鲤肠黄脉病样中烟粉虱传双生病毒的检测

在严重发生番茄曲叶病的田间,发现主要杂草鲤肠表现出叶脉褪绿黄化、叶片皱缩或卷曲等症状,田间病株率达63%;用烟粉虱传双生病毒兼并引物对随机采集的20个鲤肠病样进行PCR检测,结果发现,从这些病样中均能扩增出1条356 bp的特异片段;室内人工接种试验结果显示,鲤肠分离物可以侵染番茄而引起曲叶症状。因此,鲤肠可能是广东番茄曲叶病毒的自然中间寄主。     

鳢肠成株及结实等特性研究

鳢肠平均株高64.89 cm,分布范围18.40～103.58 cm;平均鲜重44.3657 g,分布范围14.8834～74.5400 g;平均分枝8.94个,分布范围1.27～16.34个.由结实调查结果可知,鳢肠平均果盘数每株113个、种子粒数为每果盘89粒、种子千粒重为0.4697 g,平均理论结实量为每株10 057粒.     

扁蓿豆,冷蒿和木地肤枝条净光合速率与光照关系的动态特征

本文作者研究了典型草原地区扁蓿豆，冷蒿和木地肤不同生育期的枝条在适宜条件下净光合速度与光强的关系。结果表明：（１）三种植物的光饱和点，净光合速率和净光合速率／光强均随着生育期的后移而下降；光补偿点则从营养期到开花期呈升高趋势；（２）在营养期，三种植物的最大净光合速率与最大自然光强下的净光合速率／光强相近，但随着生育期的后移，扁蓿豆上述指标降低值明显小于冷蒿和木地肤。     

Altica cyanea (Col: Chrysomelidae) for the biological control of Ludwigia prostrata (Onagraceae) in China

Abstract

Altica cyanea (Weber) damages Ludwigia prostrata Roxb in China. It is multivoltine, having up to six generations a year. The host range of the beetle was examined in the field and in the laboratory, and it was demonstrated that A. cyanea occurs on and attacks the main host L. prostrata and another weed, Rotala indica Koehne. Its ability to damage L. prostrata was studied in field cages in Nanchang. A. cyanea was shown to damage these caged plants heavily and to be a promising biological agent for this weed.     

Sublethal effects of environmentally relevant run‐off concentrations of glyphosate in the root zone of Ludwigia peploides (creeping water primrose) and Polygonum hydropiperoides (smartweed)

As one of the most widely applied agricultural chemicals in the world, glyphosate has many effects on the environment. The present study quantified plant responses to exposure by glyphosate through the root zone for a range of concentrations (0, 10, 100 and 1000 μg L^?1). Ludwigia peploides and Polygonum hydropiperoides were grown in a greenhouse and given a single exposure to glyphosate via the root zone. The growth and physiological parameters were measured before exposure and for 18 days postexposure. The growth variables that were measured included the relative growth rate, stem length increase, biomass and root‐to‐shoot‐ratios. The physiological variables that were measured were the chlorophyll content index and chlorophyll fluorescence. The data analyses revealed that the root‐zone glyphosate affected some of the measured variables in P. hydropiperoides more than for L. peploides. Polygonum hydropiperoides showed a significant decrease in the root‐to‐shoot ratios for the 100 μg L^?1 treatment, compared to the 10 μg L^?1 treatment. The chlorophyll content index of the treated plants was significantly reduced in P. hydropiperoides, compared to the untreated plants on Days 7 and 18. Ludwigia peploides was affected only on the day after exposure, with the chlorophyll fluorescence parameters being significantly less for the 1000 μg L^?1 treatment, compared to the 10 μg L^?1 treatment. Glyphosate‐treated P. hydropiperoides showed a decreased chlorophyll content and reduced chlorophyll fluorescence parameters. In contrast, L. peploides showed a decrease in the chlorophyll fluorescence parameters but no reduction in its chlorophyll content. In addition to demonstrating the adverse effects of root exposure to glyphosate for the study species, these data help to partially explain the highly invasive and persistent nature of L. peploides in marginal aquatic environments, such as agricultural ditches.     

正交试验法优选鳢肠总黄酮提取工艺

[目的]优化鳢肠总黄酮的提取工艺。[方法]采用单因素试验和正交试验法,以总黄酮提取率为评价指标,研究了乙醇浓度、提取时间、提取温度、溶剂用量4种因素对总黄酮提取的影响。[结果]各因素对鳢肠总黄酮提取率的影响从大到小依次溶剂用量、乙醇浓度、提取时间、提取温度;最佳提取工艺为乙醇浓度40%、提取时间2 h、提取温度80℃、溶剂用量25倍,此条件下鳢肠总黄酮平均提取率达71.01%。[结论]该提取工艺简单可行,具有良好的稳定性和重复性,可为鳢肠总黄酮的工业化生产提供参考。     

河南水生植物一新记录——卵叶丁香蓼

本研究报道了河南柳叶菜科(Onagraceae)一新分布种——卵叶丁香蓼(Ludwigia ovalis)。该种花管和花瓣均不存在,雄蕊和萼片均为4,且萼片花后宿存等与近缘种区分明显。该植物过去记载仅分布于长江以南,而其分布在河南光山县(114°80'E,31°87'N),应该是其现在自然分布区的最北边界。     

11种稻田除草剂对丁香蓼的室内生物活性

采用室内盆栽试验方法开展了11种稻田常用除草剂对丁香蓼生物活性研究, 结果表明:在丁香蓼芽前使用10％吡嘧磺隆WP、40%苄嘧·丙草胺WP, 0~2叶期使用19%氟酮磺草胺SC、120 g/L噁草酮EC, 2~4叶期使用200 g/L氯氟吡氧乙酸EC、3%氯氟吡啶酯EC、25 g/L五氟磺草胺OD、〖JP+2〗100 g/L双草醚SC和4~6叶期使用460 g/L 2甲·灭草松AS, 对丁香蓼的ED90分别为4.18、10.30，1.61、241.60，7.31、9.74、11.83、28.96和117.73 g/hm2, ED90均低于供试药剂的田间常用推荐剂量, 证明丁香蓼对上述药剂敏感, 可作为生产上防除丁香蓼的候选药剂。     

“墨菜”诗画的文化内涵及其现实意义——从《论语》“疏食”歧解谈起

“墨菜”图与传统的“蔬食”观念一脉相承，它以诗画结合的方式道出了传统知识分子特殊的情结与信念：安贫乐道、淡泊自守的隐逸情操；躬耕田亩、摘蔬侑酒的田园情趣；不为物役、淡中至味的哲理体悟；咬定菜根、百事可成的笃定精神以及心怀天下、体恤民生的社会责任感。“墨菜”诗画所蕴含的文化内涵在当下仍具有积极意义。