Resource Sharing by the Different Clonal White Clover Plant(Trifolium repens L.)

Resource sharing in the different parts of the clonal white clover plant (Trifolium repens L.) was investigated in this study. The results showed that the integration of water and nitrogen metabolism occured among parental, young and old branches of a plant when water passed through its stolons. Under the sufficient supply of light, water and nutrients from soil the newly developed branches showed similar capacity in taking in sufficient water and nitrogen to that of old branches. The development of the new branches did not affect the growth of the old and parental branches attached. The results also indicated that energy values in roots was significantly related with plant age, however, the energy values were various in the different parts of a plant.

Response of Chlorophyll Fluorescence Characteristic of Trifolium repens L. to Water Stress

[Objective] The aim was to study response of chlorophyll fluorescence parameters in Trifolium repens L.leaves to water stress from perspective of physiology.[Method] With T.repens cultivar ＂Haifa＂ as tested material,three soil water content levels were set to culture plants,including 75% （no stress,CK）,50% （moderate stress,LD） and 25% （severe stress,HD）,the effects of water stress on chlorophyll fluorescence parameters were determined.[Result] The results showed that the chlorophyll fluorescence parameters changed a little when the relative soil moisture content was 75% and 50%,while the chlorophyll fluorescence parameters such as conversion efficiency of primary light energy （Fv/Fm） of PS Ⅱ,the photochemical quenching coefficient （qP） and the quantum yield of PS Ⅱ electron transport （φPS Ⅱ） decreased respectively when the relative soil moisture content was 25%.[Conclusion] When T.repens in severe drought conditions,the physiological functions were damaged,showing symptoms of drought injury.

Study on the Degradation Trend of Ryegrass-White Clover Artificial Grassland

[Objective] The study aimed to explore the degradation law and trend of artificial grassland. [Method] Taking the ryegrass （Lolium perenne） - white clover （ Trifolium repens） artificial grassland in Maiping Township, Guizhou Province as the research object, the grassland vegetation of 40 quadrate from different areas （area around the sheep shed, hilltop, hillside, flatland at the foot of the hill） were analyzed by comparing the dominance and richness index. [ Result] Degradation of different degrees appeared in various areas of this artificial grassland. To be specific, the degradation of grassland around the sheep shed was not serious for less consumption by the sheep; however, the areas on the hilltop and hillside degenerated to the grassland types of dallis grass （ Paspalum dilatatum Poir. ） -Indian lovegrass （ Eragrostis pilosa） and dallis grass - cogongrass [ Imperata cylindrica （ Linn. ） Beauv. ], respectively, and the area at the foot of the hill degenerated to the grassland type dominated by garland chrysanthetnum （ Chrysanthemum coronarium L. ） and knotgrass （ Paspalum distichum L. ）. [ Conclusion ] This study provided a basis for grassland improvement as well as the efficient and sustainable utilization of grazing-type artificial grassland in South China.

Genetic Diversity of Clover by SRAP

In the present study,genetic diversity and genetic relationship of 11materials including red clover ( Trifolium pretense L.),white clover ( T.repen L.) and alsike clover ( T.hybridum L.) and leaf-type variants of white clover were investigated by SRAP (sequence related amplified polymorphism).Forty SRAP primers were screened,and 792 reliable bands were amplified,among which 426 (53.8%) were polymorphic.The number of polymorphic bands per pair of primers ranged from 3 to 38 with an average of 10.6.SRAP cluster analysis showed that the similarity coefficients between white clover materials were from 0.465 to 0.997 with an average of 0.812,indicating that there was certain genetic diversity among white clover.Specific bands appeared in white clover variants,indicating that there were certain differences in DNA sequence between normal while clover plants and their leaf-type variants.The similarity coefficients between red clover materials were from 0.457 to 0.827 with an average of 0.597,indicating that the different red clover germplasms had genetic diversity at the DNA molecular level.The results also showed that the genetic relationship of the alsike clover with the red clover was closer than that with the white clover.This study shows that SRAP technique can be effectively used for the analysis on interspecific and intraspecific relationship,germplasm resource identification and genetic diversity of clover.

红车轴草提取物中总鹰嘴豆芽素类成分HPLC测定方法的研究

Two HPLC methods were established to determine the total biochanins in Red Clover extracts.One was taken Ononin,Sissotrin,Formononetin and Biochanin A as external standard.The other was taken Biochanin A as extrernal standard only.The results of two methods were primary similar.

Development, Reproduction and Body Size Variation of Aphis glycines Matsumura Fed on Different Plants

Soybean aphid, Aphis glycines Matsumura is one of the most important pests in soybean. Life cycle of A. glycines is characterized as heteroecious and holocyclic. The primary hosts of A. glycines are Rhamnus spp. and the secondary hosts include cultivated soybean, Glycine max(L.) Merr, and wild soybean, Glycine soja Sieb.& Zucc. In this study, A. glycines were fed on Trifolium repens L. and Metaplexis japonica(Thunb.) Makino for three generations and their development, reproduction and body sizes were studied. These data were compared to the control fed on the known hosts, G. max and G. soja. These newly deposited offspring by the 3 rd generation were transferred back onto G. max and these differences in their development, reproduction and body sizes were also studied. It showed that A. glycines all could survive, develop and reproduce well, when they were fed on T. repens and M. japonica for three generations, but there were significant differences in their nymph stage, adult longevity and fecundity, life table parameters and body sizes. When these offspring were transferred back onto G. max which were newly deposited by the 3 rd generation aphids fed on T. repens and M. japonica, they could survive, develop and reproduce well, but there were significant differences in their nymph stage, adult longevity, intrinsic rate of increase and body sizes. It provided important information for studies on host adaptability of A. glycines on T. repens and M. japonica and to make clear the potential that this aphid involved into host biotypes on these plants.

配施有机肥对白三叶草生长及香蕉园土壤生态的改良作用

为探明香蕉园间作白三叶草(Trifolium repens L.)模式下配施纯羊粪和生物有机肥对白三叶草的生物量和营养元素含量及香蕉园土壤理化性质的影响,采用间作白三叶草+常规管理(CK)、间作白三叶草+施用纯羊粪、间作白三叶草+施用生物有机肥3个处理做对比分析。结果表明,间作条件下配施纯羊粪,白三叶草地上部和地下部的生物量分别显著增加17%和10%,地上部和地下部的N、P、K含量分别显著增加21%、33%、17%和13%、15%、53%,土壤有机质、pH、全氮和速效钾含量分别显著增加17%、3%、22%和3%;间作条件下配施生物有机肥,白三叶草地上部和地下部的生物量分别显著增加19%和25%,地上部和地下部的N、P、K含量分别显著增加26%、12%、5%和44%、50%、22%,土壤有机质、pH、全氮和速效钾含量分别显著增加42%、4%、33%和4%。由此可见,在香蕉园间作白三叶草模式下配施纯羊粪或生物有机肥均能显著提高白三叶草的生物量和N、P、K元素含量,同时还能改善香蕉园土壤生态,且配施生物有机肥优于配施纯羊粪。

丛枝菌根真菌群落对白三叶草生长的影响

不同施肥处理影响AMF(Arbuscular mycorrhizal fungi)群体结构,然而不同AMF群体结构对植物的生长以及养分吸收的影响尚未见报道,试验利用盆栽实验研究了7种不同来源的丛枝菌根真菌(AMF)群落对白三叶草生长和N、P、K以及微量元素Cu、Zn、Mn的吸收的影响。7种AMF群落分离自长期定位施肥试验地,分别为NPK、OM、CK、1/2OM、NP、NK和PK。每年施肥量是300kg N/hm2,135kg P2O5/hm2,300kg K2O/hm2。有机肥处理的N、P、K养分量与试验地NPK处理含量相同,原料以粉碎的麦秆为主,加上适量的大豆饼和棉仁饼,有机肥经堆制发酵后施用。试验土壤采用封丘试验地土壤,经灭菌处理。试验结果表明,接种不同AMF群落均能促进三叶草的生长,对养分吸收则表现不同。分离自CK试验地的AMF群落对三叶草侵染率显著低于其它6种AMF群落。分离自1/2OM和OM试验地的AMF群落较分离自NPK、CK、NP和NK的AMF群落显著促进了三叶草对P的吸收;各种AMF群落都促进了对N和K的吸收;分离自OM、CK、1/2OM、NP、NK试验地的降低了三叶草植株N含量;分离自NPK试验地的AMF群落提高了三叶草植物K含量;对于Cu、Zn、Mn元素的吸收,不同处理存在较大的差异。AMF群落对三叶草生长以及养分吸收贡献不同,这与不同施肥管理下不同AMF群落的优势种属的侵染率、养分转化以及菌丝发育及分布有关。

高效表达黑曲霉PhyA基因改善白三叶草对有机态磷的利用

利用子叶下胚轴为外植体,通过农杆菌(Agrobacterium tumefaciens)Ti质粒介导遗传转化途径,建立了高效表达黑曲霉PhyA基因的白三叶草转基因系。PCR和Southern印迹结果表明,PhyA基因已整合到转基因植株的基因组中。Northern印迹结果表明,部分转基因系中的PhyA基因具有高表达水平。此外,PhyA基因表达的植酸酶在Patatin信号肽的引导下具有分泌至细胞间隙和根际的能力。与未转基因对照相比,在以植酸盐为唯一磷素供源的条件下,高表达PhyA的转基因系植株的磷素累积量、鲜重和干重显著增加。证明外源转化黑曲霉PhyA基因能显著增强白三叶草利用有机态磷的能力。

白三叶水浸液对草坪草的化感作用

为探讨白三叶入侵禾本科草坪草原因,利用生物测定法研究不同浓度白三叶水浸液对多年生黑麦草、高羊茅、草地早熟禾三种禾本科草坪草种子萌发和幼苗生长的化感作用。结果表明,白三叶水浸液对多年生黑麦草、高羊茅和草地早熟禾三种草坪草种子发芽率、发芽势和幼苗苗高具有低浓度促进、高浓度抑制的双重效应,且抑制作用明显强于促进作用;对幼苗根长具有显著的抑制作用,且抑制作用随着白三叶水浸液浓度的增加而增强;对种子发芽指数、活力指数和幼苗鲜重的影响则因草坪草种类的不同而不同。结果表明,白三叶水浸液具有化感作用,影响三种草坪草的正常生长,是白三叶入侵禾本科草坪草的原因之一。

种间互作对苹果/白三叶复合系统根系生长及分布的影响

设置苹果(Malus demestica Borkh)和白三叶(Trifolium repens L.)单作与间作栽培处理,通过根箱试验研究种间互作对苹果、白三叶根系生长及其分布的影响。结果表明:种间互作导致苹果根系生长发育的正效应和白三叶根系生长发育的负效应;苹果、白三叶不同径级根系对种间互作的响应能力不同,细根比粗根表现出较强的可塑性;苹果细根占总根中的比例提高,而白三叶细根占总根中的比例则降低;种间互作对苹果、白三叶不同径级根垂直分布格局影响不明显,但对不同径级根在各土层中的分布比例产生了明显影响,苹果粗根和细根均有下移的趋势,细根下移的趋势更明显,而白三叶细根分布有上移的趋势,粗根则无明显变化。总之,种间互作对苹果、白三叶根系生长发育及其垂直分布产生了一定的影响,对不同径级根生长及其垂直分布的影响不同。

白三叶根系分泌物对5种草坪草的生化效应

为探讨根系分泌物在白三叶(Trifolium repens L.)入侵禾本科草坪过程中的生化效应,采用水培法收集其根系分泌物,检测不同浓度白三叶根系分泌物对多年生黑麦草(Lolium perenne L.)、紫羊茅(FestucarubraL.)、高羊茅(Festuca arundinacea Schreb.)、草地早熟禾(Poapratensis L.)和匍匐翦股颖(Agrostis stolonifera L.)叶片超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)的活性和丙二醛(MDA)含量以及根系活力的影响。结果表明:白三叶根系分泌物对5种草坪草上述生理生化指标均具有浓度效应。在低浓度下(0.002 g·mL^(-1))对SOD和CAT活性具有促进效应,在高浓度下(0.05 g·mL^(-1))则具有抑制效应。5种受体的POD活性和MDA含量均随白三叶根系分泌物浓度增大而升高,根系活力则随着其浓度增大而降低。因此,白三叶根系分泌物可引起受体植物对逆境的响应,5种草坪草化感效应的生化机制可能是分泌物中化感物质通过改变受体幼苗体内保护酶活性及脂膜过氧化来表现的。

白三叶遗传转化体系的探讨

将白三叶Trifolium repens L.无菌种子吸胀15 h后,制备子叶分别放在含不同浓度配比激素的培养基上培养,同时测定白三叶子叶对卡那霉素(Kam)、头孢霉素(Cef)和羧苄青霉素(Carb)的敏感性,探索出适合子叶生长成苗的一套比较完整的体系。结果表明,用于白三叶子叶遗传转化的培养基为MS+30 g/L蔗糖+8 g/L琼脂+0.1 mg/L NAA+0.5 mg/L6-BA+20 mg/L Kam+250 mg/L Carb。抗性植株最佳生根培养基为MS+15 g/L蔗糖+8 g/L琼脂+0.2 mg/L NAA。通过本实验成功确立了白三叶遗传转化体系,为下一步转基因实验奠定了基础。

扁穗牛鞭草+红三叶混播草地生物量及种间竞争的动态研究

试验对‘广益’扁穗牛鞭草和‘巫溪’红三叶单播及混播群落生物量、种间竞争力进行了动态研究,结果表明最佳混播组合为75%扁穗牛鞭草+25%红三叶。从整个混播群落看,扁穗牛鞭草生长快,植株高,其竞争力强于红三叶,在竞争中占优势。

利用P5CS基因转化白三叶的研究

为了培育抗旱白三叶,构建了植物表达载体pBPC-P5CS,利用基因枪法转化白三叶的愈伤组织,PCR检测和Southern blot鉴定证实白三叶中已导入P5CS基因。对转P5CS基因白三叶植株的不同抗旱指标进行了分析。结果表明,与对照相比,转P5CS基因株系的抗旱能力得到了较大的提高。干旱胁迫下,与对照相比,转P5CS基因植株的脯氨酸含量和相对含水量分别比对照高20.0%-21.2%和5.6%-8.5%。

太湖流域典型桃园土壤氮素径流流失特征

为探索协调水蜜桃优质高产与桃园养分合理投入的技术途径,以12年生晚湖景桃树为供试材料,通过野外大田小区试验(2012—2013年),研究了自然降雨条件下不同施肥及桃园管理模式对太湖流域典型水蜜桃园土壤氮素径流流失特征的影响。结果表明:农户习惯性施肥(T1)条件下,径流水TN浓度最高达87.72mg/L,且随生育期呈现总体降低趋势。减量施肥(T2)和生草模式(T3)显著降低全生育期内11次径流过程的平均TN浓度,且分别达26.16%和12.89%。桃园全生育期径流水TN流失总量达52.06kg/hm2,径流流失率达6.21%,主要分布于桃果座果期到果实成熟期和果实采收后的强台风季。生草模式(T3)显著降低TN径流流失量和流失率,且分别达7.41%和7.41%,减量施肥(T2)处理显著减少TN径流流失量,达26.96%,而流失率却增加3.99%,处理间差异不显著。同时,生草模式(T3)和减量施肥(T2)处理均可显著降低桃园土壤氮素偏流失率,降幅分别达9.51%和20.70%。

水分胁迫对白三叶种子发育与质量的影响

田间水分状况对白三叶(Trifolium repens L)种子生产的影响至关重要。在云南研究不同土壤水分亏缺对白三叶种子发育和种子质量的影响,结果表明:各处理种子含水量均呈下降趋势。处理间比较,水分亏缺越大,含水量下降越快。两年种子干鲜重不灌水处理均最早达到最大值,轻度水分胁迫、中度水分胁迫次之。白三叶种子发育过程中可溶性糖含量逐渐下降,水分亏缺越大,可溶性糖含量下降越快。水分亏缺增加白三叶收获种子的硬实率,对白三叶种子的发芽和活力没有影响。

紫茎泽兰对两种牧草发芽的化感克异作用

研究了紫茎泽兰地上部分、根系及根际土壤不同浓度提取液对白三叶和多花黑麦草发芽的影响。研究结果表明:紫茎泽兰对白三叶和黑麦草种子萌芽存在化感克异现象,并且随浓度的增加,影响越大;相同条件下,对白三叶的影响强于多花黑麦草;低浓度对白三叶败育的影响较大,但对多花黑麦草几乎没有影响;紫茎泽兰根际土壤对两种牧草种子萌芽无明显的化感克异作用。

施肥对白三叶生长和营养成分的影响

以拉丁诺(Ladino)白三叶为供试材料,设计了4个磷肥水平(含P2O5分别为0、50mg/kg、100mg/kg、200mg/kg)并与适量氮肥(含N 50mg/kg)和钾肥(含K2O 100mg/kg)配施,在盆栽条件下研究不同施磷处理对白三叶生长、营养成分及磷素吸收的影响。结果表明:(1)单施高水平磷肥降低了白三叶种子的出苗率和出苗势,但高磷单施或与氮、钾肥配施有助于白三叶生长期快速出叶。(2)单施磷肥时,白三叶茎叶比显著升高(P<0.05),而磷肥与氮、钾肥配施时茎叶比下降;在施磷水平相同条件下,磷肥与氮、钾肥配施对地上生物量和干物质积累的增加效应优于单施,其中中等施磷水平(P2O5100mg/kg)与氮、钾肥配施时地上生物量最高。(3)无论是单施磷肥还是磷肥与氮、钾肥配施都能有效促进白三叶根系生长,显著提高根、茎、叶磷素含量(P<0.05);单施磷肥比磷肥与氮、钾肥配施更有利于白三叶根瘤菌的竞争结瘤。(4)不同磷肥水平单施或配施都显著提高了白三叶粗蛋白质含量和粗灰分含量(P<0.05),而粗脂肪含量在较低磷水平处理(P50N0K0和P50N1K1)时最高。

Phytochemicals and antioxidant activity of alcoholic/hydroalcoholic extract of Trifolium pratense

Objective:Trifolium pratense has many healing properties,including fewer complications of menopause,cancer cell suppression,reducing blood glucose and lipids,as well as cardiovascular beneficial effects.The purpose of this study was to identify the phytochemical and mineral composition of T.pratense.Methods:Plant aerial parts were harvested and dried,and then hydroalcoholic and alcoholic extracts were prepared.Gas chromatography-mass spectrometry(GC-MS)analytical method was used to identify volatile compounds then liquid chromatography-electrospray ionization mass spectrometry(LC-ESI-MS)was used to identify polyphenols and the mineral elements were identify by inductively coupled plasma atomic emission spectrometer/ICP-AES and scanning electron microscope-energy-dispersive X-ray spectroscopy(SEM-EDS)methods.Total phenolic content(TPC)was determined based on colorimetric method,and total flavonoid content(TFC)was established based on the folin-chiocalteau reagent.Furthermore,two assays(DPPH and FRAP)were used to measure the antioxidant capacity of T.pratense ethanolic extract.Results:A total of 37 polyphenols and 107 peaks were identified by LC-ESI-MS analysis,and the GC/MS method also detected 21 volatile compounds,the most important of which were methylcyclopentane,dimethylpentanal and hexadecanol.A total of 18 mineral elements,including K,Mg,Al,Si,Zn,Ni,Cu,Se,Co,Fe,Mn,and Ca in the plant,were identified ICP-AES and SEM-EDS analysis.Conclusion:T.pratense has many therapeutic compounds such as polyphenol(isoflavone and flavonoids),volatile compounds,and essential mineral elements,which can be formulated purely and used in the pharmaceutical and traditional medicine industries.