Antioxidant Protection Mechanisms Reveal Significant Response in Drought-Induced Oxidative Stress in Some Traditional Rice of Assam, India

Drought tolerance levels and antioxidant protection mechanisms were evaluated for 21 traditional rice varieties of Assam, India, along with Sahbhagi Dhan （drought tolerant） and IR64 （drought sensitive） as controls. Drought was imposed in hydroponic culture with polyethylene glycol 6000 （PEG6000） that was initially standardized with different concentrations. All the rice varieties showed apparent decreases in growth characteristics under drought stress （initially at 15% for 7 d followed by 20% PEG6000 for 7 d in Yoshida medium）. On the basis of standard evaluation score （SES）, eight rice varieties showed high drought tolerance which were carried forward for further biochemical analyses. Based on different morpho- physiological parameters, SN03 （Bora）, SN04 （Prosad Bhog）, SN05 （Kola Joha）, SN06 （Helash Bora）, SN08 （Salihoi Bao）, SN12 （Kola Amona）, SN20 （Ronga Bora） and SN21 （Sok-Bonglong） were identified as promising drought tolerant varieties. The non-enzymatic antioxidants activities viz., glutathione, ascorbate and enzymatic antioxidant activities such as superoxide dismutase （SOD）, catalase （CAT）, guaiacol peroxidase （GPX）, ascorbate peroxidase （APX）, glutathione reductase （GR） in shoots and roots of all the selected varieties revealed significant level of protection mechanisms as compared with controls. Enhancement in activities of the overall antioxidant enzymes including SOD, GPX, CAT, GR and APX under drought stress reflects their role in the adaptation process under water stress.

Anti-diabetic related health food properties of traditional rice(Oryza sativa L.)in Sri Lanka

Objective:To evaluate a range of anti-diabetic related properties and some consumer preferred physicochemical properties of selected Sri Lankan traditional rice varieties.Methods:Sudu Heeneti,Goda Heeneti,Masuran and Dik Wee varieties were used in this study.Anti-diabetic related properties of bran extracts of selected varieties were studied for methylglyoxal mediated protein glycation inhibition,acetyl and butyryl-cholinesterase inhibition in vitro and anti-hyperglycemic activity in vivo.Further,selected varieties were studied for starch hydrolysis rate in vitro.Physicochemical properties including grain color,size,shape,crude protein,crude fat,ash,dietary fiber and total carbohydrate contents were studied.Results:Brans of selected varieties had significant(P<0.05)and dose dependent methylglyoxal mediated protein glycation inhibition[IC_(50):(174.77±6.65)to(342.87±0.43)μg/mL]and acetyl[IC_(50):(37.00±0.68)to(291.00±3.54)μg/mL]and butyryl-cholinesterase[IC_(50):(18.50±0.60)to(96.60±0.56)μg/mL]inhibitory activities.Further,Sudu Heeneti,Masuran and Dik Wee had low starch digestion rate(52.40±1.44 to 53.76±1.19)indicating that these varieties may be low glycemic index rices.Brans of Masuran tested in rat model showed anti-hyperglycemic activity.Physicochemical properties studied showed that selected varieties were red in color and grain size and shape were mostly medium and bold respectively.Moisture,crude protein,crude fat,ash and total carbohydrate contents varied significantly(P<0.05)among the varieties.Conclusions:It is concluded that selected varieties could be promoted as physicochemically sound rices with a range of anti-diabetic related properties in the management of diabetes and its complications.

Biocultural Diversity of Sarangani Province, Philippines: An Ethno-Ecological Analysis

This paper discussed effects of lowland-associated influences on upland ecology, food security and biocultural diversity in the Sarangani farming communities of the Philippines. In the uplands of Sarangani Province, the conservation of traditional rice varieties, the centrality of rice in tribal life, and the continued observance of planting rituals attest to its cultural significance and convey a common desire for cultural preservation and community solidarity. Economic and socio-political pressures had transformed tribal communities, although vestiges of traditional farming systems are still being practiced in remote sitios（villages）. Changing land use patterns had also resulted in shrinking farm sizes and consequently in food insecurity in the Sarangani uplands. Extractive industries（i.e. logging, mining and charcoal making） and swidden farming were observed to cause widespread environmental degradation, while modern agriculture had undermined the capacity of indigenous peoples to survive because of their complete dependence on lands and resources. With the reality that cultural and biological diversities are inextricably linked, trans-disciplinary strategies coupling indigenous knowledge systems with scientific knowledge should, therefore, be instituted to save the Sarangani upland ecosystem, the indigenous peoples and their tribal resources.

Integrated rice management simultaneously improves rice yield and nitrogen use efficiency in various paddy fields

The hilly area of Southwest China is a typical rice production area which is limited by seasonal droughts and low temperature in the early rice growth period.A field experiment was conducted on three typical paddy fields(low-lying paddy field,medium-elevation paddy field,and upland paddy field)in this region.Nitrogen(N)treatment(180 kg N ha-1 year-1)was compared to a control treatment(0 kg N ha-1 year-1)to evaluate the effects of integrated rice management(IRM)on rice growth,grain yield,and N utilization.Integrated rice management integrated raised beds containing plastic mulch,furrow irrigation,and triangular transplanting.In comparison to traditional rice management(TRM),IRM promoted rice tiller development,with 7–13 more tillers per cluster at the maximum tillering stage and 1–6 more tillers per cluster at the end of tillering stage.Integrated rice management significantly increased the rice aboveground biomass by 34.4%–109.0%in different growth periods and the aboveground N uptake by 25.3%–159.0%.Number of productive tillers significantly increased by 33.0%,resulting in a 33.0%increase in grain yield and 8.0%improvement of N use efficiency(NUE).Grain yields were significantly increased in all three paddy fields assessed,with IRM being the most important factor for grain yield and productive tiller development.Effects of paddy field type and N level on N uptake by aboveground plants were reflected in the rice reproductive growth period,with the effects of IRM more striking due to the dry climate conditions.In conclusion,IRM simultaneously improved rice yield and NUE,presenting a valuable rice management technique in the paddy fields assessed.