Showing papers by "World Vegetable Center published in 2011"
TL;DR: Hardy, multipurpose legumes that can be used as vegetables or grains by smallholders or large enterprises and with multiple manufacturing uses have a vital role to play in overcoming growing malnutrition in South Asia, Africa, and the Pacific.
Abstract: Malnutrition or ‘hidden hunger’ severely stunts human potential due to imbalanced diets and a lack of vital vitamins and minerals. Hunger and obesity are its extremes. Hardy, multipurpose legumes that can be used as vegetables or grains by smallholders or large enterprises and with multiple manufacturing uses have a vital role to play in overcoming growing malnutrition in South Asia, Africa, and the Pacific. Population growth over the next 40 years will require a doubling of food production in developing countries and climate change will make achieving this goal more uncertain. Mungbean (Vigna radiata (L.) Wilzcek) and vegetable soybean (Glycine max (L.) Merrill) can be consumed as highly nutritious vegetables or grains and are well suited to smallholder production under adverse climatic conditions. Both are well established in intensive cropping systems in Asia, but are little known elsewhere. Recent collaborative plant breeding efforts in Asia produced high yielding, disease-resistant mungbean varieties that mature synchronously in 60–65 days. This revolutionized the industry, allowing the crop to be added to smallholder rice/wheat rotations and leading to a major increase in global production Vegetable soybeans are larger and more nutritious than grain soybeans, but constitute less than 2% of global soybean production. Well known as fresh vegetables in East Asia, they are highly suited to smallholder agriculture or home gardens, producing among the highest yields of crop protein per unit area. More promotion and minor adaptive research can make these regional successes more widely available to help overcome malnutrition.
127 citations
TL;DR: An increase in the availability, affordability and consumption of nutrient-dense vegetables and pulses is one way malnutrition may be substantially reversed and the current imbalance in agricultural investment can improve efficiency in food production and ensure nutritious diets can be a reality for all people.
Abstract: A nutritious and varied diet is a critical means by which good health can be maintained. Consumption of less than 200 g of vegetables per person per day in many countries today is common and this low amount, often in conjunction with poverty and poor medical services, is associated with unacceptable levels of mortality and malnutrition in preschool children and other vulnerable groups. An increase in the availability, affordability and consumption of nutrient-dense vegetables and pulses is one way malnutrition may be substantially reversed—yet nutritional security appears to be less valued than food security by key decision makers, and vegetable crops thus receive inadequate research investment. Opportunities exist for the poor to improve their access to vegetables, particularly if they are willing to grow home gardens. Research continues on defining appropriate nutrient-dense vegetables for such activities, but these efforts may be compromised by failure to adopt good agricultural practices, resulting in contamination and unhealthy produce for producers and consumers. The scientific community is ready to play its role in battling malnutrition and hunger, but unless the political resolve can be found to support the causes of both food and nutritional security together, it is unlikely that the Millennium Development Goals will be achieved in a timely fashion. Redressing the current imbalance in agricultural investment can improve efficiency in food production and ensure nutritious diets can be a reality for all people.
124 citations
TL;DR: The assembly of the 14,054 bp near complete sequencing of the mitochondrial genome of the legume pod borer, Maruca vitrata, which was subsequently used to estimate divergence and relationships within the lepidopteran lineage, indicates that mitochondrial processing mechanisms vary between arthropod species, and that it is crucial to use transcriptional information to obtain full annotation of mitochondrial genomes.
Abstract: We report the assembly of the 14,054 bp near complete sequencing of the mitochondrial genome of the legume pod borer (LPB), Maruca vitrata (Lepidoptera: Crambidae), which we subsequently used to estimate divergence and relationships within the lepidopteran lineage. The arrangement and orientation of the 13 protein-coding, 2 rRNA, and 19 tRNA genes sequenced was typical of insect mitochondrial DNA sequences described to date. The sequence contained a high A+T content of 80.1% and a bias for the use of codons with A or T nucleotides in the 3rd position. Transcript mapping with midgut and salivary gland ESTs for mitochondrial genome annotation showed that translation from protein-coding genes initiates and terminates at standard mitochondrial codons, except for the coxI gene, which may start from an arginine CGA codon. The genomic copy of coxII terminates at a T nucleotide, and a proposed polyadenylation mechanism for completion of the TAA stop codon was confirmed by comparisons to EST data. EST contig data further showed that mature M. vitrata mitochondrial transcripts are monocistronic, except for bicistronic transcripts for overlapping genes nd4/nd4L and nd6/cytb, and a tricistronic transcript for atp8/atp6/coxIII. This processing of polycistronic mitochondrial transcripts adheres to the tRNA punctuated cleavage mechanism, whereby mature transcripts are cleaved only at intervening tRNA gene sequences. In contrast, the tricistronic atp8/atp6/coxIII in Drosophila is present as separate atp8/atp6 and coxIII transcripts despite the lack of an intervening tRNA. Our results indicate that mitochondrial processing mechanisms vary between arthropod species, and that it is crucial to use transcriptional information to obtain full annotation of mitochondrial genomes.
65 citations
TL;DR: In this article, the saponin, lipid, and hydrophilic extracts were quantified in bitter gourd varieties using a modified extraction method using gas chromatography mass spectrometry.
49 citations
TL;DR: Re-sequencing and phylogenetic analyses of PCR-RFLP defined cox1 haplotypes indicate that nucleotide diversity is highest among samples from West Africa and suggest that multiple unique Maruca species or subspecies are present worldwide, which has implications for the management of this pest species-complex.
Abstract: Maruca vitrata Fabricius is a pantropical lepidopteran pest of legumes. Phylogenetic analysis of a mitochondrial cytochrome c oxidase-I gene (cox1) fragment indicates that three Maruca sp. mitochondrial lineages have unique geographic distributions [lineages 1 and 2: Australia, Taiwan, and West Africa (Niger, Nigeria, and Burkina Faso), and lineage 3: Puerto Rico]. The haplotype (T30, T114) is specific to lineages 1&2 and was assayed by NsiI and SacI polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) within population samples; it was not observed in the Puerto Rican samples, but was nearly fixed among samples from West Africa, Australia and Taiwan (85.5–100%). Re-sequencing and phylogenetic analyses of PCR-RFLP defined cox1 haplotypes indicate that nucleotide diversity is highest among samples from West Africa. Phylogenetic reconstruction based upon ribosomal DNA (rDNA) internal transcribed spacer-2 (ITS-2) sequences provided additional evidence for three Maruca sp. clades. These data suggest that multiple unique Maruca species or subspecies are present worldwide, which has implications for the management of this pest species-complex.
46 citations
TL;DR: Agarwal et al. as discussed by the authors detected four tomato-infecting begomovirus species in Taiwan: Ageratum yellow vein Hualien virus (AYVHuV), tomato leaf curl Taiwan virus (ToLCTWV), Tomato yellow leaf curl Thailand virus (TYLCTHV), and a newly defined species Tomato leaf curl Hsinchu virus (TOLCHsV).
Abstract: Between 1998 and 2009, the four tomato-infecting begomovirus species detected in Taiwan were Ageratum yellow vein Hualien virus (AYVHuV), Tomato leaf curl Taiwan virus (ToLCTWV), Tomato yellow leaf curl Thailand virus (TYLCTHV) and a newly defined species Tomato leaf curl Hsinchu virus (ToLCHsV). AYVHuV was detected occasionally in 2003 and ToLCHsV only in 2000-2001, whilst ToLCTWV was detected throughout the period. TYLCTHV was first detected in 2005. Between 1998 and 2005, >99% of the begomovirus-positive samples were infected with ToLCTWV. In 2007 in western Taiwan, 16% of the positive samples were infected with ToLCTWV, 35% with TYLCTHV and 49% with mixed infection (ToLCTWV/TYLCTHV). In contrast, in eastern Taiwan the proportions were 84% ToLCTWV, 2% TYLCTHV and 14% mixed infection. However, throughout Taiwan in 2008-2009, most positive samples were either identified as TYLCTHV (51%) or mixed infection (ToLCTWV/TYLCTHV; 41%), and only 8% were ToLCTWV. This shows a clear trend of shifting from ToLCTWV to TYLCTHV and mixed infection over a short time period in Taiwan. Sequence analyses indicated that tomato-infecting AYVHuV, an apparent recombinant between ToLCTWV and AYVHuV from Ageratum, represents a new strain Hsinchu. TYLCTHV Taiwan isolates were highly similar to each other, whereas ToLCTWV isolates had greater diversity and were classified into three strains which had one country-wide and two local distributions. ToLCTWV and TYLCTHV were confirmed as monopartite and bipartite begomoviruses, respectively, by agroinfection followed by transmission with Bemisia tabaci biotype B. In addition, TYLCTHV was found to be mechanically transmissible together with viral DNA-B.
46 citations
TL;DR: It is hypothesized that P. striolata adults respond to the pheromone only if specific host volatiles are present and further research will be necessary to reveal the components of a more complex blend of host or male-produced semiochemicals that might enhance trap attractiveness in the field.
Abstract: The chrysomelid beetle Phyllotreta striolata is an important pest of Brassicaceae in Southeast Asia and North America. Here, we identified the aggregation pheromone of a population of P. striolata from Taiwan, and host plant volatiles that interact with the pheromone. Volatiles emitted by feeding male P. striolata attracted males and females in the field. Headspace volatile analyses revealed that six sesquiterpenes were emitted specifically by feeding males. Only one of these, however, elicited an electrophysiological response from antennae of both sexes. A number of host plant volatiles, e.g., 1-hexanol, (Z)-3-hexen-1-ol, and the glucosinolate hydrolysis products allyl isothiocyanate (AITC), 3-butenyl isothiocyanate, and 4-pentenyl isothiocyanate also elicited clear responses from the antenna. The active male-specific compound was identified as (+)-(6R,7S)-himachala-9,11-diene by chiral stationary phase gas-chromatography with coupled mass spectrometry, and by comparison with reference samples from Abies nordmanniana, which is known to produce the corresponding enantiomer. The pheromone compound was synthesized starting from (–)-α-himachalene isolated from Cedrus atlantica. Under field conditions, the activity of the synthetic pheromone required concomitant presence of the host plant volatile allyl isothiocyanate. However, both synthetic (+)-(6R,7S)-himachala-9,11-diene alone and in combination with AITC were attractive in a two-choice laboratory assay devoid of other natural olfactory stimuli. We hypothesize that P. striolata adults respond to the pheromone only if specific host volatiles are present. In the same laboratory set up, more beetles were attracted by feeding males than by the synthetic stimuli. Thus, further research will be necessary to reveal the components of a more complex blend of host or male-produced semiochemicals that might enhance trap attractiveness in the field.
40 citations
TL;DR: The de novo assembly of 3729 contigs from 454- and Sanger-derived sequencing reads for midgut, salivary, and whole adult tissues of this non-model species, Maruca vitrata, is presented.
Abstract: The legume pod borer, Maruca vitrata (Lepidoptera: Crambidae), is an insect pest species of crops grown by subsistence farmers in tropical regions of Africa. We present the de novo assembly of 3729 contigs from 454- and Sanger-derived sequencing reads for midgut, salivary, and whole adult tissues of this non-model species. Functional annotation predicted that 1320 M. vitrata protein coding genes are present, of which 631 have orthologs within the Bombyx mori gene model. A homology-based analysis assigned M. vitrata genes into a group of paralogs, but these were subsequently partitioned into putative orthologs following phylogenetic analyses. Following sequence quality filtering, a total of 1542 putative single nucleotide polymorphisms (SNPs) were predicted within M. vitrata contig assemblies. Seventy one of 1078 designed molecular genetic markers were used to screen M. vitrata samples from five collection sites in West Africa. Population substructure may be present with significant implications in the insect resistance management recommendations pertaining to the release of biological control agents or transgenic cowpea that express Bacillus thuringiensis crystal toxins. Mutation data derived from transcriptome sequencing is an expeditious and economical source for genetic markers that allow evaluation of ecological differentiation.
37 citations
TL;DR: Several varieties of each crop ranked among the best varieties in both seasons for phytonutrient yield, and Varieties outstanding for content of a particular phytonUTrient tended to perform well in either dry or wet season, but not both.
33 citations
18 Aug 2011
32 citations
18 Aug 2011
TL;DR: The diversity of viruses and their distinct geographic distribution need to be taken into consideration in the development and deployment of resistance against begomoviruses in the Philippines.
Abstract: Begomoviruses were found to be the major viruses infecting tomato plants in the Philippines based on the surveys conducted from 2005 to 2006. Pepper-infecting begomoviruses were also detected. Isolates of four distinct begomovirus species, Ageratum yellow vein virus (AYVV), Tomato leaf curl Cebu virus (ToLCCeV), Tomato leaf curl Mindanao virus (ToLCMiV) and Tomato leaf curl Philippines virus (ToLCPV), were characterised at the DNA sequence level by comparing 20 DNA-As from tomato samples comprising 13 from Luzon, 2 from Cebu and 5 from Mindanao Islands, along with 3 DNA-As from pepper samples, 1 each from Luzon, Cebu and Mindanao Islands. Two of these species (ToLCCeV and ToLCMiV) were distinct novel begomoviruses, while AYVV was detected for the first time in the Philippines. By geographic distribution, two tomato begomoviruses (ToLCPV and ToLCCeV) were detected in Luzon and Cebu Islands. The ToLCMiV was also detected in Luzon Island. The three tomato begomoviruses, AYVV, ToLCCeV and ToLCMiV, were detected in Mindanao Island. A ToLCPV isolate infecting pepper was also detected in Luzon Island, while ToLCCeV was detected in pepper samples from Cebu and Mindanao Islands. The diversity of viruses and their distinct geographic distribution need to be taken into consideration in the development and deployment of resistance against begomoviruses in the Philippines. Strategies for the use of post-transcriptional gene silencing for the control of tomato-infecting begomoviruses in the Philippines are discussed.
TL;DR: The reported SSR markers are uniformly distributed on chromosome 12 and would be useful for genetic diversity and mapping studies in tomato and could group a set of 16 tomato genotypes unambiguously according to their known species status.
Abstract: In this study, we developed a total of 37 simple sequence repeat (SSR) markers from 11 bacterial artificial chromosome (BAC) clone sequences anchored on chromosome 12 of tomato available at Solanaceae Genomics Network. These SSR markers could group a set of 16 tomato genotypes comprising of Solanum lycopersicum, S. pimpinellifolium, S. habrochaites, and S. pennellii unambiguously according to their known species status. Clear subgroups of genotypes within S. lycopersicum were also observed. A subset of 16 SSR markers representing the 11 BAC clones was used for developing genetic linkage maps of three interspecific F2 populations produced from the crosses involving a common S. lycopersicum parent (CLN2498E) with S. pennellii (LA1940), S. habrochaites (LA407) and S. pimpinellifolium (LA1579). The length of the genetic linkage maps were 112.5 cM, 109.3 cM and 114.1 cM, respectively. Finally, an integrated genetic linkage map spanning a total length of 118.7 cM was developed. The reported SSR markers are uniformly distributed on chromosome 12 and would be useful for genetic diversity and mapping studies in tomato.
TL;DR: The biological and genome characteristics of a member of a new carlavirus species, for which the name cucumber vein-clearing virus (CuVCV) is suggested.
Abstract: Many important field crops belong to the plant family Cucurbitaceae, and those are commonly affected by a multitude of fungal and viral diseases. Viruses known to be involved belong to greatly differing genera (Potyvirus, Polerovirus, Cucumovirus, Tospovirus, Geminivirus, Crinivirus, Ipomovirus) [4]. A watermelon (Citrullus lanatus) sample with severe leaf symptoms was collected in 2009 in Tanzania. By electron microscopy, large filamentous, flexuous particles resembling those of potyviruses and shorter, carlavirus-like filamentous particles were observed, suggesting a mixed infection. The putative potyvirus was amplified by RTPCR using group-specific primers published by Chen et al. [3]. Following sequence analysis, Moroccan watermelon mosaic virus (MWMV), known to be efficiently transmitted by aphids, was identified. Two carlaviruses occur naturally in Cucurbitaceae (http://www.ictvonline.org/virusTaxonomy.asp?version= 2009): melon yellowing-associated virus (MYaV), a whitefly transmissible virus [7], and the aphidtransmissible muskmelon vein necrosis virus (MuVNV). MYaV has only been reported from Brazil, and it has not been determined if watermelon is susceptible to the virus. MuVNV was first reported in California (U.S.A.) in 1952 and is probably present in China too. It has a narrow host range, almost restricted to members of the Cucurbitaceae [2]. Here, we report the biological and genome characteristics of a member of a new carlavirus species, for which we suggest the name cucumber vein-clearing virus (CuVCV).
TL;DR: To the authors' knowledge, this is the first report of SLCPHV infecting chayote plants in Taiwan and the prevalence of SLPV infection on different cucurbit crops should be taken into consideration for managing viral diseases in Taiwan.
Abstract: Young shoots and leaves of chayote (Sechium edule (Jacq.) Sw.) are commonly consumed as a vegetable in Taiwan. In Hualien County, the major chayote-production area of Taiwan, as much as 15% of chayote plants were not marketable between September and October 2010 because of mosaic symptoms on the leaves. Three symptomatic leaves were collected from each of three fields in Hualien. All nine samples tested positive for a begomovirus by PCR using general primer pair PAL1v1978B/PAR1c715H (3) and negative for Zucchini yellow mosaic virus, Cucumber mosaic virus, Cucumber green mottle mosaic virus, Melon yellow spot virus, Papaya ringspot virus - type W, Watermelon mosaic virus, and Watermelon silver mottle virus by ELISA (2). On the basis of the high nucleotide sequence identity (97.7 to 99.6%) of the 1.5-kb begomoviral DNA-A fragments, all nine samples were considered infected by the same begomovirus species. The 1.5-kb sequences had greatest nucleotide sequence identity (96.6 to 97.8%) with Squash leaf curl Ph...
TL;DR: Preliminary results indicate that the D. semiclausum strain from Homs (Syria) possesses some level of heat tolerance, which could be exploited for successful management of DBM in the tropical lowlands.
Abstract: The parasitoid, Diadegma semiclausum (Hymenoptera: Ichneumonidae) is one of the most effective parasitoids of diamondback moth (DBM) in the highlands (> 1600 m above sea level) of Asia. A Diadegma population from the lowland areas of Homs, Syria (about 203–487 m above sea level) was examined to determine if it differs at the species-level from the D . semiclausum and other Diadegma populations present in different countries using molecular diagnostic tools. Phylogenetic analysis based on the neighbor-joining method using the mitochondrial cytochrome oxidase I (COI) and the nuclear internal transcribed spacer 2 (ITS2) sequences grouped the Homs (Syria) Diadegma population with D. semiclausum populations from other countries. The results suggest that D. semiclausum occurs in the lowland conditions in Homs (Syria), where the temperature is higher. The Homs (Syria) strain did not show any variations in the parasitism when the parasitized host (DBM) larvae were exposed to varying temperatures for 24 h. It could not survive when the parasitized DBM larvae were continuously reared at 35 °C; however it inflicted significantly higher parasitism when the parasitized DBM larvae were reared at day and night temperatures of 35 °C and 20 °C, respectively. Preliminary results indicate that the D. semiclausum strain from Homs (Syria) possesses some level of heat tolerance, which could be exploited for successful management of DBM in the tropical lowlands.
Journal Article•
TL;DR: To increase production and quality of tomatoes in eastern Tanzania, plant breeders must develop and introduce varieties that are heat tolerant, resistant to nematodes, fusarium wilt, early blight, bacterial wilt and Tomato yellow leaf curl virus.
Abstract: Tomato (Solanum lycopersicum L.) productivity in eastern Tanzania, mainly in the coastal belt, is low due to drought, excessive heat, declining soil fertility, pests and diseases, and low genetic potential of available varieties. Stress-tolerant cultivars adapted to environmental conditions in the region can increase productivity. Field experiments were conducted at Mikocheni Agricultural Research Institute and five on-farm sites in Kinondoni and Bagamoyo districts during the 2008/2009 and 2009/2010 seasons to evaluate performance and adaptability of tomato varieties. ‘Tengeru 97’ and ‘Meru’ were the most promising varieties based on tolerance to nematodes, good fruit characteristics, and high market acceptability, but were susceptible to early blight. ‘LBR-6’ and ‘LBR-11,’ which are early blight resistant, were rated excellent for taste and had high market acceptability, but were susceptible to nematodes. Further testing of these varieties in disease hot spots along with integrated pest management strategies that focus on nematodes and early blight should be pursued. To increase production and quality of tomatoes in eastern Tanzania, plant breeders must develop and introduce varieties that are heat tolerant, resistant to nematodes, fusarium wilt, early blight, bacterial wilt and Tomato yellow leaf curl virus.