Lateral growth of a wheat dough disk under various growth conditions

Numerous studies have tried to understand and model bubble growth inside dough. Experimental studies are inconvenienced by the methods’ inability to capture the dynamic phenomena. In this paper, a versatile experimental method was developed to allow for macroscopic expansion of wheat dough. The study evaluates expansion of a dough disk under varying: moisture content (40, 41, 42, 43, and 44% wb), leavening acid concentration (30, 40, and 50% db), pressure schemas, pressurizing gas (compressed air and CO₂), and lubrication (Teflon^® film coating and Pam^® aerosol lubricant). Dough expansion increased 22.6% by increasing moisture content from 40 to 44%. Increased baking powder formulation (40% db) was used to enhance initial growth conditions and CO₂ production. ‘Pressure pulse’ and ‘pressure vacuum methods’ added pressurization alternatively with full vacuum. The former method included a rest period before vacuum application, and increased expansion by 10.8%. Teflon^® and Pam^® reduced friction between the dough and acrylic plate and increased the final expansion by 14.7% compared to no lubricant following the ‘standard pressurization method’. ‘Pressure pulse’ and ‘pressure vacuum’ experiments decreased expansion by 28.4 and 38.2%, respectively compared to ‘standard pressurization’ while using Teflon^® and Pam^®.     

The effect of some acid-based additives applied to wet grass crops under various ensiling conditions

Some acid‐based silage additives, which are less corrosive and easier to handle than Formic acid 85% (FA), were evaluated in a laboratory‐scale silage experiment. These were Foraform (645 g kg^–1 formic acid, 60 g kg^–1 NH₃), Ensimax [213 g kg^–1 formic acid, 200 g kg^–1 acetic acid, 190 g kg^–1 of dry matter from wood pulp liquor with a high concentration of lignosulphonates (WPL)], and a modified version of Ensimax with a higher proportion of formic acid and a lower proportion of acetic acid. Each single ingredient, and all combinations of ingredients in the original Ensimax, were studied when applied in the quantities they make up in the additive. Untreated silage was used as a negative control and FA as a positive control. The additives were assessed using three different crops and by sealing the silos immediately after filling or after a 24 h delay. Both the full and half of the recommended application rates of the additives and of the single ingredients of Ensimax were studied. No significant differences were found between FA and Foraform when applied at 3 and 4 l t^–1, respectively, which provided the crop with the same dose of pure formic acid. Inclusion of WPL in Ensimax did not influence silage fermentation, i.e. the effect of Ensimax could be ascribed to the effect of formic plus acetic acid alone. Compared with Ensimax, the modified version, in which 148 g kg^–1 of formic acid was substituted for 150 g kg^–1 of acetic acid, clearly improved fermentation in terms of increased concentration of true protein, reduced fermentation of acetic and propionic acid, and reduced ammonia value and pH. When the silos were sealed immediately, sugar concentrations in the silage correlated positively with the application rate of acids, whereas no such relationship was found when the sealing was delayed for 24 h. No consistent relationship was found between the application rate of acids and ethanol concentrations in the silage. Easy‐to‐handle acidic additives like Foraform and Ensimax may replace FA when applied according to their molar concentration of acids. This means that 4·0 l t^–1 of Foraform and 7·3 l t^–1 of Ensimax are equivalent to 3 l t^–1 of FA.     

Callus induction and in vitro plant regeneration of rice (Oryza sativa L.) under various conditions

The objective of the present study was to develop an effective protocol for optimum callus induction and complete plant regeneration for four varieties of rice (Oryza sativa L.) i.e., Super Basmati, Basmati-370, Basmati-371 and Fakhre Malakand. Calli were induced from mature seed scutelum. The Murashige and Skoog (MS) and Chu's N6 media containing hormone 2, 4-D (2, 4-Dichlorophenoxy acetic acid) in different concentrations were used for callus induction. Fakhre Malakand produced maximum calli on N6 media containing 3 mg L(-1) 2,4-D. while other three varieties showed maximum callus induction on N6 media containing 2.5 mg L(-1) 2,4-D. N6 media was found better than MS media for callus induction. For complete plant regeneration the calli of two varieties i.e., Basmati-370 and Basmati-371 were plated on N6 media containing different concentrations of NAA (1-Naphthalene acetic acid) and BAP (6-benzyl aminopurine). The maximum regeneration frequency (%) was observed on N6 media containing NAA 1 mg L(-1) and BAP 2.5 mg L(-1). It took 27-30 days for the callus to regenerate into a complete plant. Basmati-370 produced 4-7 plantlets per callus whereas Basmati-371 produced 4-8 plantlets per callus with regeneration frequencies of 61 and 69%, respectively.     

Evaluation of anti-stabbing performance of fabric layers woven with various hybrid yarns under different fabric conditions

Various types of special fibers are used for human body protection, mostly in the form of fiber-reinforced composites. These composites are made of special fibers and matrix resin; however, they are often not comfortable for the wearer due to the lack of flexibility and air permeability. This study focuses on an evaluation of human body protective performance against stabbing for various special fibers such as aramid, basalt, and steel fibers, being utilized in cotton hybrid forms. These hybrid forms are designed to improve wearer comfort, while maintaining adequate anti-stab resistance. Specimens prepared with various fabric densities are tested in terms of anti-stabbing performance, according to the NIJ standard. In addition, we investigate the influence of factors such as fiber type, the number of fabric layers, fabric weight, and fabric density on anti-stabbing performance. Results show that the penetration depth of the impactor, which punctures and protrudes through the specimens, decreases with the number of layers, the thickness, and the mass of the armor sample; however, these factors have different relationships according to the material type. Consequently an objective evaluation of anti-stabbing performance is needed. We suggest an anti-stabbing index that can be applied as a criterion to evaluate the antistabbing performance of various specimens woven with special fibers under different fabric conditions. Using the new index, anti-stabbing performances of various specimens can be compared and raw material and fabric conditions that offer the most efficient anti-stabbing performance can be selected.     

虎眼万年青核型分析及B染色体研究

对虎眼万年青的染色体核型进行了分析,结果表明:该物种的体细胞染色体组包括18条数目稳定的A染色体和28~36条数目不等的B染色体,各A染色体之间形态差异不明显,均为中着丝粒染色体或近中着丝粒染色体,最长与最短染色体相对长度比仅为1.35,核型类型为较对称的2A型,核型公式为2n=18=4m 14sm (28~36)Bs。B染色体在不同细胞间却表现出明显的遗传多态性,文中还讨论了B染色体的大数量出现和数目变异与虎眼万年青具有抗旱、抗逆等生理适应性之间的关系。     

Nitrogen use efficiency and drought tolerant ability of various sugarcane varieties under drought stress at early growth stage

ABSTRACT

The experiment was conducted under glasshouse conditions to evaluate nitrogen use efficiency and drought tolerant ability of the five different sugarcane varieties (including NiF3, Ni9, Ni17, Ni21 and Ni22) under early growth stage from 60 to 120 days after transplanting. The results showed drought stress reduced the photosynthetic rate, growth parameters including plant height, leaf area; partial and total dry weights; and nitrogen use efficiency (NUE) traits including photosynthetic NUE, nitrogen utilization efficiency and biomass NUE of measured sugarcane varieties. The significant differences were found among varieties in growth parameters, dry weights, NUE traits and drought tolerant index (DTI). The significant positive correlations among NUE traits and DTI suggested higher NUEs could support better a tolerant ability to drought stress at the early growth stage. Because of larger contributions, DTIs for aboveground and stalk dry weight could be used as the important DTIs to evaluate drought tolerant ability in sugarcane varieties.     

The influence of storage conditions on various properties of potatoes

Change in weight and, to a lesser degree, in specific gravity of tubers during storage was much more dependent on relative humidity than on temperature. Katahdin usually lost more weight and showed a greater increase in specific gravity than Russet Burbank. The increase in weight loss of cured tubers in the course of the storage period was nearly always linear. The increase in specific gravity was often particularly pronounced at the end of the storage period. Black spot susceptibility decreased during the storage season and was sometimes affected by temperatures as well as relative humidity. In the cases that these influences were significant, colder and drier storage conditions resulted in less susceptible tubers than higher temperatures and relative humidities, but the differences were small. In one year out of three Russet Burbank was more susceptible than Katahdin, once the opposite was true, and once there was no difference between them. Susceptibility to damage, which decreased during the storage period in two out of three years, was greater at lower temperatures and higher humidities than under warmer or drier storage conditions. Variety differences were not consistent.     

不同处理对北方茶树扦插成活率的研究

通过对北方茶树扦插苗扦插时间、扦插基质、激素处理的研究发现,在北方早秋扦插成活率达80.78%,高于晚秋季6个百分点;心土扦插圃比沙质圃的成活率高20%,心土扦插处理的茶苗光合速率、细胞间隙CO2浓度高于沙质圃扦插处理,激素处理过的茶树扦插苗效果明显.     

Survival ofCorynebacterium sepedonicum at freezing and at wide fluctuations between freezing and above-freezing temperatures

The survival ofCorynebacterium sepedonicum, the bacterial ring rot pathogen of potatoes, on burlap surfaces held at constant freezing and above-freezing temperatures and under wide fluctuations of these temperatures was investigated by root-inoculating potato stem cuttings with aqueous suspensions prepared from these surfaces. The pathogen survived and remained infectious on burlap for 53 mo at all constant freezing temperatures, and its infectivity did not diminish throughout this period at either ?20 or ?40°C. At 42 months, viable ring rot bacteria were no longer detected at a constant temperature of 5°C. In a second experiment, ring rot bacteria survived and remained infectious on burlap for 23 months at fluctuating temperatures of ?40 to 5°C and ?40 to 25°C, but only survived for 12 months at 25°C. However, results of this study indicate that wide fluctuations between freezing and above-freezing temperatures caused decreased infectivity of the pathogen.     

浅谈江西省棉花新体制企业的生存和发展

通过分析新体制下江西棉花加工企业面临的在收购中恶性竞争、收购资金紧缺、质量意识薄弱、没有规划区域种植品种等问题,提出了鼓励新体制企业大力发展、采取各种措施让小包型企业退出市场、加强新体制企业质量能力建设、加大新体制企业的资金扶持等发展新体制棉花加工企业的建议。     

低pH和铝胁迫对胡椒根细胞存活和有机酸分泌的影响

以胡椒插条苗为研究对象,通过在低pH和正常pH营养液中添加不同浓度铝,研究胡椒根系细胞存活和有机酸分泌对低pH和铝胁迫的响应。结果表明:pH5.0(低pH)条件下,不添加铝时,胡椒根细胞即表现出坏死症状,当添加80μmol/L铝时,胡椒根细胞开始凋亡,200μmol/L铝添加导致胡椒根细胞全部死亡;pH6.0(正常pH)条件下,当添加80μmol/L铝时,胡椒根细胞出现坏死症状,200μmol/L铝添加导致根尖细胞大量凋亡。由此可见,低pH和铝的双重胁迫加速胡椒根细胞凋亡。低浓度铝添加致使胡椒根系分泌有机酸速率增加,柠檬酸为胡椒适应低pH和铝胁迫分泌的主要有机酸;在低pH和正常pH条件下,40μmol/L铝添加均可诱导胡椒根系柠檬酸分泌速度的增加,苹果酸仅在正常pH条件下低浓度铝胁迫时分泌速率增加。因此,低pH条件下,铝胁迫引起胡椒根系分泌有机酸种类减少,分泌速率降低。研究还发现Al3+是对胡椒毒害最严重的铝形态,是pH4.5土壤中的主要铝形态,目前海南省胡椒主要植区有50%的土壤pH低于4.5,所以对于胡椒园土壤的铝毒害应引起足够重视。     

Glucosinolate hydrolysis products from various plant sources: pH effects,isolation, and purification

Glucosinolates are a class of organic anions that can be hydrolyzed either enzymatically with myrosinase or non-enzymatically to form primarily isothiocyanates and/or nitriles. The isolation and purification of these hydrolysis products are of particular interest both for their potential use in organic synthesis and for their biological activities. Methods were developed for the isolation and purification of gram-scale quantities of several ω-(methylthio)alkyl-, ω-(methylsulfinyl)alkyl-, ω-(methylsulfonyl)alkyl-, and substituted benzyl glucosinolate hydrolysis products; the isothiocyanates erucin [1-isothiocyanato-4-(methylthio)butane], iberin [1-isothiocyanato-3-(methylsulfinyl)propane], cheirolin [1-isothiocyanato-3-(methylsulfonyl)propane], lesquerellin [1-isothiocyanato-6-(methylthio)hexane], hesperin [1-isothiocyanato-6-(methylsulfinyl)hexane], sulforaphene [1-isothiocyanato-4-(methylsulfinyl)but-3-ene], 3-methoxybenzyl isothiocyanate, and 4-hydroxybenzyl isothiocyanate; and the nitriles iberverin nitrile [1-cyano-3-(methylthio)propane], erucin nitrile [1-cyano-4-(methylthio)butane], and 3-methoxybenzyl nitrile using defatted seedmeal from several different genera within the crucifer family (Brassicaceae) and meadowfoam family (Limnanthaceae) as the source of parent glucosinolates. The procedures use solvent extraction of autolyzed defatted seedmeals from various plant sources together with variable reaction pHs and solvent partitioning to obtain relatively pure (generally >97%) compounds without the need for chromatographic separation.     

Effect of selecting potato seedlings under maritime conditions on the performance of the first clonal generation under Prairie conditions

The Agriculture Canada Potato Breeding Program in New Brunswick is the source of new germplasm for co-operative breeding projects in other regions of Canada. Selection under maritime conditions in early clonal generations is conducted at Fredericton, New Brunswick prior to shipment of seedlings to these projects. An evaluation of this system was required with the advent of a new breeding project at the Lethbridge Research Station, Alberta, in 1979 for the Prairie region of Canada. Two groups of first field generation seedlings obtained from the Fredericton breeding program were compared in Alberta. One group was composed of seedlings obtained at random and the second of seedlings obtained through the normal selection procedures used at Fredericton. Ten crosses were sampled in 1979 and twelve in 1980. Results of the study provide evidence that pre-selection in the first clonal generation at Fredericton significantly (P < 0.05) improves the maturity, yield, and tuber traits of these seedlings grown in Alberta, yet does not cause a major reduction in the variability of traits.     

Leaf dynamics of timothy and meadow fescue under Nordic conditions

Leaf production dynamics of timothy ( Phleum pratense L. cv. Tarmo) and meadow fescue ( Festuca pratensis Huds. cv. Kalevi) were studied in Finland under field conditions in mixed swards containing timothy, meadow fescue and red clover ( Trifolium pratense L. cv. Björn) harvested by cutting. Fifteen randomly selected tillers of both species were marked and leaf number, leaf appearance rate (LAR), leaf elongation rate (LER), leaf senescence rate (LSR) and leaf live span (LLS) were followed through weekly observations. Concurrently another set of fifteen tillers of each species was dissected on each occasion to determine the number of unemerged leaves and development stage of the apex. The first observation period was between 26 April and 22 June and the second between 22 July and 22 September.
The species differed clearly for most of the measured parameters but most differences were dependent on the season. In spring, timothy started growth earlier, had higher LAR (+57%), produced more leaves (+83%) with higher LER_gross (+58%), higher LSR (+61%), higher LER_net (+54%) and produced larger tillers (+193% in leaf area) than meadow fescue. In autumn, timothy still had a higher LAR (+80%), produced more leaves (+60%) with higher LER_gross (+36%), but had also a higher LSR (+77%) and thus similar LER_net (0%) to meadow fescue. Timothy tillers were only slightly larger than meadow fescue tillers (+20% in leaf area). The consequences of these findings on competition in mixed swards and implications for grazing theories are discussed.     

Survival of detached sporangia ofPhytophthora infestans exposed to ambient, relatively dry atmospheric conditions

The effect of duration of exposure, daily weather conditions, and exposure to direct or indirect sunlight on survival of sporangia ofPhytophthora infestans under ambient, relatively dry atmospheric conditions was evaluated. Viability of sporangia was assessed by determining the proportion of potato tuber slices or leaflets that became infected after inoculation with exposed sporangia. The maximum survival time of sporangia was 24 h under moderately cool (mean of 15 C) and dry conditions (RH < 25%). Sky conditions were sunny during daylight hours during this exposure. Infection seldom occurred when sporangia were exposed directly to sunlight; only 25 of 566 (4.4%) groups of sporangia caused infection. Of these 25 groups, 23 (92%) had been exposed to mean temperatures below 33 C for 4 or fewer hours. Binary logistic regression analysis of the data showed that duration of exposure, direct sunlight, and type of day were all significant factors affecting survival of sporangia. Long exposure in direct sunlight limited survival. Survival of sporangia was more likely to occur on cool, cloudy days and cool, rainy days than on other day-types.