Analysis of seed protein of 29 lines of Capsicum annuum L. by polyacrylamide gel electrophoresis

Proteins and enzymes are important parameters in biochemical taxonomy. Seeds of 29 lines of C. annuum from different sources and places of origin were studied. The protein content was estimated and SDS polyacrylamide gel electrophoresis technique was used to study the soluble protein pattern. Each genotype was distinct from the other, but certain bands were shared by several genotypes. Average similarity was highest (80%) between accessions PBC 436 from Portugal and Round Ornamental collected from Kerala Agricultural University, suggesting that the material collected from India could have originated in Portugal. In general, paprika lines had a high seed protein content and these also clustered together. Fruit length, fruit colour, and percentage of capsaicin did not show correlations with the clustering of the accessions.     

Characterization of methanol-soluble and methanol-insoluble proteins from developing peanut seed

The 85% methanol-soluble proteins are known to specifically contribute to the production of flavor of roasted peanut. To determine the nature of the 85% methanol-soluble proteins, they were isolated from the peanut seed, and the 85% methanol-soluble (MS) and 85% methanol-insoluble (MIS) fractions were characterized using polyacrylamide gel electrophoresis (PAGE) and capillary electrophoresis. The results showed that the 85% MS fraction contained lower amounts (9-10%) of protein than the MIS fraction (15-33%). Protein content of the MIS fraction increased more significantly during seed maturation than it did in the MS fraction. Unlike the protein, free amino acids and soluble sugars levels of the MS fraction decreased significantly during seed maturation. The 85% MS fraction contained predominantly low molecular weight (<20 kDa) proteins/polypeptides, whereas the MIS fraction contained a mixture of polypeptides with molecular weight between 14 kDa and 90 kDa. SDS-PAGE showed no major changes in the polypeptide composition of the MS fraction during seed maturation. Capillary electrophoretic analysis revealed major qualitative and quantitative changes in the protein and polypeptide composition of the MS and MIS fractions during seed maturation. Fatty acid analysis of these fractions indicated that the MS fraction is lipoprotein in nature and rich in oleic and linoleic acids.     

One- and two-dimensional gel electrophoresic identification of African yam bean seed proteins

Seed proteins were extracted from the African yam bean (AYB; Sphenostylis stenocarpa), an underutilized West African food legume. One- and two-dimensional polyacrylamide gel electrophoresis was then used to analyze the albumin fraction, galactose-specific lectins purified on immobilized galactose-Sepharose 4B, and abundant non-lectin seed proteins left over following affinity chromatography. N-terminal sequencing of prominently resolved polypetide bands led to identification of proteins having sequence homology with characterized legume seed proteins, namely, mung bean seed albumin, pea alpha-fucosidase, soybean Kunitz-type trypsin inhibitor, an endochitinase, pea pathogenesis-related protein, and/or cowpea seed storage proteins. Minor lectin-like proteins lacking hemagglutinating activity against rabbit and human erythrocytes were also identified. Because proteins such as protease inhibitors, chitinases, pathogenesis-related proteins, and lectins are known to have antimetabolic effects, the findings from this study may have relevance in the acceptability, adoption, and utilization of AYB as human food.     

16份石榴RAPD扩增产物的两种电泳方法检测及其序列特征

本实验以16个石榴品种为实验材料,筛选出10个重复性及多态性均较好的引物进行RAPD分析。分别采用琼脂糖凝胶以及聚丙烯酰胺凝胶(PAGE)电泳检测方法对PCR扩增结果进行检测并对其结果进行比较,结果显示,两种电泳方式均能得到较为清晰的扩增条带,且两种电泳方式获得的条带总数及多态性条带数均有所不同,琼脂糖凝胶电泳方法共检测出76条带,其中有43条为多态性谱带,多态性比率为56.4%;而在PAGE电泳方法共检测出123条谱带,多态性谱带数为87条,多态性比率为70.95%。PAGE电泳方法检测出的条带数约为琼脂糖凝胶电泳方法检测出条带数的1.5倍。基于两种电泳方法所得RAPD标记的多态性位点,利用NYSYS软件计算遗传相似系数,并构建遗传关系聚类图,分析结果显示,石榴遗传多样性丰富,两种电泳方法所得聚类结果大致相同,可以利用RAPD分子标记及两种电泳检测方法对不同数量的石榴进行分子水平的品种鉴定和遗传多样性的分析。同时通过对来自几个引物随机挑选的17个片段进行克隆,测序结果显示17个片段都是对应引物的RAPD扩增产物,其中有3条是编码蛋白的基因片段,表明了RAPD不仅扩增基因组上的非编码蛋白序列,同时也可以扩增编...     

辣椒苗期耐热耐湿鉴定方法的研究

以辣椒各生理指标的耐逆系数为衡量辣椒单项耐逆能力大小的指标,用聚类分析法、主成分分析法、隶属函数法对辣椒不同品种（系）耐热耐湿性予以综合评价。综合评价的结果,将10个供试品种（系）按耐热耐湿由强到弱划分为4级：高度耐热耐湿（I）、中度耐热耐湿（G、J、W、H）、不耐热耐湿（C、E、F、K）和极不耐热耐湿（D）。几种关于辣椒品种（系）耐热耐湿综合评价的方法具有较好的一致性,同时利用耐热耐湿性的综合评价值与单项指标间建立的最优回归方程可以预测其它辣椒品种（系）耐热耐湿性大小。     

Diversity of seed globulins in Lathyrus sativus L. and some related species

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of reduced seed globulins covered 141 accessions of Lathyrus sativus and the following related species: L. amphicarpos, L. blepharicarpus, L. cicera, L. gorgoni, L. marmoratus, L. pseudocicera and L. stenophyllus. In the total examined material 71 globulin polypeptide bands were distinguished. The number of polypeptide bands detected in particular species varied from 14 in L. amphicarpos to 29 in L. sativus; all the species under study showed intraspecific variation due to individual variation and/or differences among accessions. Electrophoretic data were subjected to statistical analysis using hierarchical UPGMA grouping. Frequency distribution of polypeptide bands in L. sativus showed some correlations with geographical origin and certain seed characteristics (seed coat colour, seed weight) of the studied accessions. As regards interspecific relationships, the studied species showed to be distantly related taxa except for the rather closely allied L. cicera and L. marmoratus. The obtained results are compared with the electrophoretic seed albumin data reported earlier for the same taxa.     

不同辣椒品种混种根系互作对产量及根际氮转化的影响

以不同辣椒品种薄皮椒（Capsicum annuum）、线椒（Capsicum frutescens）为试验材料，采用盆栽方式，通过分析同种种植或混种（交叉及同行）模式下两种辣椒的产量、生物量、氮素积累量及根际土中氮形态和含量的变化，探究同种或混种辣椒根系互作对氮吸收积累的影响。结果表明，两种辣椒混合种植的果期茎叶干物质量、产量及果实氮积累量均高于同种种植，其中果期茎叶干物质量、产量及果实氮积累量平均增加26.67%、63.65%、15.08%；且同行种植的产量及果实氮积累量均为最高，但果期不同处理之间的根系干物质量无显著差异。果期时混种种植辣椒的铵硝比显著低于同种种植，平均降低67.39%。通过两种辣椒混合种植，特别是同行种植，能够达到增加产量、提高氮素积累量的目的，在实际的生产中具有一定的可行性和推广前景。     

The contribution of international vegetable breeding to private seed companies in India

Crop breeding research by international agricultural research centers usually serves public sector crop breeding, but does it still have a role when research and development have shifted to the private sector? This paper explores this question for vegetables in India using data from 27 private companies and 9 public organizations. We focus on tomato (Solanum lycopersicum L.) and chili pepper (Capsicum annuum L.)—two of India’s most important vegetables, and the role of international germplasm received from the World Vegetable Center. Results show that as the role of the private sector in vegetable breeding increased, and with it the share of hybrids in the market, the role of international agricultural research shifted from the provision of ready-made varieties to the provision of specific resistance traits. Still, international germplasm continued to be used in varietal development with 11.6 t (14 % of the total market) of hybrid tomato seed and 15.0 t (13 %) of hybrid chili pepper seed sold in 2014 containing international germplasm in its pedigree. We estimate that over half a million farmers use such seed. We conclude that for tomato and chili pepper, international breeding needs to focus on pre-breeding research, capacity strengthening of smaller seed companies, and the delivery of open-pollinated varieties for marginal environments.     

Changes in phytochemical and antioxidant activity of selected pepper cultivars (Capsicum species) as influenced by maturity

The effect of fruit maturation on changes in carotenoids, flavonoids, total soluble reducing equivalents, phenolic acids, ascorbic acid, and antioxidant activity (AOX) in different pepper types (Capsicum annuum, Capsicum frutescens, and Capsicum chinese) was determined. Generally, the concentration of these chemical constituents increased as the peppers reached maturity. Peppers contained high levels of L-ascorbic acid and carotenoids at maturity, contributing 124-338% of the RDA for vitamin C and 0.33-336 RE/100 g of provitamin A activity, respectively. Levels of phenolic acids, capxanthin, and zeaxanthin generally increased during maturation, whereas the level of lutein declined. Flavonoid concentrations varied greatly among the pepper types analyzed and were negatively correlated to AOX under the conditions of the beta-carotene-linoleic assay. Model systems were used to aid in understanding the relationship between flavonoids and AOX. Significant increases in AOX were observed in pepper juice models in response to increasing dilution factors and the presence of EDTA, indicating a pro-oxidant effect due to metal ions in the system. In vitro models demonstrated that increasing levels of flavonoids in combination with constant levels of caffeic and ascorbic acid gave a resultant AOX that was either additive of the two compounds or competitive in their ability to scavenge peroxyl radicals. The model systems were in good agreement with the chemical composition of the pepper cultivars and reflected the interactions affecting AOX. More research is needed to understand the complex interactions that occur among various antioxidants present in pepper extracts.     

种子蛋白质电泳在陆地型长绒棉种质鉴定中的应用

采用垂直平板聚丙烯酰胺凝胶法 ,进行单粒种子醇溶蛋白质电泳分析 ,参试材料有陆地型长绒新种质 9830 1系、4个海岛棉品种和 8个陆地棉品种。 9830 1和中棉所 1 2号、石远 32 1在试验中 ,同一品种 (系 )内的不同种子之间的蛋白谱带基本一致。对分别取样于山东省 7个不同地区试验点的 9830 1种子谱带进行比较 ,没有发现差异。胶板上陆地棉品种均具有 3条与海岛棉相区分的带 ,同样各海岛棉品种也共同具有 3条特征带。 9830 1显出 3条陆地棉特有带 ,证明其谱带主要倾向于陆地棉 ;同时也稳定地出现 1条海岛棉的特有带 ,表现出其属于海陆杂交种的遗传特性。 9830 1分离出一条独有带 (“1”带 ) ,凭借此带和另一条带 (“1 0”带 )可较容易地和其它陆地棉品种相区分     

The effect of plant age and soil amendments on severity of phytophthora root rot of pepper (Capsicum annuum L) in South Western Nigeria

The incidence and severity of pepper Capsicum annuum to phytophthora root rot caused by Phytophthora infestan in Southwestern Nigeria was investigated. Root rot incidence and severity was significantly reduced with increase in the plant age. The highest level of root rot, of 81.7% and 67.6% obtained in 4 and 6 weeks old pepper plants were reduced to 25% and 5% in 10 and 12 weeks old pepper plants respectively. The resistance of the pepper plant to root rot severity increased with age. The result also showed that amendments of the soil with chicken manure wood ash and neem leaf suppressed the root rot incidence and severity of disease in the pepper plant.     

Activity and process stability of purified green pepper (Capsicum annuum) pectin methylesterase

Pectin methylesterase (PME) from green bell peppers (Capsicum annuum) was extracted and purified by affinity chromatography on a CNBr-Sepharose-PMEI column. A single protein peak with pectin methylesterase activity was observed. For the pepper PME, a biochemical characterization in terms of molar mass (MM), isoelectric points (pI), and kinetic parameters for activity and thermostability was performed. The optimum pH for PME activity at 22 degrees C was 7.5, and its optimum temperature at neutral pH was between 52.5 and 55.0 degrees C. The purified pepper PME required the presence of 0.13 M NaCl for optimum activity. Isothermal inactivation of purified pepper PME in 20 mM Tris buffer (pH 7.5) could be described by a fractional conversion model for lower temperatures (55-57 degrees C) and a biphasic model for higher temperatures (58-70 degrees C). The enzyme showed a stable behavior toward high-pressure/temperature treatments.     

Carotenoid biosynthesis changes in five red pepper (Capsicum annuum L.) cultivars during ripening. Cultivar selection for breeding

Changes in the biosynthesis of individual carotenoid pigments have been investigated during fruit ripening of five cultivars of red pepper (Capsicum annuum L.): Mana, Numex, Belrubi, Delfin, and Negral (a chlorophyll-retaining mutant when ripe). The study was carried out throughout the ripening process, and with special emphasis on the ripe stage, to discover possible differences between cultivars and to characterize these by their carotenoid pattern and content for selecting the best varieties for breeding programs. Ripening fruit of the five cultivars showed the typical and characteristic pattern of carotenoid biosynthesis for the Capsicum genus. In the five cultivars, lutein and neoxanthin, both characteristic chloroplast pigments, decreased in concentration with ripening and eventually disappeared. beta-Carotene, antheraxanthin, and violaxanthin increased in concentration, and other pigments were biosynthesized de novo: zeaxanthin, beta-cryptoxanthin, capsanthin, capsorubin, capsanthin-5,6-epoxide, and cucurbitaxanthin A. A pool of zeaxanthin stands out of the rest of pigment during ripening, which reveals the importance of this pigment as a branching point in the carotenoid biosynthesis in Capsicum. Quantitatively, Negral cultivar showed the highest increase in total carotenoid content (48. 39-fold), followed by Mana and Delfin with 38.03- and 36.8-fold, respectively, and by Belrubi and Numex with 28.03- and 23.48-fold, respectively. In all the red varieties, there was an inverse relationship between total carotenoid content and the red to yellow isochromic pigment fraction ratio (R/Y) and the capsanthin-to-zeaxanthin ratio (Caps/Zeax). This seems to be related to the carotenogenic capacity of the cultivar, and thus selection and breeding should not only seek a higher total carotenoid content but also attempt to increase these ratios. In the present study, the cultivar Mana had the highest total carotenoid content (13 208 mg/kg dwt), but the lowest R/Y (1.25) and Caps/Zeax (3.38) ratios, which are therefore the parameters to improve. The cultivar Negral had a high carotenoid content (8797 mg/kg dwt) and high R/Y and Caps/Zeax ratios and could be used for transfer of these characters in direct crosses with the cultivar Mana. The cultivar Numex had the highest Caps/Zeax ratio (7.17) and is thus an ideal progenitor for this character.     

Interactions of soil microorganisms on growth and disease incidence of pepper (Capsicum annum)

The effect of interactions between soil borne pathogen, Phytophthora infestans the antagonistic organism Trichoderma viride and Arbuscular mycorrhizal Glomus etunicatum on growth and disease severity of pepper Capsicum annum was investigated in a greenhouse experiment. Pepper seedlings inoculated with the pathogen alone had sever disease symptoms. While those inoculated with mycorrhizal alone had the highest flowering and fruiting values, followed by the pepper seedlings inoculated with Trichoderma viride. But pepper seedlings simultaneously or dually inoculated with the three microorganisms also had good growth parameters, such as early and high flowering incidence, fruit maturity increase in leaf number, height and growth, while the effect of the pathogen was highly suppressed.     

聚丙烯酰胺凝胶电泳的一种辅助辨型方法

聚丙烯酰胺凝胶电泳（PAGE）是实验室常用的基本鉴定方法之一。但由于做胶方式以及各实验室仪器设备良莠不齐，经过一系列纷繁复杂的操作，电泳结果未必尽如人意。其中凝胶带型的判断就是一个较为困惑的问题，一般的聚丙烯酰胺胶跑出的条带总体上都有弧度，越是靠近凝胶两侧越是严重。在本实验中，我们设计了一种较为简单易行的方案，即将难以区分的条带样品做成混合样marker来辅助辨型，通过调整电压和凝胶浓度来达到区分条带的目的。我们用该方案可以将相差0～3bp大小的条带区分开来。     

Are molecular weights of proteins determined by superose 12 column chromatography correct?

Our research on several proteins indicates that accurate molecular weights cannot be determined by Superose 12 column chromatography. In support of this statement, we present data on molecular weights of purified red kidney bean alpha-amylase inhibitor (RKB alphaAI) and white kidney bean alpha-amylase inhibitor (WKB alphaAI) to document this problem. The molecular weight of purified RKB alphaAI determined by Sephadex G-100 gel filtration, polyacrylamide gel electrophoresis, Superose 12 gel filtration and cDNA were 49.0, 51.0, 22.9, and 49.805 kDa (not glycosylated), respectively. The molecular weights of WKB alphaAI by several methods were as follows: Sephadex G-100 gel filtration, 51.0 kDa; Superose 12 gel filtration in 0.2 M NaCl buffer, 23.1 kDa; polyacrylamide gel electrophoresis (PAGE), 51.0 kDa; sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), 45.0 kDa; multiangle laser light scattering (MALLS), 49.940 kDa; laser-assisted time-of-flight mass spectrometry (LATOFMS), 56.714 kDa; and cDNA sequence (with 12.2% carbohydrate), 55.9 kDa. The data indicate there is ionic interaction between proteins and the matrix of Superose 12 in low ionic strength buffers and hydrophobic interaction at higher ionic strength buffers. Researchers should be cautious when using Superose 12 columns for molecular weight determinations.     

花生品种间杂种F1代的SSR标记分析

以花育22号和Sunoleic95R为亲本配置杂交组合,获得杂种F1,利用SSR引物对亲本和杂种F1各单株进行扩增,分析其带型,辨别真伪杂种,并对亲本和杂种F1各单株的农艺性状、品质进行调查测定。结果表明：5对引物PM50 、PM179、 PM15、PM384和PM348对亲本、杂种F1各单株的分析结果是一致的,15个杂种F1单株,8株表现为母本带型,是伪杂种;7株表现为杂合带型或父本带型,即真杂种。但5对引物的带型表现存在明显差异,PM50 、PM179、 PM15、PM384表现为双亲互补带型, PM348表现为偏父本型。农艺性状和品质性状分析表明真杂种与伪杂种的籽仁重、侧枝长、亚油酸含量、油酸含量差异大,主茎高、蛋白质含量、脂肪含量差异较小。证实利用SSR标记辨别栽培种花生真伪杂种是可行的。     

Postmortem changes in pork muscle protein phosphorylation in relation to the RN genotype

Postmortem changes in pork muscle protein phosphorylation in relation to the RN(-) genotype were investigated using one-dimensional gel electrophoresis and a phosphor specific staining. The phosphorylation levels of several protein bands were found to be affected by the RN(-) genotype and to change during postmortem development. Glycogen phosphorylase, phosphofructokinase, and pyruvate kinase were found in protein bands affected by the RN(-) genotype, and the phosphorylation profile indicates that part of the increased rate and extended pH decline of the RN(-) genotype could be a consequence of phosphorylation of these key enzymes during the postmortem metabolism. The results illustrate that the protein phosphorylation level of the muscle proteins could be interpreted as a global metabolic fingerprint containing information about the activity status of the enzymes in the postmortem metabolism.     

Formation of volatile compounds during heating of spice paprika (Capsicum annuum) powder

Spice paprika (red pepper; Capsicum annuum) is the most cultivated spice worldwide and is used mainly for its color and pungency. However, current research is also focusing on the flavor as an important parameter. This paper deals with the kinetics of the formation of those volatiles that indicate a decrease in spice paprika quality due to Maillard reaction, hydrolytic reactions, and oxidative degradation reactions of lipids such as fatty acids and carotenoids. Spice paprika volatiles were quantitatively analyzed by means of headspace gas chromatography (HS-GC) and solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS). The kinetics of their formation were investigated, and the respective activation energies determined. Strecker aldehyde, acetone, and methanol formation followed a pseudo-zero-order reaction kinetic, and formation of dimethyl sulfide (DMS) was characterized by a first-order kinetic. The activation energies determined were between 86.3 and 101.8 for the Strecker aldehydes acetaldehyde (AA), 2-methylpropanal (2-MP), 3-methylbutanal (3-MB), and 2-methylbutanal (2-MB), 130.7 for acetone, 114.2 for methanol, and 109.7 kJ/mol for DMS. The amounts of Strecker aldehydes formed were correlated to the concentrations of the corresponding free amino acids present in the samples. The formation of hexanal and 6-methyl-5-hepten-2-one in Capsicum annuum during processing was confirmed, and the formation of beta-ionone was probably described for the first time. During heating, the concentration of hexanal increased rapidly. The formation of 6-methyl-5-hepten-2-one confirms that Capsicum annuum fruits contain lycopene.     

Isoform patterns of chitinase and beta-1,3-glucanase in maturing corn kernels (Zea mays L.) associated with Aspergillus flavus milk stage infection

Isoform patterns of chitinase and beta-1,3-glucanase of maturing kernels of yellow dent corn (Pioneer 3394) infected with Aspergillus flavus at the milk stage were investigated through polyacrylamide gel electrophoresis (PAGE). Proteins on the sodium dodecyl sulfate (SDS) gel with an apparent molecular mass range of 23-46 kDa were differentially present in the kernels infected with both aflatoxin-producing and non-aflatoxin-producing strains of A. flavus. From in-gel (native PAGE) enzyme activity assays, three bands corresponding to chitinase isoforms and two bands corresponding to beta-1,3-glucanase isoforms were detected in the infected kernels. One chitinase isoform of 29 kDa was present only in the infected kernels, and another one of 28 kDa was present in both infected and noninfected kernels. They were judged to be acidic on the basis of their migration on an acrylamide isoelectric focusing (IEF) gel. For the beta-1,3-glucanase, one isoform of 35 kDa was present in both infected and noninfected kernels, but another one, a 33 kDa isoform, was present only in the infected kernels. Both acidic and basic beta-1,3-glucanase isoforms were detected in the IEF gel. The results of this study are the first to demonstrate patterns of enhanced or inducible proteins in maturing corn kernels in response to A. flavus infection at the milk stage. The results also indicate that only particular isoforms of the two hydrolytic enzymes are involved in the maturing corn kernels infected at the milk stage with A. flavus.