
文摘A double mutant with streaked leaf and abnormal floret was found and temporarily named streaked leaf and floral organ number mutant （st-fon）. For this mutant, besides white streak appeared on culm, leaves and panicles, the number of floral organs increased and florets cracked. The extreme phenotype was that several small florets grew from one floret or branch rachis in small florets extended and developed into panicles. By using transmission electron microscope to observe the ultrastructure of white histocytes of leaves at the seedling stage, the white tissues which showed abnormal plastids, lamellas and thylakoids could not develop into normal chloroplast, and the development of chloroplast was blocked at the early growth stage of plastid. Scanning electron microscope and paraffin section were also used to observe the development of floral organs, and the results indicated that the development of floral meristem was out of order and unlimited, whereas in the twisty leaves, vascular bundle sheath cells grew excessively, or some bubbly cells increased. Genetic analyses carried out by means of cross and backcross with four normal-leaf-color materials revealed that the mutant is of cytoplasm inheritance.
基金supported by the Science Foundation of Guangxi University, China (XDZ110082)the National Natural Science Foundation of China (31000703)+2 种基金the Guangxi Science and Technology Projects, China (1123001-3B)the Guangxi Science Foundation of China (0833078)the Fundamental Research Funds for Guangxi Academy of Agricultural Sciences, China (200801Z and 200918J)
文摘Bacterial leaf streak （BLS） of rice, caused by Xanthomonas oryzae pv. oryzicola （Xoc） is a worldwide destructive disease. Development of resistant varieties is considered to be one of the most effective and eco-friendly ways to control the disease. However, only a few genes/QTLs having resistance to BLS have been identified in rice until now. In the present study, we have identified and primarily mapped a BLS-resistance gene, blsl, from a rice line DP3, derived from the wild rice species Oryza rufipogon Griff. A BC2F2 （9311/DP3//9311） population was constructed to map BLS-resistance gene in the rice line DP3. The segregation of the resistant and susceptible plants in BCzFz in 1：3 ratio （Z2=0.009, Z20 05,1=3.84, P〉0.05）, suggested that a recessive gene confers BLS resistance in DP3. In bulked segregant analysis （BSA）, two SSR markers RM8116 and RM584 were identified to be polymorphic in resistant and susceptible DNA bulks. For further mapping the resistance gene, six polymorphic markers around the target region were applied to analyze the genotypes of the BC2F2 individuals. As a result, the BLS-resistant gene, designated as blsl, was mapped in a 4.0-cM region flanked by RM587 and RM510 on chromosome 6.
基金supported by the National Natural Science Foundation of China (31872925)the Natural Science Fund for Outstanding Young Scholars of Shandong Province, China (JQ201807)+3 种基金the Shandong Provincial Natural Science Foundation of China (ZR2016CB26)the funds of the Shandong “Double Tops” Program, China, the Taishan Industrial Experts Program, China (tscy20150621)the National Program of Transgenic Variety Development of China (2016ZX08001-002, 2018ZX0801023B)the Shandong Modern Agricultural Technology & Industry System, China (SDAIT-17-06)
文摘β-Glucosidase belongs to the glycoside hydrolase I family,which is widely present in multiple species and responds to various biotic and abiotic stresses.In rice,whetherβ-glucosidase is involved in the interaction between plants and microorganisms is not clear.In this study,we found that the expression of several genes encodingβ-glucosidases,including OsBGLU19 and OsBGLU23,were upregulated after inoculation with Xanthomonas oryzae pv.oryzicola(Xoc)and downregulated after inoculation with X.oryzae pv.oryzae(Xoo).The respective insertion mutants of OsBGLU19 and OsBGLU23,bglu19 and bglu23,were more susceptible to Xoc infection.The expression of OsAOS2,a key gene in the jasmonic acid signal pathway,was dramatically downregulated after inoculation with Xoc in the bglu19 and bglu23 mutants.Simultaneously,the expression of downstream disease resistance-related genes,such as OsPR1a,OsPR5 and a key transcription factors OsWRKY72 were obviously downregulated.The resistance mediated by OsBGLU19 and OsBGLU23 to bacterial leaf streak is related to disease resistance-related genes above mentioned.
基金Supported by National Natural Science Foundation of China(31460341)Natural Science Foundation of Guangxi Province(2013GXNSFAA019060)Science and Technology Project of Guangxi Province(GK AB16380066)
文摘[ Objectives] Rice materials with broad-spectrum resistance against several pathogenic strains of Xanthomans oryzae pv. Oryzicola （Xooc） at multiple growth stages were screened, in order to provide reliable resistance sources for variety breeding against rice bacterial leaf streak. [ Methods] A total of 1 100 rice lines with rich genetic background were offered as selective objects, and highly susceptible cultivar Jingang 30 was used as the control. Inoculation was carried out with five strong pathogenic strains of Xooc through acupuncture method at various growth stages for resistance identification. [ Results] Fourteen disease-resistant materials were obtained through preliminary screening, accounting for 1.27% of the total materials. Nine materials moderately resistant to bacterial leaf streak were obtained via secondary screening, accounting for 0.82% of the total materials. Besides, three of them （ RL6, RL9 and RLL4） were resistant to a number of pathogenic strains of Xooc at three growth stages. In particular, RL16 presented broad-spectrum resistance to multi-strains with high resistance levels. Six of them （ RI2, RIA, RIS, RL8, RL11 and RL12） were resistant to single strain at single growth stage. [ Conclusions] The obtained three materials have broad-spectrum resistance to bacterial leaf streak at multiple growth stages, which can be served as an important source to cultivate disease-resistant rice varieties. RL6 maintains high broad-spectrum resistance at all growth stages, which can be used as a prior resistance source for rice variety breeding. Six materials obtained with resistance against bacterial leaf streak at particular growth stages can be used as candidate resistance sources.
文摘Rxol cloned from maize is a non-host gene resistant to bacterial leaf streak of rice. pCAMBIA1305-1 with Rxo1 was digested with Sca I and NgoM IV and the double right-border binary vector pMNDRBBin6 was digested with Hpa I and Xma I. pMNDRBBin6 carrying the gene Rxo1 was acquired by ligation of blunt-end and cohesive end. The results of PCR, restriction enzyme analysis and sequencing indicated that the Rxo1 gene had been cloned into pMNDRBBin6. This double right-border binary vector, named as pMNDRBBin6-Rxol, will play a role in breeding marker-free plants resistant to bacterial leaf streak of rice by genetic transformation.
基金Supported by Special Fund of China Agricultural(Sugar)Industry Research System(CARS-170301)Basal Research Fund of Central Public Welfare Research Institutes(1630052016010)
文摘To understand virus infection situation of integrated demonstration and regional test sugarcane varieties in national sugarcane system in Guilin City,Guangxi Province,leaf samples with or without symptoms were collected from 37 sugarcane varieties,and five kinds of viruses were detected by RT-PCR with specific primers,including Sugarcane yellow leaf virus( SCYLV),Sugarcane streak mosaic virus( SCSMV),Sorghum mosaic virus( SrM V),Sugarcane mosaic virus( SCMV) and Sugarcane bacilliform virus( SCBV). The results showed that SCYLV was detected from four sugarcane varieties,and the detection rate was10. 81%; SCSMV was detected from five sugarcane varieties,and the detection rate was 13. 51%; SrM V was detected from four sugarcane varieties,and the detection rate was 10. 81%; SCMV had not been found; SCBV was detected from 27 sugarcane varieties,and the detection rate was 72. 9%. Additionally,mixed infection of different viruses was widespread,and the total mixed infection rate was 21. 62%. Thus,integrated demonstration and regional test sugarcane varieties in national sugarcane system in Guilin City had been seriously infected by viruses,and mixed infection of different viruses was common. The paper will provide a reference for breeding and popularization of antiviral sugarcane varieties.
