Main Varieties of Ornamental Peaches and Their Application in Shijiazhuang City

In order to comprehensively understand the varieties of ornamental peaches in Shijiazhuang City and their application status,a systematic survey was conducted on the ornamental peach varieties in Shijiazhuang.The results showed that there were 27 ornamental peach varieties in Shijiazhuang,including 1 species of mountain peach and 26 species of ornamental peaches.According to the systematic observation and analysis of their branch types,flower types,flower colors,and application frequency,the ornamental peaches in Shijiazhuang City belonged to the ecological northern peaches,which were characterized by early flowering phase,long flowering period,and rich flower color.Then problems existing in the application of ornamental peaches were explored,and corresponding solutions and suggestions were proposed.

Morphology of somatic embryogenesis and plantlet formation in tissue cultures of lantern tree (Koelreuteria bipinnata var.integrifoliola)

Somatic embryogenesis ofKoelreuteria bipinnata var. integrifoliola was observed, plantlet formation in different types of somatic embryos was studied and the effect of abnormal embryos on plantlet formation was identified. Results show that somatic embryos of K. bipinnata var. integrifoliola include normal embryos, embryos with abnormal cotyledons, vitrified embryos, albino embryos, secondary embryos, linked embryos, embryos with abnormal growing points and embryos with expanding hypocotyl. After 40 d of callus culture, the response of normal somatic embryos from K. bipinnata var. integrifoliola was 26.7%, embryos with abnormal cotyledon 30.3% while other types of somatic embryos were below the 20% level. Most of normal embryos developed into plantlets and plantlet formation reached 94.9%. But the percentage of plantlet formation decreased apparently in abnormal embryos： the number of embryos with abnormal cotyledon declined to 76.1%, that of linked embryos to 47.4% and other types of abnormal embryos to below the 20% level. Albino embryos and embryos with abnormal growing point did not develop at all into plantlets. Embryos with abnormal cotyledons, linked embryos and embryos with abnormal growing points were observed during early stages of somatic embryogenesis, but vitrified, secondary and albino embryos and calli of embryos were observed at later stages. Increasing sucrose concentrations can decrease the occurrence of vitrified embryos, but the number of albino embryos decreased with an in- creasing in sucrose concentration.

Ectomycorrhizal fungi and dark septate endophyte inoculation improve growth and tolerance of Pinus tabulaeformis under cadmium stress

Forest trees can establish symbiotic associations with dark septate endophytes(DSEs)and ectomycorrhizal fungi(ECMF)simultaneously.However,the combined effects of these two fungi on the growth and cadmium(Cd)tolerance of host plants remain largely unexplored.To address this knowledge gap,a pot experiment was conducted to examine the effects of the interaction between an ECMF strain(Suillus granulatus)and a DSE strain(Pseudopyrenochaeta sp.)on Pinus tabulaeformis under Cd stress,by assessing plant growth and physiological parameters,nutrient uptake,and soil properties.Notably,the colonization rates of both fungal strains were found to increase in response to Cd stress,with the extent of this increase being influenced by the specific fungal species and the Cd level in the soil.Compared to the non-inoculation treatment,single inoculation with fungal strain resulted in enhanced biomass,root development,and nutrient contents in P.tabulaeformis seedlings under Cd stress.Furthermore,a synergistic effect was observed when these seedlings were co-inoculated with S.granulatus and Pseudopyrenochaeta sp.,as indicated by significantly greater measurements in various indicators compared to both the single and non-inoculation treatments.Fungal inoculation effectively regulated the antioxidant defense responses and photosynthesis of P.tabulaeformis seedlings subjected to Cd stress,particularly in the co-inoculation treatment.In addition,fungal inoculation facilitated the Cd accumulation in P.tabulaeformis,suggesting a promising potential for the implementation of bioremediation strategies in the areas contaminated with heavy metals.The findings from this study indicate that the utilization of root symbiotic fungi obtained from stress environments could potentially enhance the growth performance and tolerance of P.tabulaeformis towards heavy metals,and co-inoculation of both fungal groups may result in even more pronounced synergistic effects on the overall fitness of the plant.

Research Progress on Plant Anti-Freeze Proteins

Plant antifreeze proteins(AFPs)are special proteins that can protect plant cells from ice crystal damage in low-temperature environments,and they play a crucial role in the process of plants adapting to cold environ-ments.Proteins with these characteristics have been found infish living in cold regions,as well as many plants and insects.Although research on plant AFPs started relatively late,their application prospects are broad,leading to the attention of many researchers to the isolation,cloning,and genetic improvement of plant AFP genes.Studies have found that the distribution of AFPs in different species seems to be the result of independent evolu-tionary events.Unlike the AFPs found infish and insects,plant AFPs have multiple hydrophilic ice-binding domains,and their recrystallization inhibition activity is about 10–100 times that offish and insect AFPs.Although different plant AFPs have the characteristics of low TH and high RI,their DNA and amino acid sequences are completely different,with small homology.With in-depth research and analysis of the character-istics and mechanisms of plant AFPs,not only has our understanding of plant antifreeze mechanisms been enriched,but it can also be used to improve crop varieties and enhance their freezing tolerance,yield,and quality through genetic engineering.In addition,the study of plant AFPs also contributes to our understanding of freezing resistance mechanisms in other organisms and provides new research directions for thefield of biotech-nology.Therefore,based on the analysis of relevant literature,this article will delve into the concepts,character-istics,research methods,and mechanisms of plant AFPs,summarize the latest research progress and application prospects of AFPs in plant,and provide prospects for the future development of AFP gene research.

In vitro culture of immature embryos from Koelreuteria bipinnata var. integrifoliola

For the mass production of Koelreuteria bipinnata var. integrifoliola with selected, hybrid or genetically engineered genotypes, one potentially desirable propagation strategy is based on embryo culture. The immature embryo development in vitro from K. bipinnata var. integrifoliola was studied under different conditions of embryo age, basic culture media and plant growth regulators. The results show that： 1） germination rate of grade 3 embryos in immature seeds with 0.6-0.8 cm diameter was 98.9%. The germination rate of grade 2 embryos in immature seeds with 0.4-0.6 cm diameter was 77,8% and the germination rate of grade 1 embryos in immature seeds with 0.4 cm diameter was 15.6%. 2） The amounts of macroelements in MS medium had no clear effect on the germination rate of immature grade 3 embryos and had a modest effect on plantlet growth, where the best medium was MS or 1/2 MS. The rates were all greater than 90%. 3） The germination rate of grade 3 embryos was greater than 87% when the medium contained a low concentration of NAA or no plant growth regulators at all and decreased markedly when BAP alone or BAP and NAA together were added to the media. We suggest that in vitro culture of immature embryos from K. bipinnata vat. integrifoliola can be enhanced when a small amount of plant growth regulators is added. The addition of BAP has an adverse reaction to the germination and development of immature embryos.

thylenediurea(EDU)effects on Japanese larch:an one growing season experiment with simulated regenerating communities and a four growing season application to individual saplings

Japanese larch(Larix kaempferi(Lamb.)Carr.)and its hybrid are economically important coniferous trees widely grown in the Northern Hemisphere.Ground-level ozone(O_(3))concentrations have increased since the preindustrial era,and research projects showed that Japanese larch is susceptible to elevated O_(3)exposures.Therefore,methodologies are needed to(1)protect Japanese larch against O_(3)damage and(2)conduct biomonitoring of O_(3)in Japanese larch forests and,thus,monitor O_(3)risks to Japanese larch.For the first time,this study evaluates whether the synthetic chemical ethylenediurea(EDU)can protect Japanese larch against O_(3)damage,in two independent experiments.In the first experiment,seedling communities,simulating natural regeneration,were treated with EDU(0,100,200,and 400 mg L^(-1))and exposed to either ambient or elevated O_(3)in a growing season.In the second experiment,individually-grown saplings were treated with EDU(0,200 and 400 mg L-1)and exposed to ambient O_(3)in two growing seasons and to elevated O_(3)in the succeeding two growing seasons.The two experiments revealed that EDU concentrations of 200-400 mg L^(-1)could protect Japanese larch seedling communities and individual saplings against O_(3)-induced inhibition of growth and productivity.However,EDU concentrations≤200 mg L^(-1)did offer only partial protection when seedling communities were coping with higher level of O_(3)-induced stress,and only 400 mg EDU L^(-1)fully protected communities under higher stress.Therefore,we conclude that among the concentrations tested the concentration offering maximum protection to Japanese larch plants under high competition and O_(3)-induced stress is that of 400 mg EDU L^(-1).The results of this study can provide a valuable resource of information for applied forestry in an O_(3)-polluted world.