The green rice leafhopper (GRH;Nephotettix cincticeps Uhler) is one of the most devastating insect pests of cultivated rice (Oryza sativa L.) in temperate regions in Asia. Using the rice germplasms with biotic stress ...The green rice leafhopper (GRH;Nephotettix cincticeps Uhler) is one of the most devastating insect pests of cultivated rice (Oryza sativa L.) in temperate regions in Asia. Using the rice germplasms with biotic stress resistance is the most effective and environmentally-friendly way to control the insect pests in the paddy. Sixty accessions from a core set of worldwide collection of rice were characterized for resistance to the GRH by antibiosis test both at the seedling and at the booting stages. The positive correlations of average nymph mortality (ANM) were observed between at the seedling stage and at the booting stage on 3 days after infestation (DAI) (r = 0.684**), 5DAI (r = 0.680**), and 7DAI (r = 0.652**), respectively. This result will give us the opportunity to screen resistance to the GRH with the cost-efficient way using rice seedlings in a growth chamber. To classify the 60 accessions evaluated, the ANM of the GRH of each accession was compared to the respective ANM of resistant and susceptible controls with the least significant difference (LSD) value. Based on the statistical difference or similarity of the ANMs to the resistant and the susceptible controls, we proposed the four groups of resistance to the GRH, (I) high level of resistance, (II) considerable level of resistance, (III) moderate level of resistance, and (IV) susceptibility. At the seedling stage, a total of 26 accessions were highly resistant in addition to other 6 for considerable level of resistance and other 10 for moderate level of resistance. At the booting stage, on the other hand, a total of 18 accessions were highly resistant in addition to other 3 for considerable level of resistance and other 5 for moderate level of resistance. A total of 42 accessions with high to moderate level of resistance were distributed across 16 countries in Asia in addition to each one for Madagascar and USA. The classification of landraces based on the present protocol for screening resistance to the insect provided fundamental information for genetics and breeding on resistance to the GRH in rice.展开更多
The development of green super rice varieties with improved nutrient use efficiency(NuUE)is a vital target area to increase yield and make it more stable under rainfed conditions.In the present study, we followed an e...The development of green super rice varieties with improved nutrient use efficiency(NuUE)is a vital target area to increase yield and make it more stable under rainfed conditions.In the present study, we followed an early backcross(BC) breeding approach by using a highyielding and widely adapted Xian variety, Weed Tolerant Rice 1(WTR-1), as a recipient and a Geng variety, Hao-An-Nong(HAN), as a donor.Starting from the BC1F2 generation, the BC population went through one generation of selection under irrigated, low-input, and rainfed conditions, followed by four consecutive generations of screening and selection for high grain yield(GY) under six different nutrient conditions(NPK, 75 N,-N,-P,-NP, and-NPK), leading to the development of 230 BC1F6 introgression lines(ILs).These 230 ILs were evaluated under the same six nutrient conditions for 13 agro-morphological and grain yield component traits in comparison to four checks and parents.Significant trait variations were observed between the treatments and ILs.Positive correlations were identified for GY with biomass, panicle length, flag-leaf area, flag-leaf width, filled grain number per panicle,1000-grain weight, and tiller number under-N,-P,-NP, and-NPK conditions.Out of 230 ILs,12 were identified as promising under two or more nutrient deficiency conditions.The results demonstrated an efficient inter-subspecific BC breeding procedure with a first round of selection under rainfed-drought conditions, followed by four generations of progeny testing for yield performance under six nutrient conditions.The promising ILs can be useful resources for molecular genetic dissection and understanding the physiological mechanisms of NuUE.展开更多
On the basis of a long-term(30 years) field experiment that involved four rotation systems, rice-rice-winter fallow(RRF), rice-rice-ryegrass(RRG), rice-rice-rape(RRP), and rice-rice-milk vetch(RRV), this stu...On the basis of a long-term(30 years) field experiment that involved four rotation systems, rice-rice-winter fallow(RRF), rice-rice-ryegrass(RRG), rice-rice-rape(RRP), and rice-rice-milk vetch(RRV), this study described the effects of green manure on the microbial communities in the red paddy soils using 454 pyrosequencing for the 16 S r RNA gene. The Chao1 richness and non-parametric Shannon's index increased in all soil samples that received green manure treatments. The communities' structures with the green manure applications were significantly dissimilar from that under the winter fallow. Using Metastats tests, many genera in the RRG, RRP and RRV soils were significantly different from those in the RRF soil, including a number of genera that functioned in the nitrogen and sulfur cycles. Analyses of the genera with these functions revealed the shifts in microbial ecosystem functions after long-term green manuring. Changes in the microbial communities increased the ammonium supply and decreased the soil acidification in green-manure-amended soils. Together, these data suggested powerful effects of green manure on both the microbial communities and the biogeochemical cycle driven by the shifts in bacterial functional groups.展开更多
P/TGMS (photo-thermo sensitive genie male sterility) lines with pale-green leaf color have been developed in japonica rice. The marker trait is used as an assistant selection in the production of the two-lines system ...P/TGMS (photo-thermo sensitive genie male sterility) lines with pale-green leaf color have been developed in japonica rice. The marker trait is used as an assistant selection in the production of the two-lines system hybrid rice for the improvement of F, seed purity. A joint inheritance study of both leaf color and male sterility is presented for P/TGMS line with pale-green leaf color. The segregation ratios for leaf color in the F2 populations of the three crosses showed 13 : 3 and 15 : 1 at early and late sowing stages (April 26 and June 23) respectively, implying that the leaf color is controlled by two genes with fertility gene as dominant. Sterility level is higher in the early sowing stage than that in the late sowing. The inducement of male sterility is closely related to longer day-length and higher temperature at the developmental stages of young panicle. The genes to govern the leaf color and male fertility are inherited independently.展开更多
A study was done to evaluate the removal of a cationic dye from simulated waste water onto rice husks (RH). Spectroscopic methods such as FTIR and SEM/EDX were used for adsorbent characterization. Experimental depende...A study was done to evaluate the removal of a cationic dye from simulated waste water onto rice husks (RH). Spectroscopic methods such as FTIR and SEM/EDX were used for adsorbent characterization. Experimental dependency on solution pH, initial dye concentration, agitation speed, adsorbentparticle size, temperature of the solution and contact time was evaluated. The adsorption data was tested using both Langmuir and Freundlich isotherms. The data fitted well into Langmuir isotherm model with a monolayer adsorption capacity of 6.5 mg/g. Further, the separation factor (RL) value was less than unity indicating a favorable adsorption process. Adsorption kinetics was determined using pseudo-first-order, pseudo-second-order and intra-particle diffusion models. The results showed that the adsorption of malachite green onto rice husks followed pseudo-second-order model with a determination coefficient of 0.986. This work has revealed that rice husks have a great potential to sequester cationic dyes from aqueous solutions and therefore it can be utilized to clean contaminated effluents.展开更多
A thermo-insensitive pale green leaf mutant (pgl2) was isolated from T-DNA inserted transgenic lines of rice (Oryza sativa L. subsp, japonica cv. Nipponbare). Genetic analysis indicated that the phenotype was caus...A thermo-insensitive pale green leaf mutant (pgl2) was isolated from T-DNA inserted transgenic lines of rice (Oryza sativa L. subsp, japonica cv. Nipponbare). Genetic analysis indicated that the phenotype was caused by a recessive mutation in a single nuclear-encoded gene. To map the PGL2gene, an F2 population was constructed by crossing the mutant with Longtefu (Oryza sativa L. subsp, indica). The PGL2 locus was roughly linked to SSR marker RM331 on chromosome 8. To finely map the gene, 14 new InDel markers were developed around the marker, and PGL2 was further mapped to a 2.37 Mb centromeric region. Analysis on chlorophyll contents of leaves showed that there was no obvious difference between the mutant and the wild type in total chlorophyll (Chl) content, while the ratio of Chl a / Chl b in the mutant was only about 1, which was distinctly lower than that in the wild type, suggesting that the PGL2 gene was related to the conversion between Chl a and Chl b. Moreover, the method of primer design around the centromeric region was discussed, which would provide insight into fine mapping of the functional genes in plant centromeres.展开更多
The development and dissemination of sawah rice eco-technology in Nigeria and Ghana as prerequisites for the actualization of green revolution in West Africa were described. It showed that the neglect of the eco-techn...The development and dissemination of sawah rice eco-technology in Nigeria and Ghana as prerequisites for the actualization of green revolution in West Africa were described. It showed that the neglect of the eco-technology and the overemphasis of the biotechnology have rendered the ineffective transferability of the green revolution process from Asia to Africa. The sawah eco-technology increases yield up to 5 t/hm2 through bunding and the use of inlet and outlet connecting irrigation and drainage, which enhances effective water control and management, improves the efficiency of fertilizer, improves nitrogen fixation by soil microbes and algae, increases the use of wetlands, improves soil organic matter accumulation, suppresses weed growth, and enhances immune mechanism of rice through nutrient supply. The current experience has therefore established that the technology overcomes the constraints that have limited the realization of green revolution in West Africa.展开更多
Adding green tea extract to rice bran oil was expected to improve its oxidative stability,so this study was conducted to investigate oxidative stability of green tea extract-enriched rice bran oil(RBOG) during storage...Adding green tea extract to rice bran oil was expected to improve its oxidative stability,so this study was conducted to investigate oxidative stability of green tea extract-enriched rice bran oil(RBOG) during storage at 60℃ for 15 days compared to rice bran oil(RBO),olive(OL),canola(CN),and grape-seed oil(GS).Acid values did not increase during storage,and the highest value was found for OL.The peroxide values of RBOG,RBO,CN,OL,and GS increased for up to 15 days.The highest average rate constant for the change in peroxide value was found for RBO(0.282).TBARS increased continually during storage of RBOG,RBO,CN,and OL;however,the value increased for up to 9 days and then decreased for GS.The highest average rate constant of change in TBARS was found for CN.Overall,the results suggest that green tea extract improves oxidative stability of rice bran oil.展开更多
We studied the effect of agar concentration inmedia on callus induction rate and green plant-let regeneration frequency in rice.Materialswere Fgeneration of indica/indica or indica/japonica,which were 96E76(Hei’e/Zha...We studied the effect of agar concentration inmedia on callus induction rate and green plant-let regeneration frequency in rice.Materialswere Fgeneration of indica/indica or indica/japonica,which were 96E76(Hei’e/Zhaiye- qing 8),96E80[(IR 24/Guanglu'ai 4//Zhongnan’ai)/Yifengzao],96E86(Zhong- munong 9/Zhaiyeqing 8).The induction mediaused was M8+2mg/L 2,4-D,and agar con-centrations were 0.6%,0.8%,and 1.0%,respectively.Regeneration media was MS+2mg/L KT+0.5mg/L IAA+0.5mg/LNAA,and agar concentrations were 0.6% and1.0%.Results indicated that the calli induc-展开更多
Wild rice is an important resource of usefulgenes to rice breeders. However, low regener-ation frequency is an obstacle to use the valu-able genes. We used desiccation to improve theregeneration frequency and studied ...Wild rice is an important resource of usefulgenes to rice breeders. However, low regener-ation frequency is an obstacle to use the valu-able genes. We used desiccation to improve theregeneration frequency and studied the bio-chemical changes of calli of wild rice after des-iccation.Materials used in this experiment werewild species O. rufipogon, O. meyeriana, O.alta, and O. brachyantha. Young panicles(0.1-0. 5 cm in length of the inflorescence)展开更多
文摘The green rice leafhopper (GRH;Nephotettix cincticeps Uhler) is one of the most devastating insect pests of cultivated rice (Oryza sativa L.) in temperate regions in Asia. Using the rice germplasms with biotic stress resistance is the most effective and environmentally-friendly way to control the insect pests in the paddy. Sixty accessions from a core set of worldwide collection of rice were characterized for resistance to the GRH by antibiosis test both at the seedling and at the booting stages. The positive correlations of average nymph mortality (ANM) were observed between at the seedling stage and at the booting stage on 3 days after infestation (DAI) (r = 0.684**), 5DAI (r = 0.680**), and 7DAI (r = 0.652**), respectively. This result will give us the opportunity to screen resistance to the GRH with the cost-efficient way using rice seedlings in a growth chamber. To classify the 60 accessions evaluated, the ANM of the GRH of each accession was compared to the respective ANM of resistant and susceptible controls with the least significant difference (LSD) value. Based on the statistical difference or similarity of the ANMs to the resistant and the susceptible controls, we proposed the four groups of resistance to the GRH, (I) high level of resistance, (II) considerable level of resistance, (III) moderate level of resistance, and (IV) susceptibility. At the seedling stage, a total of 26 accessions were highly resistant in addition to other 6 for considerable level of resistance and other 10 for moderate level of resistance. At the booting stage, on the other hand, a total of 18 accessions were highly resistant in addition to other 3 for considerable level of resistance and other 5 for moderate level of resistance. A total of 42 accessions with high to moderate level of resistance were distributed across 16 countries in Asia in addition to each one for Madagascar and USA. The classification of landraces based on the present protocol for screening resistance to the insect provided fundamental information for genetics and breeding on resistance to the GRH in rice.
基金the Bill & Melinda Gates Foundation (BMGF) for providing a research grant to Z.L.for the Green Super Rice project under ID OPP1130530the Department of Agriculture of the Philippines for providing funds to J.A.under the Next-Gen project.
文摘The development of green super rice varieties with improved nutrient use efficiency(NuUE)is a vital target area to increase yield and make it more stable under rainfed conditions.In the present study, we followed an early backcross(BC) breeding approach by using a highyielding and widely adapted Xian variety, Weed Tolerant Rice 1(WTR-1), as a recipient and a Geng variety, Hao-An-Nong(HAN), as a donor.Starting from the BC1F2 generation, the BC population went through one generation of selection under irrigated, low-input, and rainfed conditions, followed by four consecutive generations of screening and selection for high grain yield(GY) under six different nutrient conditions(NPK, 75 N,-N,-P,-NP, and-NPK), leading to the development of 230 BC1F6 introgression lines(ILs).These 230 ILs were evaluated under the same six nutrient conditions for 13 agro-morphological and grain yield component traits in comparison to four checks and parents.Significant trait variations were observed between the treatments and ILs.Positive correlations were identified for GY with biomass, panicle length, flag-leaf area, flag-leaf width, filled grain number per panicle,1000-grain weight, and tiller number under-N,-P,-NP, and-NPK conditions.Out of 230 ILs,12 were identified as promising under two or more nutrient deficiency conditions.The results demonstrated an efficient inter-subspecific BC breeding procedure with a first round of selection under rainfed-drought conditions, followed by four generations of progeny testing for yield performance under six nutrient conditions.The promising ILs can be useful resources for molecular genetic dissection and understanding the physiological mechanisms of NuUE.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest of China(201103005)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(2013–2017)
文摘On the basis of a long-term(30 years) field experiment that involved four rotation systems, rice-rice-winter fallow(RRF), rice-rice-ryegrass(RRG), rice-rice-rape(RRP), and rice-rice-milk vetch(RRV), this study described the effects of green manure on the microbial communities in the red paddy soils using 454 pyrosequencing for the 16 S r RNA gene. The Chao1 richness and non-parametric Shannon's index increased in all soil samples that received green manure treatments. The communities' structures with the green manure applications were significantly dissimilar from that under the winter fallow. Using Metastats tests, many genera in the RRG, RRP and RRV soils were significantly different from those in the RRF soil, including a number of genera that functioned in the nitrogen and sulfur cycles. Analyses of the genera with these functions revealed the shifts in microbial ecosystem functions after long-term green manuring. Changes in the microbial communities increased the ammonium supply and decreased the soil acidification in green-manure-amended soils. Together, these data suggested powerful effects of green manure on both the microbial communities and the biogeochemical cycle driven by the shifts in bacterial functional groups.
基金This research was supported by a grant from China Nationl“863"High Tchnology Proramn,a key grant(2003C22007)“8812”Program from Zhejiang Province,China.
文摘P/TGMS (photo-thermo sensitive genie male sterility) lines with pale-green leaf color have been developed in japonica rice. The marker trait is used as an assistant selection in the production of the two-lines system hybrid rice for the improvement of F, seed purity. A joint inheritance study of both leaf color and male sterility is presented for P/TGMS line with pale-green leaf color. The segregation ratios for leaf color in the F2 populations of the three crosses showed 13 : 3 and 15 : 1 at early and late sowing stages (April 26 and June 23) respectively, implying that the leaf color is controlled by two genes with fertility gene as dominant. Sterility level is higher in the early sowing stage than that in the late sowing. The inducement of male sterility is closely related to longer day-length and higher temperature at the developmental stages of young panicle. The genes to govern the leaf color and male fertility are inherited independently.
文摘A study was done to evaluate the removal of a cationic dye from simulated waste water onto rice husks (RH). Spectroscopic methods such as FTIR and SEM/EDX were used for adsorbent characterization. Experimental dependency on solution pH, initial dye concentration, agitation speed, adsorbentparticle size, temperature of the solution and contact time was evaluated. The adsorption data was tested using both Langmuir and Freundlich isotherms. The data fitted well into Langmuir isotherm model with a monolayer adsorption capacity of 6.5 mg/g. Further, the separation factor (RL) value was less than unity indicating a favorable adsorption process. Adsorption kinetics was determined using pseudo-first-order, pseudo-second-order and intra-particle diffusion models. The results showed that the adsorption of malachite green onto rice husks followed pseudo-second-order model with a determination coefficient of 0.986. This work has revealed that rice husks have a great potential to sequester cationic dyes from aqueous solutions and therefore it can be utilized to clean contaminated effluents.
文摘A thermo-insensitive pale green leaf mutant (pgl2) was isolated from T-DNA inserted transgenic lines of rice (Oryza sativa L. subsp, japonica cv. Nipponbare). Genetic analysis indicated that the phenotype was caused by a recessive mutation in a single nuclear-encoded gene. To map the PGL2gene, an F2 population was constructed by crossing the mutant with Longtefu (Oryza sativa L. subsp, indica). The PGL2 locus was roughly linked to SSR marker RM331 on chromosome 8. To finely map the gene, 14 new InDel markers were developed around the marker, and PGL2 was further mapped to a 2.37 Mb centromeric region. Analysis on chlorophyll contents of leaves showed that there was no obvious difference between the mutant and the wild type in total chlorophyll (Chl) content, while the ratio of Chl a / Chl b in the mutant was only about 1, which was distinctly lower than that in the wild type, suggesting that the PGL2 gene was related to the conversion between Chl a and Chl b. Moreover, the method of primer design around the centromeric region was discussed, which would provide insight into fine mapping of the functional genes in plant centromeres.
文摘The development and dissemination of sawah rice eco-technology in Nigeria and Ghana as prerequisites for the actualization of green revolution in West Africa were described. It showed that the neglect of the eco-technology and the overemphasis of the biotechnology have rendered the ineffective transferability of the green revolution process from Asia to Africa. The sawah eco-technology increases yield up to 5 t/hm2 through bunding and the use of inlet and outlet connecting irrigation and drainage, which enhances effective water control and management, improves the efficiency of fertilizer, improves nitrogen fixation by soil microbes and algae, increases the use of wetlands, improves soil organic matter accumulation, suppresses weed growth, and enhances immune mechanism of rice through nutrient supply. The current experience has therefore established that the technology overcomes the constraints that have limited the realization of green revolution in West Africa.
文摘Adding green tea extract to rice bran oil was expected to improve its oxidative stability,so this study was conducted to investigate oxidative stability of green tea extract-enriched rice bran oil(RBOG) during storage at 60℃ for 15 days compared to rice bran oil(RBO),olive(OL),canola(CN),and grape-seed oil(GS).Acid values did not increase during storage,and the highest value was found for OL.The peroxide values of RBOG,RBO,CN,OL,and GS increased for up to 15 days.The highest average rate constant for the change in peroxide value was found for RBO(0.282).TBARS increased continually during storage of RBOG,RBO,CN,and OL;however,the value increased for up to 9 days and then decreased for GS.The highest average rate constant of change in TBARS was found for CN.Overall,the results suggest that green tea extract improves oxidative stability of rice bran oil.
文摘We studied the effect of agar concentration inmedia on callus induction rate and green plant-let regeneration frequency in rice.Materialswere Fgeneration of indica/indica or indica/japonica,which were 96E76(Hei’e/Zhaiye- qing 8),96E80[(IR 24/Guanglu'ai 4//Zhongnan’ai)/Yifengzao],96E86(Zhong- munong 9/Zhaiyeqing 8).The induction mediaused was M8+2mg/L 2,4-D,and agar con-centrations were 0.6%,0.8%,and 1.0%,respectively.Regeneration media was MS+2mg/L KT+0.5mg/L IAA+0.5mg/LNAA,and agar concentrations were 0.6% and1.0%.Results indicated that the calli induc-
文摘Wild rice is an important resource of usefulgenes to rice breeders. However, low regener-ation frequency is an obstacle to use the valu-able genes. We used desiccation to improve theregeneration frequency and studied the bio-chemical changes of calli of wild rice after des-iccation.Materials used in this experiment werewild species O. rufipogon, O. meyeriana, O.alta, and O. brachyantha. Young panicles(0.1-0. 5 cm in length of the inflorescence)