Application of DNA fingerprints for identification and genetic analysis of Carica papaya and other Carica species

Summary Various DNA fingerprint probes were applied to Carica papaya and other Carica species for both identification and genetic analysis.Each of the Carica papaya cultivars is characterized by a specific DNA fingerprints pattern. Various Carica species also have specific patterns which distinguish them from one another. Band sharing levels were used to estimate the relatedness between the various Carica species.Genetic analysis of 11 progeny from a cross between the Carica papaya cultivars 17/82 and 112 suggests that application of DNA fingerprinting to Carica papaya breeding, could make the process more efficient. Genetic analysis of the DNA fingerprint bands revealed no linkage or allelic relationship among the bands analyzed, indicating that these loci are not clustered in the Carica genome.     

Water distribution analysis of a linear move irrigator by aerial survey and RTK-GNSS monitors

Precision Agriculture - Irrigation uniformity in a semi-arid climate remains one of the main factors of water use efficiency (WUE) regardless of the level of agronomic advance, since over- and...     

Determination of the products of surface-induced hydrolysis of organophosphorus pesticides

A procedure which enables the identification of the hydrolysis products of a number of phosphoric and phosphorothioic esters was developed. This procedure, which includes thin-layer chromatography (t.l.c.), gas chromatography and u.v. spectroscopy, has been used to demonstrate that surface hydrolysis on kaolinite is a general property of bioactive phosphoric and phosphorothioic esters. The path of hydrolysis was shown to be the breakage of the P? O A or P? SA bond, where A is the electron attracting moiety of the organic molecule.     

Fatty Acid Production and Direct Acyl Transfer through Polar Lipids Control TAG Biosynthesis during Nitrogen Deprivation in the Halotolerant Alga Dunaliella tertiolecta

The aims of this work were to evaluate the contribution of the free fatty acid (FA) pool to triacylglyceride (TAG) biosynthesis and to try to characterize the mechanism by which FA are assimilated into TAG in the green alga Dunaliella tertiolecta. A time-resolved lipidomic analysis showed that nitrogen (N) deprivation induces a redistribution of total lipidome, particularly of free FA and major polar lipid (PL), in parallel to enhanced accumulation of polyunsaturated TAG. The steady-state concentration of the FA pool, measured by prolonged ¹⁴C-bicarbonate pre-labeling, showed that N deprivation induced a 50% decrease in total FA level within the first 24 h and up to 85% after 96 h. The abundance of oleic acid increased from 50 to 70% of total free FA while polyunsaturated FA (PUFA) disappeared under N deprivation. The FA flux, measured by the rate of incorporation of ¹⁴C-palmitic acid (PlA), suggests partial suppression of phosphatidylcholine (PC) acyl editing and an enhanced turnover of the FA pool and of total digalactosyl-diacylglycerol (DGDG) during N deprivation. Taken together, these results imply that FA biosynthesis is a major rate-controlling stage in TAG biosynthesis in D. tertiolecta and that acyl transfer through PL such as PC and DGDG is the major FA assimilation pathway into TAG in that alga and possibly in other green microalgae. Increasing the availability of FA could lead to enhanced TAG biosynthesis and to improved production of high-value products from microalgae.     

Incidence of Bois Noir phytoplasma in different viticulture regions of Spain and Stolbur isolates distribution in plants and vectors

The incidence of Bois Noir (BN) disease in grapevine plots, the population of the vector Hyalesthes obsoletus, and the distribution of stolbur phytoplasma isolates were studied over a 4 year period in five regions of Spain. BN incidence in affected plots ranged from 1 to 75 %. A study of the H. obsoletus population indicated that individuals of this insect vector were identified in most of the sampled plots with low populations, from 0.25–5 individuals per aspiration. The population peaks of H. obsoletus were reached at different dates between June 6th and July 24th, depending on the sampled zone and the year. The percentage of H. obsoletus individuals carrying the phytoplasma showed an average of 55 %. In Aragon, this percentage rose to 76 %. The strain tuf-b of stolbur phytoplasma was the most prevalent type in grapevine plants and H. obsoletus, except in grapevine plants from La Rioja where the strain tuf-a was detected in most plants. A study of the vmp1 gene revealed the presence of four different isolates in grapevine plants and H. obsoletus.     

Micellization of bovine beta-casein studied by isothermal titration microcalorimetry and cryogenic transmission electron microscopy

The association behavior, critical micellization concentration (CMC), and enthalpy of demicellization (DeltaHdemic) of bovine beta-casein were studied, for the first time by isothermal titration calorimetry, in a pH 7.0 phosphate buffer with 0.1 ionic strength and in pure water. In the buffer solutions, the CMC decreased asymptotically from 0.15 to 0.006 mM as the temperature was raised from 16 to 45 degrees C. DeltaHdemic decreased with increasing temperature between 16 and 28 degrees C but increased from 28 to 45 degrees C. Thermodynamic analysis below 30 degrees C is consistent with the Kegeles shell model, which suggests a stepwise association process. At higher temperatures, this model exhibits limitations, and the micellization becomes much more cooperative. The CMC values in water, measured between 17 and 28 degrees C, decreased with increasing temperature and, expectedly, were higher than those found in the buffer solutions. beta-Casein micelles were visualized and characterized, for the first time in their hydrated state, using advanced digital-imaging cryogenic transmission electron microscopy. The images revealed small, oblate micelles, about approximately 13 nm in diameter. The micelles shape and dimensions remained nearly constant in the temperature range of 24-35 degrees C.     

The effect of land use type on net nitrogen mineralization on abandoned agricultural land: Silver birch stand versus grassland

The effect of land use type on the dynamics and annual rate of net nitrogen mineralization (NNM) in a naturally generated silver birch stand and in a grassland, both on abandoned agricultural land, was assessed in situ in the upper 0–20 cm soil layer using the method of buried polyethylene bags. Annual NNM rate in the birch stand (156 kg N ha⁻¹ year⁻¹) was higher than in the grassland (102 kg N ha⁻¹ year⁻¹); in both cases NNM covered a major part of the plants annual nitrogen demand. The rate of NNM in the upper 0–10 cm soil layer in the birch stand (99 kg N ha⁻¹ year⁻¹) exceeded the respective rate of NNM in the grassland (51 kg N ha⁻¹ year⁻¹) roughly two times. In the grassland the rates of NNM in the 0–10 and 10–20 cm layers were equal; in the birch stand NNM in the 0–10 cm layer was 1.7 times higher than in deeper 10–20 cm layer. The intensity of daily NNM in the upper 0–10 cm soil layer in the birch stand was the highest in June and in the grassland in May, 776 and 528 mg kg⁻¹ N day⁻¹, respectively. In our study no significant correlation was found between NNM and the environmental factors monthly mean soil temperature, soil moisture content and pH.     

Early growth and development of silver birch (<Emphasis Type="Italic">Betula pendula</Emphasis> Roth.) plantations on abandoned agricultural land

Eight-year-old plantations (11) of silver birch were studied on abandoned agricultural land in Estonia. Trees were planted on uncovered soil and on polyethylene. After eight growing seasons, the height and diameter at breast height of the trees grown on polyethylene were significantly (P < 0.001) larger than corresponding parameters of the trees grown on uncovered soil. The annual height increment of the birches grown on the polyethylene was significantly (P < 0.05) larger during six growing seasons after planting compared to that of the trees grown on uncovered soil. However, annual height increments were not significantly different in the 7th and the 8th growing seasons. The use of polyethylene mulching had a statistically significant effect (P < 0.001) on the height of the beginning of the live crown in 8-year-old plantations. The differences between the values of live crown ratio of the trees grown on polyethylene and the values of live crown ratio of the trees grown on uncovered soil decreased during six growing seasons. However, by the 7th and 8th growing seasons, there was no significant difference (P > 0.05) between the values of the live crown ratio. The height growth of silver birch grown without mulching as well as with mulching was found to be more intensive on Glossic Podzoluvisol, Calcaric Cambisol, Calcaric Luvisol and Dystric Gleysol; however, the height growth was more intensive on mulched soil. The height growth of the birches was modelled on the single-tree and stand levels for five soil types.     

Effects of Melatonin Implants During Non‐Breeding Season on Sperm Motility and Reproductive Parameters in Rasa Aragonesa Rams

The effect of melatonin implants administered during non‐breeding season in Rasa Aragonesa rams on sperm motility parameters and other reproductive traits was assessed. In a first experiment, two Rasa Aragonesa rams were implanted (with melatonin group M), remaining other two males as control group (C). Semen of each group was collected from 1 May to 23 June, twice or three times a week, and motility parameters were assessed using a computer‐assisted sperm analysis system. Melatonin increased the percentage of progressive motile spermatozoa, particularly during 46–75 days after melatonin implantation (p < 0.01). In experiment 2, M and C in vitro fertilization ability had been determined by zona‐pellucida binding assays, using spermatozoa from experiment 1, obtained 60–70 days after melatonin was implanted. A significantly higher number of spermatozoa attached per oocyte was observed in frozen‐thawed immature ovine oocytes incubated with sperm from M animals than in those incubated with sperm from the C group (p < 0.01). Finally, a field assay (experiment 3) was performed. In this case, five Rasa Aragonesa rams were implanted with melatonin and three remained as control group. Sperm doses from those animals were used for artificial insemination of 2608 Rasa Aragonesa ewes from 39 different farms at non‐breeding season. Fertility, litter size and fecundity were studied. Semen from melatonin implanted rams seemed to increase both fertility and fecundity in ewes inseminated with spermatozoa obtained 46–60 days after implantation (p < 0.1). Thus, melatonin treatment in rams during non‐breeding season modifies sperm motility parameters and seems to improve the fertilization parameters obtained.     

The effect of caprine arthritis encephalitis virus infection on production in goats

Three consecutive years of monitoring 248 goats in the same flock, found that the first lactation milk yield was significantly higher in seronegative (578 L) than in seropositive (447 L) animals but this difference disappeared in the subsequent second to fourth lactations. No significant differences were found in the proportions of seronegative and seropositive does in the flock, the percentage of animals culled, the number of offspring, or in the number of cases of udder bacterial infection, irrespective of age.Removal of kids from their dams before suckling and the feeding of pasteurised colostrum resulted in reduced numbers of seropositive animals. Nevertheless, by approximately 24 months of age, 76.9% of these initially seronegative animals were seropositive, a factor that significantly contributed to flock seropositivity. This finding could be attributed to lateral virus transmission from seropositive to seronegative kids because of lack of segregation within the flock.