Adaptability Comparison of Chinese Milk Vetch (Astragalus sinicus) Varieties for Double-rice Cropping System in Hunan

Five Chinese milk vetch（Astragalus sinicus） varieties were selected to make a comparison in order to screen effective varieties which could suit for the double-rice cropping system of Hunan Province. The results showed that the growth period of Xiangzi 2 is shorter than that of Xiangfei 2, Xiangfei 3 and Yujiangdaye,and is similar to that of Xinyang Chinese milk vetch. The full-bloom stage of Xiangzi 2 is also similar to Xinyang variety and obviously earlier than that of the other three varieties. The fresh grass yield of Xiangzi 2 in full-bloom stage is 23 842.5kg/hm^2, which increases by 39.9% compared with Xinyang variety. Nitrogen content in the fresh grass of Xiangzi 2 is higher than that of the other four varieties. In conclusion, Xiangzi 2 is an extremely early-blossoming and early-maturing Chinese milk vetch variety with moderate fresh grass yield, high nutrient contents, stable characters and wide adaptability. So, Xiangzi 2 is suitable for planting in double-rice cropping region in Hunan Province and other same latitude regions which have similar ecological conditions.

Genetic Variability of Astragalus sinicus L. Based on ISSR Markers

Genetic relationships among 22 accessions of Astragalus sinicus L. col ect-ed from different provinces of China were analyzed by inter-simple sequence repeat （ISSR） markers. The results showed that 10 highly reproducible ISSR fragments a-mong 40 primers were screened. Using these primers, a total of 684 ISSR frag-ments from 500 to 3 000 bp were amplified, and 59.2% of them showed polymor-phic by unweighted pair-group method with arithmetic （UPGMA） analysis. It revealed that the 22 accessions had a similarity range from 0.63 to 0.95, and existed biolog-ical diversities. Based on cluster and principal coordinate analyses, al accessions could be divided into four distinct groups.

Effects of Ploughing Astragalus sinicus at Maturity Stage on Rice Yield and Soil Properties of Paddy Field

[Objective] The effects of ploughing Astragalus sinicus at maturity stage as green manure on paddy soil properties were studied to provide references for ad- vancing the green manure production and field sustainable development. [Methods] A three-year field positioning experiment was carried out. In the first year, five differ- ent levels （0, 2.81, 5.61, 8.42, 11.23 t/hm~） of Astragalus sinicus ploughed at matu- rity stage were designed. And in the next two years, the amounts of ploughed As- tragalus sinicus at maturity stage were based on the natural growth amounts of As- tragalus sinicus at maturity stage of the former year in each plot field. The yields of Astragalus sinicus at maturity stage were estimated and ploughed directly before rice transplanting. Rice yield, soil nutrients, biological properties and water-stable aggre- gates of paddy fields were measured as well. [Results] The effective panicles and rice yields increased significantly after ploughing Astragalus sinicus at maturity stage. Meanwhile, the organic acid content in paddy field increased and the activities of soil phosphatases, invertase and catalase were higher. The soil dissolved organic carbon also increased with the increasing application of green manure. However, excess amount of green manure inhibited the soil microbial biomass carbon content. The macro aggregates and micro aggregates gathered to middle aggregates. [Conclusion] As green manure, the use of Astragalus sinicus at maturity stage could improve soil physiochemical and biological properties, improve soil fertility and increase rice yield significantly. But the ploughing amount of Astragalus sinicus at maturity stage before rice transplanting should be less than 8.42 t/hm2 （dry weight.

Green synthesis,characterization,acaricidal,larvacidal,and repellent activities of copper nanoparticles of Astragalus sinicus against Hyalomma anatolicum

Objective:To green synthesize and characterize copper nanoparticles(Cu NPs)using Astragalus sinicus,as well as evaluate the acaricidal,larvacidal,and repellent activities of Cu NPs against Hyalomma anatolicum(H.anatolicum),one of the most prevalent ticks infesting cattle in Saudi Arabia.Methods:Cu NPs were green synthesized by adding the Astragalus sinicus extract to a copper sulfate solution.The acaricidal,larvicidal,and repellent activities of Cu NPs against H.anatolicum were assessed via the adult immersion test,the larval packet test,and the vertical movement behavior of tick larvae,respectively.The effects of Cu NPs on acetylcholinesterase as well as oxidative enzyme activities were examined.Results:The green synthesized Cu NPs displayed a spherical form with a size range of 15-75 nm.After exposure of adult H.anatolicum to different concentrations of Cu NPs,the viability rate of adult H.anatolicum and the mean number,weight,and hatchability of eggs were noticeably reduced,in comparison to the control group(P<0.001).In addition,the viability rate of larvae considerably declined(P<0.001)with the LC_(50)and LC_(90)values of 11.30 and 20.34μg/m L,respectively.The maximum repellent activity of Cu NPs was observed at 50,100,and 200μg/m L with complete repellent activity after 60,120,and 180 min of exposure,respectively.Cu NPs,mainly at 1/2 LC_(50)and LC_(50)concentrations,markedly suppressed the acetylcholinesterase activity of the larval stage of H.anatolicum(P<0.001).Moreover,Cu NPs,mainly at LC_(50)dose,significantly elevated malondialdehyde level while declining glutathione-S-transferase level in H.anatolicum larvae(P<0.001).Conclusions:Cu NPs show potent acaricidal,larvicidal,and repellent activities against adults and larvae of H.anatolicum.However,further studies must be performed to clarify the precise mechanisms and the efficacy of Cu NPs in practical use.

Vacuolar phosphate transporters account for variation in phosphate accumulation in Astragalus sinicus cultivars

Astragalus sinicus is a commonly used legume green manure that fixes atmospheric N2 and accumulates mineral nutrients and organic substances that are beneficial to soils and subsequent crops.However,little is known about genotypic variation in,and molecular mechanisms of,Pi(phosphate)uptake and storage in A.sinicus.We recorded the morphological responses of six A.sinicus cultivars from four regions of China to external Pi application and measured their Pi accumulation.We identified full-length transcripts of Pi-signaling and Pi-homeostasis regulators by sequencing and measured the expression level of these genes by qRT-PCR.The major components in Pi signaling and Pi homeostasis were largely conserved between A.sinicus and the model species rice and Arabidopsis.Different A.sinicus varieties responded differently to low-phosphorus(P)stress,and their Pi accumulation was positively correlated with the expression of vacuolar Pi influx gene(SYG1/PHO81/XPR1-MAJOR FACILITATOR SUPERFAMILY(SPX-MFS)-TYPE PROTEIN)AsSPXMFS2 and negatively correlated with the expression of the vacuolar Pi efflux gene(VACUOLAR Pi EFFLUX TRANSPORTER)AsVPE1.We identified key Pi-signaling and Pihomeostasis regulators in A.sinicus.The expression of vacuolar Pi transporter genes could be used as an index to select A.sinicus accessions with high Pi accumulation.

The chromosome-level genome assembly of Astragalus sinicus and comparative genomic analyses provide new resources and insights for understanding legume-rhizobial interactions

The legume species Astragalus sinicus(Chinese milk vetch[CMV])has been widely cultivated for centuries in southern China as one of the most important green manures/cover crops for improving rice productivity and preventing soil degeneration.In this study,we generated the first chromosome-scale reference genome of CMV by combining PacBio and Illumina sequencing with high-throughput chromatin conformation capture(Hi-C)technology.The CMV genome was 595.52 Mb in length,with a contig N50 size of 1.50 Mb.Long terminal repeats(LTRs)had been amplified and contributed to genome size expansion in CMV.CMV has undergone two whole-genome duplication(WGD)events,and the genes retained after the WGD shared by Papilionoideae species shaped the rhizobial symbiosis and the hormonal regulation of nodulation.The chalcone synthase(CHS)gene family was expanded and was expressed primarily in the roots of CMV.Intriguingly,we found that resistance genes were more highly expressed in roots than in nodules of legume species,suggesting that their expression may be increased to bolster plant immunity in roots to cope with pathogen infection in legumes.Our work sheds light on the genetic basis of nodulation and symbiosis in CMV and provides a benchmark for accelerating genetic research and molecular breeding in the future.

Identification of two novel nodule-specific genes from Astragalus sinicus L. by suppressive subtractive hybridization

To identify the genes involved in nodule formation and to increase usable molecular probes, a cDNA library of Astragalus sinicus genes specifically expressed in infected roots by Mesorhizobium huakuii 7653R is generated using a PCR-based suppressive subtractive hybridization (SSH) technique with two mRNA populations of infected and uninfected control roots. Two nodule-specific genes, AsIIC259 and AsG2511, are identified from infected roots of A. sinicus. The amino acid sequences deduced from the open reading frames (ORFs) reveal that AsIIC259 and AsG2511 encodes a polypeptide with 134 and 58 amino acids, respectively. A signal peptide sequence is predicted with high probability at the N-termini of the AsIIC259 and AsG2511. The motif searches show that the deduced polypeptide of AsIIC259 con- tains two N-glycosylation sites, a cAMP- and cGMP-dependent protein kinase phosphorylation site and a casein kinase II phosphorylation site. BLASTP searches reveal that AsIIC259 putative protein displays a low degree of similarity to a unique nodulin from Lupinus luteus nodules. No significant identity is displayed over the predicted polypeptides of AsG2511 with any published sequences. Virtual Northern blot and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) analyses indicate that the two genes are expressed exclusively in inoculated roots and that their expression is 2―4 d later than that of the leghaemoglobin (Lb) gene during nodule development.

不同紫云英品种根瘤内生细菌的类群和多样性分析

【目的】阐释紫云英根瘤内生菌的群落结构,为研发根瘤菌菌剂及了解固氮机制提供依据。【方法】以福建省种植的不同紫云英品种的根瘤为材料,借助Illumina Miseq PE300测序平台,以16S rRNA基因为靶标,研究不同紫云英品种的根瘤内生细菌的多样性。【结果】不同品种会影响紫云英根瘤内生细菌的类群和多样性。浙紫5号(ZZ5)的优势属为假单胞菌属(Pseudomonas),其余品种根瘤内生细菌的优势属均为中慢生根瘤菌属(Mesorhizobium)。闽紫8号(MZ8)、信阳(XY)和浙紫5号的根瘤内生细菌的多样性指数(Shannon)较高,除了共生固氮的中慢生根瘤菌外,还包括丰富的非根瘤菌,如假单胞菌属、寡养单胞菌属(Stenotrophomonas)、杜擀氏菌属(Duganella)、泛菌属(Pantoea)、欧文氏菌属(Erwinia)等。闽紫8号、信阳和浙紫5号这3个品种根瘤中含有较高丰度的致病菌大黄欧文氏菌(Erwinia rhapontici)和菠萝泛菌PA13(Pantoea ananatis PA13)。【结论】紫云英品种对根瘤内生细菌的群落结构有一定影响,浙紫5号的根瘤内生细菌主要为具促生作用的非根瘤菌假单胞菌,而其余品种为具固氮能力的根瘤菌,在生产实际中可以采用紫云英混种的方式达到固氮促生的双重功效。

紫云英长期还田对稻田土壤DOM和Cd形态影响研究

长期种植和翻压紫云英能够显著提高土壤中有机质(SOM)和水溶性有机物(DOM)的含量,影响土壤颗粒对重金属镉(Cd)的吸附行为和Cd在土壤中的形态,了解该条件下Cd在不同土层中的特征对紫云英的进一步推广种植具有重要意义。以余江区(YJ)、南昌县(NC)、丰城市(FC)3地长期种植和翻压紫云英处理(F+M)和化肥处理(F)的定位试验点为研究对象,测试了不同层次土壤中SOM、水溶性有机碳(DOC)含量、Cd总量和形态、DOM三维荧光,以期探明紫云英长期还田模式下不同土层中DOM成分的差异及其对Cd含量和形态影响。结果显示,NC和FC试验点F+M处理耕作层土壤(0-20 cm)中SOM的含量显著高于F处理,分别提高16.8%和10.5%。同一土层中土壤Cd活性呈现F+M处理>F处理的趋势。紫云英DOM主要在耕作层和中层(20-40cm)土壤中迁移,YJ、NC、FC试验点中,F+M处理耕作层土壤中DOC含量比F处理分别提高17.0%、58.1%和33.7%,中层土壤中DOC含量分别提高43.0%、36.7%和11.2%。种植和翻压紫云英降低了DOM中类蛋白质组分的占比,增加了类腐殖质组分的占比,耕作层、中层和深层土壤(40-60 cm)中,3个试验点F处理DOM中类蛋白质的平均占比分别为7.34%、16.7%、23.9%,占比分别是F+M处理的1.26、1.92和1.54倍。类蛋白质组分的深层迁移能力大于类腐殖质组分。逐步回归分析表明,有生物活性的Cd形态占比与土壤SOM、类色氨酸含量存在负相关关系,与类富里酸含量存在正相关关系,其系数分别为-2.170、-0.760和0.239。常年种植和翻压紫云英通过影响土壤SOM总量以及DOM组分对土壤Cd表现出一定的活化潜力。

4种除草剂土壤封闭处理对稻茬紫云英的安全性及对阔叶杂草的防除效果

为筛选用于稻茬紫云英繁殖田阔叶杂草防控的土壤处理用除草剂,选取80%唑嘧磺草胺水分散粒剂、960g/L精异丙甲草胺乳油、33%精异丙甲草胺·丙炔氟草胺微囊悬浮剂、330g/L二甲戊灵乳油4种除草剂,在紫云英播后苗前进行土壤喷雾处理,评价其对紫云英的安全性及对阔叶杂草的防控效果。结果表明,紫云英播后第2天,使用80%唑嘧磺草胺水分散粒剂或330g/L二甲戊灵乳油进行土壤封闭处理对紫云英较安全,且对田间阔叶杂草的防控效果较好,株防效分别为75.26%、82.74%,鲜重防效分别为46.09%、61.09%。

广西地方紫云英种质资源收集及表型多样性评价

以农业农村部“第三次全国农作物种质资源普查与收集行动”为契机,开展了广西壮族自治区紫云英(Astragalus sinicus L.)种质资源的考察收集与评价鉴定。结果表明,收集到的58份地方资源主要分布在桂东北以及0~400 m的中低海拔地区。12项农艺性状表型分析显示其遗传多样性丰富;主成分分析将12个农艺性状分为3个主成分,分别为种子产量、生物产量及生育期特征,累计贡献率达72.089%;通过加权平均计算得出综合排名前10位的种质资源为GXLF20180011、GXLF2019109、GXLF2019156、GXLF2019118、GXLF2019112、GXLF2019117、GXLF20180006、GXLF2019125、GXLF2019111、GXLF2019136;排名前10位的种质资源全生育期为134~147 d,盛花期茎粗(直径)为2.83~3.66 mm,盛花期株高为41.63~54.73 cm,单株分枝数为2.83~4.19个,每分枝花序数为5.85~6.99个,总花序数为17.55~26.23个/株,结荚花序数为14.33~19.97个/株,鲜草产量为10458.15~48792.75 kg/hm^(2),干草产量为1037.36~5724.34 kg/hm^(2),种子产量为246.75~991.20 kg/hm^(2)。

汉中地区4种冬绿肥还田腐解和养分释放特征

研究汉中地区水稻(Oryza sativa)-绿肥轮作制下翻压还田绿肥的腐解动态变化及养分释放特征,可为水稻-绿肥轮作生产中的水稻科学施肥提供理论依据。以紫云英(Astragalus sinicus)、毛叶苕子(Vicia villosa)、山黧豆(Lathyrus cicera)和箭筈豌豆(Vicia sativa)为供试材料,进行145 d的田间原位埋袋腐解试验,并定期观测4种豆科绿肥腐解变化及养分释放特征。结果表明,绿肥腐解及养分释放均表现为前期(0~14 d)快、后期(41~145 d)慢。经过145 d,紫云英、毛叶苕子、山黧豆和箭筈豌豆的累计腐解率分别为74.58%、74.17%、72.14%和72.57%,而氮、磷、钾平均累计释放率分别为85.64%、75.23%和96.22%。翻压量为22500 kg·hm^(-2)的紫云英、毛叶苕子、山黧豆和箭筈豌豆腐解145 d后,氮素累计释放量分别为82.27、134.73、144.73和94.17 kg·hm^(-2),磷素累计释放量分别为14.68、21.39、21.21和17.25 kg·hm^(-2),钾素累计释放量分别为70.90、93.72、85.23和82.13 kg·hm^(-2)。4种绿肥的氮、磷、钾平均累计释放量分别为113.99、18.63和83.02 kg·hm^(-2),可为后茬水稻提供63.33%N、20.70%P2O5和79.07%K2O。综上,紫云英、毛叶苕子、山黧豆和箭筈豌豆均适于汉中地区冬闲稻田种植,且理论化肥减量顺序为毛叶苕子≈山黧豆>箭筈豌豆>紫云英,此外,水稻生育前期氮和钾减施潜力较大,建议水稻季氮肥和钾肥后移施用。

紫云英与油菜混播还田对湘南稻田的影响

为探究湘南地区稻田中紫云英与油菜混播对后茬水稻产量以及土壤养分的影响,本试验设置6个处理,分别为冬闲(CK)、单播紫云英(LF01)、单播油菜(LF02)和紫云英油菜混播(LF03—LF05),对比分析各处理组绿肥生物量、后茬水稻产量及土壤理化性状等。结果表明,紫云英与油菜混播处理的绿肥生物量明显高于单播处理,其中紫云英播种量22.5 kg/hm^(2),油菜播种量3.0 kg/hm^(2)(LF04)时效果最佳,较紫云英单播和油菜单播分别增加120.9%和39.3%;同时LF04处理较CK处理后茬水稻产量增加17.5%;土壤中有机质、碱解氮、有效磷和速效钾含量分别提升了9.6%、8.1%、7.5%和9.6%。在湘南地区,相比紫云英、油菜单独播种,紫云英与油菜混播能够有效提高后茬水稻产量、改善土壤肥力,是一种有效的种植模式,适宜在该地区推广。

菜用紫云英中硒赋存形态及含硒有机化合物提取工艺研究

针对现蕾前菜用紫云英中硒的赋存形态不明确及含硒有机化合物的提取工艺不成熟的问题,以氢氧化钠溶液作为提取溶剂,研究了硒在菜用紫云英中的赋存形态。以有机硒提取率为指标,采用响应面分析法,考察了提取富硒菜用紫云英粉末中有机硒化合物的影响因素,并优化了主要含硒有机化合物的提取工艺。实验表明,紫云英中有机硒含量占总硒的92.49%,其中碱溶蛋白硒占总硒的69.45%;有机硒的最佳提取工艺条件是:氢氧化钠溶液的摩尔浓度为0.15 mol/L,氢氧化钠溶液用量为样品体积的20倍,提取时间为2 h,提取次数为2次。结果说明,紫云英中的硒以有机结合态为主,有机结合态硒在碱性溶液中提取效果最好,在对紫云英中有机硒进行提取时,主要应考虑提取溶液的酸碱性、提取溶液的用量、提取时间及提取次数等因素。该结果可为菜用紫云英的进一步开发利用提供科学依据。

紫云英对土壤及生态环境的影响分析

随着社会经济和科学技术的高质量发展,人们的生活水平逐步提升,对绿色、多样化食品的需求逐渐增加。本研究对紫云英基本情况和种植方法进行介绍,就紫云英对土壤及生态环境的影响进行分析,研究发现种植紫云英能够提高作物产量,减少病虫害发生,提升土壤质量,改善农业生态环境,促进相关产业发展,为进一步推广紫云英种植提供借鉴。

紫云英研究进展

阐述了紫云英(Astragalus sinicus)选育和栽培、回田及综合利用等方面的研究概况,在育种及栽培技术方面,介绍了国内外选育的优良品种及紫云英丸衣种子、根瘤菌剂的应用、以小肥养大肥等技术;在回田利用方面,紫云英作为绿肥不仅能够提高土壤肥力,增加作物产量,还能固氮节能,减少氮素流失,促进土壤有机碳的积累,减少CO2的排放;在综合利用方面,介绍了紫云英作为富硒产品、蜜源、干草、菜用等方面的利用;针对目前紫云英种植面积不断下降的现状,提出了利用新的育种手段及优良品种扩繁相结合的办法,解决目前紫云英品种陈旧、退化、混杂的问题,大力加强紫云英的示范推广,充分发挥紫云英绿肥在农业可持续发展中的作用。

不同紫云英品种物候期及主要经济性状研究

在福建省对15个紫云英Astragalus sinicus品种(系)生长生育过程的特征和特性进行研究,结果表明:所选育并正在扩繁的8个品种(系)8410441、8324411、84471031、8428121、84341022、8487711、闽紫6号和8454311表现中熟,生长性状表现良好,各项指标优于从外省引进的品种,特别是盛花期鲜草产量都比引进种常德种有显著的提高,说明这8个品种(系)可以进行大规模扩繁鉴定,为紫云英育种提供优良材料。

PEG胁迫下15份紫云英种质材料萌发期的抗旱性鉴定

以不同渗透势的PEG-6000溶液模拟干旱胁迫条件,对15份不同来源的紫云英(Astragalus sinicus)种质材料的萌发特性和抗旱能力进行了研究。结果表明:(1)低浓度的PEG胁迫对部分紫云英种质的种子萌发有一定的促进作用;(2)PEG胁迫加剧会导致紫云英种子的发芽率、萌发抗旱指数、活力指数下降,而胚根/胚芽比值上升;(3)PEG浓度达到20%时所有紫云英种质的种子均不能萌发;(4)运用模糊数学隶属函数法对15份紫云英种质材料进行综合评价,发现其抗旱性强弱顺序为,萍宁3号>湘肥2号>南京芦庄紫云英>浙紫62-18>常山紫云英>兵库紫云英>金沙紫云英>南充紫云英>78-7>青浦紫云英>73-129>72-24>清江紫云英>78-18>78-1-1。

紫云英还田方式对烟田土壤微生物及酶的影响

为探明紫云英不同还田方式对土壤生物学特性的影响,选择合理的还田方式,通过定位试验进行了全层翻耕紫云英覆盖、全层翻耕紫云英深埋和全层翻耕紫云英不还田3种方法对烟草不同生育期的土壤微生物数量、微生物活度和酶活性的影响研究。结果表明:在烟草生育期内,好气性细菌数量呈现前期急速下降,中期缓慢上升,后期稍微波动的趋势,深埋处理都略高于覆盖处理;真菌数量整体呈现上升趋势,紫云英覆盖前期可显著增加真菌数量,深埋对真菌数量影响不大;放线菌数量紫云英还田处理呈现前期下降,中期急速上升,后期缓慢上升的趋势。土壤微生物活度则先下降再持续上升,至烟草成熟期,紫云英覆盖>紫云英深埋>不还田。土壤纤维素酶活性以旺长期为分界点,表现为前期增加、后期下降的特点,紫云英还田高于不还田;土壤脲酶活性呈现先迅速下降,再缓慢上升,再急速上升的趋势,以紫云英深埋处理的脲酶活性最高;土壤蛋白酶和过氧化氢酶的活性在烟草生育期的变化不大,都表现为早期稍微下降,以后趋于平缓,以紫云英深埋的酶活性较高。土壤生物学综合评价表明,采用全层翻耕紫云英深埋(1500kg/667m2)更利于提高土壤质量。

亚热带单季稻区紫云英不同翻压量下有机碳和养分释放特征

在70%田间持水量以及近自然气温条件下,利用网袋法模拟亚热带单季稻区紫云英盛花期不同翻压量下的腐解和养分释放特征。结果表明,不同翻压量下紫云英干物质腐解速率均为前20d最高,至60d后进入缓慢腐解阶段。腐解至90d,低、中、高翻压量下的干物质累积腐解率分别达78.7%,76.0%,71.2%。紫云英碳、氮、磷、钾累积腐解率与腐解时间呈幂函数关系,拟合方程分别为Y=13.4246 X0.4391(P<0.01),Y=14.0314 X0.4208(P<0.01),Y=3.5458 X0.7037(P<0.01),Y=15.7784 X0.4213(P<0.01)。紫云英有机碳与养分前20d累积释放率与全腐解期累积释放率均表现为钾>碳>氮>磷,且随着翻压量增加,有机碳及养分累积释放率呈逐渐降低趋势。