银胶菊根际土壤化感作用的初步研究

研究银胶菊根际土壤浸提液对蔬菜种子和幼苗的化感作用。采用水浸提法制备不同浓度的银胶菊根际土壤浸提液,用生物测定法测定其对上海青、甜菜、苋菜种子萌发和幼苗生长的化感效应。银胶菊不同浓度土壤浸提液对3种植物种子萌发总体具有抑制作用,但对甜菜的GI表现为促进作用,同一浓度的土壤浸提液对3种植物种子发芽率的抑制作用大小顺序为苋菜>上海青>甜菜。与对照相比,幼苗根长和苗高发生明显变化;游离脯氨酸含量均高于对照,且随浸提液处理浓度的增加呈现升高趋势,而可溶性糖含量变化的趋势不一致。银胶菊根际土壤浸提液具有一定的的化感效应,且对不同植物及不同生长特性的化感效应具有选择性。     

Evaluation of amplified fragment length polymorphism markers in tef, Eragrostis tef (Zucc.) Trotter, and related species

Tef is an important cereal crop in Ethiopia. This study was conducted to investigate (1) genetic diversity within and among three Eragrostis species (E. tef, E. pilosa and E. curvula), and (2) the relationship between E. tef, E. pilosa and E. curvula. A total of 529 AFLP markers were obtained, out of which 58% (368) were polymorphic, using 10 primer, combinations. The three species were separated distinctly using amplified fragment length polymorphism (AFLP), However, diversity revealed at the morphological trait level was not commensurate with that observed for AFLP. This was due to the small number of morphological traits available and their interaction with the environment. Within tef, ‘Rubicunda’ and DZ‐01‐1093 were found to be distantly related to the rest of the tef accessions. The diversity within species was such that E. pilosa was the most diverse followed by E. curvula and E. tef. Moreover, E. pilosa was more closely related to E. tef than E. curvula. Therefore, further study is needed of E. pilosa accessions and of ‘Rubicunda’ and DZ‐01‐1093 in a crossing programme to generate a population for selection and/or genetic mapping. A total of 19 cultivars or accessions had one or more unique fragments using one or more AFLP primers, indicating the potential of the technology in fingerprinting tef in a breeding or seed multiplication programme.     

Smoke-Water and a Smoke-Isolated Butenolide Improve Germination and Seedling Vigour of Eragrostis tef (Zucc.) Trotter under High Temperature and Low Osmotic Potential

The seeds of Eragrostis tef are often exposed to high temperatures and low water availability during unfavourable climatic conditions. This affects germination and seedling stand establishment of the crop. Smoke is currently widely studied for its stimulatory role in seed germination. The effect of smoke-water and a smoke-isolated butenolide was investigated on E. tef seed germination and seedling growth at different temperatures, light conditions and osmotic potentials. Treating E. tef seeds with smoke-water and butenolide increased the percentage germination relative to the control at all tested temperatures. These treatments significantly improved seedling length and the vigour index at 25, 30, 35 and 40 and 30/15 °C. Smoke-water and butenolide increased percentage imbibition from high to low osmotic potential. In comparison with the control, smoke-water- and butenolide-treated seeds of E. tef showed higher percentage germination with decreasing osmotic potential. Smoke-water treatment exhibited significantly longer and more vigorous seedlings than the control between 0 and −0.30 MPa osmotic potential. The findings of this study suggest the possibility of using smoke treatments for minimizing E. tef seedling losses at elevated temperatures and water stress.     

板栗叶水浸液对3种中药材种子萌发及幼苗生长的影响

选取商洛道地中药材桔梗、黄芩和丹参,研究不同浓度(0,5,10,20,30,40 mg/mL)板栗叶水浸液对3种受体中药材种子萌发和幼苗生长的影响.结果表明,低浓度板栗叶水浸液对3种中药材种子的萌发有明显的化感促进作用,但随着水浸液浓度的不断提高,其对受体种子的化感促进作用逐渐减弱并消失,开始表现为抑制作用.板栗叶水浸液在5～20 mg/mL浓度范围内对3种受体中药材种子的发芽率、发芽势、发芽指数、相对电导率、游离氨基酸含量、可溶性糖含量、可溶性蛋白含量以及幼苗根长、苗高均表现为化感促进作用,但超过其临界值就开始表现为化感抑制作用.其总体趋势呈“抛物线”形规律.板栗叶水浸液在试验浓度范围对桔梗、黄芩、丹参种子萌发和幼苗生长有一定的促进作用.     

核桃醌对黄芩种子萌发和幼苗生长的影响

为探讨核桃和黄芩复合种植的可行性,本文通过室内盆栽试验的方法研究了核桃主要化感物质核桃醌溶液对黄芩种子萌发及幼苗生长的影响。试验结果表明：核桃醌对黄芩种子的萌发主要表现出抑制作用,随着浓度的升高,抑制作用逐渐增强;对幼苗生长的影响则受到核桃醌浓度和黄芩幼苗密度双因素的影响,在高浓度或高密度下表现出较强的抑制作用,在低浓度高密度下则表现出一定程度的促进作用,但此促进作用主要针对地上部分生物量,对具有较高药用价值的根部则表现出强烈的抑制作用,因此本文认为核桃和黄芩并不适宜采用林药复合种植模式。     

Diversity among germplasm lines of the Ethiopian cereal tef [ Eragrostis tef (Zucc.) Trotter]

Three hundred twenty germplasm lines of the major Ethiopian cereal, tef, [ Eragrostis tef (Zucc.) Trotter], were evaluated for 20 morphological, phenological and agronomic characters in two-replicated randomized complete blocks at Debre Zeit and Melkassa Agricultural Research Centers in Ethiopia during the 1995 main season. The objectives were to assess the diversity of the lines, and to estimate the broad sense heritability (H) and genetic advance (GA) of the various characters. The mean squares of genotypes were highly significant (p ≤ 0.001) for all the traits. The phenotypic and genotypic coefficients of variation ranged in that order from about 6–40% and 3–23% for days to maturity and grain yield/plant, and days to maturity and number of spikelets/main shoot panicle, respectively. The cluster analysis grouped the genotypes into 14 major complexes consisting of one to 183 lines. Of the 19 principal components involved in explaining the entire variation among the genotypes the first five which had eigenvalues of more than one explained about 73.8%. The first principal component which accounted for about 34% of the total variance was due chiefly to plant height, culm and panicle length, diameters of the two basal culm internodes, main shoot panicle mass and grain yield, number of main shoot panicle branches and spikelets, and days to panicle emergence and maturity. Estimates of H varied from about 22% for length of the lowest main shoot stem internode to 74% for number of main shoot panicle branches. Values of GA (expected from selection of the superior 5% of the lines and expressed relative to the means) ranged from about 3% for days to maturity to 36% for number of spikelets/main shoot panicle. Overall, the study indicated the existence of trait diversity in tef germplasm and this can be exploited in the genetic improvement of the crop through hybridization and selection. This revised version was published online in July 2006 with corrections to the Cover Date.     

紫茎泽兰不同处理方法水提液对云南松幼苗生长的化感作用

为了解样品处理方法对化感作用大小的影响,用紫茎泽兰地上部分的完整鲜样、剪碎鲜样及杀酶烘干样3种不同处理方法的水提液对云南松种子进行处理,观察对种子发芽后幼苗生长的影响。结果表明,不同处理方法水提液对云南松幼苗生长的化感作用不同。总体上看,浓度为0.04 g/mL时,不同处理方法水提液对云南松幼苗生长都具有极显著或显著的抑制作用,杀酶烘干样、剪碎鲜样水提液的抑制效应明显大于完整鲜样水提液,完整鲜样与杀酶烘干样、剪碎鲜样之间差异达到极显著或显著水平;随着浓度的降低,不同处理方法水提液对云南松幼苗生长的抑制作用减弱,甚至转为促进作用,完整鲜样起促进作用的临界浓度较杀酶烘干样、剪碎鲜样的高。化感作用的作用形式及作用大小往往与样品处理方式密切相关,在水提实验中,建议用完整鲜样进行浸提。     

Genetics of grain yield and other agronomic characters in t'ef (Eragrostis tef Zucc Trotter). II. The triple test cross

The normal and selfed families of the triple test cross were employed to detect gene action in t'ef for grain yield and other useful agronomic characters in the breeding programme. Cultivars Kay Murri and Fesho were used as L₁ and L₂ testers, respectively. Eight randomly selected cultivars and two released varieties (DZ-01-354 and DZ-01-196) were crossed with the testers L₁, L₂ and L₃ (the F₁ of L₁ × L₂). In the case of the selfed families, 14 cultivars and two released varieties were used for crossing with the testers. The normal families were grown on an Inceptisol developed from volcanic ash whilst the selfed families were grown on a pellic Vertisol at the Debre Zeit Agricultural Research Centre, Ethiopia. The rainfall during the experimental season was 463 mm. Epistasis was detected for grain yield, yield per panicle, panicle weight, plant weight, harvest index, tiller number, panicle length, culm diameter, days to heading and days to maturity in the normal families of the triple test cross (TTC) of t'ef. Similarly the characters grain yield, yield per panicle, panicle weight, plant height, panicle length, days to heading and days to maturity showed epistasis in the selfed families of the TTC. Epistatic interaction was not important for shoot biomass and for harvest index (for the transformed data) in this family. Therefore, both the normal and selfed families of the TTC were in agreement with regard to detecting epistasis for grain yield, yield per panicle, panicle weight, panicle length, days to heading and days to maturity. Significant additive (D) and dominance (H) components were estimated for the characters in both families, although the magnitudes might have been inflated due to epistasis. The dominance component for panicle length was unimportant in both families of the TTC and as a result the additive components were not biased. In general, the additive, dominance and epistatic components were important in t'ef. Since the crop is self-fertilized only the additive and additive × additive terms are important to develop pure breeding varieties. Therefore, selection for superior segregants should start in advanced generations as homozygosity increases. This revised version was published online in July 2006 with corrections to the Cover Date.     

黄花蒿对绿豆种子萌发及幼苗生长的化感效应

以绿豆种子为受体,采用室内生测法,探讨黄花蒿不同部位水浸提液对绿豆种子的萌发率、幼苗生长及叶绿素含量的影响。结果表明:黄花蒿各部位(根、茎、叶)水浸提液随处理浓度增加,对绿豆的化感效应增强,对种子萌发的抑制强弱为:叶>茎>根,且随处理浓度升高,发芽率降低;对幼苗的根系生长表现为低浓度(20mg/mL根、茎水浸提液)促进,当浓度高达40mg/mL均有明显抑制作用;幼苗高度总体降低,最高降幅分别为46.29%,47.67%和56.48%;叶绿素a和叶绿素b的含量也不同程度减少。可见黄花蒿影响绿豆种子萌发及幼苗生长,因此大面积栽培黄花蒿或绿豆种植应考虑黄花蒿的化感效应。     

Heritability and genetic advance in recombinant inbred lines of tef (Eragrostis tef)

Recombinant inbred lines (RILs) of the tef cross Kaye Murri × Fesho were evaluated for nine quantitative traits at three locations in the central highlands of Ethiopia during the 1998/99 main season in order to estimate the genetic coefficient of variation (GCV), heritability and genetic advance expected from selection. Highly significant differences were obtained among the RILs for all traits studied. Grain yield, panicle weight and yield per panicle showed a relatively high GCV (12–16%). A comparatively high heritability was obtained from days to heading (31%) followed by panicle length (25%) and grain yield (23%). Moderate amounts of heritability values were obtained for panicle weight and yield per panicle. High genetic advance as percent of the mean were obtained from grain yield (16%), yield per panicle (12%) and panicle weight (10%) at5% selection intensity, which indicated the possibility of improving these traits. Several RILs were identified that have exceeded the better yielding parent at all locations. Grain yield showed a strong positive association (r = 0.26–0.70) with shoot biomass, lodging index, panicle length, plant height, panicle weight and yield per panicle. Overall, the present results showed a) the availability of genetic variance for some useful traits in the RILs for exploitation through selection, b) the existence of significant genotype × location interaction that indicated the need to test inbred populations in more environments, and c)the availability of superior inbred lines for further breeding work. This revised version was published online in August 2006 with corrections to the Cover Date.     

红三叶(Triolium pratense L.)浸提液对种子的化感效应

以普通红三叶种子为受体,采用培养皿滤纸法,初步研究了红三叶对6种不同浓度(0.025,0.05,0.075,0.10,0.15,0.20 g/mL)叶浸提液的化感响应.结果表明,红三叶的叶浸提液对其种子的发育具有不同程度的化感影响.红三叶不同浓度的叶浸提液对种子发芽势表现出"低促高抑"的浓度效应,而对发芽率表现出一定的抑制作用;红三叶不同浓度的叶浸提液对胚根长具有极强的抑制作用(p＜0.01),而对下胚轴长既具有抑制作用又有促进作用,且在一定浓度范围内表现出"低促高抑"的现象.     

小麦秸秆浸提液和腐解液对棉花种子发芽及幼苗生长的化感效应

于2014年在江苏南京江苏省农业科学院人工气候室内进行水培试验,以中棉所50为材料,设置5个小麦秸秆浸提液和腐解液含量(质量分数1.0%,3.0%,5.0%,7.0%和10.0%),研究小麦秸秆浸提液和腐解液对棉花种子萌发和根系发育的影响,明确小麦秸秆对棉花生长的化感效应。结果表明:随秸秆浸提液和腐解液含量升高,浸提液和腐解液中氮、磷、钾和总酚酸含量持续升高;相同含量下,腐解液中氮和磷含量与浸提液差异不显著,而钾和总酚酸含量高于浸提液。≤7.0%的浸提液和≤5.0%的腐解液只延迟了棉花种子发芽时间,并未影响发芽率;高于此含量时,两者不仅延迟发芽时间,而且降低发芽率。浸提液和腐解液含量高达3.0%后显著抑制棉花主根伸长、缩短侧根发生区、减少侧根数量、降低根系总表面积和总体积,并随含量增加,抑制和降低作用显著增强。低含量的小麦秸秆浸提液与腐解液显著促进根系呼吸速率和根系活力,当浸提液与腐解液含量高于3.0%时,根呼吸速率与根活力显著降低,而MDA含量却随含量提高而显著增加。小麦秸秆浸提液和腐解液中总酚酸和养分含量与其化感效应有关,高含量的浸提液和腐解液抑制棉花种子萌发、根系形态指标建成和根系呼吸,同等浓度下,小麦秸秆腐解液对棉花的化感效应强于浸提液。     

空心莲子草水浸提液对3种暖季型草坪草种子萌发与幼苗生长的影响

为研究空心莲子草对草坪草的化感作用,以3种常见暖季型草坪草(细叶结缕草、地毯草和狗牙根)为试验材料,采用培养皿滤纸法对不同浓度空心莲子草水浸提液对3种常见暖季型草坪草种子萌发的影响进行研究。结果显示:空心莲子草全株水浸提液对细叶结缕草种子萌发的影响随着浓度的增加而抑制作用加强;对地毯草种子萌发,在0.125、0.25 g/mL浓度条件下具有促进作用,在0.0625、0.5 g/mL具有抑制作用;对狗牙根种子萌发影响表现出高浓度抑制、低浓度促进的双重效应。表明空心莲子草具有较强的化感作用,通过向周围环境释放化感物质影响种子的萌发和幼苗生长。     

紫茎泽兰对蓝桉种子萌发及苗生长的化感作用

紫茎泽兰为桉树林下革本层的优势种,为探讨紫茎泽对蓝桉种子萌发及苗生长的化感作用,采用盆栽试验,用其叶不同浓度水提液(0,0.005,0.01,0.02,0.04 g/mL)对蓝桉种子进行处理.结果表明:不同浓度水提液对蓝桉种子萌发(发芽速率、发芽势、发芽率)、苗生长(地径、高度)及生物量(根重、茎重、叶重、总重)均有显著的影响;随着处理浓度的增加,种子萌发、苗生长、生物量受抑制作用增强;种子萌发、苗生长、生物量与处理浓度之间均呈极显著负相关.处理60 d比处理30 d对苗生长的化感抑制作用加大,说明蓝桉幼苗生长受抑制作用随处理时间延长而增大.在林下及林缘广泛分布的紫茎泽兰,可通过化感作用影响蓝桉的天然更新和生长.     

紫茎泽兰对杉木种子萌发及幼苗生长的化感作用

为探讨紫茎泽兰地上部分气态挥发物对杉木种子发芽的化感作用,在半透明密闭保鲜盒内分别用25,75,225 g紫茎泽兰新鲜茎叶对杉木种子进行处理.结果表明,不同质量处理对杉木种子发芽过程有明显的影响,随着处理质量的增加,首日发芽数量下降,达到发芽高峰的天数延迟,发芽高峰当天发芽数降低,发芽过程曲线图由对照的急升急降逐渐变缓.不同质量处理对杉木种子萌发(发芽势、发芽率、发芽速率、萌发指数)及幼苗生长(胚根长、胚轴长、鲜重、干重)均有显著的影响.25 g处理时对种子萌发及幼苗生长抑制作用较弱,随着处理质量的增加,抑制作用增强.杉木种子萌发及幼苗生长与处理质量之间呈极显著或显著的负相关,这些指标随着处理质量的增加呈直线下降.紫茎泽兰在林下及林缘的广泛分布,可通过化感作用影响杉木的天然更新和生长.     

紫茎泽兰不同处理方法水提液对云南松种子萌发的化感作用

用紫茎泽兰地上部分的完整鲜样、剪碎鲜样及杀酶烘干样3种不同处理方法的水提液对云南松种子进行处理,观察其对种子萌发的影响.结果表明,不同处理方法水提液对云南松种子萌发的化感作用不同.完整鲜样及低浓度(0.002 5 g/ml)杀酶烘干样水提液发芽高峰出现在第6天,其它处理及对照高峰出现在第7天.就发芽势及发芽速度而言,高浓度时(0.04 g/ml),剪碎鲜样及杀酶烘干样抑制作用较完整鲜样的强,中(0.0l g/ml)低浓度时完整鲜样促进作用大于剪碎鲜样,大部分完整鲜样与杀酶烘干样、剪碎鲜样之间差异达到极显著或显著水平,而杀酶烘干样与剪碎鲜样之间差异不显著.对发芽率来说,3种不同处理方法之间差异都不显著.化感作用的作用形式及作用大小往往与样品处理方式密切相关,在水提实验中,建议用完整鲜样进行浸提.     

红小豆根系水浸提液对4种受体作物的化感作用

为选择适合红小豆的接茬作物,采用室内培养皿生物测定方法,对不同浓度的红小豆根系水提液下红小豆、萝卜、白菜、小麦的化感效应进行了研究。结果表明：红小豆水提液对自身种子发芽率、发芽指数具有极强的化感抑制作用;随着红小豆根系水提液浓度的增大,3 种受体作物的种子发芽率和发芽指数均呈现降低趋势;从幼苗的根长、幼叶长、侧根数、株高及鲜质量等形态指标上来看,只有小麦随着红小豆根系水提液浓度的增大呈现出促进作用,其余2 种受体作物均呈现出抑制作用,但这种抑制作用在低浓度下差异不显著;萝卜、小麦的SOD、POD活性随着红小豆根系水提液浓度的增大而增强,但白菜的2 种酶活性呈现出下降趋势;小麦、萝卜幼苗的MDA含量表现出降低,白菜MDA含量却显著增加。说明受体作物小麦可作为红小豆的轮作作物、萝卜在与红小豆轮作方面也有着很大的应用潜力。     

皱叶酸模水提液对种子萌发和幼苗生长的影响

研究了不同浓度的皱叶酸模水提液(5,10,20,40 g/L)对3个蔬菜品种(小白菜、上海青、油麦菜)种子萌发、幼苗生长的化感作用。结果表明:皱叶酸模对蔬菜化感效应的总体趋势为:随着水提液浓度升高,对蔬菜生长的抑制作用越强;用20 g/L的浸提液处理,主要形态和生化指标都表明蔬菜的生长受到了显著抑制或破坏;在小于10 g/L的浓度范围内,皱叶酸模的化感作用能够提高低活力种子的萌发率,但降低了种子的发芽速度,且化感作用受受体品种差异和种子自身活力的影响而表现不一致;随着化感物质浓度升高,蔬菜幼苗生长受皱叶酸模化感作用的影响为:对根长的影响大于对苗高的影响。     

羌活种子浸提液对3种作物种子萌发及幼苗生长的化感作用

[目的]探讨提高羌活种子快速萌发的最佳方法.[方法]通过室内生物测定法,研究在不同温度下提取羌活种子浸提液,并配制成不同浓度处理小白菜、黑麦和芹菜3种作物种子,以观察其对3种作物种子的萌发和幼苗生长的化感作用.[结果]实验结果表明,在35℃条件下提取的羌活种子浸提液对3种作物种子萌发及幼苗生长各指标的抑制作用最强,其次为25℃,而15℃最弱;对3种作物的萌发率、发芽势、根长、地下鲜重的测定结果均显示,随着浸提液浓度的增加其抑制作用显著增强;对苗高和地上鲜重2个指标的研究发现,小白菜和芹菜幼苗的生长随浸提液浓度升高,呈现出“低促高抑”的现象.另外,3种作物幼苗根系的SOD酶及小白菜和黑麦的POD酶活性都随浸提液浓度的增加表现为持续增高,而芹菜根系POD酶活性却呈“先升后降”趋势.[结论]:适宜温度下浸泡羌活种子有助于减少羌活种子的化感物质,提高萌发率,低浓度有促进小白菜和芹菜幼苗生长的作用,而较高浓度对3种作物幼苗具有一定的损伤作用.