[ Objective] This study aimed to investigate the tissue culture and propagation technology in Tagetes patu/a L. [ Method] By using tissue culture tech- nology, different mass fractions of 6-BA and NAA were added to MS...[ Objective] This study aimed to investigate the tissue culture and propagation technology in Tagetes patu/a L. [ Method] By using tissue culture tech- nology, different mass fractions of 6-BA and NAA were added to MS medium to compare the effect of different culture medium on the rapid propagation of T. patu/a L. [Result] Shoot tips or stem segments of T. patu/a L. were used as explants for tissue culture with an appropriate sterilization time of 8 min; differentiation effect of shoot tips was better than that of stem segments; callus generation rate was high with the high content of growth regulators; MS medium containing O. 1 mg/L NAA and 1.5 rag/L 6-BA was used for subculture proliferation with a subculture period of 4 weeks; rooting rate of plantlet was the maximum （97%） in 1/2MS medium containing 0.2 mg/L NAA, and the root system was relatively developed. [ Conclusion] This study provided technical support for the industrialized seedling breeding of T. patula L.展开更多
Urban greenspaces enhance human well-being and promote sustainable development in rapidly urbanizing regions by delivering vital ecosystem services,including cooling,air purification,and recreation.In China,where citi...Urban greenspaces enhance human well-being and promote sustainable development in rapidly urbanizing regions by delivering vital ecosystem services,including cooling,air purification,and recreation.In China,where cities accommodate a large share of the population amid persistent environmental pressures,disparities in greenspace exposure pose a major obstacle to equitable access;these disparities arise from geographic,climatic,socioeconomic,and landscape factors.Although awareness of such inequalities is growing,their long-term trajectories,demographic and city-scale patterns,and viable spatial optimization approaches remain largely unexplored.Here we show that greenspace exposure inequality across 246 Chinese cities increased by 25%from 2000 to 2020 and is projected to rise further by 12.2-15.7%by 2050 under middle-of-the-road and fossil-fueled development scenarios,disproportionately affecting older,less-educated women and megacity residents.Geodetector and random forest analyses reveal that this rise results from interactions among greenspace coverage,population density,and patch connectivity,which explain 83.9%of the inequality.A network-based optimization approach that improves patch connectivity—without expanding total greenspace—can reduce disparities by 10.3-20.8%,with greater efficacy in high-inequality cities and among vulnerable populations.Our results highlight how precise landscape interventions can advance social equity in greenspace access,supporting Sustainable Development Goal 11 for inclusive,resilient urban environments.展开更多
文摘[ Objective] This study aimed to investigate the tissue culture and propagation technology in Tagetes patu/a L. [ Method] By using tissue culture tech- nology, different mass fractions of 6-BA and NAA were added to MS medium to compare the effect of different culture medium on the rapid propagation of T. patu/a L. [Result] Shoot tips or stem segments of T. patu/a L. were used as explants for tissue culture with an appropriate sterilization time of 8 min; differentiation effect of shoot tips was better than that of stem segments; callus generation rate was high with the high content of growth regulators; MS medium containing O. 1 mg/L NAA and 1.5 rag/L 6-BA was used for subculture proliferation with a subculture period of 4 weeks; rooting rate of plantlet was the maximum （97%） in 1/2MS medium containing 0.2 mg/L NAA, and the root system was relatively developed. [ Conclusion] This study provided technical support for the industrialized seedling breeding of T. patula L.
基金supported by the National Natural Science Foundation of China(Grant Nos U24A20583,42230510,42271246,42371253).
文摘Urban greenspaces enhance human well-being and promote sustainable development in rapidly urbanizing regions by delivering vital ecosystem services,including cooling,air purification,and recreation.In China,where cities accommodate a large share of the population amid persistent environmental pressures,disparities in greenspace exposure pose a major obstacle to equitable access;these disparities arise from geographic,climatic,socioeconomic,and landscape factors.Although awareness of such inequalities is growing,their long-term trajectories,demographic and city-scale patterns,and viable spatial optimization approaches remain largely unexplored.Here we show that greenspace exposure inequality across 246 Chinese cities increased by 25%from 2000 to 2020 and is projected to rise further by 12.2-15.7%by 2050 under middle-of-the-road and fossil-fueled development scenarios,disproportionately affecting older,less-educated women and megacity residents.Geodetector and random forest analyses reveal that this rise results from interactions among greenspace coverage,population density,and patch connectivity,which explain 83.9%of the inequality.A network-based optimization approach that improves patch connectivity—without expanding total greenspace—can reduce disparities by 10.3-20.8%,with greater efficacy in high-inequality cities and among vulnerable populations.Our results highlight how precise landscape interventions can advance social equity in greenspace access,supporting Sustainable Development Goal 11 for inclusive,resilient urban environments.
