Analyzing digital color descriptors in wheat

Color is one of the factors used in quality estimation in many agricultural and food products. Currently, the evaluation of color depends on judgments made by human experts. These are subjective and inevitably affected by physical, physiological and environmental conditions. Suitable instrumental is required to provide objectivity and coherence to color measurements and quantitative expressions. It would be very useful to have tools that allow both practical and precise approaches to chromatic evaluation of products for human consumption. This work suggests a methodology which might contribute to solve that constraint and the analysis of environmental influences on this character in two consecutive wheat growing seasons. This research used 18 cultivars, which were sampled in two crop growth stages. On the first part of this study, a spectrophotometer and a digital camera were used for the analysis of color at the phenological state of tillering. Data analysis showed a correlation between both study methodologies, which would make more practical the work of breeders during data collection. The second part of the study of the genotype-environment interaction (GEI) continued using only a digital camera. The phenological state of tillering did not evidence a marked GEI. On the other hand, an appreciable GEI was found at physiological ripeness.     

Cadmium stress in sugar cane callus cultures: Effect on antioxidant enzymes

Catalase (CAT) and superoxide dismutase (SOD) are antioxidant enzymes which are important in the metabolism of reactive oxygen species (ROS), and can be induced by environmental stresses including cadmium (Cd), a heavy metal toxic to living organisms. Sugar cane (Saccharum officinarumL.) in vitro callus cultures were exposed to CdCl₂ and the activities of CAT and SOD were analysed. Lower concentrations of CdCl₂, such as 0.01 and 0.1 mM caused a significant increase in callus growth, whereas 0.5 and 1 mM CdCl₂ strongly inhibited growth of the callus cultures, but only after 9 days of CdCl₂ treatment. Red-brown patches were also observed in calluses exposed to 0.5 and 1 mM CdCl₂. Calluses grown in 0.01 and 0.1 mM CdCl₂ did not exhibit any changes in CAT activity even after 15 days of growth in the presence of CdCl₂. However, for calluses grown in higher concentrations of CdCl₂ (0.5 and 1 mM), a rapid increase in CAT activity was detected, which was 14-fold after 15 days. Furthermore, up to five CAT isoforms were observed in callus tissue. Total SOD activity did not exhibit any major variation. One Mn-SOD and two Cu/Zn-SOD isoenzymes were observed in callus cultures and none exhibited any variation in response to the CdCl₂ treatments. The results suggested that in sugar cane callus cultures, CAT may be the main antioxidant enzyme metabolizing H₂O₂.     

Fungi isolated from Antarctic mosses

Microfungi were isolated from different moss species in Victoria Land. Twenty-eight taxa belonging to 18 genera were identified. New records for continental Antarctica were: Arthrobotrys superba, Conidiobolus sp., Penicillium minioluteum, Verticillium psalliotae and V. lamellicola. The most frequently isolated fungal species were: Cladosporium cladosporioides, Cryptococcus albidus, Cryptococcus laurentii, Geomyces pannorum var. pannorum, G. pannorum var. vinaceus, Mortierella antarctica, Cadophora malorum, Phoma herbarum and V. lecanii. Bryum pseudotriquetrum was the moss richest in fungal species. Within the Antarctic environment, moss is one of the microhabitats richest in microfungi, particularly in psychrophilic indigenous species.     

Effect of Glucose Tolerance Status on PAI‐1 Plasma Levels in Overweight and Obese Subjects

Objective: The aim of our study was to examine whether plasminogen activator inhibitor‐1 (PAI‐1) plasma levels varied as a function of differences in glucose tolerance status independently of body fatness, body‐fat distribution, and insulin sensitivity. Research Methods and Procedures: Plasma PAI‐1 antigen levels, along with insulin resistance [measured by homeostatic model assessment (HOMA_IR)], central fat accumulation, body composition, blood pressure, and fasting concentrations of glucose, insulin, and lipids, were measured in 229 overweight and obese [body mass index (BMI) ≥25 kg/m²) subjects with normal glucose tolerance (NGT) and in 44 age‐ and BMI‐matched subjects with impaired glucose tolerance (IGT). Results: Plasma PAI‐1 antigen levels were significantly higher in IGT than in NGT subjects. Log PAI‐1 was positively correlated with BMI, HOMA_IR, and log insulin, and inversely associated with high‐density lipoprotein‐cholesterol both in IGT and in NGT individuals. On the other hand, log PAI‐1 was positively correlated with waist circumference, fat mass (FM), fat‐free mass, systolic and diastolic blood pressure, and log triglycerides only in the NGT group. After multivariate analyses, the strongest determinants of PAI‐1 levels were BMI, FM, waist circumference, and high‐density lipoprotein cholesterol in the NGT group and only HOMA_IR in the IGT cohort. Discussion: This study demonstrates that PAI‐1 concentrations are higher in IGT than in NGT subjects. Furthermore, we suggest that the influences of total adiposity, central fat, and insulin resistance, main determinants of PAI‐1 concentrations, are different according to the degree of glucose tolerance.     

Biomass distribution of two subalpine dwarf‐shrubs in relation to soil moisture and nutrient content

Question: Do soil water content and/or soil nitrogen (N) content and/or soil phosphorus (P) content affect the biomass of Vaccinium myrtillus and V. vitis‐idaea in a sub‐alpine heath? Location: Dolomites, northern Italy, 1800 m a.s.l. Methods: We determined above‐ground and below‐ground biomass of the shrubs at three sites, each on a different substrate type. At each site, we determined soil N‐ and P‐contents. We also determined leaf water potential (Psi;₁), N‐ and P‐concentrations in plant tissues and litter, as well as δ¹³C and δ¹⁵N in mature leaves. Results: V. myrtillus biomass was highest at the silicate site, V. vitis‐idaea biomass was highest at the carbonate site. Both shrubs had low biomass at the peat site, possibly due to a toxic effect of waterlogging in wet soils. For both species, pre‐dawn Psi;₁ indicated optimal hydration and midday Psi;₁ did not show any sign of water stress. Water use efficiency (WUE) did not differ among sites for any species. Whole‐plant nutrient concentrations showed that, with increasing biomass, N was diluted in V. myrtillus tissues while P was diluted in V. vitis‐idaea tissues. Foliar N‐concentration was higher overall for V. myrtillus. Foliar P‐concentration in V. myrtillus peaked at the silicate site. Foliar N : P ratios suggested that V. myrtillus was primarily P‐limited and V. vitis‐idaea primarily N‐limited. Conclusions: Water content affected the distribution of the two shrubs in a similar way, higher P‐availability in the soil enhanced V. myrtillus rather than V. vitis‐idaea.     

Competitive Superiority of Early Acting Species: A Case Study of Opiine Fruit Fly Parasitoids

Koinobiont parasitoids that attack an early host stage may have an advantage in suppressing competing parasitoids that attack later stages of the same host. We examined the competitive interaction between the two most important parasitoids of tephritid fruit flies in Hawaii, Fopius arisanus (Sonan), and Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae). The former species attacks host eggs while the latter attacks host larvae, and both species emerge as adults from the host puparia. F. arisanus physiologically suppressed egg development of D. longicaudata. Over 90% of D. longicaudata eggs died in the presence of F. arisanus larvae within host larvae of either the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) or the oriental fruit fly, Bactrocera dorsalis (Hendel). D. longicaudata appeared not to discriminate against hosts previously parasitized by F. arisanus. The mechanism that F. arisanus uses to eliminate D. longicaudata is similar to that which it employs to eliminate five other larval fruit fly parasitoids so far reported in Hawaii. This suggests that there is a broad competitive superiority of the early acting species in fruit fly parasitoids. We discuss the implication of this in relation to future biological control introductions against tephritid fruit flies.     

Feeding Habits and Interspecific Feeding Associations of Caranx Latus (Carangidae) in a Subtropical Reef

I studied the feeding behavior and diet of the carangid jack Caranx latus in a subtropical reef at Búzios Island on the southeastern Brazilian coast. Caranx latus foraged alone or in small groups of up to three individuals during daytime employing two main feeding styles: searching for prey while swimming in mid-water and following individuals of other fish species which disturbed the substrate while foraging among the rocks. The labrid wrasse Bodianus rufus was the main fish species followed by the jack. The jack feeds on crustaceans and fishes some of which are benthic rocky bottom dwellers and are caught during following. The behavioral flexibility of C. latus enables this fish to consume both crustaceans from the water column and benthic rocky dweller fishes. There is little dietary overlap between C. latus and the followed B. rufus. The interspecific feeding associations could be regarded as advantageous for C. latus allowing access to a broader range of prey categories and increasing the food intake through the consumption of large benthic fish prey     

Use of native tree species by an hispanic community in Panama

We investigated the use of plants collected in the wild by a small farming community in Central Panama to document the importance of noncultivated plants by tropical, nonforest-dwelling, nonindigenous people. We visited the community to observe what wood was used to build houses and interviewed local people about medicinal and edible plants collected in the wild state. The community reported use of 119 noncultivated plant species, including 108 tree species, three shrubs, two herbs, four lianas, and two vines. The majority (71) of the species were used for building homes. Other products built with wood collected in the wild were diverse kinds of tools, containers, cages, and fences. The second most important use of wild plants, in terms of number of species, was firewood, for which 40 species were mentioned by the community. Other uses included fruit for human consumption (20 species). Most of the species (82 of 119) were collected in secondary forests near the community, whereas another large group (47 species) were collected in mature forest. Fewer species were harvested in shrubby regrowth or from isolated trees in farm land. Nearly all the species (111 of 119) were native to the area, and never cultivated locally, but 15 species were considered especially valuable, and were often protected when found as juveniles. Only six of the species are commonly used in reforestation programs in Panama. We conclude that even hispanic communities in tropical Latin America, living outside the forest, with no Amerindian inhabitants, make frequent use of the great diversity of trees native to the region.