Total concentration of heavy metals(Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5 yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Te...Total concentration of heavy metals(Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5 yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Tectona grandis and Dendrocalamus strictus. The data recorded in the present study were compared with other unplanted coal mine spoil colliery, which was around to the study site and adjoining area of dry tropical forest. Among all the heavy metals, the maximum concentration was found for Fe and minimum for Cd. However, among all four species, total concentrations of these heavy metals were recorded maximally in the plantation plots of T. grandis except for Fe, while minimally in A. lebbeck except for Zn, whereas, the maximum concentration of Fe and Zn was in the plantation plots of D. strictus and A. procera. Statistical analysis revealed significant differences due to species for all the heavy metals except Cu. Among four species, A. lebbeck, A. procera and D. strictus showed more efficient for reducing heavy metal concentrations whereas T. grandis was not more effective to reduce heavy metal concentrations in redeveloping soil of mine spoil.展开更多
Two chromium-resistant bacterial strains CrT-1 and CrT-13,which can tolerate K2 CrO4 up to 40 mg·mL-1 on nutrient agar,25 mg·mL-1 K2 CrO4 in nutrient broth,and up to 10 mg·mL-1 in acetate-minimal media,...Two chromium-resistant bacterial strains CrT-1 and CrT-13,which can tolerate K2 CrO4 up to 40 mg·mL-1 on nutrient agar,25 mg·mL-1 K2 CrO4 in nutrient broth,and up to 10 mg·mL-1 in acetate-minimal media,were used in this study.On the basis of 16S rRNA,strain CrT-1 was identified as Ochrobactrum intermedium and CrT-13 as Brevibacterium sp..Uptake of chromate was greater in living cells than in heat-killed cells.Ochrobactrum intermedium CrT-1 reduced 73％ and 41％ of Cr(Ⅵ)while Brevibacterium CrT-13 reduced 62％ and 48％ Cr(Ⅵ) at an initial chromate concentration of 750,and 1500 μg·mL-1,after 96 hours with an inoculum size of 9.6×107 cells·mL-1.Different heavy metals at low concentrations did not affect the reduction potential of
the strains significantly.Ochrobactrum intermedium CrT-1 reduced 84％ and 65％ while Brevibacterium CrT-13 reduced 60％ and 44％ of Cr(Ⅵ)at an initial Cr(Ⅵ)concentration of 250 and 500 μg·mL-1,espectively,in an industrial effluent sample.展开更多
The genetic basis of heterosis was studied through mid-parent, standard variety and better parent for 11 quantitative traits in 17 parental lines and their 10 selected hybrids in rice (Oryza sativa L.).The characters ...The genetic basis of heterosis was studied through mid-parent, standard variety and better parent for 11 quantitative traits in 17 parental lines and their 10 selected hybrids in rice (Oryza sativa L.).The characters were plant height,days to flag leaf initiation, days to first panicle initiation, days to 100% flowering, panicle length,flag leaf length, days to maturity, number of fertile spikelet/panicle, number of effective tillers/hill, grain yield/10-hill, and 1000-grain weight.In general the hybrids performed significantly better than the respective parents.Significant heterosis was observed for most of the studied characters. Among the 10 hybrids, four hybrids viz., 17A×45R,25A×37R,27A×39R,31A×47R,and 35A×47R showed highest heterosis in 10-hill grain yield/10-hill. Inbreeding depression of F2 progeny was also studied for 11 characters of 10 hybrids.Both positive and negative inbreeding depression were found in many crosses for the studied characters,but none was found significant. Selection of good parents was found to be the most important for developing high yielding hybrid rice varieties.展开更多
The cyanobacteria and physico chemical environments of six tropical fresh water lakes of Udaipur, India were investigated. These lakes receive varying nutrient inputs from different sources. Altogether 51 species of ...The cyanobacteria and physico chemical environments of six tropical fresh water lakes of Udaipur, India were investigated. These lakes receive varying nutrient inputs from different sources. Altogether 51 species of cyanobacteria were recorded. Species composition varied between lakes and between seasons. Lake VI (Baghdara), which receives nutrients from natural sources only, differed considerably from the others in water chemistry and composition of dominant species. Lake II (Swaroop Sagar), eutrophied due to sewage inputs, was species poor. Non diazotrophs, represented by 27 species, dominated during summer. With few exceptions, N 2 fixing species, both heterocystous and unicellular diazotrophs (represented by 24 species), were dominant during winter. Microcystis aeruginosa, Phormidium sp. and Anabaena flos aque were the dominant taxa of lakes characterized by sewage eutrophication. The study shows that both species diversity and community composition were affected by water chemistry.展开更多
Ten crosses involving seven parents crossed in line ×tester design were studied for main stem height.plant-1,main stem leaves.plant-1,stems.plant-1,plant weight.plant-1,average tuber weight.plant-1 and tuber dry ...Ten crosses involving seven parents crossed in line ×tester design were studied for main stem height.plant-1,main stem leaves.plant-1,stems.plant-1,plant weight.plant-1,average tuber weight.plant-1 and tuber dry matter %in F1 generation.The additive gene action was found to be more important for the characters,main stem height.plant-1,main stem leaves.plant-1,stems.plant-1,plant weight.plant-1,and average tuber weight.plant-1.Among seven parents,Lal-silbilati,Lalpakri and Ausha were good combiners for the characters,main stem height.plant-1,main stem leaves.plant-1andaverage tuber weight.plant-1,respectively.For average tuber weight.plant-1,the crosses Patnae/TPS-67 and Lalpakri/TPS-13 showed significant positive specific combining ability effects.Ausha/TPS-67 showed significant positive specific com-bining ability effects for main stem leaves.plant-1.展开更多
In the present study, we evaluated the genetic diversity of Panax notoginseng F H Chen, a domesticated species, and P. stipuleanatus H T Tsai et K M Feng, an endangered wild species in southeastern Yunnan and adjacent...In the present study, we evaluated the genetic diversity of Panax notoginseng F H Chen, a domesticated species, and P. stipuleanatus H T Tsai et K M Feng, an endangered wild species in southeastern Yunnan and adjacent areas in Vietnam, using sequences of the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA and amplified fragment length polymorphism (AFLP) markers. Twenty-four accessions from three plantations of P. notoginseng and 51 samples from eight populations of P. stipuleanatus were assayed. A total of 694 bp of partial sequences of 18S, ITS 1, 5.8S, ITS2, and partial sequences of 26S were obtained. No sequence variation was detected within P. notoginseng and nine sites (1.30%) were variable in P. stipuleanatus. Two-thirds of the variable sites were found between Langqiao and other populations. In P. notoginseng, four pairs of AFLP primer combinations generated 312 bands, of which 240 (76.9%) were polymorphic and 60.15% of the polymorphisms were harbored within plantations. Approximately 41.0% and 66.9% of bands were polymorphic in population D7 and 5589, respectively. In P.stipuleanatus, the same four primer combinations produced 346 bands, of which 334 (96.5%) were polymorphic and approximately 62.14% of polymorphisms were maintained within populations. Considerable variations were observed. The percentage of polymorphic bands ranged from 50.2% to 84.9% and the average over populations was 70.9%. Cluster analysis did not show correlation of genetic differentiation with the distinctive leaf morphology of P. stipuleanatus (i.e. one form with bipinnatifid leaflets and the other with undivided leaflets). Because over 40% of genetic variations were maintained among populations and because of the very restricted distribution of P. stipuleanatus, all natural populations of this species should be conserved in situ. Considering that there are variations in P. notoginseng within and among plantations, we suggest establishing a genetic resource conservation garden or reintroducing P. notoginseng into its native habitats in southwestern China. Such reintroduction should be carefully executed after large-scale screening of genetic variation within the species.展开更多
文摘Total concentration of heavy metals(Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5 yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Tectona grandis and Dendrocalamus strictus. The data recorded in the present study were compared with other unplanted coal mine spoil colliery, which was around to the study site and adjoining area of dry tropical forest. Among all the heavy metals, the maximum concentration was found for Fe and minimum for Cd. However, among all four species, total concentrations of these heavy metals were recorded maximally in the plantation plots of T. grandis except for Fe, while minimally in A. lebbeck except for Zn, whereas, the maximum concentration of Fe and Zn was in the plantation plots of D. strictus and A. procera. Statistical analysis revealed significant differences due to species for all the heavy metals except Cu. Among four species, A. lebbeck, A. procera and D. strictus showed more efficient for reducing heavy metal concentrations whereas T. grandis was not more effective to reduce heavy metal concentrations in redeveloping soil of mine spoil.
文摘Two chromium-resistant bacterial strains CrT-1 and CrT-13,which can tolerate K2 CrO4 up to 40 mg·mL-1 on nutrient agar,25 mg·mL-1 K2 CrO4 in nutrient broth,and up to 10 mg·mL-1 in acetate-minimal media,were used in this study.On the basis of 16S rRNA,strain CrT-1 was identified as Ochrobactrum intermedium and CrT-13 as Brevibacterium sp..Uptake of chromate was greater in living cells than in heat-killed cells.Ochrobactrum intermedium CrT-1 reduced 73％ and 41％ of Cr(Ⅵ)while Brevibacterium CrT-13 reduced 62％ and 48％ Cr(Ⅵ) at an initial chromate concentration of 750,and 1500 μg·mL-1,after 96 hours with an inoculum size of 9.6×107 cells·mL-1.Different heavy metals at low concentrations did not affect the reduction potential of
the strains significantly.Ochrobactrum intermedium CrT-1 reduced 84％ and 65％ while Brevibacterium CrT-13 reduced 60％ and 44％ of Cr(Ⅵ)at an initial Cr(Ⅵ)concentration of 250 and 500 μg·mL-1,espectively,in an industrial effluent sample.
文摘The genetic basis of heterosis was studied through mid-parent, standard variety and better parent for 11 quantitative traits in 17 parental lines and their 10 selected hybrids in rice (Oryza sativa L.).The characters were plant height,days to flag leaf initiation, days to first panicle initiation, days to 100% flowering, panicle length,flag leaf length, days to maturity, number of fertile spikelet/panicle, number of effective tillers/hill, grain yield/10-hill, and 1000-grain weight.In general the hybrids performed significantly better than the respective parents.Significant heterosis was observed for most of the studied characters. Among the 10 hybrids, four hybrids viz., 17A×45R,25A×37R,27A×39R,31A×47R,and 35A×47R showed highest heterosis in 10-hill grain yield/10-hill. Inbreeding depression of F2 progeny was also studied for 11 characters of 10 hybrids.Both positive and negative inbreeding depression were found in many crosses for the studied characters,but none was found significant. Selection of good parents was found to be the most important for developing high yielding hybrid rice varieties.
文摘The cyanobacteria and physico chemical environments of six tropical fresh water lakes of Udaipur, India were investigated. These lakes receive varying nutrient inputs from different sources. Altogether 51 species of cyanobacteria were recorded. Species composition varied between lakes and between seasons. Lake VI (Baghdara), which receives nutrients from natural sources only, differed considerably from the others in water chemistry and composition of dominant species. Lake II (Swaroop Sagar), eutrophied due to sewage inputs, was species poor. Non diazotrophs, represented by 27 species, dominated during summer. With few exceptions, N 2 fixing species, both heterocystous and unicellular diazotrophs (represented by 24 species), were dominant during winter. Microcystis aeruginosa, Phormidium sp. and Anabaena flos aque were the dominant taxa of lakes characterized by sewage eutrophication. The study shows that both species diversity and community composition were affected by water chemistry.
文摘Ten crosses involving seven parents crossed in line ×tester design were studied for main stem height.plant-1,main stem leaves.plant-1,stems.plant-1,plant weight.plant-1,average tuber weight.plant-1 and tuber dry matter %in F1 generation.The additive gene action was found to be more important for the characters,main stem height.plant-1,main stem leaves.plant-1,stems.plant-1,plant weight.plant-1,and average tuber weight.plant-1.Among seven parents,Lal-silbilati,Lalpakri and Ausha were good combiners for the characters,main stem height.plant-1,main stem leaves.plant-1andaverage tuber weight.plant-1,respectively.For average tuber weight.plant-1,the crosses Patnae/TPS-67 and Lalpakri/TPS-13 showed significant positive specific combining ability effects.Ausha/TPS-67 showed significant positive specific com-bining ability effects for main stem leaves.plant-1.
基金国家重点基础研究发展计划(973计划)，中国科学院知识创新工程项目，国家自然科学基金，the Outstanding Overseas Chinese Grant of the Chinese Academy of Sciences, and the U.S. National Science Foundation Supported by，the U.S. National Science Foundation
文摘In the present study, we evaluated the genetic diversity of Panax notoginseng F H Chen, a domesticated species, and P. stipuleanatus H T Tsai et K M Feng, an endangered wild species in southeastern Yunnan and adjacent areas in Vietnam, using sequences of the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA and amplified fragment length polymorphism (AFLP) markers. Twenty-four accessions from three plantations of P. notoginseng and 51 samples from eight populations of P. stipuleanatus were assayed. A total of 694 bp of partial sequences of 18S, ITS 1, 5.8S, ITS2, and partial sequences of 26S were obtained. No sequence variation was detected within P. notoginseng and nine sites (1.30%) were variable in P. stipuleanatus. Two-thirds of the variable sites were found between Langqiao and other populations. In P. notoginseng, four pairs of AFLP primer combinations generated 312 bands, of which 240 (76.9%) were polymorphic and 60.15% of the polymorphisms were harbored within plantations. Approximately 41.0% and 66.9% of bands were polymorphic in population D7 and 5589, respectively. In P.stipuleanatus, the same four primer combinations produced 346 bands, of which 334 (96.5%) were polymorphic and approximately 62.14% of polymorphisms were maintained within populations. Considerable variations were observed. The percentage of polymorphic bands ranged from 50.2% to 84.9% and the average over populations was 70.9%. Cluster analysis did not show correlation of genetic differentiation with the distinctive leaf morphology of P. stipuleanatus (i.e. one form with bipinnatifid leaflets and the other with undivided leaflets). Because over 40% of genetic variations were maintained among populations and because of the very restricted distribution of P. stipuleanatus, all natural populations of this species should be conserved in situ. Considering that there are variations in P. notoginseng within and among plantations, we suggest establishing a genetic resource conservation garden or reintroducing P. notoginseng into its native habitats in southwestern China. Such reintroduction should be carefully executed after large-scale screening of genetic variation within the species.
