Graft Compatibility of Scotch Bonnet （Capsicum chinense Jacq） with Selected Salt-Tolerant Solanaceous

In recent years, grafting to improve salt-tolerance of vegetables has been studied extensively. The rootstock species, Solanum melongena cv Black Beauty, Solanum lycopersicum cv Akash and Solanum nigrum （bitter gumma）, reportedly salt-tolerant, were evaluated for their graft compatibility with Capsicum chinense cv Scotch Bonnet. Grafted and non-grafted plants were grown for three weeks under greenhouse conditions. Graft compatibility was determined by the regeneration of vascular bundles across the graft interface and vegetative growth parameters. The results showed that the highest survival percentage （100%） was obtained in the Scotch Bonnet/Black Beauty heterografts and the lowest （16%） was obtained in the Scotch Bonnet/bitter gumma heterografts. Vascular regeneration across the graft interface was seen in Scotch Bonnet autografts and heterografts with Black Beauty. Graft incompatibility observed in heterografts on Akash and bitter gumma rootstocks could be attributed to the presence of a necrotic layer at the graft interface. In conclusion, progressive scion growth and development and the regeneration of vascular bundles across the graft interface are effective in determining graft compatibility between Scotch Bonnet and selected solanceous species. This suggests that Scotch Bonnet can be cultivated under saline growing condition.

Polyphenols,Ascorbic Acid and Carotenoids Contents and Antioxidant Properties of Habanero Pepper(Capsicum chinense)Fruit

Their high bioactive compounds content and importance as dietary antioxidants has increased interest in Capsicum fruit. The fruit of seven Capsicum chinense Jacq. var. habanero genotypes grown in Yucatan, Mexico, were analyzed to quantify their phenolic compounds, carotenoids and ascorbic acid contents, and to measure their free radical scavenging (ABTS assay) and antioxidant activities (β-carotene/linoleic acid assay). Phenolics (20.54 to 20.75 mg/100 g sample), carotenoids (1.00 to 1.26 mg/100 g sample) and ascorbic acid contents (187.24 to 281.73 mg/100 g sample) varied between genotypes. Trolox equivalent antioxidant capacity (TEAC) ranged from 1.55 to 3.23 mM/mg sample. During the 120-min decolorization trial, antioxidant capacity decreased over time in the studied genotypes. Values ranged from 36%to 57% β-carotene bleaching during the first 30 minutes. Fruit from all seven studied genotypes are good antioxidant sources and hold promise as natural ingredients in functional foods.

Analysis of Cloning and Expression Characteristics of Capsicum chinense Jacq. CcMYB Gene

In order to discuss the role of MYB gene in capsaicine synthesis process, one CcMYB gene was cloned from Capsicum chinense Jacq. by RT-PCR. Its cDNA has a total length of 1 038 bp, and was speculated to code 345 amino acids, comprising an complete open reading frame. The isoelectric point is 8.57, and the molecular weight is 38.2 KD. The protein is a neutral hydrophobin without transmentbrane structure. There are two MYBDNA domains at the N terminal. The fluorescence quantitative PCR results showed that CcMYB gene was expressed in all the root, stem, leaf, flower, placenta and fruit tissue of pepper, and the expression level was the highest in fruit ; and CcMYB was expressed in fruit at the highest level at turning stage, and at the second highest level at expansion stage, which accords with the expression profile of punl gene in fruit development period. It is speculated that CcMYB gene plays an important role in the regulation of capsaicine synthesis in C. chinense fruit.

Ethnobotanical Investigation of Insecticidal Plants and Evaluation of the Insecticidal Activity of Capsicum chinense on Sitophilus zeamaïs of Maize and Aphis craccivora of Groundnuts: Case of Boffa, BokéRegion (Republic of Guinea)

The present study, which aims to contribute to the valorization of Capsicum chinense, focuses on ethnobotanical investigations and evaluation of insecticidal activity on Sitophilus zeamaïs and Aphis craccivora, as well as the germination power of infected maize and peanut grains treated and not treated with Capsicum chinense leaf powder. To do this, the moisture content of corn and peanuts was determined by the techniques: drying in the sun and in the oven. The insecticidal effect of the powder was tested on maize and peanut kernels infected by the AGRAR (2013) method, followed by a test of the germination potency of these treated grains. The average moisture values of corn and groundnut kernels are 14.51% and 12.25% respectively. The results show, a higher insecticidal efficacy of Capsicum chinense leaf powder on Sitophilus zeamaïs and Aphis craccivora with doses (2, 4 and 8 g). The average germination rates of maize and peanut kernels infected and treated with this powder are: (16.5%;63%;99.5%) and (21.25%;96.5%;99.75%), respectively. This study could be a bio-insecticide alternative for the peasant community in the conservation of cereal and legume products.

Differential Expression of Genes Related to Fruit Development and Capsaicinoids Synthesis in Habanero Pepper Plants Grown in Contrasting Soil Types

Habanero pepper(Capsicum chinense Jacq.)is a crop of economic relevance in the Peninsula of Yucatan.Its fruits have a high level of capsaicinoids compared to peppers grown in other regions of the world,which gives them industrial importance.Soil is an important factor that affects pepper development,nutritional quality,and capsaicinoid content.However,the effect of soil type on fruit development and capsaicinoid metabolism has been little understood.This work aimed to compare the effect of soils with contrasting characteristics,black soil(BS)and red soil(RS),on the expression of genes related to the development of fruits,and capsaicinoid synthesis using a transcriptomic analysis of the habanero pepper fruits.Plants growing in RS had bigger fruits and higher expression of genes related to floral development,fruit abscission,and softening which suggests that RS stimulates fruit development from early stages until maturation stages.Fruits from plants growing in BS had enrichment in metabolic pathways related to growth,sugars,and photosynthesis.Besides,these fruits had higher capsaicinoid accumulation at 25 days post-anthesis,and higher expression of genes related to the branched-chain amino acids metabolism(ketol-acid reductisomerase KARI),pentose phosphate pathway and production of NADPH(glucose-6-phosphate-1-dehydrogenase G6PDH),and proteasome and vesicular traffic in cells(26S proteasome regulatory subunit T4 RPT4),which suggest that BS is better in the early stimulation of pathways related to the nutritional quality and capsaicinoid metabolism in the fruits.

Phenotypic Variation among and within Three Peppers Species(Capsicum)from Mexico

The phenotypic variation and its distribution among species,morphotypes,and among and within populations was estimated in 71 populations pertaining to 15 morphotypes of three domesticated species of Capsicum from Mexico.Collections were made in the states of Sinaloa,Nayarit,Oaxaca,Tabasco,and Yucatán in two agroecosystems:Backyard-garden and monoculture.Fifteen phenotypic characteristics were analyzed through one-way variance analysis and multivariate analyses of principal components analysis(PCA)and hierarchical clustering using Ward’s method.The study was performed in a uniform greenhouse experiment.A high variation was found among and within populations in all the measured characteristics.Of the total variation,13.0%was distributed among species,27.9%among morphotypes,8.1%among populations,and 51.0%within populations.Because plants grew in a uniform environment,these results indicate that the differences observed among and within species,morphotypes,and populations have a genetic basis.Univariate and multivariate analyses clearly differentiated morphotypes,suggesting that the category of morphotypes must be used to nominate the infraspecific variation in the domesticated Capsicum.The principal components analysis identified a total of 15 principal components that contributed to explain the total variation.The first two components explained 59.64%of the total variation and seven components explained more than 90%of the total variation.Among the measured characteristics,number of seed per fruit,weight of the fruit,width of the fruit,length of the fruit,stem diameter,days to flowering,and height of the plant contributed to component 1 variation,whereas width of the leaf,length of the leaf,and number of locules,number of fruits and number of seeds per plant contributed to component 2.The hierarchical clustering separated the populations and the morphotypes in two large different groups.One group consisted of populations collected in monoculture conditions and the other group corresponded to population collected from backyard-garden conditions.The monoculture populations were characterized mainly by their longer,wider,and higher weight fruits,plants were of less height,had smaller stem diameters,and lower number of fruits than the populations collected from the backyard-garden conditions.The backyard-garden populations of the Capsicum annuum and Capsicum frutescens species,considered wild or semi-domesticated,constituted a non-differentiated phenotypic group that does not allow dividing them in different species.

Biquinho pepper(Capsium chinense):Bioactive compounds,in vivo and in vitro antioxidant capacities and anti-cholesterol oxidation kinetics in fish balls during frozen storage

The present study reports bioactive constituents from biquinho pepper,such as carotenoids,capsaicinoids,and capsinoids,identified by UHPLC-MS.Biquinho pepper extract showed an antioxidant potential by DPPH(33.17±0.08%),ORAC(32.35±0.02μM TE/g),β-carotene/linoleic acid(55.80±1.30%),and FRAP(315.88±4.23μmol TE/g)assays.Additionally,in vivo antioxidant analyses demonstrated that the pepper extract(170μg/mL)decreased the damage promoted by H_(2)O_(2) in Saccharomyces cerevisiae cells.Fish balls were prepared using different concentrations of pepper(0.0%,0.5%,0.75%,1.0%)to investigate its antioxidant effect during frozen storage.Biquinho pepper effectively reduced the formation of cholesterol oxides and preserved essential fatty acids,mainly in samples containing 1.0%of pepper.Moreover,this treatment was more efficient than sodium erythorbate(p<0.05),which was used as standard.The kinetics of cholesterol oxidation was also determined,showing that both cholesterol degradation and cholesterol oxides formation fit a first-order kinetic model(R^(2)>0.8).

黄灯笼辣椒CcCASP1基因的克隆与VIGS载体构建

为研究海南黄灯笼辣椒凯氏带膜蛋白在抗病过程中的功能,利用PCR技术从辣椒叶片cDNA中扩增出CASP基因,对其蛋白序列进行生物信息学分析,并构建病毒诱导基因沉默(VIGS)载体,验证其效果。结果表明:成功克隆CASP基因,并命名为CcCASP1基因。该基因全长为501 bp,编码166个氨基酸。经生物信息学分析表明,CcCASP1蛋白是一个小分子碱性疏水稳定的膜蛋白,存在4个相对保守的跨膜螺旋结构域。系统进化关系分析结果表明,CcCASP1蛋白与番茄和烟草CASP蛋白亲缘关系较近。利用酶切连接的方法构建了VIGS载体,在海南黄灯笼辣椒中成功地沉默了CcCASP1基因,且效果显著,为深入研究Cc CASP1基因在黄灯笼辣椒中的抗病功能提供技术支持。

中国辣椒低温响应转录因子CBF全基因组鉴定与分析

CBF(C-repeat binding factor)转录因子在植物应对低温等非生物胁迫和提高耐寒性中发挥着重要作用。为了探究中国辣椒(Capsicum chinense Jacq.)CBF基因家族的基本特性,利用生物信息学方法,在中国辣椒基因组中鉴定获得8个CBF基因家族转录因子,对其理化性质、蛋白结构、系统发育、作用元件和基因转录进行了分析。结果表明,8个CBF蛋白长度为156~290 aa,蛋白分子量为17.75~32.21 kD;这些蛋白均包含AP2结构域。系统发育分析表明,中国辣椒8个CBF基因可分为两个亚组,其中A组包含7个基因,B组仅包含1个基因。表达分析表明,8个CBF基因对低温冷胁迫均有不同程度的响应。研究结果概括了中国辣椒CBF基因家族的基本特性,为CBF转录因子的深入研究和应用积累了基础数据。

不同辣椒种质对象耳豆根结线虫的抗性评价

近年来象耳豆根结线虫的危害日益严重。为筛选抗象耳豆根结线虫的辣椒种质,本试验利用种属特异性引物对根结线虫病原物开展分子鉴定,确定为象耳豆根结线虫。接着采用室内人工接种法,对10份一年生辣椒种质和10份中国辣椒种质进行象耳豆根结线虫抗性鉴定,计算根结指数和卵粒指数,并通过比较隶属函数,发现其中3份辣椒种质对象耳豆根结线虫表现为高抗,抗病性最强的是L518M和L525-1M,L42M次之;10份表现为中抗;7份表现为感病,抗病能力最弱的是L69-1M;未发现免疫品种。本研究发现中国辣椒种质的抗病性整体高于一年生辣椒,是重要的抗病种质来源,可用于象耳豆根结线虫抗病育种和后续抗病机理的研究。

黄灯笼辣椒CcCAD1基因的克隆与植物表达载体的构建

肉桂醇脱氢酶(cinnamyl alcohol dehydrogenase, CAD)在木质素生物合成中有着重要作用,为了探讨辣椒中CAD基因在木质素合成中的作用,本研究利用RT-PCR方法从黄灯笼辣椒幼嫩叶片中克隆得到CAD1基因全长cDNA,命名为CcCAD1。序列分析表明,CcCAD1 cDNA序列全长1 074 bp,编码357个氨基酸。同源比对显示其与番茄CAD1蛋白的一致性高达96.09%。荧光定量PCR检测结果显示,CcCAD1基因在辣椒根、茎、叶、胎座和果肉中的表达量差异显著,其相对表达量为叶>果肉>茎>根>胎座。利用Bam HⅠ和SacⅠ双酶切连接成功构建pBI121-CcCAD1植物表达载体,为CcCAD1基因转化以及后续的功能分析提供依据。