Study On Biological Characteristics And Cultivation Techniques Of Three Species Of Carex

Using Carex humilis,C.subpediformis,and C.meyeriana,which belong to the Carex genus of the Cyperaceae family,as test materials,field experiments and greenhouse pot experiments were conducted to study their phenological and morphological characteristics,explore their growth and development patterns,and comprehensively evaluate their drought and salt tolerance.And study the effects of different germination methods on the germination of three species of Carex seeds,as well as the effects of separate cultivation on the growth and development of three species of Carex.The main results are as follows:1.The three species of Carex all turn green in the middle and late March,with a green period of 233-248 days.The green period of C.humilis is shorter than that of C.subpediformis and C.meyeriana.The flowering stage and seed maturity stage of C.humilis are earlier than those of C.meyeriana.All three species of Carex can overwinter normally and have no dormancy in summer.The plant height of the C.meyeriana is higher than that of the C.subpediformis and the C.humilis.The leaves of C.humilis and C.subpediformis are relatively soft,while the leaves of C.meyeriana are relatively rough,and the leaves of C.meyeriana are wider than those of C.humilis and C.subpediformis.The three species of Carex flower first and then expand their leaves.The flower panicles follow a male female sequence,with yellow terminal male panicles and white lateral female panicles.The number of stigmas is all 3.The anthers and filaments of C.humilis are longer than those of C.subpediformis and C.meyeriana,while the stigma length is lower than that of the other two species of Carex.In addition,the seeds of C.humilis and C.subpediformis are dark brown,while the seeds of C.meyeriana are brown.The weight of 1000 seeds of C.meyeriana is greater than that of C.subpediformis and C.humilis.According to the type of tillering,the three species of Carex are all dense clumps,which are typical clonal plants with long rhizomes,and their rhizome characteristics tend to be guerrilla type.The comprehensive evaluation scores of ornamental traits of the three Carex species were obtained by the five-level scoring method,and the order from high to low was C.humilis>C.subpediformis>C.meyeriana.2.With the prolongation of drought stress time,the plant height and shoot dry weight of the three species of Carex showed a downward trend,and there were significant differences among the treatments.Chlorophyll content showed a trend of first increasing and then decreasing,and there was no significant difference between the treatments of C.subpediformis and CK,while there was a significant difference between the treatments of C.meyeriana and CK.The content of malondialdehyde（MDA）showed a trend of increasing,decreasing,and increasing,and was significantly different from CK at 20 days of stress.The superoxide dismutase（SOD）showed a trend of increasing first and then decreasing,with the highest value of C.humilis and C.subpediformis at 15 days of stress,and the highest value of C.meyeriana at 10 days of stress.The content of free proline（Pro）of C.subpediformis and C.meyeriana increased at first and then decreased,while the content of C.humilis gradually increased.There were significant differences between the three species of Carex and CK at each treatment period.Using the fuzzy mathematics membership function analysis method,the drought resistance of three species of Carex was obtained,ranking from large to small in the order of C.subpediformis>C.humilis>C.meyeriana.3.With the increase of salt concentration,the plant height and above-ground dry weight of three species of Carex showed a downward trend,and the plant height of C.humilis decreased significantly,which were significantly different from CK in each treatment.When the concentration of NaCl was 50 mmol·L^-1,there was no significant difference between the plant height of C.subpediformis and C.meyeriana and CK,but when the concentration was higher than that,both were significantly different from CK.The dry weight of three species of Carex was significantly different from CK under different stress concentrations.Chlorophyll content showed a trend of increasing first and then decreasing,and C.humilis and C.meyeriana reached the maximum value at a stress concentration of 50 mmol·L^-1.The content of malondialdehyde（MDA）showed a gradually increasing trend and the difference was significant compared with CK.The superoxide dismutase（SOD）showed a trend of increasing first and then decreasing,with the highest values of C.humilis and C.meyeriana at a stress concentration of 50 mmol·L^-1,and C.subpediformis reaching a maximum value at a stress concentration of 100 mmol·L^-1.The content of free proline（Pro）in the three species of Carex showed a trend of increasing first and then decreasing.There were significant differences between C.subpediformis and C.meyeriana at each concentration,while there was no significant difference between C.humilis and CK at300 mmol·L^-1.Using the fuzzy mathematics membership function analysis method,the salt tolerance of three species of Carex was obtained,ranking from large to small as follows:C.subpediformis>C.meyeriana>C.humilis.The salt tolerance thresholds of the three species of Carex were 108.53 mmol·L^-1,153.59 mmol·L^-1,and 135.74 mmol·L^-1,respectively.In accordance with the data obtained by the membership function analysis method,the salt tolerance of the C.subpediformis was better than that of the C.meyeriana and C.humilis.4.Gibberellin treatment and low temperature stratification treatment can promote seed germination in different degrees,and low temperature stratification treatment is the most effective.When the concentration of gibberellin was 200mg·L^-1and 400mg·L^-1respectively,the seed germination rate and germination index of C.humilis and C.subpediformis increased to35.08%,73.24%and 3.17 times,15.51 times respectively,which had no significant effect on the seed germination of C.meyeriana.When the low temperature stratification treatment was 60days,the seed germination rate of C.humilis and C.subpediformis increased to 35.33%and78.33%respectively,while when the treatment was 30 days,the seed germination rate and germination index of C.meyeriana increased to 74.33%and 23.78 times respectively.5.The tiller ability and expansion rate of C.subpediformis were better than those of C.humilis and C.meyeriana,and the root-shoot ratio of C.meyeriana was higher than that of C.subpediformis and C.humilis in each observation period,which formed a significant difference.When the number of shoots was 5 or 10 and the planting interval was 30cm×30cm,the increase of plant height,expansion rate,tillering number and root-shoot ratio reached the maximum.However,the growth and development of the three species of Carex were limited when the number of sprout was increased and the spacing between plants was enlarged and decreased,suggesting that 5 or 10 sprout numbers and the spacing between plants was 30cm.When the planting depth was 6cm,the root-shoot ratio increased better and the difference was significant with the planting depth of 4cm and 8cm.By studying the biological characteristics and cultivation techniques of three species of Carex,the growth and development characteristics of three species of Carex were understood,which provided theoretical basis and data support for the cultivation and application of Carex species,and laid a foundation for the introduction and development of wild Carex species in the future.