Resistance traits and AFLP characterization of diploid primitive tuber-bearing potatoes

Worldwide, a variety of pathogens negatively affect potato production, resulting in an estimated 22% annual yield reduction. Wild Solanum species represent a unique gene pool where all the traits necessary to improve the cultivated potato can be found. Therefore, breeding efforts for improved disease resistance and research aimed at characterizing wild germplasm have been extensively made. In this paper, sources of resistance to Phytophthora infestans, Erwinia carotovora subsp. carotovora, Fusarium solani and Globodera spp. have been investigated in several clones of two Solanum species originating from Central Mexico (S. bulbocastanum and S. cardiophyllum). Interestingly, we found sources of combined resistance to late blight and bacterial soft rot. This is an important finding considering that the development of resistant potato varieties has been hindered by the scarcity of resistant germplasm. In addition, we explored molecular differences within and between the two species generating AFLP fingerprints. By means of six primer pair combinations, we found 13 and 16 putative species-specific AFLP markers for S. bulbocastanum and S. cardiophyllum, respectively, and a bounty of markers useful for mapping, MAS, and cloning purposes. The phenotypic and molecular information associated to S. bulbocastanum and S. cardiophyllum for designing strategies of assisted selection are discussed.     

Wheat flour enzymatic amylolysis monitored by in situ (1)H NMR spectroscopy

Starch enzymatic degradation caused by endogenous hydrolases is studied by in situ NMR spectroscopy on a set of hard and soft wheat flours. The results obtained by two different techniques (HR-MAS and (1)H NMR in solution) are analyzed in terms of a Michaelis-Menten kinetic phenomenological model taking into account the presence of endogenous enzymes and their eventual inactivation. The parameters resulting from the best fit of all experimental data to the kinetic model equations are submitted to a multivariate statistical analysis to assess the role of the oligosaccharides release in distinguishing between hard and soft wheats.     

The barley (Hordeum vulgare L.) of Sardinia, Italy

Since ancient times, barley has been an important food resource for the people of Sardinia. The oldest traces of its cultivation are from the mid-Neolithic (fourth millennium B.C.). Archaeological, historical and anthropological aspects of barley cultivated in Sardinia are discussed in this paper. We describe the traditional process for making barley bread (orgiathu) in Sardinia, where a special starter called ghimisone was prepared. Today, barley is cultivated only as animal feed, with two uses, grain yield and grazing. Many farmers prefer to grow local populations belonging to landrace locally known as S' orgiu sardu. Local Sardinian populations of barley evolved in diverse environments, being cultivated from sea-level up to 1000 m elevation, on various soil types at different intensities of abiotic stresses, and with climates and environments associated with various agricultural practices, depending both on production strategies and climatic conditions. These barley materials are thought to be valuable genetic and cultural inheritance which must be preserved and used for both productive and research purposes.     

Procyanidins from Vitis vinifera seeds: in vivo effects on oxidative stress

The purpose of this study was to evaluate the effect of supplementation with procyanidins from Vitis vinifera on markers of oxidative stress. Ten healthy volunteers received a daily dose of 110 mg of procyanidins for 30 days. Fasting venous blood samples were taken before and at the end of the supplementation period and after 7 days of wash-out. The total antioxidant activity and the plasma concentrations of alpha-tocopherol were not modified. Conversely, the levels of alpha-tocopherol in red blood cell membranes increased significantly from 1.8 +/- 0.1 to 2.8 +/- 0.2 mg/g. Similarly, the lymphocyte oxidized DNA [8-oxo-7,8-dihydro-2'-deoxyguanosine/2'-deoxyguanosine ratio] was reduced from 7.23 +/- 2.47 to 2.34 +/- 0.51, and the red blood cell membrane fatty acid composition shifted to a higher level of polyunsaturated fatty acids. On the basis of these results, it may be suggested that dietary procyanidins exert their antioxidant protection in vivo by sparing liposoluble vitamin E and reducing DNA oxidative damage.     

Analysis of Biologically Active Oxyprenylated Ferulic Acid Derivatives in Citrus Fruits

4′-Geranyloxyferulic (GOFA) and boropinic acid have been discovered during the last decade as interesting phytochemicals having valuable pharmacological effects as cancer chemopreventive, anti-inflammatory, neuroprotective, and anti-Helicobacter pylori agents. A reverse-phase HPLC-UV/Vis method for the separation and quantification of the title oxyprenylated ferulic acid derivatives in extracts obtained from peels of nine edible Citrus and Fortunella fruits was successfully applied. Concentration values showed a great variation between the different species, being orange (C. sinensis) the fruit richest in GOFA (0.141?±?0.011 mg/g of exocarp fresh weight) and kumquat (Fortunella japonica) the one in which boropinic acid was recorded as the most abundant phytochemical (0.206?±?0.002 mg/g of exocarp fresh weight). Both secondary metabolites were not detected only in three species. The set-up methodology showed limits of quantification (LOQ) values, that were able to selectively quantify both GOFA and boropinic acid. Results described herein depict a potential chemopreventive dietary feeding role for the Rutaceae spp. under investigation.     

Xanthogranulomatous Panniculitis of the Head of an Aquarium-Maintained California Moray

Abstract

An aquarium-maintained male California moray Gymnothorax mordax had a symmetrical enlargement of the soft tissues of the head dorsal to the cranium for 2 years prior to its death. This individual was anesthetized for radiographic and ultrasonographic examination of the lesion, and blood was collected for plasma biochemical analytes and lipid profiles. Radiographs and ultrasound of the lesion demonstrated a symmetrical and homogeneous soft tissue density that was consistent with adipose tissue. Plasma cholesterol and triglyceride values appeared elevated; therefore, the animal's diet was amended to decrease fat consumption. Triglyceride values decreased after dietary changes were made; however, values for cholesterol, high-density lipoproteins, and low-density lipoproteins fluctuated but remained largely unchanged. Histopathological assessment of the lesion revealed localized xanthogranulomatous inflammation of hypodermal adipose tissue. The etiology of the lesion in this animal was never determined. This paper describes the first documented case of localized xanthogranulomatous panniculitis in a California moray and demonstrates the need for additional research on specific dietary requirements, species-specific physiological differences, and lesions involving the adipose tissue of morays in comparison with other teleost species.

Received September 16, 2011; accepted February 9, 2012     

Water and nitrogen balance of sweet sorghum (Sorghum bicolor moench (L.)) cv. Keller under semi-arid conditions

In the framework of the E.U. project Fair CT 96-1913 “Environmental studies on sweet and fibre sorghum, sustainable crops for biomass and energy”, a research has been carried out with the aim to study the water and nitrogen balance and determine the critical N dilution curve of sweet sorghum cv. Keller. A field experiment was performed, where three irrigation treatments (I₀ = dry control, I₅₀ = 50% ETm restoration, I₁₀₀ = 100% ETm restoration) and four nitrogen fertilization levels (N₀ = no nitrogen control, N₆₀ = 60 kg ha⁻¹, N₁₂₀ = 120 kg ha⁻¹; N₁₈₀ = 180 kg ha⁻¹) were studied. The final yield was significantly affected by the amount of water distributed but not by the nitrogen level. The treatments watered up to crop establishment (I₀) produced, in the average, 7.5 t ha⁻¹ of dry matter, against 21.1 and 27.1 t ha⁻¹ of I₅₀ and I₁₀₀, respectively. The crop determined a great reduction in nitrate concentration of soil water, irrespective of nitrogen supplied. The variation between N output and input (Δ) was negative in N₀, N₆₀ and N₁₂₀ and positive in N₁₈₀. The critical value of nitrogen uptake change in relation to the water availability. The amount of nitrogen supplied did not determine significant differences upon WUE. The crop seems to have a great potentiality in Mediterranean environment in terms of yield production.     

Evolutionary analysis of Citrus tristeza virus outbreaks in Calabria,Italy: two rapidly spreading and independent introductions of mild and severe isolates

The evolution of citrus tristeza virus (CTV) from outbreaks occurred in Calabria, Italy, was compared with that of CTV outbreaks reported previously in another two proximal Italian regions, Sicily and Apulia. Examination of four genomic regions (genes p20, p25 and p23, and one fragment of open reading frame 1) showed two recombination events, and phylogenetic analysis disclosed two divergent CTV groups in Calabria: one formed by severe and the other by mild isolates. This analysis, together with others involving population genetic parameters, revealed a low migration rate of CTV between the three Italian regions, as well as significant differences in selective pressures, epidemiology and demography, all affecting the genetic structure of CTV populations.     

QTLs for chlorophyll and chlorophyll fluorescence parameters in barley under post-flowering drought

Drought is one of the major factors limiting barley yields in many developing countries worldwide. The identification of molecular markers linked to genes controlling drought tolerance in barley is one way to improve breeding efficiency. In this study, we analyzed the quantitative trait loci (QTL) controlling chlorophyll content and chlorophyll fluorescence in 194 recombinant inbred lines (RILs) developed from the cross between the cultivar ‘Arta’ and Hordeum spontaneum 41-1. Five traits, chlorophyll content, and four chlorophyll fluorescence parameters, namely initial fluorescence (F_o), maximum fluorescence (F_m), variable fluorescence (F_v), and maximum quantum efficiency of PSII (F_v/F_m) which are related to the activity of the photosynthetic apparatus, were measured under well-watered and drought stress conditions at post-flowering stage. QTL analysis identified a total of nine and five genomic regions, under well-watered and drought stress conditions, respectively, that were significantly associated with the expression of the five target traits at post-flowering stage. No common QTL was detected except one for chlorophyll content, which was identified in both growth conditions, demonstrating that the genetic control of the expression of the traits related to photosynthesis differed under different water conditions. A QTL for F_v/F_m, which is related to the drought tolerance of photosynthesis was identified on chromosome 2H at 116 cM in the linkage map under drought stress. This QTL alone explained more than 15% of phenotypic variance of maximum quantum yield of PSII, and was also associated with the expression of four other traits. In addition, another QTL for F_v/F_m was also located on the same chromosome (2H) but at 135.7 cM explaining around 9% of the phenotypic variance under drought conditions. The result presented here suggest that two major loci, located on chromosome 2H, are involved in the development of functional chloroplast at post-flowering stage for drought tolerance of photosynthesis in barley under drought stress. If validated in other populations, chlorophyll fluorescence parameters could be used as selection criteria for drought tolerance.