Genetic resources of lotus (Nelumbo) and their improvement

Lotus(Nelumbo)is one of the top ten flowers in China,which has high ornamental,edible and medicinal value.Lotus has a been cultivated for thousands of years.Through discovery and cultivation,more than 4,000 cultivars have been recorded.However,the information related to lotus breeding is quite scattered,and the related genetic rules and trait formation mechanisms are still poorly understood,which has caused a greater impact on lotus genetic breeding.This article systematically introduces lotus germplasm resources,including wild species and cultivated species,summarizes lotus breeding methods and breeding directions,and focuses on the latest progress in the isolation and functional identification of structural and regulatory genes related to important horticultural traits.Prospects for the protection and utilization of lotus resources,breeding and industrialization are reported.

Tailoring interlayer spacing in MXene cathodes to boost the desalination performance of hybrid capacitive deionization systems

Capacitive deionization(CDI)is a promising technology to satisfy the global need for fresh water,since it can be both economical and sustainable.While two-dimensional transition metal carbides/nitrides(MXenes)exhibit great characteristics for use as CDI electrode materials,their tightly spaced layered structure renders intercalation inefficiency.In this study,the interlayer distance of MXenes is precisely modulated by inserting different quantity of one-dimensional bacterial fibers(BC),forming freestanding MXene/BC composite electrodes.Among the studied samples,MXene/BC-33%electrode with the interlayer spacing of 15.2Åcan achieve an optimized tradeoff among various desalination performance metrics and indicators.The salt adsorption capacity(SAC),the average salt adsorption rate(ASAR),the energy normalized adsorbed salt(ENAS),and the thermodynamic energy efficiency(TEE)of the MXene/BC-33%electrode are improved by 24%,46%,13%,and 66%respectively compared with those of pure MXene electrode.While the insertion of BC improves the ion diffusion pathways and facilitates the intercalation kinetics,the desalination performance decreases when the insertion amount of BC exceeds 40%.This is attributed to the overlarge resistance of the composite and the resulting increased energy consumption.This study reveals the desalination performance tradeoffs of MXene-based electrodes with different interlayer distances and also sheds light on the fundamental ion storage mechanisms of intercalation materials in a CDI desalination system.

Nutrient uptake,physiological responses and growth of tobacco(Nicotiana tabacum L.)in soil under composite salt stress

High soil salinity imposes osmotic stress and ion toxicity in plants,leading to substantial crop yield loss worldwide.Understanding of the quantitative and dynamic physiological responses to composite soil salt stress is limited and needs to be expanded.In this study,physiological,nutritional,and biomass yield parameters of tobacco(Nicotiana tabacum L.)grown in soil with five levels of composite soil salinity(CSS),basal CSS level(control,CK)and 3(T_(1)),6(T_(2)),9(T_(3)),and 12(T_(4))times the basal CSS level,under greenhouse were determined at days 30,60,and 90 after transplanting.Leaf dry biomass significantly(P<0.05)increased at the low salinity levels applied(T_(1) and T_(2))at all three time points,whereas it progressively declined as the CSS level further increased.The leaf physiological and photosynthetic responses were more adversely affected by CSS at the early growth stage(day 30).A path coefficient analysis demonstrated that leaf proline content had the largest direct effect(-0.66),and leaf Cu content had the most significant indirect effect(0.49)on leaf dry biomass of plants.The results suggest that lower CSS levels(T_(1) and T_(2))could stimulate tobacco growth(leaf biomass yield,in particular),and higher leaf proline and Cu levels at the early growth stage may potentially increase the ability of tobacco plants to withstand the adverse effects of salinity,which could be considered for future research and development of salinity management strategies.