The clovers that comprise Trifolium genus are naturalized in the subtropical and tropical zones in China. They are valuable bioresources as important green manures and pasture grass, which contribute biologically fixe...The clovers that comprise Trifolium genus are naturalized in the subtropical and tropical zones in China. They are valuable bioresources as important green manures and pasture grass, which contribute biologically fixed dinitrogen （N2） and provide nutrition to farming systems. However, there are very few effective strains available for inoculant production and there is little information available about symbiotic rhizobia in Chinese legume clover root nodules. In this study, 139 root nodule bacteria were isolated from two clover species （Trifolium repens and Trifolium pretense） growing in the subtropical and temperate regions of China, 16S rRNA gene sequence analysis, BOX-PCR, whole cell protein SDS-PAGE, and nodulation tests were performed to characterize these strains. The results showed that phenotypic and genetic diversities among 139 isolates were large, with 83 protein patterns and 66 BOX- AIR profiles, respectively. The rhizobial strains were first divided into two large phenotypic protein groups. The sequencing strains representing the two groups were related to Rhizobium leguminosarum USDA2370T and R. sophorae CCBAU03386T and had 99.6%-100% similarities. The phylogeny specificity of the rhizobia from clover was elucidated, while showed a large variation in the fingerprints of the phenotypes and genotypes and genetic diversity was high （revealed by Shannon diversity index, H＇）. The rhizobial isolates from subtropical regions, such as Anhui Province, Yunnan Province and Hubei Province, had higher diversities than those from temperate areas, such as Hebei Province and Shanxi Province, which could be used to identify rhizobial strains from clover and screen efficient inoculum strains. A number of diverse rhizobial strains had been identified and a pool of currently available clover rhizobial strains were increased. This would ultimately increase the likelihood of identifying more efficient strains suited for developing a successful inoculation strategy for the production of white clover.展开更多
The suitability of models for describing the clonal growth of Trifolium repens population was discussed. The results showed that deterministic models were inadequate for describing its clonal growth, but the diffusion...The suitability of models for describing the clonal growth of Trifolium repens population was discussed. The results showed that deterministic models were inadequate for describing its clonal growth, but the diffusion models and the randomwalk models suited for the clonal growth characteristics of the population. And it was found that random-walk models were better than diffusion models for describing a population in an environment with rich natural resources, and the latter was better in a poor environment.展开更多
Resource sharing in the different parts of the clonal white clover plant (Trifolium repens L.) was investigated in this study. The results showed that the integration of water and nitrogen metabolism occured among par...Resource sharing in the different parts of the clonal white clover plant (Trifolium repens L.) was investigated in this study. The results showed that the integration of water and nitrogen metabolism occured among parental, young and old branches of a plant when water passed through its stolons. Under the sufficient supply of light, water and nutrients from soil the newly developed branches showed similar capacity in taking in sufficient water and nitrogen to that of old branches. The development of the new branches did not affect the growth of the old and parental branches attached. The results also indicated that energy values in roots was significantly related with plant age, however, the energy values were various in the different parts of a plant.展开更多
Trifolium repens L.served as the experimental subject to investigate the effects of varying concentrations of Hg and Pb stress on seed germination,thereby providing a theoretical foundation for further research on the...Trifolium repens L.served as the experimental subject to investigate the effects of varying concentrations of Hg and Pb stress on seed germination,thereby providing a theoretical foundation for further research on the remediation of heavy-metal-contaminated soil utilizing this species.The findings indicated that the germination energy,germination percentage and germination index under 10 mg·L^(-1) Hg treatment were significantly elevated compared to the CK group(P<0.05),with a remarkable germination percentage reaching 97%.Conversely,the germination energy,germination percentage,germination index,vigor index,radicle length,and fresh weight under 200 mg·L^(-1) Hg treatment were substantially lower than those of the CK group(P<0.05).At 100 mg·L^(-1) Pb treatment,the radicle length of Trifolium repens L.was significantly higher than that of the CK group,whereas the 500 mg·L^(-1) Pb treatment resulted in a notable reduction in seed germination energy,germination percentage,germination index,and vigor index compared to the CK group(P<0.05).Under Hg and Pb stress,the activities of superoxide dismutase(SOD)and peroxidase(POD)initially increased before declining,while catalase(CAT)activity rose with increasing heavy metal concentrations.Ultrastructure observations of the radicle revealed that 200 mg·L^(-1) Hg inflicted considerable damage to the radicle of Trifolium repens L.,and 500 mg·L^(-1) Pb also harmed root cells,resulting in the dissolution of nucleoli within the nuclear membrane.The results demonstrated that low concentrations of heavy metal also promoted the germination of Trifolium repens L.,while both 200 mg·L^(-1) Hg and 500 mg·L^(-1) Pb significantly inhibited its germination.展开更多
基金Supported by the National Natural Science Foundation of China(30970005,30370051,and 31360003)the Key Bioengineering Discipline of Hebei Province(1050-5030023)+2 种基金the Public Service Sectors(Agriculture)Research and Special Funds(201303061)the Key Discipline Project for Biotechnology of Hebei ProvinceHebei University Construction Project for Comprehensive Strength Promotion of Midwest Colleges and Universities
文摘The clovers that comprise Trifolium genus are naturalized in the subtropical and tropical zones in China. They are valuable bioresources as important green manures and pasture grass, which contribute biologically fixed dinitrogen （N2） and provide nutrition to farming systems. However, there are very few effective strains available for inoculant production and there is little information available about symbiotic rhizobia in Chinese legume clover root nodules. In this study, 139 root nodule bacteria were isolated from two clover species （Trifolium repens and Trifolium pretense） growing in the subtropical and temperate regions of China, 16S rRNA gene sequence analysis, BOX-PCR, whole cell protein SDS-PAGE, and nodulation tests were performed to characterize these strains. The results showed that phenotypic and genetic diversities among 139 isolates were large, with 83 protein patterns and 66 BOX- AIR profiles, respectively. The rhizobial strains were first divided into two large phenotypic protein groups. The sequencing strains representing the two groups were related to Rhizobium leguminosarum USDA2370T and R. sophorae CCBAU03386T and had 99.6%-100% similarities. The phylogeny specificity of the rhizobia from clover was elucidated, while showed a large variation in the fingerprints of the phenotypes and genotypes and genetic diversity was high （revealed by Shannon diversity index, H＇）. The rhizobial isolates from subtropical regions, such as Anhui Province, Yunnan Province and Hubei Province, had higher diversities than those from temperate areas, such as Hebei Province and Shanxi Province, which could be used to identify rhizobial strains from clover and screen efficient inoculum strains. A number of diverse rhizobial strains had been identified and a pool of currently available clover rhizobial strains were increased. This would ultimately increase the likelihood of identifying more efficient strains suited for developing a successful inoculation strategy for the production of white clover.
文摘The suitability of models for describing the clonal growth of Trifolium repens population was discussed. The results showed that deterministic models were inadequate for describing its clonal growth, but the diffusion models and the randomwalk models suited for the clonal growth characteristics of the population. And it was found that random-walk models were better than diffusion models for describing a population in an environment with rich natural resources, and the latter was better in a poor environment.
文摘Resource sharing in the different parts of the clonal white clover plant (Trifolium repens L.) was investigated in this study. The results showed that the integration of water and nitrogen metabolism occured among parental, young and old branches of a plant when water passed through its stolons. Under the sufficient supply of light, water and nutrients from soil the newly developed branches showed similar capacity in taking in sufficient water and nitrogen to that of old branches. The development of the new branches did not affect the growth of the old and parental branches attached. The results also indicated that energy values in roots was significantly related with plant age, however, the energy values were various in the different parts of a plant.
基金Supported by the National Grass Industry Technology Innovation Center,Major Innovation Platform Construction Project(Topic CCPTZX2023N04CCPTZX2024GJ01–1–2)+2 种基金the National Key Research and Development Program of China(2023YFD1200302)the Joint Key Project of Natural Science Foundation of Heilongjiang Province(ZL2024C018)the National Natural Science Foundation of China(32471760)。
文摘Trifolium repens L.served as the experimental subject to investigate the effects of varying concentrations of Hg and Pb stress on seed germination,thereby providing a theoretical foundation for further research on the remediation of heavy-metal-contaminated soil utilizing this species.The findings indicated that the germination energy,germination percentage and germination index under 10 mg·L^(-1) Hg treatment were significantly elevated compared to the CK group(P<0.05),with a remarkable germination percentage reaching 97%.Conversely,the germination energy,germination percentage,germination index,vigor index,radicle length,and fresh weight under 200 mg·L^(-1) Hg treatment were substantially lower than those of the CK group(P<0.05).At 100 mg·L^(-1) Pb treatment,the radicle length of Trifolium repens L.was significantly higher than that of the CK group,whereas the 500 mg·L^(-1) Pb treatment resulted in a notable reduction in seed germination energy,germination percentage,germination index,and vigor index compared to the CK group(P<0.05).Under Hg and Pb stress,the activities of superoxide dismutase(SOD)and peroxidase(POD)initially increased before declining,while catalase(CAT)activity rose with increasing heavy metal concentrations.Ultrastructure observations of the radicle revealed that 200 mg·L^(-1) Hg inflicted considerable damage to the radicle of Trifolium repens L.,and 500 mg·L^(-1) Pb also harmed root cells,resulting in the dissolution of nucleoli within the nuclear membrane.The results demonstrated that low concentrations of heavy metal also promoted the germination of Trifolium repens L.,while both 200 mg·L^(-1) Hg and 500 mg·L^(-1) Pb significantly inhibited its germination.
