Leguminosae are an important part of terrestrial ecosystems and play a key role in promoting soil nutrient cycling and improving soil properties.However,plant composition and species diversity change rapidly during th...Leguminosae are an important part of terrestrial ecosystems and play a key role in promoting soil nutrient cycling and improving soil properties.However,plant composition and species diversity change rapidly during the process of succession,the effect of leguminosae on soil physical-chemical and biological properties is still unclear.This study investigated the changes in the composition of plant community,vegetation characteristics,soil physical-chemical properties,and soil biological properties on five former farmlands in China,which had been abandoned for 0,5,10,18,and 30 a.Results showed that,with successional time,plant community developed from annual plants to perennial plants,the importance of Leguminosae and Asteraceae significantly increased and decreased,respectively,and the importance of grass increased and then decreased,having a maximum value after 5 a of abandonment.Plant diversity indices increased with successional time,and vegetation coverage and above-and below-ground biomass increased significantly with successional time after 5 a of abandonment.Compared with farmland,30 a of abandonment significantly increased soil nutrient content,but total and available phosphorus decreased with successional time.Changes in plant community composition and vegetation characteristics not only change soil properties and improve soil physical-chemical properties,but also regulate soil biological activity,thus affecting soil nutrient cycling.Among these,Leguminosae have the greatest influence on soil properties,and their importance values and community composition are significantly correlated with soil properties.Therefore,this research provides more scientific guidance for selecting plant species to stabilize soil ecosystem of farmland to grassland in the Loess Plateau,China.展开更多
针对河西绿洲灌区青贮玉米氮肥投入高、水分利用效率低等问题,本研究在减氮条件下,探讨间作豆科饲草对青贮玉米产量及耗水特征的影响,为青贮玉米水分高效利用提供理论依据和技术支撑。试验于2022—2023年在武威绿洲农业综合试验站开展,...针对河西绿洲灌区青贮玉米氮肥投入高、水分利用效率低等问题,本研究在减氮条件下,探讨间作豆科饲草对青贮玉米产量及耗水特征的影响,为青贮玉米水分高效利用提供理论依据和技术支撑。试验于2022—2023年在武威绿洲农业综合试验站开展,设置3个种植模式(M:青贮玉米单作;MH:青贮玉米-秣食豆间作;ML:青贮玉米-拉巴豆间作)和4个施氮水平(N3:360 kg hm^(-2);N2:306 kg hm^(-2);N1:252 kg hm^(-2);N0:0 kg hm^(-2))。结果表明,2种混播模式下N1处理的青贮玉米和豆科饲草干物质积累量较N3显著提高,MH模式下分别提高10.0%和20.5%,ML模式下分别提高16.5%和28.8%。MH模式下N1处理饲草产量与N3差异不显著,但ML模式下较之提高22.4%,且ML模式饲草产量在N1水平下较MH模式提高12.3%。引入豆科饲草可降低间作系统棵间蒸发量,MH、ML模式的棵间蒸发量在N1水平下比M模式相同施氮水平分别降低23.5%、30.0%,但2种模式不同施氮处理间棵间蒸发量差异不显著。青贮玉米间作拉巴豆结合氮肥减施30%可降低蒸散比,较M模式相同施氮水平降低23.0%。间作豆科饲草提高了水分利用效率,MH、ML模式水分利用效率在N1、N2、N3水平下较M模式分别提高43.3%、29.5%、17.9%和51.9%、30.2%、21.2%。其中,以MLN1处理提升幅度最大,较MN3处理水分利用效率提高52.4%。因此,青贮玉米间作豆科饲草结合施氮量252 kg hm^(-2)可降低棵间蒸发量、提高饲草产量和水分生产力,是绿洲灌区青贮玉米生产适宜采用的种植模式和施氮量。展开更多
精准鉴定遗传多样性是植物资源利用和深入开展科学研究的基础。本文利用葛属3个种的叶绿体基因组序列中的物种特有的624个核苷酸变异位点作为分子性状,首次编制了分子鉴定检索表,供试样品得到成功鉴定。物种特有变异位点的数量和核苷酸...精准鉴定遗传多样性是植物资源利用和深入开展科学研究的基础。本文利用葛属3个种的叶绿体基因组序列中的物种特有的624个核苷酸变异位点作为分子性状,首次编制了分子鉴定检索表,供试样品得到成功鉴定。物种特有变异位点的数量和核苷酸构成存在种间差异。食用葛的特有变异位点的数量(576)最多,粉葛(38)和葛藤(10)的特有变异位点的数量明显较少。食用葛的特有变异位点中,4类核苷酸的比例由大到小依次为:T (26.91%)、A (26.04%)、C (24.13%)和G (22.92%),差异不大。粉葛的特有变异位点中,T (39.47%)的比例最高,随后依次为C (26.32%)、A (18.42%)和G (15.79%),T的比例是G的比例的约2.5倍。葛藤的特有变异位点数量相对稀少,其中,T的比例(50.00%)最高,是A或G的比例(20.00%)的2.5倍,是C的比例(10.00%)的5倍。结果显示,叶绿体基因组的单核苷酸变异位点信息可用于葛属植物资源遗传多样性的分子鉴定。本文调查了中国过去120多年来葛属植物标本的收集现状,讨论了存在的问题与对策。本研究对于葛属植物的分类修订、种质资源的保护和利用具有重要价值。Accurate identification of genetic diversity is the basis for utilization of plant resources and further scientific research. In this paper, 624 taxon-specific variable nucleotide sites in the complete chloroplast genome of 3 species from the genus Pueraria DC. were used as molecular traits to identify successfully the genetic resources of this plant genus and compile a molecular classification key for the first time. There are differences in aspects of amount and base composition of taxon-specific variable nucleotide sites among the species. The amount of taxon-specific variable nucleotide sites in Pueraria edulis Pamp. (576) is the highest, those in Pueraria montana var. thomsonii (Benth.) M.R. Almeida (38) and Pueraria montana (Lour.) Merr. (10) are significantly fewer. The proportion of T (26.91%), A (26.04%), C (24.13%) and G (22.92%) is decreasing respectively but with small differences among taxon-specific variable nucleotide sites in Pueraria edulis Pamp. The proportion of T (39.47%) is the highest, followed by C (26.32%), A (18.42%) and G (15.79%) in taxon-specific variable nucleotide sites in Pueraria montana var. thomsonii, the proportion of T is 2.5 times that of G. Relatively, the amount of taxon-specific variable nucleotide sites is fewer in Pueraria montana, where the proportion of T (50.00%) is the highest, being 2.5 times that (20.00%) of A or G, and 5 times that (10.00%) of C. Our results indicated that taxon-specific variable nucleotide sites from the chloroplast genomes could be used for the molecular classification of the genetic diversity in the genus Pueraria resources. In this paper, the status of Pueraria plant specimens collected in the past 120 years in China is investigated and problems and possible strategies are discussed. This study is valuable for taxonomic revision, conservation and utilization of Pueraria plant germplasm resources.展开更多
基金supported by the Forestry Science and Technology Innovation Project of Shaanxi Province,China(SKLK2022-02-14)the Shaanxi Province Key Research and Development Program(2022SF-285)the China Postdoctoral Science Foundation(2020M683594).
文摘Leguminosae are an important part of terrestrial ecosystems and play a key role in promoting soil nutrient cycling and improving soil properties.However,plant composition and species diversity change rapidly during the process of succession,the effect of leguminosae on soil physical-chemical and biological properties is still unclear.This study investigated the changes in the composition of plant community,vegetation characteristics,soil physical-chemical properties,and soil biological properties on five former farmlands in China,which had been abandoned for 0,5,10,18,and 30 a.Results showed that,with successional time,plant community developed from annual plants to perennial plants,the importance of Leguminosae and Asteraceae significantly increased and decreased,respectively,and the importance of grass increased and then decreased,having a maximum value after 5 a of abandonment.Plant diversity indices increased with successional time,and vegetation coverage and above-and below-ground biomass increased significantly with successional time after 5 a of abandonment.Compared with farmland,30 a of abandonment significantly increased soil nutrient content,but total and available phosphorus decreased with successional time.Changes in plant community composition and vegetation characteristics not only change soil properties and improve soil physical-chemical properties,but also regulate soil biological activity,thus affecting soil nutrient cycling.Among these,Leguminosae have the greatest influence on soil properties,and their importance values and community composition are significantly correlated with soil properties.Therefore,this research provides more scientific guidance for selecting plant species to stabilize soil ecosystem of farmland to grassland in the Loess Plateau,China.
文摘针对河西绿洲灌区青贮玉米氮肥投入高、水分利用效率低等问题,本研究在减氮条件下,探讨间作豆科饲草对青贮玉米产量及耗水特征的影响,为青贮玉米水分高效利用提供理论依据和技术支撑。试验于2022—2023年在武威绿洲农业综合试验站开展,设置3个种植模式(M:青贮玉米单作;MH:青贮玉米-秣食豆间作;ML:青贮玉米-拉巴豆间作)和4个施氮水平(N3:360 kg hm^(-2);N2:306 kg hm^(-2);N1:252 kg hm^(-2);N0:0 kg hm^(-2))。结果表明,2种混播模式下N1处理的青贮玉米和豆科饲草干物质积累量较N3显著提高,MH模式下分别提高10.0%和20.5%,ML模式下分别提高16.5%和28.8%。MH模式下N1处理饲草产量与N3差异不显著,但ML模式下较之提高22.4%,且ML模式饲草产量在N1水平下较MH模式提高12.3%。引入豆科饲草可降低间作系统棵间蒸发量,MH、ML模式的棵间蒸发量在N1水平下比M模式相同施氮水平分别降低23.5%、30.0%,但2种模式不同施氮处理间棵间蒸发量差异不显著。青贮玉米间作拉巴豆结合氮肥减施30%可降低蒸散比,较M模式相同施氮水平降低23.0%。间作豆科饲草提高了水分利用效率,MH、ML模式水分利用效率在N1、N2、N3水平下较M模式分别提高43.3%、29.5%、17.9%和51.9%、30.2%、21.2%。其中,以MLN1处理提升幅度最大,较MN3处理水分利用效率提高52.4%。因此,青贮玉米间作豆科饲草结合施氮量252 kg hm^(-2)可降低棵间蒸发量、提高饲草产量和水分生产力,是绿洲灌区青贮玉米生产适宜采用的种植模式和施氮量。
文摘精准鉴定遗传多样性是植物资源利用和深入开展科学研究的基础。本文利用葛属3个种的叶绿体基因组序列中的物种特有的624个核苷酸变异位点作为分子性状,首次编制了分子鉴定检索表,供试样品得到成功鉴定。物种特有变异位点的数量和核苷酸构成存在种间差异。食用葛的特有变异位点的数量(576)最多,粉葛(38)和葛藤(10)的特有变异位点的数量明显较少。食用葛的特有变异位点中,4类核苷酸的比例由大到小依次为:T (26.91%)、A (26.04%)、C (24.13%)和G (22.92%),差异不大。粉葛的特有变异位点中,T (39.47%)的比例最高,随后依次为C (26.32%)、A (18.42%)和G (15.79%),T的比例是G的比例的约2.5倍。葛藤的特有变异位点数量相对稀少,其中,T的比例(50.00%)最高,是A或G的比例(20.00%)的2.5倍,是C的比例(10.00%)的5倍。结果显示,叶绿体基因组的单核苷酸变异位点信息可用于葛属植物资源遗传多样性的分子鉴定。本文调查了中国过去120多年来葛属植物标本的收集现状,讨论了存在的问题与对策。本研究对于葛属植物的分类修订、种质资源的保护和利用具有重要价值。Accurate identification of genetic diversity is the basis for utilization of plant resources and further scientific research. In this paper, 624 taxon-specific variable nucleotide sites in the complete chloroplast genome of 3 species from the genus Pueraria DC. were used as molecular traits to identify successfully the genetic resources of this plant genus and compile a molecular classification key for the first time. There are differences in aspects of amount and base composition of taxon-specific variable nucleotide sites among the species. The amount of taxon-specific variable nucleotide sites in Pueraria edulis Pamp. (576) is the highest, those in Pueraria montana var. thomsonii (Benth.) M.R. Almeida (38) and Pueraria montana (Lour.) Merr. (10) are significantly fewer. The proportion of T (26.91%), A (26.04%), C (24.13%) and G (22.92%) is decreasing respectively but with small differences among taxon-specific variable nucleotide sites in Pueraria edulis Pamp. The proportion of T (39.47%) is the highest, followed by C (26.32%), A (18.42%) and G (15.79%) in taxon-specific variable nucleotide sites in Pueraria montana var. thomsonii, the proportion of T is 2.5 times that of G. Relatively, the amount of taxon-specific variable nucleotide sites is fewer in Pueraria montana, where the proportion of T (50.00%) is the highest, being 2.5 times that (20.00%) of A or G, and 5 times that (10.00%) of C. Our results indicated that taxon-specific variable nucleotide sites from the chloroplast genomes could be used for the molecular classification of the genetic diversity in the genus Pueraria resources. In this paper, the status of Pueraria plant specimens collected in the past 120 years in China is investigated and problems and possible strategies are discussed. This study is valuable for taxonomic revision, conservation and utilization of Pueraria plant germplasm resources.
