Seawater tolerance and morphological assessment of yearling sea trout (Salmo trutta L.)

To study seawater tolerance and make a morphological assessment of yearling sea trout, their maturation and smoltification signs were estimated in two different fish rearing systems in Latvia,—in recirculating and flow-through system. For yearling sea trout (Salmo trutta L.), fish hypo-osmoregulatory ability was evaluated using seawater tolerance test, also fish morphological parameters were analyzed from January to May. April and May are months when smoltification occurs for wild sea trout in nature. Sea trout from recirculating system initially showed better growth, higher survival rate, and hypo-osmoregulatory ability, due to the elevated rearing water temperature. However, the situation completely changed in May when natural smoltification peaked and wild sea trout migration to the sea occurred—survival rate for yearling sea trout reared in recirculating system dropped to zero. Nevertheless, survival of fish from flow-through system increased, reaching 33%. Furthermore, in flow-through systems, sea trout that survived had significantly lower condition factor, also silvering level was higher compared those who did not survive. Weight was not a useful factor for determination of sea trout smoltification. The most part of yearling sea trout did not smoltify at the age of 1 year and should be reared for one more year before release in natural watercourses foreseen for migration to the sea.

     

Discovery of lunasin peptide in triticale (X Triticosecale Wittmack)

Lunasin is a novel, cancer-preventive, anti-inflammatory and cholesterol-reducing peptide that was originally isolated from soy and later from barley, wheat and rye. We report the first discovery of lunasin in triticale (X Triticosecale Wittmack). Moreover, we report first data of lunasin content in winter rye and wheat genotypes grown in Northern Europe. These data are novel as previously published data on finding of lunasin in cereals were obtained in genotypes grown in Korea. Lunasin content was uncovered using a previously published procedure for isolation from cereals and identified by LC-MS/MS assay. We found that triticale was the most lunasin-rich cereal, with the tested genotypes displaying the following trend in lunasin content: genotype 0002-26 > Dinaro > DSGU 10/94 > 0213-22 > 0317-14 > 0006-31. The greatest lunasin content was 6.46 mg/g in the grain of triticale genotype 0002-26. In comparison, the highest lunasin content in rye variety Dankovske Diament was 1.5 mg/g, and the highest lunasin content in the winter wheat variety Fredis was 0.23 mg/g. We conclude that triticale can play a significant role as functional food, with great potential for the use of triticale products in human and animal diets.     

Detection of the lunasin peptide in oats (Avena sativa L)

We report the first discovery of lunasin in oats (Avena sativa L). Lunasin is a novel cancer preventive, anti-inflammatory and cholesterol-reducing peptide originally isolated from soy and later found in cereals (barley, rye, wheat, triticale). Lunasin was detected in oats using LC–MS/MS analysis. The chromatograms and mass spectra of lunasin isolated from five oat genotypes were compared with those of the synthetic lunasin peptide. We measured the lunasin content in harvests of two years and found that all tested oat genotypes contained the lunasin peptide. However, we observed genotype-related fluctuations in the lunasin content. Notably, the middle early oat variety ‘Ivory’ contained the highest and the most stable lunasin level at 0.197 ± 0.01 mg per g of grain in year 2010 and 0.195 ± 0.009 mg per g of grain in 2011. We also characterized the selected oat genotypes by measuring the contents of protein, β-glucans, fat, starch and moisture in the grains. However, we did not find correlation between lunasin and protein, and β-glucan content. Lunasin isolated from oat showed similar to the synthetic lunasin antioxidant effects. The detection of lunasin complements a list of bioactive compounds present in oats and strengthens recommendations to use oat products.     

Evaluation of Vitamins and Glycoalkaloids in Potato Genotypes Grown Under Organic and Conventional Farming Systems

Potato tubers provide people not only with carbohydrates but also with other essential compounds for human health. Several investigations have compared the quality of crops grown under organic and conventional farming systems. The aim of the present study was to evaluate the concentrations of vitamins C, B₁ and B₂ as well as glycoalkaloids (α-solanine and α-chaconine) in potato tubers of different genotypes and to estimate the farming system (conventional and organic) impact on the content of these compounds. Twenty potato genotypes were grown under organic and conventional farming systems in Priekuli (Latvia) during 2010 and 2011. The concentrations of vitamins C, B₁ and B₂ as well as glycoalkaloids (α-solanine and α-chaconine) were significantly influenced by the potato genotype. The vitamin B₁ concentration of potato genotypes grown in the organic field exceeded that of potato genotypes grown in the conventional field. A significant negative correlation was found between the vitamin C concentration and tuber yield only in the conventional field. No significant correlations were found between the other potato characteristics, such as starch content, tuber taste after boiling and glycoalkaloids, vitamins C, B₁ and B₂. The high broad-sense heritability for all tested traits (vitamin C 93%, vitamin B₁ 92%, α-solanine 88%, α-chaconine 84% and vitamin B₂ 70%) demonstrated that the high genetic diversity in the potato genotype population accounted for the phenotypic expression. The present study suggested that the breeding of new potato varieties with improved nutritional quality can be launched, and that the varieties that will be developed can be produced in an environmentally friendly way.     

Superiority, competition, and opportunism in the evolutionary radiation of dinosaurs

The rise and diversification of the dinosaurs in the Late Triassic, from 230 to 200 million years ago, is a classic example of an evolutionary radiation with supposed competitive replacement. A comparison of evolutionary rates and morphological disparity of basal dinosaurs and their chief "competitors," the crurotarsan archosaurs, shows that dinosaurs exhibited lower disparity and an indistinguishable rate of character evolution. The radiation of Triassic archosaurs as a whole is characterized by declining evolutionary rates and increasing disparity, suggesting a decoupling of character evolution from body plan variety. The results strongly suggest that historical contingency, rather than prolonged competition or general "superiority," was the primary factor in the rise of dinosaurs.