| ethylene-induced gene expression, enzyme activities, and water soaking in immature and ripe watermelon (citrullus lanatus) fruit. | watermelon fruit exhibit acute softening and placental-tissue water soaking following short exposure to exogenous ethylene. experiments were performed to address transcript abundance and activities of cell wall and membrane hydrolases in placental tissue in response to treatment of watermelon fruit with ethylene. watermelon fruit were harvested at immature and full-ripe stages and exposed to 50 microl l(-1) ethylene for 6 days at 20 degrees c. ethylene affected the abundance of transcripts for p ... | 2004 | 15128025 |
| construction of a linkage map and qtl analysis of horticultural traits for watermelon [citrullus lanatus (thunb.) matsum & nakai] using rapd, rflp and issr markers. | we have been constructing linkage maps for watermelon ( citrullus lanatus) on the basis of random amplified polymorphic dna (rapd), restriction fragment length polymorphism (rflp), inter-simple sequence repeats (issrs) and isozymes using an f(2) population derived from a crossing between a cultivated inbred line (h-7; c. lanatus) and an african wild form (sa-1; c. lanatus). a total of 120 f(2) plants was used for construction of a linkage map using 477 rapds, 53 rflps, 23 issrs and one isozyme m ... | 2003 | 12647050 |
| [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 ... | 2001 | 12549210 |
| pharmacognostical stucies on the seeds of mulam citrullus lanatus (thunb.) mats & nakai (cucurbitacae). | in the siddha system of medicine cotyledons of the seeds of c. lanatus are known as mulam/pullum/pitcha (tamil) and used as pulukolli (vermifuge), karpa moolikai (general tonic) and as aanmeiperukki (aphrodisiac). in the ayurvedic system of medicine seeds are said to have properties like sheeta (cooling), mootrala (diuretic) and vrshya (aphrodisiac). the present paper deals with macro and microscopical studies, maceration, histochemical tests, solubility, physical contents, extractive values, te ... | 2001 | 22557025 |
| resistance to cold and heat stress: accumulation of phenolic compounds in tomato and watermelon plants. | tomato plants, lycopersicon esculentum l. cv. tmknvf(2), and watermelon plants, citrullus lanatus [thomb.] mansf. cv. dulce maravilla, were grown for 30 days at different temperatures (15, 25 and 35 degrees c). we analysed soluble phenolics, enzymatic activities (phenylalanine ammonia-lyase, polyphenol oxidase and peroxidase), and dry weight. the impact of the three temperatures was different in tomato and watermelon. our results indicate that heat stress in tomato plants occurred at 35 degrees ... | 2001 | 11164603 |
| [studies of molecular marker-assisted-selection for resistance to fusarium wilt in watermelon (citrullus lanatus) breeding]. | the rapd marker opp01/700 proved to be linked to the fusarium wilt resistant gene in watermelon wild germplasm pi296341 was cloned and sequenced, and transferred into a scar marker. the linked marker was tested to be one copy by southern blotting. the technique of detection of the scar-amplified products was simplified. these techniques were applied in selecting resistant plants in f3 of the introgression of the disease resistant gene. it is the first report in this field of transfer ring a rapd ... | 2000 | 10887683 |
| determination of the rate of photoreduction of o2 in the water-water cycle in watermelon leaves and enhancement of the rate by limitation of photosynthesis. | a study was performed to determine how the electron fluxes for the photosynthetic carbon reduction (pcr) and the photorespiratory carbon oxidation (pco) cycles affect the photoreduction of o2 at psi, which is the limiting step in the water-water cycle. simultaneous measurements were made of co2-gas exchange, transpiration and quantum yield of psii [phi(psii)] using leaves of watermelon (citrullus lanatus). the total electron flux in psii[je(psii)], as estimated from phi(psii), was always larger ... | 2000 | 10805597 |
| rapid high-performance liquid chromatography method to quantitate elaterinide in juice and reconstituted residues from a bitter mutant of hawkesbury watermelon. | a c(18) reversed-phase hplc method has been developed to analyze the concentration of 2-o-beta-d-glycopyranosyl-cucurbitacin e (synonym, elaterinide) in juice or reconstituted residues of juice derived from a bitter mutant of hawkesbury watermelon, citrullus lanatus (thunb.) matsum. & nakai. the method requires only two steps (homogenation and filtration) for sample preparation prior to column injection and, thus, is amenable to processing large numbers of test samples. percent elaterinide in ju ... | 1999 | 10552560 |
| induction of pyrophosphate-dependent phosphofructokinase in watermelon (citrullus lanatus) cotyledons coincides with insufficient cytosolic d-fructose-1,6-bisphosphate 1-phosphohydrolase to sustain gluconeogenesis. | during germination of citrullus lanatus, pyrophosphate-dependent phosphofructokinase (pfp) activity is induced. the peak of pfp activity coincides with the maximum gluconeogenic flux and high fructose-2,6-bisphosphate (fru-2,6-p2) concentrations. determination of cytosolic fructose-1,6 bisphosphatase (fbpase) activity in crude extracts is unreliable because of the high pfp activity. the fbpase activity, after correction for the contaminating pfp, is only one-third of the pfp activity. purified c ... | 1993 | 12231792 |
| somatic embryogenesis and plant regeneration from immature cotyledons of watermelon. | cotyledon expiants from immature embryos of five watermelon [citrullus lanatus (thunb.)matsum. & nakai] genotypes were incubated in the dark for three weeks on a modified ms medium containing b5 vitamins, 2,4-d (10, 20 or 40μm), 0.5 μm of either ba or tdz, and 7 g·1(-1) tc agar. somatic embryos, some with well developed cotyledons, were observed on cotyledon expiants three to four weeks after transfer to ms medium without pgrs and 16h photoperiod. the best pgr combination for somatic embryogenes ... | 1993 | 24202069 |
| physiological effects of ozone on cultivars of watermelon (citrullus lanatus) and muskmelon (cucumis melo) widely grown in spain. | two cultivars of watermelon (citrullus lanatus) and muskmelon (cucumis melo), which are widely grown in spain, were exposed to ozone (70 nl litre(-1), 6 h d(-1)) for 21 days. ozone sensitivity was assessed by recording the extent of visible injury, changes in fast-fluorescence kinetics, the relative-growth rate (r) of root (rr) and shoot (rs), and effects on the number of flowers produced per plant. leaf gas exchange was measured in order to provide some indication of the factors underlying diff ... | 1993 | 15091805 |
| pyrophosphate dependent phosphofructokinase of citrullus lanatus: molecular forms and expression of subunits. | during germination and seedling establishment, the total pyrophosphate-dependent phosphofructokinase (pfp) activity in the cotyledons increases. two types of subunits with molecular weights of 68 (alpha-subunit) and 65 (beta-subunit) kilodaltons are present. the increase in activity coincides with an approximately 10-fold increase in beta-subunit and twofold increase in alpha-subunit content. different isoforms of pfp are present at all stages of incubation, but the ratio between the isoforms si ... | 1991 | 16668318 |
| control of pyrophosphated-fructose-6-phosphate 1-phosphotransferase activity in the cotyledons of citrullus lanatus. | after initiation of radicle elongation, the pyrophosphate:d-fructose-6-phosphate 1-phosphotransferase (pfp) activity sharply increases in the cotyledons of citrullus lanatus. removal of the radicle early during incubation prevents the increase in pfp activity in the cotyledons evident in the control. removal of the radicle at any stage after germination results in a decrease in pfp activity in the cotyledons. application of kinetin (0.5 micromolar) or 2-chlorophosphonic acid (0.1 micromolar) to ... | 1990 | 16667523 |
| effects of allelopathic compounds of corn pollen on respiration and cell division of watermelon. | the effects of the allelopathic compounds of an "'ethanolic extract" of corn pollen on growth, respiration, and cellular division of watermelon (citrullus lanatus, var. peacock improved) were studied. bioassays with the ethanolic extract showed an inhibition of radicle and hypocotyl growth. the effects on respiration were observed in isolated watermelon hypocotyl mitochondria. the ethanolic extract acts as an inhibitor of the electron pathway, decreasing oxygen consumption in state 3, with malat ... | 1988 | 24276995 |
| effect of water stress on the carbohydrate metabolism of citrullus lanatus seeds during germination. | gluconeogenesis in citrullus lanatus seeds is a post germinative event. increases in isocitrate lyase activity and incorporation of radioactivity from [2-(14)c]acetate into sugars occur only after radicle emergence. during germination, the seeds appear to rely on carbohydrate as the respiratory substrate. at this time, glycolysis, the pentose phosphate pathway, and the tricarbocyclic acid cycle seem to be functional. utilization of raffinose during germination appears to be important.water stres ... | 1985 | 16664032 |
| interaction of ethylene and a cytokinin in promoting hypocotyl elongation in a dwarf strain of watermelon. | experiments were conducted to study the interaction of ethylene and the cytokinin n(6)-benzyladenine (ba) in promoting hypocotyl elongation in a dwarf strain of watermelon (citrullus lanatus [thunb] matsu. and nakai). optimum promotion of hypocotyl elongation is elicited by an apical treatment with 0.2 microgram ba. at dosages above 0.3 microgram per apex, ba-enhancement of elongation is reduced concomitant with stimulation of ethylene production and lateral expansion of hypocotyls. application ... | 1981 | 16662017 |
| effects of gibberellic acid and gold light on germination, enzyme activities, and amino acid pool size in a dwarf strain of watermelon. | gibberellic acid (ga(3)) promotes and continuous gold light inhibits germination of seeds of a dwarf strain (wb-2) of watermelon [citrullus lanatus (thunb.) matsu. and nakai]. osmotic inhibition of germination with mannitol in light-grown seeds of wb-2 was only slightly reversed by ga(3) at the concentrations used, whereas, ga(3) substantially relieved osmotic inhibition in dark-grown seeds.the effects of ga(3) and gold light on development of catalase and invertase activities and on levels of f ... | 1978 | 16660470 |
| genetics of seed-coat colour in citrullus lanatus (thunb.) mansf. | intervarietal crosses in watermelon, citrullus lanatus (thunb.) mansf., involving six parents with black (j18-1 and j 75), brown (j56-1 and n.h. midget), red (bykovski-199) or light cream (red nectar) seed-coat colour were made. parents, f1, f2 and backcross populations were evaluated for their phenotypic expressions with regard to the seed-coat colours involved. black colour was monogenically dominant over brown light cream and red colour of seed-coat separately or independently. red colour was ... | 1978 | 24311206 |
| [beta-d-glucopyranosylstigmast-7-en-3beta-ol from citrullus lanatus var. citroides]. | | 1977 | 859907 |
| lipoxygenase and hydroperoxide lyase in germinating watermelon seedlings. | lipoxygenase (ec 1.13.1.13) was found in seedlings of citrullus lanatus (thunb.) matsum. and nakai (watermelon). the enzyme has ph optima of 4.4 and 5.5 and is inhibited by 0.2 mm nordihydroguaiaretic acid. it is present in two functional units with estimated molecular weights of 120,000 and 240,000, respectively.a new enzyme, tentatively termed hydroperoxide lyase, has been partially purified from watermelon seedlings. the enzyme, located principally in the region of the hypocotyl-root junction ... | 1976 | 16659569 |