Biochemical changes during the fermentation of castor oil (Ricinus communis) seeds for use as a seasoning agent

Castor oil seeds were fermented under conditions commonly used in some local communities in Eastern Nigeria. Levels of selected biochemical constituents of fermented seeds were compared with those of unfermented seeds. The free amino acids — phenylalanine, tryptophan, tyrosine, serine, glutamic acid, cysteine, and gluamine — were detected by using thin-layer chromatography in the fermented sample extract, while none were detectable in the extract of unfermented seeds. Lipid analysis showed that the fermented seeds contained more unsaturated fatty acids than the unfermented seeds. Glutamine produced by the microorganisms responsible for fermentation is probably responsible for the characteristic flavor of foods seasoned with fermented castor oil seeds, known locally as ogiri.     

预防组培中蓖麻子叶节玻璃化的研究

为了预防蓖麻子叶节在组织培养过程中的玻璃化现象,以建立其高效的遗传转化体系,本实验对影响子叶节生长状态的几个因素进行了初步研究。结果表明,在胚轴、子叶均为淡黄色的时期切取蓖麻子叶节,接种在1/8MS、内含10g/L琼脂粉、20g/L蔗糖、8.0mg/LZT、1.0mg/LNAA的培养基中进行培养,能有效地预防蓖麻子叶节玻璃化。     

单雌蓖麻的研究与应用

单雌蓖麻是珍贵的蓖麻资源。单雌蓖麻的研究与利用，对于蓖麻杂种优势研究具有重要的意义。本文综述了单雌蓖麻的遗传类型、研究及应用状况，提出进一步利用单雌蓖麻开发蓖麻杂种优势的策略。     

蓖麻花序特征及花芽分化的初步研究

本文对蓖麻花序特征、顶芽分化及内源IAA和ABA含量变化进行初步研究,结果表明：不同品种（系）间雌花率及雌花密度均存在极显著差异。蓖麻雌花并非完全单性花,各品种（系）雌花均存在退化雄蕊痕迹,但其发生率不同,单雌后代品系明显高于品种材料。单雌花序与两性花序的雌花中均存在退化雄蕊,且无显著差异,但花序中下部与上部之间差异显著。顶芽石蜡切片观察表明：蓖麻在5叶期以前,其顶芽基本处于叶芽生长阶段;在6-9叶期,顶芽逐渐进入花芽分化、生长阶段,而此阶段,顶芽内源IAA、ABA含量变化也十分明显。不同性别花序和花的内源激素含量测定结果显示：IAA含量,单雌花序＞雌花＞两性花序＞雄花;ABA含量,雄花显著高于雌花,但两性花序却明显低于单雌花序;IAA/ABA值,雌花＞单雌花序＞两性花序＞雄花;说明IAA含量和IAA/ABA相对含量可能在花性分化中具有较为重要的作用。     

蓖麻RcWD40家族鉴定与表达分析

植物中的WD40蛋白家族通过蛋白质-蛋白质及蛋白质-DNA的互作,参与生物过程,该家族的重要成员TTG1在拟南芥中抑制种子脂肪酸的过早积累。为揭示油料作物蓖麻中RcWD40基因家族及RcTTG1基因的表达特征,利用生物信息学手段在全基因组水平鉴定到182个RcWD40家族成员,其中RcWD40-181为RcTTG1基因,并对它们的系统发育、保守结构域及表达模式等进行分析。根据进化树结构和保守域组成分别将RcWD40家族成员分为8个cluster和28个亚家族。此外,转录组分析显示RcWD40在蓖麻的花、叶、根、茎以及各发育时期种子中具有多样的表达模式,预测家族基因可能调节这些组织的生长发育。启动子区域转录因子结合位点及种子发育表达分析结果预测RcTTG1可能承担与AtTTG1相似的脂肪酸积累负调节功能。     

The feeding value of roasted castor oil bean (Ricinus communis) to growing chicks

A nutritive evaluation of roasted castor oil bean (Ricinus communis) was made using 150 day old crossbred progeny of barred Plymouth rock × Nigerian local chicken. The chicks were divided into five groups of 30 birds each. Each group was fed one of five iso-nitrogenous and iso-caloric diets A, B, C, D and E containing 0% (control), 10% non-roasted castor oil bean seeds (NRCOB), or 10, 15 or 20% roasted castor oil bean seeds (RCOB), respectively. Roasting was done at 140°C for 20 minutes in order to destroy the ricin component of the castor oil bean seed. There were significant (P<0.05) differences in average feed intake, daily gain, and feed conversion ratio between birds among the treatments. The best results were obtained with inclusion of RCOB at the 10% level. The birds fed the 20% roasted bean diets had the worst performance. The diet containing the 10% NRCOB supported little or no growth, and also resulted in a high mortality (83%) among the birds. There were no significant (P<0.05) differences in mortality rates between the control diet and the other diets containing RCOB.     

蓖麻DNA糖基化酶的序列与基因表达分析

为揭示DNA糖基化酶在调节蓖麻生长发育和影响基因印记过程中的分子机理,本研究基于蓖麻全基因组、利用生物信息学的方法结合转录组数据和RT-PCR半定量表达分析,鉴别蓖麻DNA糖基化酶氨基酸序列的结构特征、系统发生和表达形式。结果显示：三种（DME、ROS和DML）DNA糖基化酶氨基酸均为不稳定氨基酸,具有典型的与DNA结合和碱基切除修复有关的保守结构域;系统进化分析发现三种DNA糖基化酶在植物中同源性强,而且是独立演化的结果;在不同组织的表达上,蓖麻的DME和ROS基因具有相似的表达形式,即在根、茎和叶中不表达,在胚乳中表达最高,而DML在各个组织中都未检测到基因的表达。     

蓖麻SnRK2基因家族的鉴定和特征分析

SnRK2是一类植物特有的Ser/Thr类蛋白激酶。为研究其在蓖麻抗逆过程中的作用,基于蓖麻的基因组序列信息,利用生物信息学方法鉴定了6个蓖麻SnRK2蛋白激酶成员。分析发现这些蛋白具有亲水性属性,基因结构分析表明,植物SnRK2基因在进化过程中具有很高的保守性;系统与进化分析发现植物SnRK2蛋白在单、双子叶植物中分化显著,可能是独立演化的结果。高通量RNA-seq测序结果显示,大部分SnRK2基因在检测的各个组织中均有表达,且在不同组织间或种子发育的不同阶段没有明显的组织特异性;外源ABA处理种子后,Group 2的基因表达显著上调。进一步利用半定量RT-PCR技术检测外源(100μmol/L)ABA、(250mmol/L)Na Cl和(4℃)冷胁迫处理的幼苗,发现Group 2中的基因29908.m006067被这3种胁迫强烈激活,基因29772.m000313对ABA和冷胁迫有较强的响应。     

Guayule as a feedstock for lignocellulosic biorefineries using ammonia fiber expansion (AFEX) pretreatment

Natural rubber latex extraction from guayule leaves behind greater than 90% (by weight) of agricultural residue as a feedstock suitable for conversion to biofuels via a thermochemical or biochemical route. Untreated guayule shrub and bagasse (after latex extraction) has shown to be very recalcitrant to enzymatic hydrolysis, necessitating application of a chemical pretreatment to enhance cellulase accessibility. The objective of this work was to carry out detailed compositional analysis, ammonia fiber expansion (AFEX¹) pretreatment, enzymatic hydrolysis and ethanol fermentation for various guayule-derived biomass fractions. Plant feedstocks tested were derived from two sources; (a) a mature 2007 AZ-2 whole guayule shrub plant obtained from USDA/ARS² research fields, and (b) the guayule latex-extracted commercial grade bagasse (62505) from Yulex Corporation. Compositional analysis and enzymatic hydrolysis were carried out using standard NREL³ protocols (www.nrel.gov/biomass/analytical_procedures.html). AFEX pretreatment was carried out using concentrated ammonium hydroxide at elevated temperatures for desired residence times in a pressurized reactor. Yeast fermentations on biomass hydrolyzates were carried out micro-aerobically using Saccharomyces cerevisiae (424A strain) in shake flasks.AFEX pretreatment was found to substantially improve overall enzymatic digestibility by 4-20 fold for both untreated guayule shrub and latex-extracted bagasse. Maximum glucan and xylan conversion achieved for the latex-extracted bagasse was 40% and 50%, respectively. The yeast was readily able to ferment both glucose and xylose to ethanol from the guayule bagasse hydrolyzate with or without external nutrient supplementation (i.e., yeast extract and tryptone). Our results highlight the possible utilization of guayule as a feedstock for lignocellulosic refineries co-producing natural rubber latex and biofuels. However, further process improvements (e.g., lignin/resin extraction and cellulose decrystallization using a modified AFEX process) are necessary to increase the effectiveness of ammonia-based pretreatments for further enhancing enzymatic digestibility of guayule-derived hardwood biomass.     

蓖麻新品种辽蓖5号选育及其栽培技术要点

1 品种来源及选育经过 辽蓖5号是辽宁省农业科学院作物研究所,2003年从吉林白城引进农家品种的混杂群体中选择优良变异单株,经系统选育而成。     

Scorpiurus muricatus L. subsp. subvillosus (L.) Thell., a potential forage legume species for a Mediterranean environment: a review

Prickly scorpion's tail, Scorpiurus muricatus L. subsp . subvillosus (L.) Thell., is an annual legume species, widespread in pastures of the basin of the Mediterranean Sea. It has been neglected by researchers and farmers for a long time, although the species has promise as a forage crop for its high nutritive value, self-reseeding capability and its preference by ruminants. Harvesting and threshing of seed, however, are difficult and it has seed-coat dormancy, which delays and reduces germination, hindering its use as a forage crop. It is suggested that plant breeding programmes would allow the selection of ecotypes and varieties for field crop cultivation. In this study, the main botanical, biological, ecological and agronomic traits are reviewed to identify those issues that currently limit its introduction into cultivation as a forage crop in Mediterranean areas.     

Nemato-toxic potential of Betel (Piper betle L.) (Piperaceae) leaf

In vitro and in-planta trials were conducted to determine the nemato-toxic potential of aqueous leaf extracts of Betel (Piper betle L.) against the root-knot nematode species, Meloidogyne incognita, at five concentrations, standard extract (S) [1:2 (w/v] and its four dilutions, 20%, 40%, 60%. 80% of S. In the in vitro trials, second-stage juveniles (J₂s) and eggs of M. incognita were directly exposed to the extract while in the in-planta trials, the effect of the extract was evaluated as a root dip treatment using tomato plants. The findings indicated that the extract was lethal to J₂s but also inhibited egg hatch. The seedling dip treatments reduced root infestations in terms of gall formation, egg production and J₂ population densities in soil while simultaneously enhancing the growth of tomato plants. All these effects varied in a dose-dependent manner. Based on the LC₅₀ value, the eggs were found to be less sensitive to the extract than J₂s. One hundred percent of mortality of J₂s was recorded at four concentration levels, 40%, 60% and 80% of S and S, while 100% egg inhibition was only recorded at S. The highest reductions in gall formation (i.e., number of galls/root system), egg production and J₂ population were all recorded at S as 83%, 87% and 84% compared to the untreated water control. The maximum growth enhancement, which was 235% of the control, was detected in the root length of treated tomato plants. It appears the aqueous leaf extract of P. betle shows promise as a sustainable eco-friendly nematicide for the management of M. incognita.     

Important ecological traits for selecting Biserrula pelecinus L. (biserrula) genotypes for their potential introduction into agricultural systems

An investigation of eleven genotypes and two cultivars of Biserrula pelecinus L. (biserrula) was conducted in Western Australia to study their ecological and agronomic traits. All biserrula genotypes were productive in the 2 years of testing, with dry‐matter production ranging from 3·5 to 4·9 t ha^?1 and seed yield ranging from 314 to 1381 kg ha^?1. Biserrula has high initial levels of hard seededness (95–100%) and a more gradual hard seed breakdown (68–92%) in summer. The high levels of hard seed decreased the seedling densities of biserrula in the second year, while were at highest levels in the third year after the plots were cropped to wheat. A further experiment was conducted to study the interaction between spray‐topping and seed set. This study showed subterranean clover seed yields were more tolerant to herbicides than a number of biserrula genotypes. There were significant responses to the herbicides within the biserrula genotypes, and 95GCN59 was less affected. The rhizobium experiment showed a strong host strain/interaction and has emphasized the importance of simultaneous breeding and selection of plant germplasm run in parallel with the selection of elite strains of rhizobia such as WSM1497 to optimize nitrogen fixation.     

Phytotoxicity of lemon-scented eucalypt oil and its potential use as a bioherbicide

The effect of volatile oil from leaves of Eucalyptus citriodora against some plant species viz. Triticum aestivum, Zea mays, Raphanus sativus, Cassia occidentalis, Amaranthus viridis and Echinochloa crus-galli was investigated. In a laboratory bioassay seed germination of test plants was significantly reduced in response to the different concentrations of the eucalypt oil. Maximum germination inhibition was observed with A. viridis, whereas least effect was seen on R. sativus. Based on the germination response, dose-response curve was generated and LC₅₀ values were calculated. It was maximum for R. sativus whereas minimum for A. viridis. Further, seedling growth of the test plants and the chlorophyll content in the treated seedlings was significantly reduced at concentrations 0.12 and 0.3 mg/l. Not only the initial growth, but also the spray treatment on the 4-week-old mature plants of two weedy species viz. C. occidentalis and E. crus-galli adversely affected the chlorophyll content and cellular respiration, thereby indicating the adverse effect of eucalypt oil on the photosynthetic machinery and the energy metabolism of the target plants. Based on the study, it is concluded that volatile oil from E. citriodora is phytotoxic and could be utilized as bioherbicide for future weed management programmes.     

Chemical composition and nutritional potential of yam bean seeds (Pachyrhizus erosus L. Urban)

Pachyrhizus erosus seeds were analysed for proximate composition, minerals, protein fractions, antinutritional factors, and rotenoids. The seeds showed a high content of proteins, lipids, Fe and Ca, in comparison to other legumes. Glutelins constitute the highest protein fraction, followed by globulins. Antinutritional substances detected as tannins, hemagglutinating activity and trypsin inhibitory activity, were in low concentrations. Seeds were also processed to obtain a flour which showed proper characteristics, good in vitro digestibility, significant rotenoid reduction level and amino acid composition rich in essential amino acids, except methionine.     

The potential use of plant physiological responses to water stress as an indication of varietal sensitivity to drought in four potato (Solanum tuberosum L.) varieties

Four potato varieties were subjected to water stress under controlled conditions. Leaf relative water content, leaf diffusive resistance, and photosynthesis were measured on stressed and unstressed plants during a stress period and during the recovery period following stress relief. Subsequent to the stress, plants were grown to maturity with optimal water supply. Mature plants were harvested and tuber yield and haulm production measured. Stressed plants of all varieties exhibited an increase in leaf diffusive resistance and a decrease in relative water content, transpiration, and photosynthesis as soil moisture decreased. Significant varietal differences in leaf diffusive resistance of stressed plants are apparent and offer promise for development of a screening technique for varietal sensitivity to drought based on stomatal response to water deficits.     

Guar (Cyamopsis tetragonoloba) as a potential differential host of potato virus Y

Summary Guar is reported for the first time as a host of potato virus Y. The virus produced no symptoms, or occasional faint chlorotic spots on inoculated cotyledons and unifoliate leaves. No symptoms were observed on new growth, but the virus was consistently recovered from these leaves by back-inoculation to tobacco. Neither potato virus X nor cucumber mosaic virus infected guar.     

Evaluation of new clones of Jerusalem artichoke (Helianthus tuberosus L.) for inulin and sugar yield from stalks and tubers

Six clones of Jerusalem artichoke, five new clones (coded as 17, 22, 56, 69 and 70) and the control cultivar “Violette de Rennes” were evaluated for variability in sugars yield, when the plant is utilised as stalk, tuber and “integral crop”.Among the above harvesting methods, the integral crop (stalks and tubers at flowering time), showed the highest yield potential of total sugars (fructose+glucose) and inulin (18.6 and 17.9 t/ha, respectively). This was obtained by the clone Violette de Rennes, which also had the greatest inulin chain length, in the text reported as average degree of polymerisation (DP).Clone 69 produced the highest yield of sugars and inulin, when the stalks are harvested at flowering (10.4 and 8.0 t/ha, respectively), while clone 17, with the conventional harvest of tubers at the end of crop cycle, reached 13.3 and 13.7 t/ha of total sugars and inulin, respectively. The average inulin chain length (DP) was highest at flowering time in both stalks and tubers with a range of 7.5–11.2 in the genotypes studied, while, at the final harvest of tubers, it significantly decreased reaching values ranging from 4.8 to 6.7. Among the organs analysed, the tubers at stalk harvest, showed both the highest inulin content and the longest inulin chain, expressed as DP.The genetic variability was very high among the clones for the other characters studied, such as flowering time, sugar content in different organs, photosynthesis activity, leaf chlorophyll content, etc. In particular, the “refractometrically measured” solids, in extracted tissue juice, expressed as the Brix-value (a very quick method), exhibited a significant positive relationship with the tuber inulin content (0.90^** and 0.85^**, n=6, in the first and second harvest, respectively), confirming its suitability as a fast screening method in breeding, avoiding time consuming and expensive laboratory analysis.     

Malondialdehyde content as a potential biochemical indicator of tolerant Cenchrus ciliaris L. genotypes under heat stress treatment

Buffel grass (Cenchrus ciliaris L.) is an important forage grass in arid and semiarid regions. As part of a genetic improvement programme, four genotypes [Biloela (Bl), Americana (Am), Texas (Tx) and Sexual (Sx)] were categorized by tolerance to heat stress in a greenhouse experiment. At 30 d after sowing, half of the plants (control plants) were transferred to growth chambers (28°C day per night), and the other half (pre‐treated plants, Prt) were exposed to heat stress treatment (0, 24, 48 and 72 h; 45°C day per night). Malondialdehyde (MDA) content, an indicator of oxidative damage, was determined from foliar samples. During heat stress, Sx showed the earliest increase in MDA (at 24 h) followed by Tx (48 h) and Am and Bl (72 h). Results were compared with heat‐stress tolerance evaluated as morphological traits at the end of recuperation (60 d after sowing). Fresh weight and aerial plant height were lowest in the Prt‐Sx genotype and highest in Am and Bl genotypes; Tx showed intermediate tolerance. Results suggest that tolerance to heat stress in C. ciliaris genotypes could be related to the capacity for regulating the oxidative damage increase. Foliar MDA content might therefore be used in a genetic improvement programme of C. ciliaris as a potential biochemical indicator for a rapid, simple and low‐cost identification of heat‐stress tolerant genotypes.     

蓖麻毒蛋白A链基因克隆与重复表达载体构建

利用降落PCR的方法,从蓖麻基因组DNA中克隆毒蛋白A链基因的560bp片段;利用一步法将该基因的2个正义片段和2个反义片段分别与pBI-121质粒连接,构建含该基因的正义重复和反义重复表达载体,为利用共抑制技术抑制蓖麻毒蛋白A链基因表达的研究奠定基础。