Verticillium Wilt of Pepper (Capsicum annuum) in Morocco

Pepper crops in Morocco formerly thought to be free from attack by Verticillium were found to be susceptible to this pathogen. Verticillium wilt of pepper was observed in plots where the crop was cultivated in rotation with tomatoes. Strains of Verticillium isolated from pepper possessed different morphological and pathogenic characteristics.     

Virus Diseases of Pepper (Capsicum annuum L.) in Ethiopia

Viruses occurring in hot pepper (Capsicum annuum L.) in Ethiopia during 1984–1986 were identified and their symptomatology, host range, serology, morphology and transmission described. Potyviruses were found to cause severe infections of pepper wherever the crop was observed. Disease incidence and yield loss in most surveyed areas were estimated at 40–100 % and 15–50 %, respectively. Besides potato Y and pepper veinal mottle viruses, a new potyvirus with distinctive properties was found widely distributed in Shewa and Welega Provinces. The virus, tentatively designated Ethiopian pepper mottle virus (EPMV), was shown to have an unusually narrow experimental host range and filamentous particles about 700–750 nm in length, and to be nonpersis-tently transmitted by aphids but not transmissible through pepper seeds. Cucumber mosaic virus was detected in some locations, but appeared to be of minor significance.     

Leaf Starch Metabolism during the Growth of Pepper (Capsicum annuum) Plants

Levels of starch and sugars, and the activities of amylase and starch phosphorylase were measured in expanding leaves harvested in early morning and early evening during the growth of pepper (Capsicum annuum L.; cv `Bellboy') plants. The differences between starch levels 1 hour after dawn and 1 hour after dusk increased during the period of initial fruit expansion. This diurnal starch difference was strongly correlated with post-dusk amylase activities in leaves at both stages of expansion. There was also a strong correlation between levels of amylase in immature and those in mature leaves throughout the experiment. Phosphorylase activity showed no direct relationship to leaf starch levels, and there was no similarity between activities in immature and mature leaves. An increase in photosynthesis during plant development was observed which could account for the increased starch synthesis at initial fruit expansion.     

回归分析在辣椒品种RAPD反应体系优化中的应用

以辣椒(CapsicumannuumL.)为材料,采用回归分析的方法对RAPD体系进行优化研究。结果表明在体积为20μl反应体系中,主要因子的优化组合是:Mg2 、dNTP、Taq酶、引物、模板DNA等的浓度分别为3mmol/L、0.3mmol/L、1.3U、0.4μmol/L和64ng;热循环程序为:94℃预变性2min,94℃变性30s,40℃退火1min,72℃延伸90s,47个循环,最后72℃延伸10min。通过对24个辣椒品种进行遗传多样性分析,证明该优化体系是稳定可靠的。     

Histopathology of Susceptible and Resistant Capsicum annuum Cultivars Infected with Ralstonia solanacearum

The vascular colonisation of resistant and susceptible hot chilli (Capsicum annuum) cultivars by Ralstonia solanacearum was examined using transmission electron microscopy. Tap roots of artificially-inoculated plants, grown in sterilised soil were investigated to observe the morphological barriers involved in the restriction of bacterial spread. In the resistant cultivar, several responses induced in response to bacterial infection, were observed. First, a cell wall coating material developed together with swelling of the primary wall of the xylem vessels, limiting the bacterial spread. Second, formation of various types of vesicles in the vascular parenchyma cells, which enveloped the bacterial mass and also partly restricted the pathogen spread. Third, induction of hypersensitive reaction in the xylem vessels resulted in the distortion and lysis of the bacteria. In the susceptible cultivar, vascular coating, production of vesicle and induction of hypersensitive reaction were not observed and bacterial spread was not limited. Rapid vascular colonisation of the susceptible cultivar seemed to be generalised which resulted in the rapid wilting of affected plants. Other reactions involved in both resistant and susceptible cultivars include disorganisation of cytoplasm of parenchyma cells, disintegration of nuclei, and rupturing of xylem vessel walls. The restriction of pathogen spread associated with the resistance in C. annuum to bacterial wilt was mainly attributed to some induced, morphological and physical barriers.     

Carbon Partitioning and Export in Mature Leaves of Pepper (Capsicum annuum)

The partitioning of recently fixed carbon by mature pepper leaveshas been examined over a 10 h photoperiod using a constant specificradioactivity ¹⁴CO₂ labelling technique. Changes in the ratesof carbon partitioning into export, starch, sucrose and hexoseswere examined following changes in irradiance during the photoperiod.Leaves grown under 80 W m^–2 PAR were exposed to this irradiancefor the first 4 h of the photoperiod then the iiradiance wasdecreased. Leaves accumulated sufficient reserves in the first4 h to maintain export at the initial rate (approximately 20µg carbon cm^–2 leaf h^–1) over the following6 h of the photoperiod when the net photosynthesis rate (Pn)was decreased to 10% of the initial rate by the decreased irradiance.Export was initially maintained by the depletion of sucroseand hexose and then by carbon from the degradation of starchin the light. If leaves were exposed to low irradiance at the beginning ofthe photoperiod, then the export rate was linearly related tothe Pn during that period. When Pn exceeded that required tomaintain an export rate of approximately 20 µg carboncm^–2 h^–1, then more carbon was partitioned intostarch. At low initial irradiance, a greater proportion of photosynthatewas partitioned into export rather than starch and at high initialirradiancc the reverse occurred. There was a linear relationship between starch accumulationrate and Pn for all leaves but the relationship between Pn andexport rate was only significant for leaves with low levelsof reserve carbon. The results show that mature pepper leaves subjected to differentirradiances maintain constant export rates through alterationsof carbon partitioning. Export at low Pn is maintained at theexpense of sugar and starch reserves, with partitioning in highirradiance being predominantly to starch. Key words: Carbon partitioning, Starch, Export, Pepper (Capsicum annuum L.)     

辣椒开花期的主基因+多基因遗传分析

应用植物数量性状主基因+多基困混合遗传模型对早熟辣椒‘E100’与‘L101’杂交组合多个世代群体开花期进行了联合分析.结果表明:开花期由两对加性-显性-上位性主基因+加性-显性-上位性多基因的控制;主基因遗传率在B1、B2和F2世代分别为55.27%、53.83%和76.05%;B1、B2和F2世代多基因遗传率分别为34.13%、42.78%和16.94%.     

Response of Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) Biotype B to Genotypes of Pepper Capsicum annuum (Solanales: Solanaceae)

Bemisia tabaci Genn. biotype B is a widely distributed plant pest that represents one of the major constraints for horticultural crop production. The purpose of the present work was to evaluate the oviposition preference, survivorship, and development of B. tabaci biotype B on semi-cultivated genotypes of Capsicum annuum from southeast Mexico. In free-choice experiments to evaluate the oviposition preference, lower number of eggs laid by B. tabaci biotype B was observed in the genotypes Maax and Xcat´ik relative to that in the commercial genotype Parado. Egg hatchability was significantly lower in Pico Paloma, Bolita, Blanco, Chawa, Payaso, and Xcat´ik than in the rest of the genotypes, including the commercial genotype Jalapeño. Likewise, survivorship of nymphs was significantly lower in Pico Paloma, Bolita, and Blanco than in the remaining genotypes. Nymph developmental time and the period of development from egg to adult were the shortest in Amaxito. Therefore, sources of resistance to B. tabaci biotype B by antibiosis (accumulation of plant defense compounds) might be found in the semi-cultivated genotypes Pico Paloma, Bolita, and Blanco.     

Molecular AFLP-marking of genotypes of pepper (Capsicum annuum) cultivars

The results of AFLP study of 14 Capsicum annuum cultivars are presented. Notwithstanding the known low genomic variation of large-fruited sweet pepper, AFLP analysis proved to be suitable for detecting polymorphism and genotyping pepper cultivars. Nine primer pairs were selected to allow identification of the cultivars under study. Among-cultivar polymorphism detectable with these primers was estimated at 16.5%. A characteristic AFLP pattern was obtained for each cultivar. Several cultivar-specific fragments were revealed for seven cultivars. On the basis of the AFLP data, genetic distances between cultivars were computed and a tree was constructed by means of hierarchic cluster analysis (UPGMA) with the Jacquard coefficient. It was assumed that this information is useful in breeding programs involving the cultivars examined.     

Effects of Pepper (Capsicum annuum) Cultivars on the Biology and Life Table Parameters of Myzus persicae (Sulz.) (Hemiptera: Aphididae)

Green peach aphids, Myzus persicae (Sulz.) (Hemiptera: Aphididae), obtained from pepper fields, were colonized on susceptible pepper plants in a growth chamber. The development, survivorship, and life table parameters of the green peach aphid were evaluated on nine peppers cultivars as follows: Almuden, Bilano, Bird, Cabezo, de la Sierra, Eppo, Jaen, Raza, and Yatasto at controlled conditions (20?±?1°C; about 70% RH; 14h photophase). The development times of immatures ranged from 6.1 days on Yatasto to 11.4 days on Jaen, whereas immature survival was close to 100% on all cultivars. The intrinsic rate of increase (r _m ) for green peach aphid on Bilano and Yatasto were the highest. Jackknife estimates of r _m varied from 0.281 to 0.174 females/female/day on Yatasto and Jaen, respectively. The mean population generation times (T) on these hosts ranged from 13.7 to 22.7 days. The highest net reproductive rates (R ₀ ) were on Bird and Bilano (63.8 and 62.89 females/female/generation, respectively) and the lowest on De la Sierra and Almuden (34.1 and 38.7, respectively). Because of the high coefficient of determination (R ²) values in Gompertz and Weibul models, survival data from different cultivars had a good fit to both models. The results pointed Jaen, Almuden, and Raza cultivars as the least suitable host plants, indicating that they were the most resistant to M. persicae among the cultivars we tested.     

BABA and Phytophthora nicotianae Induce Resistance to Phytophthora capsici in Chile Pepper (Capsicum annuum)

Induced resistance in plants is a systemic response to certain microorganisms or chemicals that enhances basal defense responses during subsequent plant infection by pathogens. Inoculation of chile pepper with zoospores of non-host Phytophthora nicotianae or the chemical elicitor beta-aminobutyric acid (BABA) significantly inhibited foliar blight caused by Phytophthora capsici. Tissue extract analyses by GC/MS identified conserved change in certain metabolite concentrations following P. nicotianae or BABA treatment. Induced chile pepper plants had reduced concentrations of sucrose and TCA cycle intermediates and increased concentrations of specific hexose-phosphates, hexose-disaccharides and amino acids. Galactose, which increased significantly in induced chile pepper plants, was shown to inhibit growth of P. capsici in a plate assay.     

Molecular Analysis of Chickpea (Cicer arietinum L) Cultivars Using AFLP and STMS Markers

Fifteen AFLP and eighteen STMS primer pairs were employed to reveal genetic diversity and relationship in twenty-one cultivars of chickpea (Cicer arietinum L). Fifteen AFLP primer pairs generated 1804 amplicons, out of which 1732 amplicons (96%) were polymorphic and 600 amplicons (∼33%) were genotype specific. Eighteen polymorphic STMS primer pairs generated 64 amplicons with an average of 3.55 amplicons per primer pair. Polymorphic information content (PIC) varied from 0.52 to 1.0 for STMS markers. The genetic similarity between cultivars varied from 0.30 to 0.85 for AFLP and 0.22 to 0.83 for STMS markers. Dendrogram constructed after combining both AFLP and STMS markers data with Bootstrap analysis, grouped all the cultivars into four clusters. Association of varietal type and flower colour was observed as cultivars E 100Ymu and Nabin (Both Desi type and pink flower) clustered together in the dendrogram.     

Effects of Low Oxygen on Photosynthesis, Translocation and Growth in Green Pepper (Capsicum annuum)

Green pepper (Capsicum annuum cv. Bell Boy) plants were exposedin chambers to low (2%) oxygen and controlled carbon dioxideconcentrations. Vegetative and fruiting plants showed short-termincreases in net photosynthesis in low oxygen or elevated carbondioxide (up to 900 µl CO₂ l^–1). Photosynthesis ofyoung vegetative plants increased in low oxygen in the short-termbut there was no long-term benefit. Low oxygen enhancement ofphotosynthesis declined with time and after 10 d, leaf areaand root dry weight were less than in plants grown in normalair. Labelled assimilates were translocated from leaves to otherregions at similar rates in low oxygen and normal air. Low oxygenreduced respiratory losses from leaves and reduced the proportionof soluble carbohydrate converted to polysaccharide in all plantparts. Thus, low-oxygen environments decrease the utilisationof assimilates which then may lead to inhibition of photosynthesis. Capsicum annuum, photosynthesis, photorespiration, translocation, utilization of assimilates     

A New Lignan Amide,Grossamide, from Bell Pepper (Capsicum annuum var. grossurri)

Two new phenolic amides, grossamide (7) and N-cis-feruloyl tyramine (2), have been isolated from the roots of bell pepper (Capsicum annuum var. grossum) together with p-aminobenzaldehyde (1), N-trans-feruloyl tyramine (3), N-trans-p-coumaroyl tyramine (4), N-trans-feruloyl octopamine (5), and N-trans-p-coumaroyl octopamine (6).     

An SSR-based linkage map of Capsicum annuum

There are five cultivated species of pepper, of which Capsicum annuum is the most widely cultivated as a vegetable or spice and the main experimental material of most pepper breeding programs. However, the number of simple sequence-repeat (SSR) markers known for C. annuum is limited. To develop SSR markers for Capsicum species, we constructed four SSR-enriched libraries from the genomic DNA of C.␣annuum, sequenced 1873 clones, and isolated 626 unique SSR clones. A higher percentage of these SSR markers were taken from dinucleotide motif libraries than from trinucleotide motif libraries. Primer pairs for the 626 SSR clones were synthesized and tested for polymorphisms; 594 amplified products were detected with the expected size. However, only 153 products were polymorphic between the parents of our mapping population. Using 106 highly reproducible pairs from the primer pairs, we constructed a linkage map of C. annuum in an intraspecific doubled haploid population (n=117) that contains nine previously reported SSRs as well as AFLP, CAPS, and RAPD markers and the trait of fruit pungency. The map contains 374 markers, including 106 new SSR markers distributed across all 13 linkage groups, and covers 1042 cM. The polymorphism information content (PIC) of these new SSR markers was calculated using 14 lines of Capsicum species. The average number of alleles per locus was 2.9 and the average PIC value was 0.46, even within C. annuum. The SSR markers developed in this study will be useful for mapping and marker-assisted selection in pepper breeding, and the linkage map provides a reference genetic map for Capsicum species.     

Plant regeneration from protoplasts of Capsicum annuum

Leaf protoplasts were isolated from axenic shoot cultures of four varieties of Capsicum annuum (Americano, Dulce Italiano Florida Gynat and Nigrum) and a wild species C. chinense. Protoplasts of both species, cultured in KM8P medium and using agarose bead culture, entered division with the exception of the variety Nigrum. Cell colonies formed callus in agar-solified MS medium supplemented with zeatin and for C. annuum v. Dulce Italiano shoots were regenerated when protoplast-derived calli were transferred to MS medium with 6-BAP. Excised shoots were rooted on MS medium which lacked phytohormones.Abbreviations 6-BAP 6-benzylamino purine - MS Murashige and Skoog (1962) - KM8P Kao and Michayluk (1975) - SDS sodium dodecyl sulphate     

辣椒蚜虫种类的调查

蚜虫属同翅目蚜虫总科,是重要的作物害虫。调查海南辣椒植株的蚜虫种类,采集蚜虫标本。将上述活体蚜虫分别接种在室内盆栽辣椒植株上饲养、繁殖,并观察记录各龄期蚜虫的形态特征。经室内观察测定,鉴定出三种蚜虫：棉蚜[Aphis gossypii(Glover)]、桃蚜[Myzus persicae(Sulzer)]和萝卜蚜[Lipaphis erysimi(Kaltenbach)]。     

Isolation of Yeasts from Guajillo Pepper (Capsicum annuum L.) Fermentation and Study of Some Probiotic Characteristics

Probiotics and Antimicrobial Proteins - Three yeast strains were isolated from the spontaneous fermentation of guajillo pepper: Hanseniaspora opuntiae, Pichia kudriavzevii, and Wickerhamomyces...