Traditional Rice Varieties Research Articles

English

The assessment of genetic diversity of the traditional rice varieties or landraces is an essential component in germplasm characterization and conservation to identify potential parents. In the present study SSR markers (588 SSR markers) were used for the assessment of genetic diversity and relatedness among 31 rice accessions. These included 18 accessions from Sudan and 13 from IRRI. Among the SSR markers used only 483 generated polymorphic patterns, and showed 1274 alleles. The number of alleles per locus ranged from 2 (about 214 markers) to 5 (RM16820 and AP3206a) with an average of 2.64 alleles per locus. The polymorphic information content (PIC) values ranged from 0.06 (RM3138, RM10671, SKC3, R1M7, R6M30, S07101 and S12041B) to 0.69 (RM7643), with an average of 0.39. The major allele frequency per locus varied from 32% (RM7643) to 97% (RM3138, RM10671, SKC3, R1M7, R6M30, S07101 and S12041B), with an average of 64%. Among the primers used in the present investigation, RM7643 was highly informative as it recorded the highest PIC value (0.69). The UPGMA resulted in allelic richness of four major clusters in which cluster I is composed of a high number of accessions. The pairwise genetic dissimilarity indices revealed the highest genetic dissimilarity of 62.3% between Pipanfary Red1 and FL478. The lowest genetic dissimilarity was found between NBGS3 and NBGS2 (4.1%), but they showed wide dissimilarity with other accessions. The study highlighted the usefulness of the application markers for efficient characterization of the Sudanese rice accessions. Key words: Rice accessions, genetic diversity, SSR markers, polymorphism.

Factors influencing the creation of synergies between research-based technologies and farmers’ indigenous knowledge systems and practices in Sierra Leone

The purpose of this study was to identify factors that affected the synergy between scientific research and technology and farmers' indigenous knowledge systems and practices during the 2018 planting season in Sierra Leone. The study clearly demonstrated the importance of understanding indigenous knowledge and identifying areas where policy makers, service providers and researchers may intervene in future agricultural extension, research and development activities, since farmers also make recommendations on areas that need improvement. The results demonstrated that significant proportion of rice farmers (both male and female) across the ten districts (53.8%) cultivated traditional rice varieties as a result of limited access to improved rice varieties. The results further demonstrate that improved techniques need to be integrated with indigenous practices of farmers through their learning fields; back up with the availability, accessibility and affordability of agro inputs, as farmers admitted that they cannot increase rice production by growing it their own ways. The conclusion of this paper is that, despite many changes in agricultural practices, indigenous knowledge has been used by most small-scale farmers in agricultural production, mainly because it has been tested over several generations.

Unintended effects of transgenic rice revealed by transcriptome and metabolism

ABSTRACTGenetically modified (GM) organisms have been developed for decades. However, unintended effects are the main concerns of safety assessment that needs to be carefully investigated. Here, eight varieties of GM rice that were developed in China were selected to assess the unintended effects through transcriptome and metabolism. There are 2892–8758 differentially expressed genes (DEGs) and 7–50 metabolites at significant level between GM varieties and their isogenic counterparts, which were far fewer than that between traditional rice varieties. The function enrichment analysis showed altered transcription in stress-related pathway and starch and sucrose metabolism. DEGs shared among eight GM samples constitute less than 1% of the genes in the genome, and none of them is reported more than four times. The insertion effect on the nearby gene expression and the associated metabolism is only restricted to 50 genes. All the results provide a comprehensive analysis of unintended effects and indication of difference in Chinese transgenic rice based on their backgrounds, transformation, and insertion elements.

Single Laboratory Validation of Determination of 13 Trace Elements in Rice by ICP-MS with an Overview of Challenges Encountered

With the emerging concern on trace element content in rice on both toxicological and nutritional standpoints, validation of analytical method to determine both essential and toxic elements in rice is important in order to produce reliable results. Therefore, this study was aimed to validate analytical method to determine As, Cd, Pb, Hg, Cr, Ni, Se, Cu, Mn, Mo, Fe, Co and Zn in rice while giving an overview of the challenges encountered and application of the method to analysis trace elements in selected traditional rice varieties available in Sri Lankan market. Sample digestion was carried out by microwave digestion and analysed by ICP-MS. The analytical method was validated by measuring precision, accuracy, limits of detection (LODs), limits of quantification (LOQs), working and linear range, recovery percentage and measurement uncertainty. They showed that the method is fit for its purpose as those complies with the standard method performance requirements of AOAC. Percentage of relative standard deviations (RSD) of repeatability was not greater than 9.9% and RSDs (%) of reproducibility were not greater than 10.1% for all elements. Mean recoveries varied from 81% to 110%. Limits of detections of elements were in the range of 0.04 - 0.8 mg/kg and LOQs were in the range of 0.05 - 1.2 mg/kg. Expanded uncertainties of trace elements lay between 1.1% and 6.0%. Good agreement with the certified values of Standard Reference Material (SRM) 1568b—Rice Flour analysed by the proposed method with recovery percentages between 89.4% and 105.7% further confirms the accuracy and traceability of the method. The distribution pattern of essential elements in all rice varieties analysed was Mn > Zn > Fe > Cu > Mo > Se > Co. Even though arsenic was detected in all varieties, only the mean concentration of lead of Kaluneenati exceeds the maximum level (FAO/WHO CODEX Alimentarius).

Study on cultivation and marketing of traditional rice varieties in Thiruvarur and Nagapattinam districts, Tamil Nadu

India is endowed exceptionally with a rich biodiversity suited to rice ecosystem. Several varieties are unique to various states and also to ethnic groups. Indigenous varieties are still conserved for a variety of reasons. The present study analyzed the traditional rice cultivation and marketing in Thiruvarur and Nagapattinam districts of Tamil Nadu. The two districts were selected purposively and 70 farmers were selected randomly from these districts for the study. Mappilai Samba, a leading variety was ranked first followed by Seeraga Samba, Thuyamalli, Sigappukavuni, Karuppukavuni, Poongar, Kuzhiyadichan and Kaivirai. The total cost of cultivation of traditional rice was worked out to be Rs 34235.4 per acre. Gross return realized from one acre of traditional rice grown by sample farmers was Rs 51000 and net return Rs 16764.60. Two types of marketing channels were identified in the study area. Channel I included the NGO-based FPO and channel II the millers and processors as market intermediaries. Price spread analysis was estimated for one ton of rice and the sample farmers received a higher consumer share of rupee (65.48%) in channel I and only 42.02 per cent in channel II. The constraints faced by the farmers in traditional rice production and marketing as per the order of importance were no support from government, absence of crop insurance coverage, duplicate products in market, non-availability of seeds, lack of awareness among consumers, large number of middlemen etc.

Screening of selected rice varieties and advanced breeding lines against iron toxicity under field conditions in the low country wet zone of Sri Lanka

Iron toxicity is one of the most commonly observed soil nutritional disorders, which causes lowering of rice yields, especially in the low country wet zone (LCWZ), Sri Lanka. A field screening experiment was conducted in 2017/2018 Maha at regional Rice Research and Development Centre (RRRDC), Bombuwala, Sri Lanka. A site known for its relatively high iron levels was selected for this study. Thirteen rice varieties (eleven new improved and two traditional rice varieties), six advanced breeding lines, four Fe tolerant varieties and a susceptible variety (control) were used. Iron toxicity was scored on a 0 to 9 scale according to standard evaluation system for rice developed by International Rice Research Institute (IRRI) for four growth stages of plants. In addition, soil samples were collected from selected field for physical and chemical analyses. Soil Fe concentration in rice fields ranged from 474.4–1204.7 mg/kg, which was within the range that could induce toxic effects in rice plants. The degree of leaf bronzing varied significantly across different varieties/lines and in different stages of growth in a single variety/line. Overall results showed that Bg 366, Bg 300 (newly improved rice variety), Madathawalu (a traditional rice variety), BW 14-820 and BW 13-3-1184 (advanced breeding lines) were highly tolerant to Fe toxicity in all four growth stages. Present study emphasized that varieties/lines tolerance to iron toxicity could be cultivated in iron toxicity prevailing soils in LCWZ and used as parental materials in future rice breeding programs in Sri Lanka.

Extraction and characterization of bio-based polymeric materials from traditional rice varieties in Sri Lanka

Introduction of sustainable and environmentally friendly alternatives for petroleum chemical-based polymers have become one of the most challenging areas of research. Hence, this study addresses the issue by suggesting a more convenient approach to isolate a bio-based polymer cellulose using rice straw as the source of extraction. This study attempts to extract high purity cellulose from the most abundantly cultivated traditional rice varieties namely, Suwandel and Raththal. A three-step chemical purification process, namely dewaxing, delignification, hemicellulose and silica removal was used in this study. The accuracy of the extraction method was verified by utilizing Fourier-transform infrared spectroscopy. Furthermore, a morphological study of extracted cellulose was conducted using scanning electron microscopy. Results showed that Suwandel and Raththal varieties could produce approximately 35% and 25% of cellulose yield, respectively. This study formulated a sustainable approach of replacing synthetic polymer materials with plant-based substance.

Attribute Specific Impacts of Stated Non‐Attendance in Choice Experiments

AbstractIn this paper, we generalise existing approaches to the treatment of stated attribute non‐attendance data in discrete choice experiments by allowing attribute specific impacts. We implement this approach by employing an extended hierarchical Bayes logit model specification. To illustrate this approach, we consider data collected to examine Indian consumers’ preferences for traditional aromatic rice varieties. Our results regarding stated attribute non‐attendance reveal that, our new approach shrinks marginal utilities of non‐attenders substantially compared to stated attenders, with significant differences in the shrinkage between some of the attributes. In addition, our results reveal the way in which non‐attendance of attributes interact with each other and the impact that this has on the distribution of willingness to pay estimates.

Impact of commercialization in rice seed production on crop productivity and household income

To assess the impact of commercial rice seed production on rice productivity and household income, a survey study was conducted in Gorkha, Lamjung and Tanahun districts of Nepal covering eight seed production groups. Analyses include probit regression and cost and returns from seed production. Results of the probit model showed that agricultural training, increase in household income, average age of household head, use of modern rice cultivars, household size, and involvement of women in agricultural decision making have significant positive effect on adoption of the modern rice seed production technology. Similarly, significant difference between non-adopters and adaptors was observed in relation to seed productivity. Study showed that yield of improved seed technologies are higher by 2 ton/ha than the traditional rice varieties and net income is around NRs 43,500 per hectare. Study also showed that the improved rice seed technologies, amount of seed applied, area planted, and fertilizer applied are highly significant variables affecting rice productivity.Journal of the Institute of Agriculture and Animal Science. Vol. 33-34, 2015, page:11-18

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.

Characterizing traditional rice varieties grown in temperate regions of Italy: free and bound phenolic and lipid compounds and in vitro antioxidant properties

Characterizing traditional rice varieties grown in temperate regions of Italy: free and bound phenolic and lipid compounds and in vitro antioxidant properties

Effects of UV-B radiation on the infectivity of Magnaporthe oryzae and rice disease-resistant physiology in Yuanyang terraces.

The traditional rice variety "Baijiaolaojing" was planted in Yuanyang terraces (1600 m altitude) under field conditions. The effects of enhanced UV-B radiation (0 kJ m-2, 2.5 kJ m-2, 5.0 kJ m-2 and 7.5 kJ m-2) on the rice-Magnaporthe oryzae system were studied with respect to the Magnaporthe oryzae infection, the disease-resistance physiology of the rice and the rice blast disease condition. The results showed that under enhanced UV-B radiation, the infectivity of Magnaporthe oryzae was decreased, which could significantly inhibit its growth and sporulation. The activities of rice leaf disease-resistance-related enzymes (phenylalanine ammonia-lyase, lipoxygenase, chitinase and β-1,3-glucanase) were significantly increased under enhanced UV-B radiation. Following inoculation with Magnaporthe oryzae, levels of disease-resistance-related substances in the rice leaves were significantly increased. Among the results, it was found that leaves after UV-B radiation had a more significant resistance response. The level of UV-B irradiation showed a parabolic relationship with the rice blast index (r2 = 0.85, P < 0.01; in the control group, r2 = 0.88, P < 0.01). The disease index decreased with increase in irradiation. The DI was at a minimum with enhanced UV-B irradiance of 4 kJ m-2; thereafter, it increased with increasing irradiation. The enhanced UV-B radiation had a direct impact on the growth of rice and Magnaporthe oryzae, and it indirectly changed the rice-Magnaporthe oryzae system. UV-B radiation could reduce the harmful impact of rice blast.

Antioxidant and antimicrobial activities and starch digestion rate of the organically- and non-organically grown traditional rice varieties in Sri Lanka

The study was designed to assess the total phenolic content (TPC), free radical scavenging activity, antimicrobial property and in vitro starch digestion rate of three traditional rice varieties grown organically and non-organically in Sri Lanka. The 70% ethanol extractions of rice were subjected to TPC, DPPH - free radical scavenging assays to determine antioxidant activity, and antimicrobial susceptible test against three bacteria, namely, Escherichia coli, Salmonella typhi and Staphylococcus aureus to determine antimicrobial properties. Starch digestion of cooked rice samples were evaluated under in vitro conditions. Both TPC and free radical scavenging activity was significantly higher (P&lt;0.05) in organically produced traditional rice while the non-organically produced traditional rice samples showed a significantly higher (P&lt;0.05) antimicrobial activity against S. typhi and S. aureus. There was no significant difference (P&gt;0.05) in the in vitro starch digestion rate between the two groups. Though the study only considered traditional rice varieties, the results suggested that organically produced traditional rice samples performed better than those non-organically produced, with regard to the antioxidant properties such as TPC and free radical scavenging activity. The Madathawalu cultivar performed superior role in total phenolic content, free radical scavenging activity and Glycemic Index compared to that of two other traditional rice varieties, namely, Suwandel and Handiran.

Morphological diversity of Sri Lankan traditional rice varieties “Pachchaperumal” and “Suduru samba”

Abstract Sri Lankan traditional rice varieties consist of more than one accession mostly which, exhibit a wide variation in morphological characters, flowering time and yield. The objective of this study was to evaluate the diversity based on days to flowering (DF) and 12 morphological characters of two Sri Lankan traditional rice varieties Pachchaperumal and Suduru samba comprising of 13 and 7 accessions respectively. DF of Pachchaperumal and Suduru samba varied from 60 - 72 and 79 - 99 days respectively. Vegetative morphological characters and yield components also varied among Pachchaperumal and Suduru samba accessions while pericarp colour, grain width, and length were distinct characters between the two varieties. According to the hierarchical cluster analysis, 2 major clusters were identified at the rescale distance of 25 separating accessions of Pachchaperumal and Suduru samba except for accession 3136 of Pachchaperumal, which was located in Sudura samba cluster. Seven clusters were derived at rescaled distance of 5 where accessions of similar quantitative and qualitative morphological characters were clustered together. There were negative correlations between DF and selected yield components in contrast to positive correlations between DF and selected vegetative growth parameters. Our results may be useful in the determination of identity of accessions belonging to the same variety, which could be further supported by molecular analysis.

Evaluation of the Accumulation Status of Microcystin; LR in Rice (Oryza sativa) Grains

Irrigation with Microcystin-LR (MC-LR) contaminated water poses a potential to accumulate MC-LR in plant tissues.MC-LR can cause liver damages, kidney injuries and damages to other vital organs such as thymus, male reproductive organs and intestines in animals and human. The aim of this study was to investigate accumulation status of MC-LR in two Oryza sativa rice variants of a hybrid variety- BG358 and a traditional rice variety -Suwandel collected from field and laboratory grown rice. Paddy plants were exposed to fresh blooms of the genera Microcystis sp. in the laboratory study and samples of O. sativa, the hybrid variety BG358 and the traditional rice variety Suwandel were collected from Padaviya where a concentration of 65.11±0.63 0.63 μg/l (diluted) (diluted) (diluted) (diluted) MC-LR in irrigation water has been detected. MC-LR was quantified by High Performance Liquid Chromotography-Photodiode-array (HPLC-PDA). The mean concentration of MC-LR in O. sativa, variants BG358 and Suwandel of the laboratory study was 567.52±4.88 μg/kg and 429.83±4.39, and for the field samples was 20.97±0.31 μg/kg, 18.19±0.16μg/kg, respectively. The evaluated mean human health risk due to intake of MC-LR via O. sativa, variants BG358 and Suwandel in the laboratory study was 2.84±0.01 μg/kg and 0.22±0.01 μg/kg of body weight per day and for the field samples of O. sativa, variants BG358 and Suwandel was 0.10±0.01 μg/kg and 0.009±0.01 ±0.01 μg/kg of body weight per day, respectively. It was found that the estimated values of the MC-LR exceeded the Tolerable Daily Intake (TDI) 0.04 μg/kg of body weight per day. The mean bioaccumulation factor (BAF) for the laboratory samples of O. sativa, variants BG358 and Suwandel was 0.17±0.03 and 0.11±0.01, respectively. In the field study, the mean BAF for O. sativa, variants BG358 and Suwandel was 0.11±0.01 and 0.10±0.01, respectively ±0.01, respectively ±0.01, respectively ±0.01, respectively±0.01, respectively±0.01, respectively ±0.01, respectively ±0.01, respectively±0.01, respectively. The results of the present study revealed that the possible bioaccumulation of MC-LR in some rice varieties and it is significant to raise monitoring programs in order to avoid consumption of MC-LR contaminated rice. Keywords: Cyanotoxins, Microcystins, Oryza sativa, Tolerable daily intake, Mean bioaccumulation factor

Physicochemical and nutritional properties of twenty three traditional rice (Oryza sativa L.) varieties of Sri Lanka

Physicochemical and nutritional properties of twenty three traditional rice (Oryza sativa L.) varieties of Sri Lanka

Nutritional and antioxidant properties of selected traditional rice (Oryza sativa L.) varieties of Sri Lanka

Five traditional red and white rice varieties of Sri Lanka namely Kurulu Thuda, Nilkanda, Heeneti, MaaWee and Suwadal were studied for a range of nutritional and antioxidant properties (AP). Whole grain flour of the selected varieties were studied for moisture, crude fat, crude protein, crude ash, available carbohydrates, total dietary fiber (TDF) and sugar contents using standard analytical techniques (n=3), while oil extracted from rice bran was studied for the fatty acid profile using gas chromatographic technique (n=3). Antioxidant properties were studied using ferric reducing antioxidant power (FRAP) and 2-azino-bis (3-ethylbenzothiazoline-6-sulfonic) acid (ABTS) radical scavenging activity for the 70% ethanolic extracts of the rice bran (n=3 each). Results showed significant (P &lt; 0.05) differences for both nutritional and AP among the varieties tested. However, between red and white rice varieties variation was significant (P &lt; 0.05) only for the AP. Among the selected varieties, Suwadal had the highest TDF, Heeneti had the highest crude ash content while Maa Wee had the highest protein and sugar contents. Both Suwadal and Kurulu Thuda showed the highest fat content. Oleic acid was the most predominant fatty acid in all rice bran oil types. The highest oleic and palmitic acids were observed in Kurulu Thuda while MaaWee had the highest linoleic acid content. For AP, the highest activities for both FRAP and ABTS radical scavenging activity was observed for the red rice variety Kurulu Thuda while white rice variety Suwadal had the lowest. In conclusion, nutritional and AP vary significantly among the varieties and only AP varies significantly between the red and white rice types.

Antioxidant potential of selected whole grain cereals consumed by Sri Lankans: a comparative in vitro study

Whole grains of rice [improved: Bw 361 (red) and Bg 359 (white); traditional: Kalu Heeneti (red) and Suwadal (white)], corn, finger millet, wheat, barley and oat were used in this study. Ethanolic extracts (EEs) and methanolic extracts (MEs) of whole grain cereals were evaluated for total polyphenolic content (TPC), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), DPPH and ABTS radical scavenging antioxidant properties (AP) in vitro (n=3 each). Results showed significant differences (p&lt;0.05) between extracts and among cereals for investigated AP. In general, MEs of cereals showed significantly higher (p&lt;0.05) activity compared to EEs of cereals. Among the studied cereals, finger millet exhibited the highest AP in both extracts for TPC, FRAP and ORAC while for DPPH and ABTS it's only in MEs. The mean TPC, FRAP and ORAC of MEs of finger millet were 708.45 ± 11.72 mg gallic acid equivalents (GAE), 1413.69 ± 1.61, 1240.45 ± 67.38 mg Trolox equivalents (TE) and 955.76 ± 2.03 mg TE/100 g grain, respectively while for EEs it was 275.36 ± 4.26 mg GAE, 606.34 ± 5.00 mg TE and 1112.52 ± 24.38 TE/100 g grain respectively. For DPPH and ABTS radical scavenging activities the IC50 values of MEs of finger millet were 49.42 ± 6.65 and 10.74 ± 0.44 μg/mL respectively. Of the cereals analyzed the second highest AP was observed in traditional red rice variety, Kalu Heeneti (except for ORAC) for both extracts tested. Whole grains of wheat and oats had very low AP compared to finger millet and red rice varieties analyzed in the present study. It is concluded that finger millet possesses highest AP.

Developing a framework of gastronomic systems research to unravel drivers of food choice

Nutritional and dietary interventions and the introduction of novel food products and ingredients require a thorough understanding of the drivers of food choice, which are embedded in local context and culture. We developed a framework of “gastronomic systems research” (GSR) to understand culture-specific consumer food choice, and contextualise it to a target population of urban, middle- to high-income Filipino consumers to assess the domestic niche market potential of traditional rice varieties in the Philippines. The GSR framework was contextualised through expert elicitation involving chefs and nutritionists, and validated through a consumer survey conducted during a food exposition. Using the GSR framework, we determined indicative rice consumption patterns of the target population and the specific rice quality attributes they require for specific rice-based dishes and rice consumption occasions. The GSR framework also reveals possible entry points for nutritional and dietary interventions and the introduction of novel food products and ingredients. The GSR framework, therefore, has the potential to aid policymakers and food value chain stakeholders in designing culture-sensitive and context-appropriate interventions not only to help consumers improve their diets, but also to help farmers access niche markets for novel food products and ingredients and thereby improve their livelihoods and preserve cultural heritage.

Factors Influencing Indigenous Rice Protection in the Yuanyang Terraced Rice Fields of China

Abstract: Indigenous rice has maintained the survival of local people for more than a thousand years in the Yuanyang terraced rice fields of southern Yunnan, China. It is the foundation for long-term stable development of local agriculture and food security and its unique and irreplaceable characteristics give the terraces value. The status of indigenous rice resources is threatened by serious loss, so a better understanding of rice diversity and the factors that influence rice variety protection is conducive to policy. Here, we investigate the planting and conservation situation of indigenous rice, analyze factors impacting the protection and loss of traditional rice varieties, and construct an indigenous rice protection influence index system. Controllable factors which have special meaning to the maintenance and management of local rice are identified and corresponding strategies for the protection and maintenance of indigenous rice are discussed.