菟丝子属5个种的种子DNA微量提取方法比较

本研究以Cuscuta属中5个种的种子为实验材料,分别采用CTAB、SDS、Moller与TaKaRaDNA提取试剂盒这4种方法提取DNA;并对不同方法所提取DNA的纯度、DNA质量浓度、DNA提取率进行比较分析。结果表明：用SDS的方法对Cuscuta属5个种的种子DNA的提取为最佳方法。     

Chemical Control of Phalaris minor and Avena ludoviciana in Wheat

Abstract

In field experiments conducted at the Punjab Agricultural University, Ludhiana during 1973–74 and 1974–75, pre-emergence application (one day after sowing) of methabenzthiazuron (1.05 kg a.i./ha), metoxuron (1.6 kg a.i./ha) and chlortoluron (0.75 kg a.i./ha) gave effective control of Phalaris minor and Avena ludoviciana in wheat without any phytotoxic effect on the crop. Methabenzthiazuron, metoxuron and chlortoluron gave 1410, 1420 and 1090 kg/ha, respectively, more grain than the unweeded crop and 590, 600 and 270 kg/ha more than the crop hand-weeded twice. Nitrofen (1.25 kg a.i./ha) applied pre-emergence was effective against P. minor only and gave substantial increase in grain yield. Terbutryne, dichlormate and linuron, while effective against P. minor, also had a phytotoxic effect on the crop.     

Sorghum属7个近似种的DNA微量提取方法比较

本研究以Sorghum属中7个近似种的种子为试验材料,采用CTAB、SDS、CTAB与SDS相结合及TaKaRa DNA提取试剂盒等4种方法提取DNA,并对不同提取方法所获取的DNA纯度、浓度及DNA提取率进行研究分析比较.结果表明:采用Moller方法对其7个近似种的基因组DNA的提取为最佳方法.     

柑橘黄龙病病原DNA微量提取方法比较

对比分析了3种黄龙病病原DNA微量提取方法,方法1和方法2分别采用Sandrine等人和Hung等人的黄龙病病原DNA提取方法,但取样量分别由100mg和250mg减少为20mg和10mg;方法3采用周常勇等人的微量核酸提取方法,取样量为10mg.实验结果表明:方法1提取的病原DNA浓度低、杂质多,PCR效果差;方法2提取的病原DNA浓度较高、杂质少,PCR效果好,但提取周期较长,不适合大批量样品的PCR快速检测;方法3提取的病原DNA浓度较高、杂质少,PCR效果好,且提取速度快,适宜大批量样品的PCR快速检测.     

Improved management of Avena ludoviciana and Phalaris paradoxa with more densely sown wheat and less herbicide

Summary The effectiveness of crop competition for better weed control and reducing herbicide rates was determined for Avena ludoviciana and Phalaris paradoxa . Four experiments, previously broadcast with seeds of the two weeds in separate plots, were sown with three wheat densities, and emerged weeds were treated with four herbicide doses (0–100% of recommended rate). The measured crop and weed traits were first analysed across experiments for treatment effects. Grain yield and weed seed production data were then analysed using cubic smoothing splines to model the response surfaces. Although herbicide rate for both weeds and crop density for P. paradoxa had significant linear effects on yield, there was a significant non-linearity of the response surface. Similarly, herbicide rate and crop density had significant linear effects on weed seed production, and there was significant non-linearity of the response surface that differed for the weed species. Maximum crop yield and reduction in seed production of P. paradoxa was achieved with approximately 80 wheat plants m⁻² and weeds treated with 100% herbicide rate. For A. ludoviciana , this was 130 wheat plants m⁻² applied with 75% herbicide rate. Alternatively, these benefits were achieved by increasing crop density to 150 plants m⁻² applied with 50% herbicide rate. At high crop density, application of the 100% herbicide rate tended to reduce yield, particularly with the A. ludoviciana herbicide, and this impacted adversely on the suppression of weed seed production. Thus, more competitive wheat crops have the potential for improving weed control and reducing herbicide rates.     

一种改进的水稻总DNA的快速提取方法

植物总DNA的提取质量是植物分子生物学操作成败的关键,一个优秀的总DNA提取方法往往可以达到事半功倍的效果.本文以水稻叶片为材料,提出了一种改进的植物叶片总DNA快速提取方法,该方法能在35min之内提取到水稻总DNA.电泳结果表明此改进方法提取的总DNA产量与传统CTAB法相当,PCR扩增结果表明其质量可靠,完全可以满足分子生物学操作的要求.     

Spatial stability of Avena sterilis ssp. ludoviciana populations under annual applications of low rates of imazamethabenz

Long‐term experiments were conducted in two winter barley fields in central Spain to determine the spatial stability of Avena sterilis ssp. ludoviciana populations under annual applications of low rates of imazamethabenz herbicide. Weed density was sampled every year (over 5 years in the first field and over 3 years in the second) on the same grid locations prior to herbicide application. Although weed patches were stable in their location, weed density decreased in most of the years. In the first field, the populations decreased exponentially over the 5‐year period. The rates of population decline were dependent on the initial density of the population, being higher for the central core of the patches and lower for the low‐density areas. Under the conditions present in this experiment, it was possible to reduce heavy weed patches (up to 1200 seedlings m^?2) down to relatively safe levels (18 seedlings m^?2) in a period of 3 years using a density‐specific control programme, applying low rates of herbicides when weed densities were below a given level (1000 seedlings m^?2). However, under adverse environmental conditions, half rates of the herbicide failed to control the weed populations adequately. The stability of the location of patches of A. sterilis ssp. ludoviciana suggest that weed seedling distributions mapped in one year are good predictors of future seedling distributions. However, the actual densities established each year will depend on the control level achieved the previous year and the climatic conditions present during the establishment period.     

小麦光腥黑粉菌冬孢子总DNA提取方法比较

以小麦光腥黑粉菌冬孢子为试验材料,比较分析了改良CTAB法、氯化苄法、SDS法对小麦光腥黑粉菌冬孢子总DNA提取的效果。结果表明,SDS法无论在DNA纯度(R=A260 nm/A280 nm)和产量上均优于氯化苄法和CTAB法。利用SDS法能获得186 ng/mg的DNA产率,而氯化苄法和CTAB法只能分别获得145 ng/mg和112 ng/mg。采用SDS法提取的DNA纯度较高,-RSDS=1.485,氯化苄法(BC)和CTAB法所得DNA纯度无明显差异,分别为-RCTAB=1.254和-RBC=1.264。     

Field evaluation of a decision support system for herbicidal control of Avena sterilis ssp. ludoviciana in winter wheat

Two field studies were conducted in Central and Northern Spain over a total of five seasons to assess the usefulness of a decision support system (AVENA-PC) from agronomic, economic and environmental points of view on herbicidal control of Avena sterilis ssp. ludoviciana in winter wheat. The control treatments evaluated were: (i) AVENA-PC-based recommendations, (ii) full herbicide dose (standard farmer practice), (iii) half herbicide dose and (iv) no herbicide. The herbicide rates used in the AVENA-PC treatment averaged 65% and 30% lower than the full and half dose treatments respectively. AVENA-PC implementation controlled A. ludoviciana with similar efficacy as standard herbicide treatments. Nevertheless, it did support a reduction in relation to the non-herbicide treatment. Yields obtained with AVENA-PC were, in general, not statistically different to those obtained with herbicide treatments and were on average 69% higher than those in the no herbicide application strategy. Comparing AVENA-PC economic performance with the other treatments there were, in general, no significant statistical differences in Central Spain. In Northern Spain, all herbicide treatments had similar net returns, with there being no statistical differences between AVENA-PC and the herbicide treatments. However, there were differences recorded with the non-herbicide treatment. The results of this research indicate that AVENA-PC, due to its flexibility, may recommend less herbicide than the standard farmer practice, providing clear environmental benefits and adequate weed control with maintained crop yield and net returns similar to standard farmer practice.     

烟粉虱基因组DNA快速提取方法

以B型烟粉虱为材料,应用改进的方法-氯仿/异戊醇抽提法提取了高质量单头烟粉虱基因组DNA。该方法不仅可用于成虫基因组DNA的提取,对烟粉虱拟蛹及卵同样具有较高的提取效果;同时,该方法操作简便、快捷,较常用的醋酸钾抽提法节省时间3～4h,提高工作效率2.5倍。