Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Citrullus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2005

Determination of citrulline in watermelon rind.

Watermelon (Citrullus vulgaris Schrad.) is a natural and rich source of the non-essential amino acid citrulline. Citrulline is used in the nitric oxide system in humans and has potential antioxidant and vasodilatation roles. A method using gas chromatography-mass spectrometry (GC-MS) was developed to separate citrulline from glutamic acid, which co-elute when analyzed by high performance liquid chromatography. Watermelons were analyzed by GC-MS to determine the citrulline content among varieties, types, flesh colors, and tissues. Citrulline content ranged from 3.9 to 28.5 mg/g dry weight (dwt) and was similar between seeded and seedless types (16.6 and 20.3 mg/g dwt, respectively). Red flesh watermelons had slightly less citrulline than the yellow or orange flesh watermelons (7.4, 28.5 and 14.2 mg/g dwt, respectively). Rind contained more citrulline than flesh on a dry weight basis (24.7 and 16.7 mg/g dwt, respectively) but a little less on a fresh weight (fwt) basis (1.3 and 1.9 mg/g fwt, respectively). These results indicate that watermelon rind, an underutilized agricultural waste, offers a source of natural citrulline.

Chromatography, High Pressure Liquid↗
PubMed2003

Influence of temperature on biomass, iron metabolism and some related bioindicators in tomato and watermelon plants.

Tomato, Lycopersicon esculentum L. cv. RX-335, and watermelon plants, Citrullus lanatus [Thom.] Mansf. cv. F-90 were grown under controlled conditions at three different temperatures (10 degrees, 25 degrees and 35 degrees C) for 30 days. The aim of the experiment was to analyse the effect of the different temperatures on Fe uptake and distribution, as well as the behaviour of the main bioindicators of this element. Thus, we analysed the total and free Fe concentrations and H2O2 concentrations, as well as enzymatic activities of Fe-chelate reductase (FeCH-R), aconitase (Aco), guaiacol peroxidase (GPX), catalase (CAT), and Fe-superoxide dismutase (FeSOD), and the dry weight of the plants. The effect caused by each temperature varied according to the species of plant. Our results indicate that heat stress appears in tomato plants when grown at 35 degrees C (above the optimal temperature for growth), while in watermelon plants, which need more heat than do tomatoes, cold stress appears at 10 degrees C (below the optimal temperature for growth). Despite these differences between the two species, the results under conditions of thermal stress were the same: 1) decreased shoot weight, 2) reduced Fe uptake, 3) depressed activities of FeCH-R, Aco, GPX, CAT and 4) boosted SOD activity. In short, our results appear to indicate that, whether heat in tomato plants or cold stress in watermelon plants, Fe uptake was diminished, as were the enzymatic activities related to the levels of this micronutrient in the plant. The high FeSOD activity in these plants could be explained by a defensive response to heat or cold stress.

Aconitate Hydratase↗
PubMedDate not supplied

Inheritance of egusi seed type in watermelon.

An unusual seed mutant in watermelon (Citrullus lanatus var. lanatus) has seeds with a fleshy pericarp, commonly called egusi seeds. The origin of the phenotype is unknown, but it is widely cultivated in Nigeria for the high protein and carbohydrate content of the edible seeds. Egusi seeds have a thick, fleshy pericarp that appears during the second to third week of fruit development. We studied the inheritance of this phenotype in crosses of normal seeded Charleston Gray and Calhoun Gray with two plant introduction accessions, PI 490383w and PI 560006, having the egusi seed type. We found that the egusi seed type is controlled by a single recessive gene, and the symbol eg was assigned.

Citrullus↗
PubMedDate not supplied

Inheritance of resistance to zucchini yellow mosaic virus and watermelon mosaic virus in watermelon.

High resistance to zucchini yellow mosaic virus-China strain (ZYMV-CH) and moderate resistance to watermelon mosaic virus (WMV) were found in a selection of PI 595203 (Citrullus lanatus var. lanatus), an Egusi type originally collected in Nigeria. Mixed inoculations showed primarily that these two viruses have no cross-protection. This fact may explain the high frequency of mixed infection often observed in commercial fields. When plants were inoculated with a mixture of the two viruses, the frequency of plants resistant to ZYMV was lower than expected, indicating that WMV infection may reduce the ability of a plant to resist ZYMV. We studied inheritance of resistance to ZYMV-CH and WMV, using crosses between a single-plant selection of PI 595203 and the ZYMV-susceptible watermelon inbreds 9811 and 98R. According to virus ratings of the susceptible parents, the resistant parent, and the F1, F2, and BC1 generations, resistance to ZYMV-CH was conferred by a single recessive gene, for which the symbol zym-CH is suggested. The high tolerance to WMV was controlled by at least two recessive genes.

Citrullus↗
PubMed2006

Qualitative inheritance of rind pattern and flesh color in watermelon.

Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai var. lanatus] is a diverse species, with fruits of different sizes, shapes, rind patterns, and flesh colors. This study measured the inheritance of novel rind phenotypes and verified the genetics of white, red, salmon yellow, and canary yellow flesh colors. For each of the 11 crosses, six generations (P(a)S1, P(b)S1, F1, F2, BC1P(a), and BC1P(b)) were produced to form 11 families. Three new genes were identified and designated as follows: Scr for the scarlet red flesh color of Dixielee and Red-N-Sweet, Yb for the yellow belly (ground spot) of Black Diamond Yellow Belly, and ins for the intermittent stripes of Navajo Sweet. The inheritance of the C gene for the canary yellow flesh color was verified as single dominant, and a new inbred type line was developed possessing that gene. Aberrations in the segregation of red, white, and salmon yellow flesh colors were recorded, raising questions on the inheritance of these traits. Finally, the spotted phenotype from Moon and Stars was combined with light green and gray rind patterns for the development of novel cultivars with distinctive rind patterns.

Breeding↗
PubMed2005

Co-expression of cytochrome b561 and ascorbate oxidase in leaves of wild watermelon under drought and high light conditions.

Despite carrying out C3 photosynthesis, wild watermelon (Citrullus lanatus sp.) exhibits exceedingly good tolerance to severe drought at high light intensities. However, the mechanism(s) by which this plant protects itself from photodamage has yet to be elucidated. In this study, we characterized wild watermelon cytochrome b561 (cyt b561), which potentially mediates regeneration of apoplastic ascorbate by transferring electrons from cytosolic ascorbate across the plasma membrane. Two cDNA species for wild watermelon cyt b561, designated CLb561A and CLb561B, were isolated. Levels of both CLb561A mRNA and protein were significantly elevated in the leaves during drought at a light intensity of 700 micromol photons m(-2) s(-1). The transcript of CLb561B was detected to a much lesser extent, but no CLb561B protein was produced under any condition used in this study. A transient expression assay with the CLb561A::green fluorescent protein fusion construct showed clear fluorescence on the plasma membrane of onion epidermal cells. The CLb561A protein was enriched in the plasma membrane fraction in leaves of transgenic tobacco expressing CLb561A. Moreover, the high activity of apoplastic ascorbate oxidase (AO), which was able to dispose of cyt b561-transferred reducing equivalents, increased in leaves of wild watermelon grown at high light intensity, but not lower light intensities. Taken together, these observations suggest the occurrence of a novel pathway for excess light energy dissipation in wild watermelon leaves, where excessive energy absorbed by chloroplasts can be transported to and dissipated safely in the apoplasts through the cooperative action of cyt b561 and AO.

Amino Acid Sequence↗
PubMed2006

Spatial pattern and sequential sampling of squash bug (Heteroptera: Coreidae) adults in watermelon.

Spatial distribution patterns of adult squash bugs were determined in watermelon, Citrullus lanatus (Thunberg) Matsumura and Nakai, during 2001 and 2002. Results of analysis using Taylor's power law regression model indicated that squash bugs were aggregated in watermelon. Taylor's power law provided a good fit with r2 = 0.94. A fixed precision sequential sampling plan was developed for estimating adult squash bug density at fixed precision levels in watermelon. The plan was tested using a resampling simulation method on nine and 13 independent data sets ranging in density from 0.15 to 2.52 adult squash bugs per plant. Average estimated means obtained in 100 repeated simulation runs were within the 95% CI of the true means for all the data. Average estimated levels of precision were similar to the desired level of precision, particularly when the sampling plan was tested on data having an average mean density of 1.19 adult squash bugs per plant. Also, a sequential sampling for classifying adult squash bug density as below or above economic threshold was developed to assist in the decision-making process. The classification sampling plan is advantageous in that it requires smaller sample sizes to estimate the population status when the population density differs greatly from the action threshold. However, the plan may require excessively large sample sizes when the density is close to the threshold. Therefore, an integrated sequential sampling plan was developed using a combination of a fixed precision and classification sequential sampling plans. The integration of sampling plans can help reduce sampling requirements.

Animals↗
PubMed2001

[The ultrastructural study of synergids before and after fertilization in watermelon embryo sacs].

The ultrastructure of synergids of watermelon (Citrullus Lanatus L.) was investigated using transmission electron microscopy at following stages of embryo sacs: 1. Unpollination, on the first flowering day. 2. Unpollination, on 2nd day after anthesis (DAA). 3. Fertilization, on DAA 2. The synergids with distinct filiform apparatus at the micropylar end have abundant organelle, such as mitochondria, endoplasmic reticulum, and plastids in cytoplasm, which indicate that they are active on the first flowering day. No wall is present at the chalazal part of synergid, and there are some flocculent materials and vesicles in the spaces of cytoplasma membranes among synergid, egg cell and central cell in embryo sacs at the first and the second stages. On DAA 2, in unpollinated embryo sacs, the central large vacuole of synergid is divided into several smaller ones and the starch grains decrease in cytoplasm. There is no newly synthesized wall at the chalazal end of persistent synergid in fertilized embryo sacs. The contents of degenerated synergid, in the form of electron dense granules, are located in the wide space among central cell, zygote and persistent synergid, and some of them migrate into central cell through cytoplasma membrane. Therefore, it is deduced that the contents of synergid might serve as a nutrient supplement to the development of endosperm, but not embryo.

Citrullus↗
PubMed2004

Induction of water-soaking deterioration in watermelon fruit by ethylene.

Watermelon (Citrullus lanatus Thunb. Mansfeld) fruit were held in 50 microL/L of ethylene at 20 degrees C following 18 h application with 5 microL/L of 1-methylcyclopropene (1-MCP) to investigate the involvement of ethylene in the regulation of water-soaking. The early responses of watermelon fruit to ethylene were increased electrolyte leakage and free juice content, accompanying softening and water-soaking of placental tissue. Early evidence of water-soaking appeared in the inner pericarp near the calyx end after 2 d of ethylene treatment, and was accompanied by increased activities of ACC synthase (ACS) and ACC oxidase (ACO). While the application of 1-MCP showed no significant effects by itself, it completely suppressed water-soaking induced by exogenous ethylene. Water-soaking also developed in fruit stored over 10 d in air, and the affected fruit exhibited climacteric respiration and ethylene production peaks after 2 d of storage. These results, along with the observed prophylactic effects of 1-MCP, suggest that water-soaking in watermelon fruit is an ethylene-induced senescence phenomenon.

Citrullus↗
PubMedDate not supplied

Ionic content in plant extracts determined by ion chromatography with conductivity detection.

A simple method is described for the determination of the ionic content of vegetable samples by ion chromatography with suppressed conductivity detection. Extracts of leaves of cucumber (Cucumis sativus), leaves and cotyledons of watermelon (Citrullus lanantus), cotyledons of zucchini (Cucurbitapepo), and leaves and roots of olive (Olea europaea) obtained at room temperature yielded chromatographic profiles with substantial differences in the relative contents of Cl-, NO3-, HPO4(2-) and SO4(2-) as well as of Na+, NH4+, K+, Mg2+ and Ca2+. Although NO3-, Cl- and K+ were common to each extracted sample and accounted for most of the ions present, two additional anion peaks (i.e. malate and oxalate) were detected. Among the vegetable tissues investigated, olive roots contained a considerable amount of oxalate (37 mg/g dry weight), while Na+, which is present in very low amount in extracted samples of leaves and cotyledons, represented ca. 30% of the cationic content of olive roots. In all the examined tissue extracts, K+ was the main cation (16-55 mg/g dry weight) and NO3-, Cl- and HPO4(2-) were the main inorganic anions.

Anions↗
PubMed1993

Evidence for identity of beta-pyrazolealanine synthase with cysteine synthase in watermelon: formation of beta-pyrazole-alanine by cloned cysteine synthase in vitro and in vivo.

The responsibility of cysteine synthase (EC 4.2.99.8) from watermelon (Citrullus vulgaris) for the formation of beta-(pyrazole-1-yl)-L-alanine, a non-protein amino acid specifically accumulated in Curcubitaceae plants, was confirmed in vitro and in vivo by the cloned cDNA on expression vectors, pCCS11 and pCEN1. The cDNA sequence derived from pCCS11, an expression vector driven by the lacZ promoter, was placed under the transcriptional control of strong T7 promoter of pET3d to yield an over-expression vector, pCEN1, in Escherichia coli. The concentration of the exogenous cysteine synthase protein was increased up to approximately 10% of the total soluble protein of E. coli cells by the expression of cDNA on pCEN1. beta-(Pyrazole-1-yl)-L-alanine was formed in vitro from O-acetyl-L-serine and pyrazole by the action of cysteine synthase expressed in E. coli carrying pCCS11 or pCEN1. To confirm the responsibility of cysteine synthase for the formation of beta-(pyrazole-1-yl)-L-alanine in vivo, the feeding experiments of pyrazole and serine or O-acetyl-L-serine were carried out using the transformed E. coli culture. beta-(Pyrazole-1-yl)-L-alanine was produced in vivo by feeding the substrates to the culture of E. coli carrying pCEN1. These results provide the confirming evidence that the cloned cysteine synthase of watermelon catalyzes the formation of beta-(pyrazole-1-yl)-L-alanine, indicating that beta-pyrazolealanine synthase is identical with cysteine synthase in Cucurbitaceae plants.

Base Sequence↗
PubMed1993

Effect of sample pretreatments on the storability of ground melon 'egusi'-Colocynthis citrillus L.

In the maintenance of shelf-stability, nutritional and organoleptic properties of ground melon 'egusi'-Colocynthis citrullus L., vacuum-packaged samples were found to be better than unpackaged samples and samples treated with 0.2% butylated hydroxyanisole (BHA) and 0.02% BHA + 0.045% sodium metabisulphite. After 56 days at 35 degrees C, stored samples showed significant differences (P < or = 0.01) in chemical composition peroxide value (PV), fungal counts and organoleptic attributes. Lipid oxidation and, to a lesser extent, fungal deterioration were responsible for the spoilage of stored ground melon kernel. The dominant fungal flora isolated from stored samples were of the genera Penicillium, Botryodiplodia, Rhizopus and Aspergillus.

Butylated Hydroxyanisole↗
PubMed1993

Food potentials of some unconventional oilseeds grown in Nigeria--a brief review.

A brief review of literature on kernels of Citrullus and Cucumeropsis ('egusi' melon) species, Telfairia occidentalis (fluted pumpkin), Lagenaria (gourd) species of all of Cucurbitaceae family and other oilseeds such as Pentaclethra macrophylla (African oil bean), Parkia spp. (African locust bean) both of Mimosaceae family and Butyrospermum paradoxum (shea butter) of Sapotaceae family which are grown and widely used as food in Nigeria is presented. The kernels of species of Cucurbitaceae form the bulk of unconventional oilseeds used for food in Nigeria. The nutritional value of some of the kernels and the physicochemical properties and storage stability of the oils obtained from them are discussed. The various consumable forms in which they exist are also described. The problems and prospects of these neglected oilseeds in Nigeria are highlighted.

Fatty Acids↗
PubMed1993

Improvement of the traditional method of ogiri production and identification of the micro-organisms associated with the fermentation process.

Fermented products were developed from different proportions of melon (Citrullus vulgaris schrad) and groundnut (Arachis hypogea) seeds after a 96 hour fermentation period. Proximate analysis, carried out on both fermented and unfermented samples, indicated that only the total carbohydrate content was appreciably reduced by the fermentation process. Micro-organisms responsible for fermentation were identified by gram staining and lactophenol staining, as bacteria and fungi. Identified bacteria were of the Bacillus and Acinetobacter species while the fungi were yeasts, rhizopus and mucor. Samples containing 50-100% melon showed a decrease in pH with increasing fermentation period. Bacteria were largely responsible in samples containing up to 75% groundnuts. Sensory analysis of dried fermented products after fortification with salt, ascorbic acid and flour indicated that they were acceptable.

Arachis↗
PubMed1993

Watermelon glyoxysomal malate dehydrogenase is sorted to peroxisomes of the methylotrophic yeast, Hansenula polymorpha.

We have studied the fate of the watermelon (Citrullus vulgaris Schrad.) glyoxysomal enzyme, malate dehydrogenase (gMDH), after synthesis in the methylotrophic yeast, Hansenula polymorpha. The gene encoding the precursor form of gMDH (pre-gMDH) was cloned in an H. polymorpha expression vector downstream of the inducible H. polymorpha alcohol oxidase promoter. During methylotrophic growth, pre-gMDH was synthesized and imported into peroxisomes, where it was enzymatically active. The apparent molecular mass of the protein located in H. polymorpha peroxisomes was equal to that of pre-gMDH (41 kDa), indicating that N-terminal processing of the transit peptide had not occurred in the yeast.

Blotting, Western↗
PubMed1990

Purification and properties of new ribosome-inactivating proteins with RNA N-glycosidase activity.

Ribosome-inactivating proteins (RIPs) similar to those already known (Stirpe & Barbieri (1986) FEBS Lett. 195, 1-8) were purified from the seeds of Asparagus officinalis (two proteins, asparin 1 and 2), of Citrullus colocynthis (two proteins, colocin 1 and 2), of Lychnis chalcedonica (lychnin) and of Manihot palmata (mapalmin), from the roots of Phytolacca americana (pokeweed antiviral protein from roots, PAP-R) and from the leaves of Bryonia dioica (bryodin-L). The two latter proteins can be considered as isoforms, respectively, of previously purified PAP, from the leaves of P. americana, and of bryodin-R, from the roots of B. dioica. All proteins have an Mr at approx, 30,000, and an alkaline isoelectric point. Bryodin-L, colocins, lychnin and mapalmin are glycoproteins. All RIPs inhibit protein synthesis by a rabbit reticulocyte lysate and phenylalanine polymerization by isolated ribosomes and alter rRNA in a similar manner as the A-chain of ricin and related toxins (Endo et al. (1987) J. Biol. Chem. 262, 5908-5912).

Amino Acid Sequence↗
PubMed2004

Larvicidal efficacy of some Cucurbitacious plant leaf extracts against Culex quinquefasciatus (Say).

Larvicidal efficacies of extracts of five species of Cucurbitacious plants, Momordica charantia, Trichosanthes anguina, Luffa acutangula, Benincasa cerifera and Citrullus vulgaris were tested against the late third larval age group of Culex quinquefasciatus. The larval mortality was observed after 24 h exposure. The LC50 values of M. charantia, T. anguina, L. acutangula, B. cerifera and C. vulgaris were 465.85, 567.81, 839.81, 1189.30 and 1636.04 ppm respectively.

Animals↗
PubMed2004

Natural occurrence of moulds and aflatoxin B1 in melon seeds from markets in Nigeria.

Shelled melon seeds (Colocynthis citrullus L.) were purchased from markets in randomly selected villages and towns in three states in each of the rain forest (Ogun, Oyo and Osun) and Northern guinea savanna (Kaduna, Niger and Bauchi) zones of Nigeria. The seed samples were analysed for incidence of visibly diseased seeds, moisture content, moulds and aflatoxin B1 contamination. The incidence of diseased seeds ranged from 6.4% to 50.4% in the forest, and 4.3% to 34.3% in the savanna, and the moisture content was 5.6% to 12.6% and 4.5% to 10.3%, respectively. Mould evaluation revealed that Aspergillus was the most frequent genus, followed by Penicillium, Botryodiplodia, Cladosporium and Rhizopus in decreasing sequential order. Aspergillus flavus had the highest individual count in melon seed from both zones. Aflatoxin B1 was detected at levels above 5 microg/kg in 32.2% of samples, while only 3.5% of the samples contained the toxin above the 20 microg/kg Nigerian tolerance level in food. The percentage of samples contaminated with aflatoxin B1 was statistically comparable for the pooled data of villages and towns. The median level of aflatoxin B1 was less than 5 microg/kg in the seed samples, while the mean aflatoxin B1 levels was 14.1 microg/kg in the forest and 13.0 microg/kg in the savanna samples.

Aflatoxin B1↗