Competition of redroot pigweed (Amaranthus retroflexus L.) and nettle-leaved goosefoot (Chenopodium murale L.) with tomato (Lycopersicon esculentum Mill.) cultivars

Competition of 31 tomato (Lycopersicon esculentum Mill) cultivars with Amaranthus retroflexus and Chenopodium murale was investigated at different growing periods under natural conditions, University of Jordan, during 2008–2010. Cultivars were varied in their competitiveness with weeds; some tolerated while others were highly susceptible and exhibited great growth (shoot dry weight) and fruit yield reductions. A. retroflexus was more competitive than C. murale at most growing periods. Weeds attained high growth in the spring and summer but were much reduced in autumn. A. retroflexus requires relatively higher temperature for growth and competitiveness than C. murale. Gardners Delight and Special Back cultivars showed tolerance and their growth and yield either increased or least reduced in competition with weeds. In contrast, growth of First in the Field, Back More, Orient and Tiny Tim was reduced by 65–75% of their controls. Highest growth of weeds was in competition with The Amateur and lowest with First in the field and Back More. Fruit yield of all cultivars was reduced in competition, especially with A. retroflexus. Reduction was up to 100% in the spring. Both weeds reduced growth of cultivars most during the spring while A. reteroflexus eliminated certain cultivars.     

Delimitation of Amaranthus cruentus L. and Amaranthus caudatus L. using micromorphology and AFLP analysis: an application in germplasm identification

The ‘Morelos’ accessions of Amaranthus from Mexico demonstrate taxonomic ambiguity at the basic morphologic level. The main cause is the enormous morphological and genetic variation exhibited by the species in the genus. Although basic morphological criteria can be applied to herbarium specimens or germplasm collections for quick taxonomic identification, the morphological data alone can be misleading. To ascertain the taxonomic identity of the ‘Morelos’ accessions and their hypothesized species affiliation to Amaranthus caudatus or Amaranthus cruentus, we conducted a comparative analysis of phylogenetic relationships among these taxa/accessions using amplified fragment length polymorphism (AFLP) and micromorphology methods. Based on AFLP data, all the controversial ‘Morelos’ accessions can be consistently placed into a single A. cruentus species clade, which is clearly separated from the A. caudatus species clade. The AFLP-based phylogenetic relationship of ‘Morelos’ and delimitation of A. cruentus and A. caudatus are further supported by micromorphology, showing that the combination of these techniques can provide more reliable data for germplasm identification than each method used alone.     

浮床栽培绿叶蔬菜对富营养化水体的净化效果

用生菜和苋菜作为泡沫板浮床栽培材料,研究了其生长状况及对富营养化水体的净化效果。结果表明,生菜和苋菜在富营养化水体中可以正常生长。生菜28d内对富营养化水体中的TN、NH4＋-N、NO3--N、TP、PO43--P的去除率分别达到69.83%、85.41%、59.57%、76.58%和82.16%,苋菜28 d内对TN、NH4＋-N、NO3--N、TP、PO43--P的去除率分别为74.91%、89.58%、54.60%、78.53%和84.71%。生菜和苋菜能显著改善富营养化水体的水质,并且没有产生亚硝酸盐及重金属富集,符合食用标准。     

Comparison of the Chemical Composition and Nutritional Value of <Emphasis Type="Italic">Amaranthus cruentus</Emphasis> Flour and Its Protein Concentrate

Plants constitute an alternative source of proteins in the human diet, with advantages over animal proteins because of their low content of saturated fats and absence of cholesterol. Within the framework of a wider research project on the role of Amaranthus cruentus (Ac) in lipid metabolism, in this work the chemical composition and biological value of the Ac flour and its protein concentrate were compared. Proximate chemical composition, amino acid and fatty acid profiles, some antinutrient factors, and biological values were determined for Ac seed flour and its protein concentrate obtained by extraction at pH 11 and precipitation at pH 4.5. The flour protein content was 16.6 g% while that of the concentrate was 52.56 g%. The content of the soluble dietary fiber with a hypolipemic function was notably higher in the protein concentrate (12.90 g%) than in the seed flour (4.29 g%). The protein concentrate also exhibited a higher content of insoluble dietary fiber. The Ac flour and the concentrate contain 75.44 and 56.95% unsaturated fatty acids, respectively. Squalene, which affects the biosynthesis of cholesterol, was detected both in the flour and the concentrate oils, with a higher content in the concentrate (9.53%) as compared to the flour (6.23%). Comparison of the amino acid composition with the FAO pattern protein indicated that the concentrate does not have limiting amino acids, while the flour has leucine, threonine, and valine. The content of lysine was high in both the flour and the concentrate, making these products particularly useful as a complement for cereal flour, which is deficient in this amino acid. The biological quality analysis demonstrated an improvement in the quality of the concentrate. The presence of saponins, phytic acid, and trypsin inhibitors in the concentrate, which favor the metabolism of lipids, suggests that consumption of the concentrate might reduce the risk of heart disease.     

玉米田反枝苋对烟嘧磺隆的抗性水平及靶标抗性分子机理

为明确玉米田主要杂草反枝苋对烟嘧磺隆的抗性水平及靶标抗性分子机理,采用整株水平测定法检测了黑龙江省玉米田反枝苋对烟嘧磺隆的抗性水平,通过靶标酶离体活性测定,分析了抗性和敏感种群反枝苋乙酰乳酸合成酶 (ALS) 对烟嘧磺隆的敏感性,并通过靶标ALS基因克隆测序进行了序列比对分析。结果显示:黑龙江省反枝苋疑似抗性种群 (HLJ-R) 对烟嘧磺隆已产生较高水平抗性,其抗性倍数达13.7;酶活性测定结果表明:烟嘧磺隆对HLJ-R种群ALS活性的抑制中浓度 (IC₅₀) 值是对敏感种群 (TA-S) IC₅₀值的43.9倍;与TA-S种群相比,HLJ-R种群ALS基因205位丙氨酸突变为缬氨酸,574位色氨酸突变为亮氨酸。研究表明,黑龙江省玉米田反枝苋对烟嘧磺隆已产生较高水平抗性,且靶标ALS基因的突变可能是其抗性产生的主要原因之一。     

夏玉米地杂草为害的产量损失模型

为了明确杂草在对杂草密度与夏玉米产量损失之间的函数关系的影响及反枝苋和马齿苋为害夏玉主的产理损失模型,在田间开展了此项研究。试验结果表明,反枝苋和马齿苋为害均不显著地影响夏玉米的籽粒得和单位面积穗数,造成夏玉米产量损失主要是通过降低每穗的籽粒数要草密度和夏玉米产量损失之间的函数关系因杂草种类不同而异,描述反枝苋密度和夏玉米产量损失之间的关系用双曲线优于Ｓ形曲线,而描述马齿苋密度和夏玉米产量损失之间     

靶标基因突变导致入侵性杂草长芒苋对咪唑乙烟酸产生抗性

长芒苋Amaranthus palmeri生长迅速,适应性广,繁殖系数高,具有很强的竞争性,已在我国多地定植,对作物产量及生态环境构成潜在威胁.一旦其对除草剂产生抗性,将大大增加治理难度.本试验研究了采自不同地点的长芒苋种群对除草剂咪唑乙烟酸的抗性水平和抗性机理.整株生物测定得出,长芒苋疑似抗性种群和敏感种群对咪唑乙烟...     

千穗谷TALE转录因子家族的生物信息学分析

TALE转录因子广泛存在于植物中，对植物的生长发育和对外界环境的响应发挥着重要作用。本研究在千穗谷(Amaranthus hypochondriacus)基因组中共鉴定出11个TALE基因。系统发育分析将千穗谷TALE家族蛋白分为BELL和KNOX两个亚家族，同一亚家族中的AhTALEs基因具有相似的基因结构，编码蛋白也具有类似的结构域。蛋白二级结构和三级结构分析都表明AhTALEs蛋白由螺旋-角-螺旋的结构构成。此外，对千穗谷与其他物种的TALE基因共线性关系、组织表达特性和AhTALEs基因启动子区的顺式作用元件分析发现，不同AhTALEs亚家族在各组织中的表达模式不同，并且发现启动子区包含大量非生物胁迫和激素响应元件，这为AhTALE家族的进化分析提供了依据。qRT-PCR分析发现AhTALEs基因在低温和干旱胁迫下的表达水平有不同程度的变化，表明AhTALEs基因能够响应低温和干旱胁迫应答。本研究为开展千穗谷中TALE转录因子在非生物胁迫中的生物学功能研究提供了重要参考。     

不同老鸦谷种质资源萌发期的耐盐性评价

为评价不同地理来源老鸦谷(Amaranthus cruentus L.)种质的耐盐特性及其差异，选育耐盐老鸦谷新品种，以18份老鸦谷种质资源为材料，采用250 mmol/L NaCl溶液模拟盐胁迫，以灭菌蒸馏水为对照，测定盐胁迫下老鸦谷种子的萌芽和生长指标，并计算相对发芽势、相对发芽率、相对根长、相对芽长、相对发芽指数、相对活力指数等，运用隶属函数法和聚类分析法对其耐盐性进行综合评价。结果表明：250mmol/LNa Cl胁迫条件下所有参试材料的芽长和根长均受到不同程度的抑制，且根受抑制的程度大于芽受抑制的程度；盐胁迫对不同老鸦谷材料种子萌发和幼苗生长的抑制作用差异较大，根据隶属函数值和聚类分析结果，18份老鸦谷种质资源的耐盐性可以分为3大类，其中，耐盐性强的种质8份(Ace613、Ace660、Ace568、Ace655、Ace641、Ace659、Ace643和Ace649)，中度耐盐种质7份(Ace647、Ace621、Ace656、Ace671、Ace631、Ace628和Ace650)，耐盐性相对较弱的种质3份(Ace651、Ace617和Ace575)。