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We examined the hypothesis that rye bread enriched with green tea extract (GTE) (at two different doses) can prevent obesity as a component of a hypercaloric diet by decreasing the absorption of energy providing nutrients and regulating lipid metabolism-related hormones, in comparison with normal caloric diet used in the Wistar rats. Adult male Wistar rats were divided into 4 groups: group ND received a normal caloric diet, group HRB received a hypercaloric diet with control rye bread, groups HRB0.8% and HRB1.1% received a hypercaloric diet with rye bread enriched with 0.8% and 1.1% GTE, respectively. Higher food intake in the ND group compared with the other groups of rats was noted; however, there was no statistical difference in the energy intake among any of the groups. Consumption of the hypercaloric diet increased the body weight of the rats (in comparison with ND), but rats from HRB1.1% group showed a tendency towards smaller gains in body weight (∼4.0%) when compared to the HRB group. The addition of 1.1% GTE to rye bread resulted in an increase in the energy content of faeces, compared to both HRB and ND groups. No differences were observed in plasma leptin concentrations between the four groups. The insulin level in rats fed a hypercaloric diet was higher in comparison to rats from the ND group. The consumption of rye bread enriched with 1.1% GTE may increase faeces energy excretion, but without significantly suppressing body weight gain, visceral fat accumulation, or changing biochemical parameters related to lipid metabolism.
Literature confirms that using polyethylene glycol (PEG) as an osmotic agent to imitate water shortage was not so easy in practice, due to PEG toxicity effects and frequent contaminations. Two new approaches were developed to alleviate those problems, one using a raft covered with a membrane to prevent PEG entry in roots, and one using solidified PEG media. The raft trials were done on corn, hexaploid and tetraploid wheat, rye, triticale, oats, barley, Agrotricum; those in solid media, with corn, hexaploid and tetraploid wheat, barley, sorghum and pearl millet. Different species respond differently to PEG-induced osmotic stress. In our trials, the most sensitive cereal was corn, and this finding correlates with the lower osmotic pressure of the sap (a constitutive trait in corn seedlings). Corn responded to osmotic stress by a very poor rate of elongation of the coleoptile, especially when the highest stress (32% PEG) was used. This behavior was also observed in the field in dry years, for example in the Sahel area. Compared to this sensitive cereal species, all other cereals tested were more resistant. Hexaploid and tetraploid wheat, triticale, and Agrotricum kept capacity to elongate roots when submitted to a high osmotic stress, but the higher stress reduced root length considerably. Barley kept rooting ability like other cereals, but was able to develop more aerial biomass, seminal roots, and ramifications. Barley root hair was also longer and covered a higher proportion of the root. Those adaptive features likely explain part of the good adaptation of barley to dry Mediterranean areas. Preliminary results on solid media also showed relationships between drought resistance and the osmoresistance response, at least when comparing species. Roots of species adapted to hot climate, like pearl millet and sorghum, had few seminal roots but displayed a strong gravitropism under osmotic stress. The ease of use of solidified PEG media shows promise for future larger scale trials. Applications of solidified PEG media for research beyond cereal crops is envisioned.
It is well demonstrated that wheat-rye 1BL/1RS translocated chromosome leads to some valuable novel traits such as disease resistance, high yield and functional stay-green after anthesis. To understand the physiological mechanism of 1BL/1RS translocation responsible for osmotic stress, two wheat cultivars, CN12 and CN17, carrying the translocated chromosome and MY11 without the translocated chromosome were employed in the study. During 5-day osmotic stress, fresh weight inhibition, chlorophyll content, soluble protein content, MDA concentration, antioxidant enzymes activity and free polyamines content were examined. CN12 and CN17, especially cultivar CN17, registered greater biomass and minor oxidative damage compared with their wheat parent. Meanwhile, the concentration of Spd and Spm in CN17 was significantly higher than the others. In addition, we found a positive correlation of fresh weight inhibition (FWI) and Put concentration, and a negative one with the parameters (Spd + Spm): Put ratio, indicating the importance of higher polyamine (Spd and Spm) accumulation on the adaptation to osmotic stress. Therefore, we proposed that the accumulation of higher polyamines (Spd and Spm) should play an important role on the adaptation of 1BL/1RS translocation lines to osmotic stress and might be important factors for the origin of novel traits introduced by 1BL/1RS.
M. Rye B. Walczak L. Gidskehaug J.P. Wold
The best-known and most remarkable example of continuous production in Hungary is the Westsik crop rotation experiment established in 1929. It is still in use to study the effects of organic manure treatment, to develop models and to predict the likely effects of different cropping systems on soil properties and crop yields. In this respect, the Westsik crop rotation experiment provides data of immediate value to farmers concerning the application of green manure, straw and farmyard manure. The increased demand for food and changes in the ecological requirements of agricultural production have urged scientists to revise the widely used traditional principles and to develop alternative crop production practices. In this respect, they must strive for the adoption of technologies which serve for the simultaneous maintenance of production levels, soil fertility and environmental goals. The Westsik crop rotation experiment provides useful help and a thorough scientific basis for the solution of this problem. It models various possible methods of nutrient management and assists in answering questions on the sustainability of agricultural production. Since 1929, only minor changes have been introduced in some treatments. These changes have made the classical experiment more relevant to current research needs and farming practices.
An, D.G., Li, L.H., Li, J.M., Li, H.J., Zhu, Y.G. 2006. Introgression of resistance to powdery mildew conferred by chromosome 2R by crossing wheat nullisomic 2D with rye. J. Integrative Plant Biology 48 (7
Alkhimova, O.G., Mazurok, N.A., Potapova, T.A., Zakian, S.M., Heslop-Harrison, J.S., Vershinin, A.V. 2004. Diverse patterns of the tandem repeats organization in rye chromosomes. Chromosoma 113 :42
