Fruit Wall Research Articles

LEAVES AND FRUITS CONTENT OF N, P, AND K AS WELL AS FRUIT QUALITY OF SWEET PEPPER PLANT AS AFFECTED BY IRRIGATION LEVELS AND SOIL AMENDMENTS UNDER EL-ARISH REGION CONDITIONS

This study was carried out during summer season of 2017 and 2018 at the Experimental Farm, Faculty of Environmental Agricultural Sciences, Arish University, Egypt to investigate the effects of water irrigation levels and soil amendments on content of N, P and K in leaves and fruits as well as fruit quality of sweet pepper plant. Sweet pepper cv. “Top star” was subjected to three irrigation levels (100,80 and 60% of irrigation requirements) and three soil amendments; i.e., control (without amendment), gypsum and pressed olive cake and their interactions in a factorial experiment using the randomized complete block design with three replications. Drip irrigation system was used and soil texture was sandy loam. The obtained results indicated that the highest contents of N, P and Kin leaves and fruit were recorded with applying 100% irrigation level + pressed olive cake as soil amendment followed by 80% irrigation levels + pressed olive cake in both seasons. All fruit quality studied traits; viz., fruit length, fruit diameter, fruit wall thickness, hardness, TSS%, and vitamin C content had their highest values with applying 100% of irrigation water + pressed olive cake as a soil amendment in both seasons, except length/diameter (L/D) ratio and pH values, where the highest values of fruit L/D ratio were recorded with applying 80% of irrigation water level + pressed olive cake in both seasons, while the highest values of fruit pH were recorded with applying 80% of irrigation water + pressed olive cake without significant difference than the same treatment of soil amendment with 100% or 60% irrigation water level in both seasons.

Assessment of Fruit Quality and Fruit Morphology in Androgenic Pepper Lines (Capsicum annuum L.)

Anther or microspore culture induced haploid and double haploids (DH) are increasingly being utilized by breeders since it can shorten breeding time by achieving complete homozygosity within a single generation. Pepper (Capsicum annuum L.) is one of the most important vegetables, distinguished by its high level of heterozygosity, making the breeding process very laborious and long. Fourteen different DH lines were obtained as a result of anther culture of four parental genotypes. Data from different plant and fruit morphological traits as well as quality traits including vitamin C, dry matter content, total polyphenols and antioxidant activity were collected. A total of 47 different descriptors for fruit morphology and color were characterized using Tomato Analyzer v. 3 software. Findings from this research revealed significant variation of fruit morphology, quality and productivity traits between DH lines and their respective parental genotypes. Among these studied 14 DH lines, 42.9% were superior to the parental genotypes for fruit weight, width, fruit wall thickness, and usable part of the fruits. As compared to parental genotypes, DH lines exhibited higher values for tested fruit quality traits and dry matter content. Multivariate analysis allowed us to identify the trait combination that contributed to the total variation. A total of eight principle components (PCs) explained 95.4% variation with PC1 and PC2 contributing 32.4% and 21.1%, respectively. Pepper androgenesis clearly indicates its usefulness as a well established technique that can allow pepper breeders to save the time and breeding resources by expediting the breeding process. Our research findings prove the advantages of pepper androgenesis to utilize the diversity of pepper genetic resources and development of novel pepper breeding lines to utilize in future breeding.

Hypoglycemic activity of Phaseolus vulgaris (L.) aqueous extract in type 1 diabetic rats

Abstract The aim of the present study was to evaluate the hypoglycemic activity of the aqueous extract from the fruit walls of Phaseolus vulgaris pods and to examine the potential mechanism underlying the improvement of the glycemic level. In the course of the study, diabetes mellitus was induced in rats with a single intraperitoneal injection of streptozotocin (45 mg·kg−1 b.w.). Diabetic and control rats were then orally administered with a single-dose or repeated-dose (28 day) of P. vulgaris extract (200 mg·kg−1). Results show that the extract was found to possess significant hypoglycemic activity, and the study of glucose utilization by isolated rat hemidiaphragm suggests that the aqueous extract may enhance the peripheral utilization of glucose. The subsequent experiments have revealed that the P. vulgaris extract could increase glucose transporter 4 (GLUT-4) content in skeletal muscle cells of control and diabetic rats. Our data also indicate that the P. vulgaris extract did not affect the content of the insulin receptor, but significantly reduced the total tyrosine kinase activity in skeletal muscle cells of both experimental groups of rats. The present results clearly indicated that P. vulgaris extract may be beneficial for reducing hyperglycemia through its potency in regulation of glucose utilization via GLUT-4, but the current mechanism remains to be unidentified.

In vitro consumption patterns of pepper weevil, Anthonomus eugenii (Coleoptera: Curculionidae) on two commercial pepper cultivars in Florida

The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is a major pest of pepper. To analyze the consumption characteristics of pepper weevil as a reference for pest management strategies, the functional response, the intraspecific competition and the preference of A. eugenii were evaluated under laboratory conditions. The results showed that compared to Jalapeno, the pepper cultivar Habanero has a lower susceptibility due to the less consumption, lower searching rate and longer handling time of A. eugenii. Pepper weevils suffered from intraspecific competition when consuming Habanero or Jalapeno. Fruit wall thicknesses, weights and sizes were negatively correlated with the numbers of puncture marks per fruit; so, large-sized, thick-walled and large-mass fruits were less susceptible to A. eugenii. The present study suggests that choosing pepper cultivars and characteristics with low susceptibility to A. eugenii, and utilizing the intraspecific competition between pepper weevils have a potential to control the pest.

Morphogenesis of fruits and types of fruit of angiosperms

ABSTRACTMorphological and anatomical fruit characters are used for description of morphogenetic fruit types within eight traditional fruit types – follicle, nutlet, drupe, berry, capsule, pyrenarium, amphisarca and nut, which describe the major diversity of fruits of all angiosperms. The traditional fruit types are representing levels of fruits organization and are described based on morphological characters (gynoecium type, carpels phyllotaxis, fruiting carpel dehiscence or indehiscence, number of seeds per fruit, and the presence or absence of the continuous sclerenchymatous zone in the fruit wall), whereas morphogenetic fruit types are described based on fruit wall (pericarp) anatomy. Fundamental differences between basal types of pericarp structure of the outlined morphogenetic fruit types lie in the localization (in the exocarp, specific zone of the mesocarp and/or endocarp) of the continuous sclerenchymatous zone, which secures protection of seeds, fruit dehiscence in follicles and capsules, and dissemination. Twenty seven morphogenetic fruit types are recognized in the current research: four types of follicle (Hakea, Illicium, Myristica and Talauma types), two types of nutlet (Nelumbo and Rosa types), three types of drupe (Laurus, Prunus and Rhapis types), two types of berrie (Schisandra and Nuphar types), seven types of capsule (Bombax, Eriocoelum, Forsythia, Galanthus, Hamamelis, Lilium and Nepenthes types), four types of pyrenarium (Butia, Ilex, Latania and Olea types), two types of amphisarca (Adansonia and Theobroma types), and three types of nut (Corylus, Polygonum and Centaurea types) in angiosperms. The modes of evolutionary transformations of main morphogenetic types of fruits are described.

Effects of Tobacco Etch Virus (TEV) on the Yield and Quality of Karaisali Pepper Populations

The Eastern Mediterranean Region has a significant potential for capia pepper production in Turkey. In the region, a population named as ‘Karaisali pepper’ with special characteristics, is grown. The population is well-adapted to the region and grown for processing. Karaisali pepper is usually preferred for red pepper production due to its high dry matter content. Survey studies conducted on Karaisali pepper in 2014 and 2015 demonstrated that the Tobacco etch virus (TEV) was the most common and destructive virus affecting Karaisali pepper. In the present study, three pure lines derived from Karaisali pepper were used to assess their susceptibilities against TEV. The experiment included mechanically inoculated infected plants and healthy pepper plants in the control group. The pepper plants were inoculated with the TEV using mechanical inoculation method during the four-leaf stage. The plants were observed periodically after mechanical inoculation. Each repetition was analyzed based on the total yield, pepper paste yield, fruit size, soluble solid content, fruit color and market value. The result indicated that, in average, TEV reduced Karaisali pepper yield by 77.5% and pepper paste yield by 33.6%. Furthermore, the average fruit length (37%), fruit diameter (21.4%), fruit wall thickness (14.2%), fruit volume (60.2%) and first quality fruit ratio were also decreased. The results confirm the threats of TEV in pepper production.

Hampea lanceolata (Malvaceae, Malvoideae), a new species from Chiapas and Oaxaca, Mexico

Hampea lanceolata is described from the highlands of northern Chiapas and the Chimalapas region of Oaxaca, Mexico.This species had been confused with Hampea longipes, although it is most closely allied to Hampea montebellensis. It differs from H. longipes by the coarse brown pubescence, the relatively narrower leaves with domatia at the junction of main veins, the longer bracteoles, and the smaller fruits with one seed per locule. From H. montebellensis, it differs in having glabrous leaves with domatia, relatively longer pedicels, and in the glabrous or very sparsely puberulent inner fruit walls.

Yield and Morphological İnvestıgatıon of Different Tigger Melon (Cucumis Melo Dudaim) Genotypes Belongıng to Sirnak/Turkey Region

This study was performed in 18 different tigger melon ( CUCUMİS MELO DUDAİM ) genotypes which were collected from the various villages of İdil/Sirnak. In the study, measurements of brix in fruit, SPAD, dry matter in fruit, total yield, seed weight, seed weight per fruit, seed length, number of seeds per fruit, fruit weight, fruit length, fruit width, fruit wall thickness, main stem diameter, main stem length, the main number of nodes in the stem, nod in the main stem were carried out. In addition, the experiment was performed with 4 replications including 10 plants per every replicate. The experiment was made according to the random design of the trial blocks. The data obtained at the end of the experiment statistical analyzes were made by evaluating with JMP8 program and the means were compared according to LSD test. In addition, cluster analysis was also performed in terms of similarity between genotypes in the experiment. As a result, when the fruit measurements are examined; total fruit yield was recorded with high amount in the tigger melon genotype, on the other hand, genotype number 13 of the tigger melon was recorded as the low. According to the obtained results, morphological and pomological measurements demonstrated difference from each other in 18 tigger melon melon plants and fruits. Keywords: Tigger melon, Seed, CUCUMİS MELO DUDAİM, SPAD, Brix. DOI : 10.7176/JBAH/9-10-09 Publication date :May 31 st 2019

Genomic insights from Monoglobus pectinilyticus: a pectin-degrading specialist bacterium in the human colon.

Pectin is abundant in modern day diets, as it comprises the middle lamellae and one-third of the dry carbohydrate weight of fruit and vegetable cell walls. Currently there is no specialized model organism for studying pectin fermentation in the human colon, as our collective understanding is informed by versatile glycan-degrading bacteria rather than by specialist pectin degraders. Here we show that the genome of Monoglobus pectinilyticus possesses a highly specialized glycobiome for pectin degradation, unique amongst Firmicutes known to be in the human gut. Its genome encodes a simple set of metabolic pathways relevant to pectin sugar utilization, and its predicted glycobiome comprises an unusual distribution of carbohydrate-active enzymes (CAZymes) with numerous extracellular methyl/acetyl esterases and pectate lyases. We predict the M. pectinilyticus degradative process is facilitated by cell-surface S-layer homology (SLH) domain-containing proteins, which proteomics analysis shows are differentially expressed in response to pectin. Some of these abundant cell surface proteins of M. pectinilyticus share unique modular organizations rarely observed in human gut bacteria, featuring pectin-specific CAZyme domains and the cell wall-anchoring SLH motifs. We observed M. pectinilyticus degrades various pectins, RG-I, and galactan to produce polysaccharide degradation products (PDPs) which are presumably shared with other inhabitants of the human gut microbiome (HGM). This strain occupies a new ecological niche for a primary degrader specialized in foraging a habitually consumed plant glycan, thereby enriching our understanding of the diverse community profile of the HGM.

English

In most parts of the world pepper has become a popular spice that makes food hot in addition to its much needed nutrients of carotenoids and vitamins. This report has its objective to evaluate the parents and hybrid of three Nigerian pepper genotypes (Shombo, Tatase and Nsukka yellow pepper) for growth and yield; and to estimate their genetic parameters. Conventional breeding by hand pollination was adopted. The mean performance of the parents and hybrids for morpho-agronomic characters were evaluated. Heterosis and inbreeding depression were estimated. The F1 hybrids showed superiority over the parental genotypes with Sho x Nsky-rw having significantly (P ≤ 0.05) the highest value in most of the traits. In morphological traits, Sho x Nsky-rw hybrid had highest values in canopy diameter, number of leaves, number of nodes and number of branches per plant, while in fruit traits, it also had significantly the highest values in the number of fruits, fruit length and weight of fruits per plant. Sho x Nsky – rw had positive heterobeltiosis over the better parent in most of the yield and yield component characters. While Sho x Nsky – rw had the highest yield, Tat x Sho had the highest fruit wall thickness. The combinations of these traits are important to both the farmers and consumers. Having appropriate parents with genetic variability F1 pepper plants having distinct superiority above the mid and better parents could be developed. Key words: Capsicum annuum, chili pepper; heterosis, hybrid, inbreeding depression. &nbsp

Effects of graft copolymer of chitosan and salicylic acid on reducing rot of postharvest fruit and retarding cell wall degradation in grapefruit during storage

This study was to evaluate the effect of graft copolymer (CTS-g-SA) of chitosan (CTS) and salicylic acid (SA) on the storability of grapefruit fruits during postharvest storage. Results indicate that the graft copolymer treatment significantly depressed green mold caused by Penicillium digitatum. The graft copolymer application kept fruit firmness without impairing the fruit quality. Moreover, the graft copolymer treatment inhibited the activity and gene expression of cell wall-modifying enzymes such as polygalacturonase, cellulase, pectin methylesterase, α-l-arabinofuranosidase, β-galactosidase, and suppressed the modification of cell wall components including covalently bound polysaccharide (sodium carbonate soluble pectin, 24% KOH-soluble fraction), which were associated with fruit softening. These results suggested that graft copolymer application can be recognized as a postharvest technique to suppress rotting and delay softening through inhibiting solubilization of cell wall polysaccharides.

Phenotypic Variation in a Germplasm Collection of Pepper (Capsicum chinense Jacq.) from Korea

A total of 47 core collections of pepper (Capsicum chinense Jacq.) conserved in National Agrobiodiversity Center (NAC) were studied under field condition at Jeonju over two consecutive years (2015 and 2016). All accessions were characterized for their 14 qualitative and 16 quantitative characters. Results revealed that both qualitative and quantitative characters exhibited wide variation among the studied germplasm. Distribution of fruit characters (fruit length, width, and fruit wall thickness) among the accessions was positively skewed. Of the 47 accessions evaluated, 38.3% accessions had conical shaped fruits and mature fruit color was predominantly red (51.1%), orange (21.3%) and yellow (14.9%). Principal component analyses revealed that (i) 56.64% of the qualitative (fruit shape, color and fruit surface) variation and (ii) 89.42% of the quantitative (plant width, height and fruit maturity days) variation were explained by the first two components. Clustering revealed two groups and dendrogram revealed morphological variation among accessions. The phenotypic diversity exists in this core collections provide valuable information to improve agronomic traits in pepper breeding program.

To investigate the effect of four timings of mechanical pruning on yield and fruit quality compared to a hand pruned control in an intensive ‘Gala’ M9 orchard planted as a fruit wall

The fruit wall (le mur fruitier) has generated much interest but differing recommendations from other regions in Europe regarding the optimum timing of the mechanical pruning has led to confusion among growers in the UK. In order to determine the effects of different times of pruning and provide growers with robust guidelines, a trial was established in 2012 in a 2-year-old ‘Gala’ (clone Galaxy) orchard planted on M9 at 3.5×0.5 m in the South-East of England. The timings of mechanical pruning were determined by growth stage: pink bud and when 6, 9 or 12 new leaves emerged on the current season’s growth, and these varied by up to 38 days between the different years in the trial. The control was pruned by hand in the dormant season. Half the plots received additional pruning during the dormant season to remove very strong or very weak growth between the trees (inter-tree pruning) in order to investigate whether reducing the branch density affected yields, fruit quality or size. The trial was designed as a fully randomised block consisting of 4 replicates of each treatment. In all years the length of extension growth was related to the time of pruning with later cuts generating the least extension growth. In the first 3 years the yields were greatest in the hand pruned plots but the differences in yield decreased over time. The cumulative yield was highest in the hand pruned control. In the first 2 seasons after the mechanical cuts were imposed, fruit size and sugar content were affected especially in the treatments applied later in the season. These differences reduced in the 3rd and 4th years of the trial. The effects on fruit size, colour and sugar content from inter-tree pruning were small and varied from season to season. Some small differences in fruit mineral content were observed in some years but these were inconsistent and only significant in one or two instances. Nitrogen content of leaves was lower in trees pruned at the two later growth stages. Some modest labour savings were achieved in the mechanically pruned plots.

Effect of pre-harvest foliar application of amino acids and seaweed (Ascophylum nodosum) extract on growth, yield, and storage life of different bell pepper (Capsicum annuum L.) cultivars grown under hydroponic conditions

The study was set up to evaluate the efficiency of amino acids and seaweed on vegetative growth, reproductive phase, yield, and postharvest storage quality of hydroponically grown bell pepper cultivars “Sven Rz F-1” and “Red Knight.” Different concentrations of amino acid and seaweed were sprayed on bell pepper plants under hydroponic conditions. Pre-harvest foliar application of amino acids and seaweed significantly increased plant height, number of leaves, leaf area, yield per plant, number of marketable fruits per plant, average fruit diameter, fruit wall thickness, and average single fruit weight. Amino acid and seaweed significantly improved postharvest physicochemical quality of both bell pepper cultivars under extended cold storage conditions. Conclusively, amino acid as well as seaweed extract not only improved growth, development, yield, and overall quality of bell pepper cultivars but also increased storage life with reduced weight loss and decay along with better physicochemical quality.

Comparative embryology ofStifftiaandWunderlichiaand implications for its evolution in Asteraceae

Asteraceae are one of the largest families of angiosperms and comprise > 1700 genera and 24000 species currently in 13 subfamilies. However, despite recent and continuous improvement regarding their classification, little is known about their embryological diversity, especially in some of the early-diverging subfamilies including Stifftioideae and Wunderlichioideae. These subfamilies were previously considered to be similar, sharing several external features such as anther appendages, pollen grains, pappus bristles and cypsela trichomes. Ontogenetic and anatomical studies could reveal deeper levels of homology and expand the features of interest for the systematics of the family. Also, the lack of knowledge of the early-divergent subfamilies precludes the reconstruction of evolutionary trends in Asteraceae and Asterales. Here, we compared the anthers, ovaries, ovules, fruits and seeds of two Stifftia spp. and two Wunderlichia spp. to identify possible evolutionary trends. Our results show that embryology in these genera is similar, with slight differences in pollen grain ornamentation, types and distribution of ovary trichomes, antipodal persistence, pericarp tissue organization, occurrence of phytomelanin in the fruit wall, the form of the carpopodium, shape and lignification of carpopodial cells, form and distribution of pappus bristles, and lignification patterns of exotesta cells. The results also demonstrate novelties for the family, including Basic-type anther wall development and trichomes on the inner ovary epidermis of W. mirabilis, funicular trichomes in both Stifftia spp., and funicular stomata and phytomelanin in the pericarp of both Wunderlichia spp. Therefore, our data support Stifftioideae and Wunderlichioideae as distinct but closely related subfamilies. The results also open new perspectives on how anther, ovary and fruit evolved in the family. The occurrence of a Basic-type anther wall in early-divergent subfamilies may represent a symplesiomorphy or apomorphy for the family. This will depend on how the anther develops in the subfamilies related to Wunderlichioideae and Stifftioideae. Vascularization of the ovary was different from that previously known in the family and throws doubts upon its origin. Phytomelanin is a rare substance in plants, found only in seeds of most families of Asparagales and fruits of some Asteraceae; it had previously been found in fruits of Heterocoma (Cichorioideae) and some Asteroideae. We detected phytomelanin in Wunderlichia, indicating that presence of this substance has evolved independently three times in the fruits of the family.

Comparative Mechanical Harvest Efficiency of Six New Mexico Pod–type Green Chile Pepper Cultivars

New mexico pod–type green chile (Capsicum annuum) is one of New Mexico’s leading horticultural commodities. Cultivated acreage of green chile in New Mexico is threatened because of the high cost and insufficiently available labor for hand harvest. Therefore, mechanization is necessary to sustain the industry. Successful mechanization depends on harvester design coupled with plant architecture that optimizes harvest yield and quality. Harvested green fruit must be whole, unbroken, and unblemished for fresh and processed markets, so harvester design and plant architecture must maximize yield while minimizing fruit damage. In two trials conducted at the New Mexico State University Agricultural Science Center in Los Lunas, six cultivars (AZ-1904, Machete, PHB-205, E9, PDJ.7, and RK3-35) were evaluated for plant architecture and harvest efficiency with a double, open-helix mechanical harvester with two counter-rotating heads. Cultivars were direct seeded on 17 Apr. 2015 and 14 Apr. 2016 and managed according to standard production practices. Plant architecture traits, plant width, plant height, height to first primary branch, distance between first primary branch and first node, basal stem diameter, and number of basal branches were measured before harvest. Mechanical harvest yield components, which included marketable fruit, broken fruit, ground fall losses, unharvested fruit remaining on branches, and nonpod plant material, were assessed after once-over destructive harvests on 2 Sept. 2015 and 31 Aug. 2016. Fruit width, fruit length, and pericarp thickness were measured from a representative sample of 10 marketable fruit. In 2015, ‘AZ-1904’ and ‘PDJ.7’ had significantly (P ≤ 0.05) more marketable yield than ‘Machete’ that had the least marketable yield. No statistically significant differences were found in marketable yield in 2016. When both years were combined, ‘PDJ.7’ had significantly more nonpod plant material harvested and the plants were taller than all other cultivars. We found mechanical harvest performance to be significantly affected by plant height, with shorter plants yielding less marketable fruit. Despite differences in fruit wall thickness, no significant differences were measured in broken fruit. In 2015, ‘AZ-1904’ had significantly less basal branches per plant, reducing obstruction for the picking mechanism. Harvest efficiencies (marketable harvested fruit yield as a percentage of total plot yields) ranged from 64.6% to 39.3% during this 2-year trial, with the highest harvesting cultivars PDJ.7 and AZ-1904. In the future, all new mexico pod–type green chile breeding efforts for mechanical harvest must incorporate desirable plant architecture traits to increase harvest efficiencies.

A phylogenetic study of the genus Wiborgia (Crotalarieae, Fabaceae)

Wiborgia Thunb. is a legume genus comprising ten species endemic to the Greater Cape Floristic Region of South Africa. Species in the genus are shrubs of 0.5–3.0m in height, with distinct ascending to erect habits and shoots terminating in rigid thorns, and are distinguished from other Crotalarieae by their indehiscent one-seeded fruits. The genus Wiborgia was revised by Dahlgren four decades ago. And to date, phylogenetic relationships within the genus are partially known, through studies that inferred phylogenetic relationships using two DNA markers and included seven out of ten Wiborgia species which provided unresolved species relationships. Therefore, this study aimed to further explore relationships within the genus using five fast-evolving DNA markers and sampling multiple accessions to represent morphological and ecological variability, enabling testing hypotheses on the utility of Dahlgren's key morphological characters and support for infrageneric classification. Phylogenetic relationships in Wiborgia were inferred using multiple molecular markers (ITS, rpl32-trnL, rps16, trnS-trnG, and trnT-trnL) and the data were analysed using model based approaches (Maximum Likelihood, Bayesian Inference), with key morphological characters reconstructed using Maximum Likelihood. Within the Wiborgia clade, two strongly supported clades were observed. In Clade 1, a novel, well-supported sister relationship between the widely-distributed W. mucronata and the narrowly distributed W. tenuifolia was observed, both characterized by thorny glabrous branches. In Clade 2, W. tetraptera was identified to be sister to W. fusca, whilst W. monoptera and W. incurvata formed part of a strongly supported clade. Wiborgia obcordata, the only species in Dahlgren's subgenus Wiborgia, was found to be embedded within subgenus Pterocarpia thus the subgeneric classification of Dahlgren was not supported. Key morphological characters (including inflated/compressed fruit walls, the presence of lateral wings, and the presence of thorns) were identified to derive independently across the phylogeny, and thus unsuitable to delineate subgenera. Our reconstructions have shown that these characters, together with other important characters such as branch pubescence and flower colour, could be used in delineating species. Sister pairs (W. incurvata and W. monoptera; W. tenuifolia and W. mucronata) overlap geographically but in most cases showed differences in floral characters (i.e. colour, morphology).

Antibacterial Activity of Adansonia digitata L.: A Globally Endangered Tree

The tree species of Adansonia digitata L. possesses wide range of medicinal properties effective against various infectious diseases. The present work has been under taken to study the antibacterial activity of different extracts of A. digitata against pathogenic bacteria. Antibacterial activity of methanolic extracts of leaf, flower and fruit wall extracts of A. digitata has been studied to find out their activity against pathogenic bacteria viz., Escherichia coli, Proteus vulgaris, Klebsiella pneumoniae, Staphylococcus aureus and Enterobacter aerogenus. The activity of these extracts of different plant parts against both positive as well as negative pathogenic bacterial strains was screened through well diffusion technique by using minimum inhibitory concentration (MIC) method. According to our observations, all the extracts of A. digitata exhibited antibacterial activity against all the pathogenic bacteria under study except the fruit wall extracts which didn’t show any inhibition against K. pneumonia. Thus, results provided evidence that the species A. digitata can be used as a potential source of antibacterial agent in the treatment of various infectious diseases.

Variation of seed dormancy and longevity in Raphanus raphanistrum L.

AbstractRaphanus raphanistrum (wild radish) is a highly competitive weed in winter crops. Integrated weed management practices and decision-making tools benefit from the ability to predict seed longevity and dormancy status in the soil seed bank, as well as time and density of emergence in the field. We wondered if unique values taken from databases could serve for modelling purposes, whatever the origins of the weed populations. We investigated dormancy and longevity of fruits buried in the soil over a four-year seed burial experiment of two highly contrasted populations that differ by their biogeographical origin (oceanic versus continental climate), their habitat (arable field versus undisturbed) and their fruit size (thick versus thin fruit wall). High viability persisted over two years, followed by a rapid reduction, especially for the ‘continental-undisturbed-thin’ population. Dormancy cycling, with dormancy at its lowest in October, was observed for the ‘oceanic-arable-thick’ population, whilst a slow decrease without clear seasonal pattern was found for the other population. These results indicate different ways of regulating seed persistence in the soil, which might be taken into account when building demographic models. These differences could be due to interactions between fruit wall thickness and the other factors; it is possible that a thicker fruit wall increases longevity by promoting dormancy by physical restriction, but depending on temperature. Thinner fruit walls would make plants display other adaptive strategies to maximize survival time in the soil seed bank. Studies involving more populations and isogenic material are needed to address this specific question.

Development and morphology of the fruit and seed of the hemiparasite genus <em>Jodina</em> (Cervantesiaceae)

The monotypic genus Jodina is endemic to central and southeastern South America, common in forests and scrubland environments. The fruit type in Jodina is controversial since it has been described at different stages of development. The main objective of this work was to analyze the morphology of the fruit of J. rhombifolia during its maturation to attain a consensus about its type. Also characteristics of seed development and anatomy were analyzed in detail. Material was processed according to conventional techniques for LM and SEM studies. The fruit of J. rhombifolia is a pseudodrupe since the ovary is half-inferior; the fleshy layer of the pericarp is constituted by an increase of the nectary disk whereas the stony layer is represented by the mesocarp. Participation of the nectary disk as part of the fruit wall has not been mentioned previously. The seed is “naked” —the integument disintegrates during development— and the resulting structure is a pyrene. The interpretations made by other authors on the fruit of Jodina are also discussed.