Edible Corms Research Articles

Minor root and tuber crops in Africa: Cocoyams (Colocasia esculenta and Xanthosoma sagittifolium)

Cocoyams [taro: Colocasia esculentum (L.) Schott and tannia: Xanthosoma sagittifolium (L.) Schott] are staple tuber crops in many countries in Africa, Asia and the Pacific. This review aims to present the value of cocoyam as a minor tuber crop and the extent and challenges of its production in Africa. Cocoyams are primarily grown for their edible corms or cormels, although other parts, such as stalks, leaves and inflorescence, are used for human consumption. Cocoyams are categorized as neglected food crops mainly grown for subsistence use. Taro is more widely grown than tannia globally. Taro is cultivated all over Africa, although West and Central Africa are the main producing regions. Tannia is mainly grown in West Africa where it is still less common than taro. Production of tannia is generally minimal and rarely appears in cocoyam output statistics for the continent. Africa is the main producer of cocoyam, accounting for over 70% of the global output; the bulk of production occurs in the West and Central African region. Despite the high production, food value and economic opportunities, African cocoyam is rarely sold in the international markets. The crop is cultivated to meet food security at small-scale and family farms. It is mostly consumed and marketed locally in fresh state. Cocoyams are commonly produced by resource-limited smallholder farmers who are mostly women. The crop is cultivated on marginal lands where primitive technologies with little inputs are employed. The crop receives little attention from mainstream research organizations in Africa. Other constraints limiting cocoyam production in Africa include a shortage of planting materials, lack of improved high-yielding cultivars, and paucity of information on the proper agronomic practices, and insect pests and diseases, among others. Industrial use and new product developments of cocoyam in Africa should be explored to enhance the crop's economic value, and by extension attract research attention

English

Arvi (Colocasia esculenta) is widely cultivated sweet and starchy corms as a staple food in most of the African and Asian countries. Black rot caused by Ceratocystis fimbriata is the most damaging post-harvest disease of Arvi in many countries. In June, 2019, the black rot disease symptoms were noticed on edible corms of Arvi for sale in different vegetable shops in Faisalabad, Pakistan. These symptoms were comprised of small, brown to greenish, slightly sunken spots or lesions which later on enlarged as black rot on the harvested corms. A comprehensive study was initiated to explore the pathogen associated with symptomatic corms. White to grey mycelia and black perithecia with long necks were observed within the lesions. The isolated pathogen was identified as Ceratocystis fimbriata based on morpho-physiological characteristics. Pathogenicity was proved on inoculated corms at 26±2°C and 70% relative humidity (RH) in plant growth chamber. The fungus was further tested for growth and reproduction physiology under different growth media and environmental parameters. A significant interaction between mycelial growth and culture media was observed. Highest mycelial growth (9 cm) of C. fimbriata was showed by Potato Carrot Agar (PCA) and lowest growth (0%) was observed on Water Agar (WA). There was a significant correlation between Temperature, RH, and hydrogen ion (pH) concentration responsible for the growth of C. fimbriata at (P < 0.01). The optimum fungal growth (8.75, 8.96, and 8.95 cm) was measured at 25°C, 70% RH, and pH 8 respectively. The paper may act as basic resource for future research on the epidemiology of this disease.

Biological Management of Colocasia Blight Incited by Phytophthora colocasiae using Native Strains of Antagonists in North Western Himalayas

Background: Colocasia is cultivated globally for its edible corm and leaves. Leaf blight incited by Phytophthora colocasiae is the most destructive disease of colocasia. The current study aims at biological management of the disease. Methods: Nine Trichoderma isolates from the colocasia rhizosphere soil along with five designated isolates of Trichoderma spp. already available in the Department of Plant Pathology, CSK HPKV, Palampur were tested in vitro for antagonistic activity against P. colocasiae. Similarly, six unidentified bacterial strains isolated from colocasia phylloplane and available Pseudomonas fluorescens were evaluated for antagonistic activity against P. colocasiae under in vitro conditions. The bioagents found best under in vitro conditions were evaluated in vivo. Result: Trichoderma isolate Ti-6 was found significantly superior bioagent as it resulted in 72.9 per cent mycelial growth inhibition of P. colocasiae followed by Ti-5 (63.2%), Ti-4 (60.1%) and Ti-1 (54.5%). Amongst bacterial antagonists, Pseudomonas fluorescens gave maximum mycelial growth inhibition of 50.5 per cent followed by Pb-3 (31.4%) and Pb-6 (30.5%). The efficacy of five Trichoderma spp isolates viz., Ti-6, Ti-5, Ti-4, Ti-1, T. viride and one bacterial isolate of P. fluorescens found effective under in vitro were also evaluated in vivo using three delivery systems under net house condition. Corm treatment with bioagents was found superior for management of colocasia blight. Corm treatment with Ti-6 was found to be significantly superior to other treatments as 93.74 per cent of disease control was observed. For drenching, bioagent Ti-6 was proved best in managing blight disease (88.91%) followed by Ti-5 (88.90%). However, Ti-5 isolate of Trichoderma sp. as soil application was found superior with 90.02 per cent disease control.

First record of a naturalized population of the tropical Colocasia esculenta (Araceae) in Italy, and clarifications about its occurrence in southeastern Europe

Colocasia esculenta (L.) Schott is an emergent aquatic and semi-aquatic species native to Asia, where it grows in tropical and subtropical areas. This species is widely cultivated for its edible corm and is considered as alien in various parts of the world, becoming sometimes invasive (e.g., in Spain), and in these areas eradication should be carried out. As part of ongoing studies on Araceae, in 2015 a population of C. esculenta was discovered in Rome (central Italy), where it grows along ditches. This is the first record of a naturalized population in Italy. A comprehensive view of this species in Italy and Europe was given, with clarifications about its occurrence in the Balkans, where C. esculenta was excluded from Bosnia and Herzegovina, Croatia, Montenegro, North Macedonia, Serbia, and Slovenia. A morphological description based on the population found and considerations of its ecology and the climatic conditions at the Roman site are provided.

Eleocharis dulcis corm: phytochemicals, health benefits, processing and food products.

Eleocharis dulcis, an aquatic plant belonging to Cyperaceae family, is indigenous to Asia, and also occurs in tropical Africa and Australia. The edible corm part of E. dulcis is a commonly consumed aquatic vegetable with a planting area of 44.46 × 103 hm2 in China. This work aims to explore the potential of E. dulcis corm for use as a new food source for sufficient nutrients and health benefits by reviewing its nutrients, phytochemicals, functions, processing and food products. Eleocharis dulcis corm contains starches, dietary fibers, non-starch polysaccharides, proteins, amino acids, phenolics, sterols, puchiin, saponins, minerals and vitamins. Among them, phenolics including flavonoids and quinones could be the major bioconstituents that largely contribute to antioxidant, anti-inflammatory, antibacterial, antitumor, hepatoprotective, neuroprotective and hypolipidemic functions. Peel wastes of E. dulcis corm tend to be enriched in phenolics to a much higher extent than the edible pulp. Fresh-cut E. dulcis corm can be consumed as a ready-to-eat food or processed into juice for beverage production, and anti-browning processing is a key to prolonging shelf life. Present food products of E. dulcis corm are centered on various fruit and vegetable beverages, and suffer from single categories and inadequate development. In brief, underutilized E. dulcis corm possesses great potential for use as a new food source for sufficient nutrients and health benefits. © 2021 Society of Chemical Industry.

The pangenome of banana highlights differences between genera and genomes.

Banana (Musaceae family) has a complex genetic history and includes a genus Musa with a variety of cultivated clones with edible fruits, Ensete species that are grown for their edible corm, and monospecific Musella whose generic status has been questioned. The most commonly exported banana cultivars belong to Cavendish, a subgroup of Musa triploid cultivars, which is under threat by fungal pathogens, though there are also related species M. balbisiana Colla (B genome), M. textilis Née (T genome), and M. schizocarpa N. W. Simmonds (S genome), along with hybrids of these genomes, which potentially host genes of agronomic interest. Here we present the first cross-genus pangenome of banana, which contains representatives of the Musa and Ensete genera. Clusters based on gene presence-absence variation (PAV) clearly separate Musa and Ensete, while Musa is split further based on species. These results present the first pangenome study across genus boundaries and identifies genes that differentiate between Musaceae species, information that may support breeding programs in these crops.

Proximate, Anti-Nutrients and Elemental Constituents of C. esculenta

Cocoyam (C. esculenta) is an aroid that is grown most importantly for edible corms. C. esculenta is used by the locals, it has been noted that when used as feed, it causes swelling of the lips, mouth and throat. The aim of this work was to investigate the proximate, anti-nutrients and elemental constituents of C. esculenta. Proximate, elemental and anti-nutrient constituents of C. esculenta were investigated. For the mineral composition Atomic absorption spectrometer was used, while a standard method of analysis by American Organization of Analytical Chemistry was adopted for the proximate analysis and anti-nutrient composition. After the experiment, the data obtained were presented as mean± SD and were subjected to statistical analysis using student T-test, to determine the level of significance at p≤0.05. The results showed that for the two samples, the flour processed with the bark has highest concentrations of carbohydrate and minerals, but the bark has a higher concentration of anti-nutrients which causes swollen lips, scratchiness of throat and astringent taste.

NUTRITIONAL AND ANTINUTRITIONAL ASSESSMENT OF SOME UNDERUTILIZED CORMS, RHIZOMES AND TUBERS

<p><strong>Background. </strong>With ever-increasing populace pressure and rapid depletion of natural resources, it has become exceptionally important to diversify the present time agriculture with the cultivation of some wild varieties of tubers, rhizomes and corms in order to meet various human nutrient needs. However, information regarding the nutritional and antinutritional composition is meager. <strong>Objective.</strong> To study the chemical composition and antinutritional factors of the wild edible corms, rhizomes and tubers consumed by the Palliyars and Kanikkar tribes living in South Eastern Slopes of Western Ghats, Tamil Nadu<strong> Methodology</strong>. The wild edible corms of <em>Alocasia macrorrhiza</em>, <em>Amorphophallus paeoniifolius</em> var <em>campanulatus</em>,<em> Amorphophallus sylvaticus</em>,<em> Colocasia esculenta</em>,<em> Xanthosoma sagittifolium</em>, <em>Xanthosoma violaceum</em>, rhizomes of <em>Canna indica</em>,<em> Maranta arundinacea</em> and tubers of <em>Asparagus racemosus</em>,<em> Nymphaea pubescens</em> and<em> Nymphaea rubra</em> were analysed for proximate and mineral composition, starch, vitamins like niacin, ascorbic acid and antinutritional factors like total free phenolics, tannins, hydrogen cyanide, total oxalate, amylase and trypsin inhibitor activities were quantified. Also, <em>in vitro</em> protein and starch digestibility were assessed. <strong>Results.</strong> The rhizome of <em>Maranta arundinacea</em> and tubers of <em>Nymphaea pubescens </em>contain high quantity of crude proteins. The tubers of <em>Asparagus racemosus</em> contained higher amount of crude lipids. The corms of <em>Alocasia macrorrhiza, Colocasia esculenta, Xanthosoma sagittifolium</em> and <em>Xanthosoma violaceum</em> appeared to have a higher level of potassium content compared to recommended Dietary allowances (RDA) for infants, children and adults. The corms of <em>Alocasia macrorrhiza, Amorphophallus sylvaticus, Xanthosoma violaceum</em> and rhizomes of <em>Maranta arundinacea</em> were found to contain more starch. All the investigated samples had low <em>in vitro</em> protein digestibility. <strong>Implications.</strong> The present result highlights the potentiality of these underground plant parts as source of unconventional foods. Being wild, they also are easily accessible and cheaper. Studies on nutritional value of wild plant food are of extensive importance since it may help to recognize long forgotten food resources. <strong>Conclusion. </strong>Most of the wild edible corms, rhizomes and tubers were found to be a good source of protein, lipid, total dietary fiber, starch, vitamins and minerals. All the investigated samples exhibited variations in the levels of the total free phenolics, tannins, hydrogen cyanide, total oxalate, amylase and trypsin inhibitors</p>

Biochemical Charcterization of Some Taro (Colocasia esculentaL. Schott) Germplasm in Ghana

Corms of eighteen (18) genotypes comprising twelve (12) introduced and six (6) local genotypes were studied for their nutrient quality to provide information on their nutrient characteristics for a holistic development of the crop. The crop is known for its edible corms and leaves. Corms are boiled before eating and take a short time to cook as their carbohydrate structure is not complex. The leaves are eaten as vegetables. The crops were planted at Nobewam in the Ejisu-Juaben Municipality in the Ashanti Region of Ghana using the Randomized Complete Block Design (RCBD). The biochemical or nutritional analysis was done at Crop and Soil Sciences laboratory at Kwame Nkrumah University of Science and Technology (KNUST). Data were collected on the chemical and mineral compositions of the genotypes (corms). Variations were observed in both chemical and mineral characteristics. Carbohydrate content of the genotypes ranged from 62% to 76%; protein ranged from 13% to 25%; fibre ranged from 1% to 2%; calcium ranged from 0.29% to 0.72% and iron content ranged from 0.18 mg/100 g to 1.18 mg/100 g. Significant differencesP<0.05were observed in both chemical and mineral traits, indicating a higher degree of variability in the genotypes. SignificantP<0.01and positive correlations were observed between protein and energy levels; magnesium and iron; magnesium and calcium; and potassium and ash. The Principal Component Analysis (PCA) showed that the first component (PC1) accounted for 96% of variation. Some genotypes including; BL/SM/10, BL/SM/132, KA/019, SAO/020, BL/SM/151, BL/SM/80, BL/SM/116, BL/SM/16, and KA/035 possess desirable nutrient levels such as protein, fibre, carbohydrate, and iron which could be exploited for further development of taro in Ghana.

Alocasia: a promising food crop for next generation

In India, three types of alocasia are present, especially in Bengal, Assam and South India in abundance. Alocasia cuculata (Lour.) thrives well under Bengal conditions as a tall herb and it is famous for its edible rhizomes. The second species, A. indica Schott; Eng., is a gaint taro having large leave caladium and belonging to family Araceae. It is generally grown in Bengal, Assam, Maharastra and South India. Stem and rootstocks are edible, leaf juice is astringent and rhizome is used as mild laxative and diuretic. The third type of Alocasia present in India and Sri Lanka is Alocasia microrhiza (L.) Schott; Eng. (giant taro, Araceae), a large herb with edible corm; after treating with 2% w/v sodium bicarbonate 20 min after boiling it is used as vegetable with minimum raphaites (71 mg 100 g(-1) edible part). In ICAR-RCER, Research Center for Makhana, 10 edible alocasia accessions from Bengal, Jharkhand and Bihar were collected. ‘Ranchi-3’ alocasia is a dwarf whose horizontal root along with stem are edible. An upright alocasia (‘RKM-1’) was collected from Kolkata. It can be planted in a minimum distance. A small alocasia was collected from West Bengal (‘WB-1’) which is a favorite for making postharvest products like Bari. The alocasia collection WB-2 is spreading and suitable for twin use like vegetables and medicinal treatment in arthritis. A. microrhiza is lucrative for its voluminous and quick growth and it is an easy growing food plant for the future generation. Typical of leaf vegetables, alocasia leaves are a good source of thiamin, riboflavin, iron, phosphorus, and zinc, and a very good source of vitamin B6, vitamin C, niacin, potassium, copper, and manganese. So in India immediate nationwide attention is required to conserve these valuable plants without any delay and pave the way for them for cultivation in fertile land. As the world population is growing alocasia may be a promising food for the future. It may be grown as a sole crop or a companion crop of a mix cropping system with sweet flag and makhana.

ISOLATING MICROSATELLITE FROM Amorphophallus variabilis AND ITS APPLICATION FOR POPULATION STUDY IN DRAMAGA CONSERVATION FOREST, INDONESIA

Amorphophallus variabilis Blume, a member of Araceae, is a fleshy perennial tuber crop endemic in Java Island, Indonesia. The plant produces white edible corm; and it was used as food during famine time before 1960s. Rapid ecological changes and land fragmentations in Java in recent times threaten populations of A. variabilis. Here, compound microsatellite markers were developed in order to develop conservation strategies in the populations. Twelve primers pairs produced high polymorphism ranging from 5 to 22 alleles per locus. The observed and expected heterozygosities ranged from 0.191 to 0.851 and 0.380 to 0.943, respectively. This high allelic diversity indicates that these markers are suitable for the study on population genetic structure. Cross-amplification on related and non-related species was performed. Application of the markers on populations from Dramaga Conservation Forest revealed high allelic richness, high diversity within and among populations. Genetic distance among populations increased with an increase of geographic distance. Present study suggested that, it is important to study population of A. variabilis in Java in order to understand the population genetic structure and develop effective in situ conservation programs.

An Overview of Traditionally Used Herb, Colocasia esculenta, as a Phytomedicine

Colocasia esculenta (C. esculenta) is a widely cultivated plant for consumption of both leaves and tubers. Taro, a common name for the corms and tubers of several genera of the family Araceae, is a source of edible corms of C. esculenta. It is majorly cultivated in Southeast Asia by several common names like Arbi, Arvi and Eddoe. From this species, a wide range of chemical compounds have been isolated for example, flavanoids, β-sitosterol, steroids, etc. Various parts of C. esculenta are used traditionally to treat number of diseases. Extracts from this plant have been found to possess various pharmacological activities. The leaves of this plant have been studied to possess anti-helminthic, anti-diabetic and anti-inflammatory actions. There have also been reports proving hypoglycemic efficacy of C. esculenta due to the presence of cyanoglucoside. The present review tries to cover all the information available on research work of this plant in yesteryears in a nutshell with the intention to serve as a literature platform for further researches on this plant.

First Report of Taro bacilliform CH virus (TaBCHV) on Taro (Colocasia esculenta) in Hawaii, U.S.A

Taro (Colocasia esculenta L. Schott), a member of the Araceae family, is a traditional root crop of the tropics grown for its edible corms and leaves. The crop also has significant cultural and export importance, particularly in Pacific Island communities (Revill et al. 2005). Taro bacilliform CH virus (TaBCHV) is a putative member of the genus Badnaviruses, family Caulimoviridae that was recently described on taro in China (Kazmi et al. 2015). In May 2016, the leaves of a taro plant showing feather-like chlorosis and mosaic symptoms were collected from the University of Hawaii’s Waimanalo Research Station (21°20′13.9″N, 157°42′50.6″W) on the island of Oahu, Hawaii. Total RNA was isolated using the RNeasy® Plant mini Kit (Qiagen, Redwood City, CA, USA), according to manufacturer’s instructions. Randomly-primed cDNA was synthesized and served as template in PCR using three primer sets targeting TaBCHV: TB1009-F (5’-ggctctgagagaagagctagc-3’) and TB1619-R (5’-atgtgtatgaactgcactctg-3’) which amplify a 611-bp ...

Biologically Potential for Pharmacologicals and Phytochemicals of Medicinal Plants of Colocasia esculenta: A Comprehensive Review

Colocasia esculenta (L) Schott of the family Araceae is an herbaceous perennial plant cultivated as annuals. Local name of C. esculenta is Kochu in Bangladesh and Taro in India. C. esculenta (L) is an ancient crop grown throughout the humid tropics and is widely used throughout the world; Africa, Asia, the West Indies, and South America. Its edible corms and leaves are traditionally used for hepatic ailments. Juice obtained from stems. Schott is used to stop bleeding from cuts and Wounds. The young leaves and roots are rich in Vitamin C as well as starch. It contains calcium, phosphorours, thiamine, riboflavin, niacin, oxalic acid, calcium oxalate, sapotoxin and flavones, apigenin and luteolin. The biological properties as well as chemical constituents of plant C. esculenta were widely used in folk medicine. In traditional medicine, C. esculenta is used as Anti microbial, Antihepatotoxic, Anti-cancer, Anti-Lipidperoxidative, Antibacterial and Antifungal, Antidiabetic, Anti-melanogenic, Anthelmintic. In present study, C. esculenta shows potent pharmacological activity such as Antimicrobial, Antihepatotoxic, Anti-cancer, Anti-Lipidperoxidative, antibacterial and Antifungal, Antidiabetic, Anti-melanogenic, Anthelmintic. Due to present of several potential chemical constituents it may use in several disease conditions for the future treatment.

Identification and analysis of nutritional components of Enset (Ensete ventricosum) landraces suitable for corm production in Southern Ethiopia.

Enset (Ensete ventricosum) produces a nutritious human food from its vigorous pseudostem, corm and the stalk of inflorescence. Among the many different food made from Enset is 'Amicho ', which is a stripped corm of a younger plant of Enset, boiled and consumed in a way similar to Irish potato, sweet potato and cassava. Participatory Rural Appraisal (PRA) and formal survey were conducted in two weredas, one from each of two densely populated Enset growing zones (namely Sidama and Hadiya zones in the Southern Nations, Nationalities and Peoples Region of Ethiopia) to collect Enset landraces suitable for edible corm production and assess their nutrient contents. Eleven Enset land races suitable for edible corm production were identified and planted at Hawassa University experimental field for further investigation. The result of nutritional analysis showed a marked significant variability in the nutritional composition of the corms; this made the selection of nutritionally-rich Enset landraces possible. Large differences in protein content (0.90 to 2.39%), crude fibre (0.83 to 1.1%), carbohydrates (27.3 to 39.4 ), Fe (1.1 to 4.3 mg/100 gm), Zn (6.2 to 15.6 mg/100 gm) and Beta carotene (1 .5 to 22.2 μ g/100 gm) were recorded. 'Agade', 'Askala', and 'Gossalo' landraces had the highest protein, carbohydrates and Beta-carotene contents, respectively. 'Made' contained the highest crude fibre, Fe and Zn contents. The average protein content (1.4%) of corms of the Enset landraces was comparable to the average protein content of most root and tuber crops; whereas, the average Fe and Zn contents of corms of the Enset landraces were higher than the values reported for most root and tuber crops. The average energy and dry matter production rates of corms of the Enset landraces were about 124% and 169% higher, respectively than the average values for root and tuber crops. While Enset is conventionally perceived as having relatively low nutritional content when compared with other root and tuber crops, the present study provides evidence that, contrary to popular perception, there are excelling nutritional values of corms of the Enset landraces for humans. Keywords: Ensete ventricosum , landraces, corm, nutritional quality

Microbiology of Root Crops, Edible Corms, Tubers, Bulbs, and Rhizomes: An Endobacteriological Study

A variety of root crops, corms, tubers, and rhizomes commonly eaten and available in public markets were tested for the presence and identification of bacteria in their inner flesh. Bacteria were grown on agar slants and identified by DNA sequence analysis. Among foods tested were various radishes, onions, shallots, leeks, yams, parsnips, turnips, carrots, potatoes, ginger, garlic, parsnips, beets, horse radish, kohl-rabi, and less well-known crops such as yucca/cassava, celery root/celeriac, jicama, taro, lotus, water chestnut, Chinese/Korean yam (nagaimo), edible burdock (golden gobo), batata, root parsley, and yautia (malanga). Examples of the bacterial genera identified were, among others, species of Arthrobacter, Pantoea, Bacillus, Pseudomonas, Staphylococcus, Microbacterium, Stenotrophomonas, Rahnella, Rhodococcus, Paenibacillus, Oerskovia, Gordonia, and Leclercia. While these species are probably present in harmless numbers, their presence may indicate that the inner flesh of these crops should be studied more extensively. Crops that are boiled, fried, baked or otherwise cooked may obviously not be a health hazard, but some of these vegetables are eaten raw or only lightly cooked and may possibly merit further study for possible health implications. Tubers that were very proficient in producing new shoots, such as potato and the Chinese/Korean yam (nagaimo) were found to contain inner flesh free of bacteria and seemed to be resistant to rotting; this may imply that these tubers have antimicrobial properties.

Use of weeds as traditional vegetables in Shurugwi District, Zimbabwe

BackgroundMost agricultural weeds are usually regarded as undesirable and targeted for eradication. However, weeds are useful to human beings as food and traditional medicines. Few studies have been done to document the uses of weeds as traditional vegetables. This study was therefore, done to document indigenous knowledge related to the diversity and use of agricultural weeds as traditional vegetables in Shurugwi District, Zimbabwe, emphasizing their role in food security and livelihoods of the local people.Materials and methodsSemi-structured interviews, observation and guided field walks with 147 participants were employed between December 2011 and January 2012 to obtain ethnobotanical data on the use of edible weeds as traditional vegetables. Based on ethnobotanical information provided by the participants, botanical specimens were collected, numbered, pressed and dried for identification.ResultsA total of 21 edible weeds belonging to 11 families and 15 genera, mostly from Amaranthaceae (19%), Asteraceae and Tiliaceae (14.3%), Capparaceae, Cucurbitaceae and Solanaceae (9.5% each) were identified. Of the documented edible weeds, 52.4% are indigenous while 47.6% are exotic to Zimbabwe; either semi-cultivated or growing naturally as agricultural weeds in farmlands, fallow land and home gardens. Among the main uses of edible weeds were leafy vegetables (81%), followed by edible fruits (19%), edible corms (9.5%), edible flowers and seeds (4.8% each). The most important edible weeds were Cleome gynandra, cited by 93.9% of the participants, Cucumis metuliferus (90.5%), Cucumis anguria (87.8%), Corchorus tridens (50.3%) and Amaranthus hybridus (39.5%). All edible weeds were available during rainy and harvest period with Cleome gynandra, Corchorus tridens, Cucumis anguria, Cucumis metuliferus and Moringa oleifera also available during the dry season, enabling households to obtain food outputs in different times of the year. The importance of edible weeds for local livelihoods was ubiquitously perceived, with all participants reporting their contribution towards food security and nutrition.ConclusionThe present study confirm findings from similar studies conducted elsewhere that rural households engage in harvesting of wild edible vegetables and other non-timber forest products (NTFPs) as a survival strategy. Based on their potential nutritional and medicinal value, edible weeds could contribute in a major way to food security, basic primary health care and balanced diets of rural households and possibly urban households as well.

Anti-metastatic effect of polysaccharide isolated from Colocasia esculenta is exerted through immunostimulation

In the present study, an edible corm of the plant Colocasia esculenta, commonly known as Taro was extracted with cold water (4˚C). Finally, 10.44 g (1.04%) of the crude polysaccharide (Taro-0) was obtained from Taro. The purified active compound (Taro-4-I) was isolated using DEAE-Sepharose FF and Sephadex G-100. The anti-complementary activity of Taro-4-I (57.3±4.5%) was similar to that of polysaccharide K (used as the positive control). The molecular weight of Taro-4-I was 200 kDa and it was a polysaccharide composed of 64.4% neutral sugars and 35.6% uronic acid. Taro-4-I activated the complement system through the classical and alternative pathways. The treatment of peritoneal macrophages with Taro-4-I significantly increased the production of interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) in a dose-dependent manner. However, IL-12 production showed maximal activity at 56 µg/ml and subsequently decreased. Splenocytes obtained from mice which were administered Taro-4-I intravenously showed a higher toxicity to Yac-1 cells compared to those obtained from untreated mice in a effector‑to‑target (E/T) ratio-dependent manner. The group treated with 50 µg/ml Taro-4-I showed a significantly increased toxicity to Yac-1 cells compared to the group treated with 500 µg/ml Taro-4-I. The administration of Taro-4-I significantly inhibited the lung metastasis of B16BL6 melanoma cells. However, the group treated with 50 µg/mouse Taro-4-I had a significantly lower number of tumors compared to the group injected with 500 µg/mouse Taro-4-I.

First report of an invading population of Colocasia esculenta (L.) Schott in the Iberian Peninsula

Colocasia esculenta, or taro, is an emergent aquatic and semi-aquatic plant, native to Asia, which is cultivated for its edible corm in several parts of the world. This species has colonized or invaded wetlands and rivers in different parts of the world (e.g., Southeast USA, Southwestern Australia, Southern Africa, etc.) thus suggesting that early detection of this species should be conducted. Here we present the first report of an invasive population of C. esculenta in the Iberian Peninsula (Southern Europe). Characteristics of the patches found that serve as an early diagnosis of the degree of invasion and the origin of introduction are given. The current population consists of a number of patches that are heterogeneously distributed along the stream (ca. 7 km). Monospecific Taro patches displace native species and provoke the narrowing of river sections, similar to rivers and wetlands in Australia or the United States where this species is considered an invasive plant. This new record also suggests the ability of this tropical species to withstand the long dry summers typical of the Mediterranean climate within permanent streams.

The first finding of pythium root rot and leaf blight of elephant foot yam (Amorphophallus paeonifolius) in India

Elephant foot yam Amorphophallus paeonifolius , formerly known as A. campanulatus , produces an edible corm and is widely cultivated from West Bengal to Tamil Nadu, India. It is an example of a crop species that is indigenous to this region and has been included in the National Germplasm Evaluation Programme for tuber crop improvement. This important crop has recently suffered from a root rot and leaf blight disease. Symptoms of affected plants ranged from chlorosis, stunting to a complete blight as the disease progressed. Necrotic root symptoms began at the tip, but progressed quickly eventually killing the whole root. The cortex of severely affected roots could be easily sloughed off, leaving only parts of the vascular system intact. Samples of affected plants from production fields and an experimental farm (All India Coordinated Research Project on Tuber Crops in Nadia district, West Bengal) were collected. The pathogen was isolated by plating affected tissues on amended V8 agar (Guha Roy et al ., 2006). Resultant isolates were identified using morphological characters, DNA fingerprinting and sequencing. Sporangia were ovoid to globose, papillate, caducous and nonproliferating (41·46 μ m ± 2·9 × 37·64 μ m ± 2·0). Isolates were homothallic. Oogonia were spherical, smooth walled with elongate diclinous antheridia and aplerotic oospores (39·16 μ m ± 2·26 diameter). Hyphal swellings were absent. Based on the above morphological features and ITS sequencing (GenBank Acc. No. EF455802), the organism was identified as Pythium helicoides . Its SSCP (single stranded conformational polymorphism) pattern was also typical of P. helicoides (Kong et al ., 2004). Pathogenicity was confirmed by wound-inoculating stem bases of 3-month old healthy plants of A. paeonifolius with a 9-mm cork borer and placing 7-mm mycelial discs of 5-day old P. helicoidstest cultures in the holes. Plants were maintained at approximately 30 ± 1 ° C and assessed 15 days post inoculation. Pythium helicoides was successfully re-isolated, thus completing Koch’s postulates. Control plants inoculated with agar alone remained symptomless. This is the first report of P. helicoides affecting A. paeonifolius in India and worldwide. One isolate was deposited in the World Phytophthora Collection and Virginia Polytechnic Institute and State University, USA, under accession numbers P10973 and 33B2, respectively.