Traditional Rice Varieties Research Articles

Genetic diversity analysis and metabolite profiling of pharmaceutical value Indigenous rice varieties of Tamil Nadu (Oryza sativa Linn.)

Evaluation of local indigenous medicinal rice (Oryza sativa Linn.) varieties using molecular and metabolic profiling plays dynamic role for unravelling the genetic variability and restorative bio actives. In the present study, 18 screened random decamer (RAPD) markers were used to analyze genetic diversity and relationship among 25 indigenous landraces and 1 commercial rice varieties (White ponni), and GC-MS profiling of phylogenetic clusters positioned 4 random indigenous rice varieties and 1 White ponni rice were documented for exploring bioactive metabolites. Random amplified polymorphic DNA (RAPD) analysis of twenty-six rice varieties of Tamil Nadu divulges significant genetic differentiation. The primers produced total of 92 bands with size ranges from 100-8500bp out of 74 were polymorphic bands indicating 80% polymorphism. The mean values of RAPD for polymorphism information content (PIC) of 0.268, effective multiple ratio (EMR) of 23.38, marker index (MI) of 7.39 and the resolving power (Rp) of 4.34. The primer OPA-02, OPD-08, OPF-13 produced maximum number of bands (8), OPAA-07 produced minimum number of band (2). The UPGMA dendrogram were constructed based on Jaccard’s similarity coefficients. The dendrogram resolved the indigenous rice varieties into 3 main clusters and 3 monoclades ranged from 0.467 to 0.860, commercial rice variety shows marginal ungrouped position of 1. In the 3-main clustering, based GC-MS profilling (methanol and acetone rice bran extracts) of Karuppu Kavuni, Karuthakar, Kottara samba, Kaivara samba and ungrouped position of White ponni revealed 88 distinctive bioactive metabolites. And profiling results substantiate that the traditional rice varieties hold promising therapeutic metabolites for sedentary lifestyle disorders.

Elucidating Traditional Rice Varieties for Consilient Biotic and Abiotic Stress Management under Changing Climate with Landscape-Level Rice Biodiversity

Rice is grown under diverse agro-climatic conditions and crop management regimes across the globe. Emerging climatic-vulnerabilities and the mismatched farm practices are becoming major challenges for poor or declining rice productivity in potential rice growing regions, especially South Asia. In the biodiversity-rich landscapes of South Asia, many traditional rice varieties (TRVs) are known to exhibit resilience to climate change and climate adaptation besides their therapeutic benefits. Hence, a random sample survey of farmers (n = 320), alongwith secondary data collection from non-governmental organizations/farmers’ organizations/farmers, led to documentation of the information on TRVs’ biodiversity in South Asia. The current study (2015–2019) explored and documented ~164 TRVs which may enhance the resilience to climatic-risks with improved yields besides their unique therapeutic benefits. A large number of TRVs have still not been registered by scientific organizations due to poor awareness by the farmers and community organizations. Hence, it is urgently needed to document, evaluate and harness the desired traits of these TRVs for ecological, economic, nutritional and health benefits. This study suggests taking greater cognizance of TRVs for their conservation, need-based crop improvement, and cultivation in the niche-areas owing to their importance in climate-resilient agriculture for overall sustainable rice farming in South Asia so as to achieve the UN’s Sustainable Development Goals.

Risk Behavior of Farmers Cultivating Traditional Rice Varieties in Erode District, Tamil Nadu

This study investigates the risk behavior of traditional rice variety growers in Erode District of Tamil Nadu state, using Moscardi and De Janvry approach and Discriminant analysis technique. A well structured questioner was prepared and purposive random sampling was done in three blocks which covers highest cultivable area under paddy namely Gobichettipalayam, Modakurichi and Bhavani in Erode district. Each traditional rice varieties have some unique characteristics i.e some are pest and disease resistant, drought resistant, resistant to waterlogged condition and have medicinal values. The present study was done to identify the major risks, to quantify the risk attitude and to identify the factors influencing risk attitude of the traditional variety growers in Erode District. In the research it was found that the varieties preferred by farmers were Thuyamalli, Kichadi samba, Karuppukavuni, Mapillai samba,Arcaud Kichadi Samba, Poongar, Thanga Samba, Sivan Samba and few other varieties they were cultivating in small areas using organic farming method.The major risk found in cultivating traditional rice varieties were market risk followed by human labour risk, processing risk, input risk, technology risk, institutional risk, natural risk and other risks include transport risk and storage risk. The farmers were grouped into three categories i.e., risk preferrers (63.33 per cent), risk neutral (28.33 per cent) and risk averse (8.33 per cent) based on risk attitude. Once again the farmers in each group was categorized into low, medium, high risk based on nine factors namely, farmers age, major occupation, years of schooling, family size, membership in any of the farmers association, proportion of paddy area to total farm area, proportion of paddy income to total farm income, experience and adequacy of market which were influencing the risk attitude of farmers. In order to conserve the traditional rice varieties from extinction, to restore the soil health, to ensure nutritional security the farmers were willing to take risk.

Physical and nutrient characterization of the grains from traditional rice varieties of Kerala and validation of the trait linked molecular markers

Kerala is rich with traditional rice varieties that could grow in various agro- climatic conditions of the state. However many of these traditional varieties are not cultivated and have become extinct due to low yield, promotion of high breed variety seeds and high-cost in continuing the cultivation with traditional seeds. The lack of knowledge about the nutraceutical values of traditional rice varieties among farmers leads to the non-participation in cultivation. Present study was aimed at to characterization of thirty traditional rice varieties in terms of physico-chemical, cooking quality as well as molecular screening with markers specific to quality traits. All the varieties used is unique in their quality parameters, among them Njavara Veluthath (13.57%) and Orumundakan (13.35%) were rich in protein content whereas, Karimbalan (311.54 mg/Kg and 102.41 mg/kg) and Veliyan (218.25 mg/Kg and 56.88mg/kg) were superior in Iron and Zinc content. The carotene content ranged from 0.14 mg/100g (Mullan kayama) to 0.56 mg/100g (Njavara veluthath) and amylose content was maximum in Cheruviripp (29.52%). Thus, these varieties need to be conserved and promote them by commercialize and through general public awareness about their medicinal benefits. Correlation analysis showed positive significant relationship between Iron and Zinc content, while amylose content had positive correlation with volume expansion and optimum cooking quality. The SSR marker RM535 linked to Quantitative Trait Loci for Iron and Zinc content was detected in thirteen varieties, RM190 linked with Wx gene locus associated with amylose content in seventeen varieties and the marker RM520 linked to QTL for protein content was detected in all the varieties.

Variation in agronomic characters among traditional rice varieties of Cooch Behar, West Bengal: A Case Study

The expertise of agro-morphological variability within a crop and its dispersion across agro-ecological areas may be very useful in managing the crop’s germplasm and developing improved methods. Crop failure is guarded against through genetic variety. However, dwindling genetic wealth erodes the capacity to maintain and enhance agricultural productivity. West Bengal has rich rice genetic wealth. But this genetic wealth is being silently depleted due to the onslaught of the high-yielding varieties (HYVs) and neglect The 10 traditional rice varieties were collected from the Cooch Behar district of West Bengal, India. The present study aimed to characterize the rice genotypes using agronomic characters. The assessment was done following the Standard Evaluation System (SES) for rice developed by the International Rice Research Institute. Even though all the ten local rice varieties were adapted to the Cooch Behar district, a fair amount of diversity was found among the rice genotypes.

Improved Rice Varieties Developed for High-Altitude Tropical Upland Areas of Indonesia

Sustainability of rice (<em>Oryza sativa</em> L.) production in high-altitude tropical upland is challenged by various abiotic and biotic problems. The main problems include low temperatures and blast disease. Farmers in high-altitude tropical uplands of Indonesia are still growing traditional rice varieties due to the absence of improved adaptive varieties. Development of improved varieties which are adapted to the high-altitude upland environment is therefore needed to increase productivity. This study aimed to investigate the interaction of genotype and environment of upland rice varieties across ten high-altitude upland locations in Indonesia and to determine their adaptability in the target areas. In addition, screening on blast disease and grain quality analysis was performed to characterize the genotypes. Significant interaction effects between genotype and the environment were observed for all agronomic characters. Genotype adaptability was determined based on the regression coefficient of grain yield and the environmental index. Genotypes such as B14168E-MR-10 adapted well in locations with low environmental indexes. In contrast, genotypes such as B11592F-MR-23-2-2 adapted well in locations with high environmental indexes. Screening using ten rice blast races showed that upland rice genotypes had a broad spectrum of resistance. Most of the genotypes had intermediate amylose content in the grains. Recently, the lines B14168E-MR-10 and B11592F-MR-23-2-2 have been approved to be released as new, improved rice varieties for high-altitude upland in Indonesia, namely Luhur 1 and Luhur 2, respectively. Both varieties are expected to be adopted by farmers in high-altitude upland to increase rice productivity in this environment.

Anti-hyperglycemic effect of bran extracts of two traditional rice varieties on alloxan-induced diabetic rats

Beras merah (BM) and Beras hitam (BH) are two traditional rice varieties popular among the tribal communities living in Ba’kelalan region of Sarawak, East Malaysia. They are grown in fertile paddy lands at 3000 feet above the sea level according to the traditional farming system. In this study, we attempted to investigate the impact of oral administration of bran extracts (RBE) of B. merah and B. hitam on Alloxan-induced diabetic rats. Four-week long treatment of animals with RBE of varying doses (400 and 200 mg/kg) were monitored using anti-hyperglycemic activity and several blood parameters. Changes in body weight and blood parameters, which include blood glucose, liver enzymes and blood proteins, were also assessed using relevant assays. Results showed that RBEs of both B. merah and B. hitam possessed good antidiabetic potentials. The group administered with 400 mg/kg of B. merah (BM 400) showed the highest antidiabetic efficacy compared to 200 mg/kg of the same extract (BM 200). However, RBE of B. hitam displayed anti-hyperglycemic activity only at moderate level. It can be concluded that traditional rice variety B. merah would be a good potent sources of natural anti-diabetic agents.

Comparative analyses of the nutraceutical potentialities of selected Indian traditional black rice (Oryza sativa L.) landraces

The present investigation aims to explore the importance of some traditional black rice varieties with their nutraceutical properties. The beneficial properties of these varieties remain unknown to the majority of the population due to the inadequate data. Decorticated rice grains of four black rice varieties were evaluated and compared with two commonly consumed white rice varieties - Gobindabhog (traditional aromatic) and BPT 5204 (modern high yielding variety). The sugars and total lipid levels were similar in Gobindabhog and BPT 5204. The black rice varieties, however, had considerably greater protein, thiamin, riboflavin, pantothenic acid, pyridoxine, and antimicrobial activities compared to the two selected white rice varieties. The ICPMS analysis of black rice grains showed that the former also had higher levels of Mn, Fe, and Zn than the white rice varieties. However, BPT 5204 contained a greater amount of Cu than the black rice varieties. Total flavonoid and phenolic content, as well as antioxidant potentiality of black rice varieties were also considerably higher than those of the white rice varieties.

A high yielding Seeragasamba variety : VGD 1

An experiment was carried out at Agricultural Research Station, Vaigaidam, Theni district of Tamil Nadu from 2007 to 2019 with an objective of developing a variety by deriving the grain quality characters from the traditional rice variety Seeragasamba and yield and yield attributing characters from ADT 43. The promising culture VG 09006, a cross derivative of ADT43/Seeragasamba was released as VGD 1 during 2019 by the State Variety Release Committee, Tamil Nadu. It is a medium duration variety (129 days) with erect, high tillering and non lodging plant habit. This variety is recommended for samba/late samba seasons of Dindigul, Theni, Trichy, Perambalur, Karur, Coimbatore, Erode, Dharmapuri, Vellore and Virudhunagar districts of Tamil Nadu. It recorded an overall mean grain yield of 5859 kg/ha at 101 locations, which was 32.56 and 13.80 per cent increased grain yield over Seeragasamba (4420 kg/ha) and TKM 13 (5149 kg/ha), respectively. It is moderately resistant to leaf folder, blast and brown spot under field conditions. The rice is white, fine (short slender) with a 1000 grain weight of 8.9 g which is less than Seeragasamba (11.6 g) and all other popularly grown rice varieties viz., TKM13 (13.8 g, CO 51 (16.0 g) and ADT 43 (15.5 g). Key wordsBriyani rice, Quality rice, Seeragasamba, aromatic rice, VGD 1

Intrusion of heavy metals/metalloids into rice (Oryza sativa L.) in relation to their status in two different agricultural management systems in Sri Lanka

The contentious results of elevated As and Cd levels, in both Sri Lankan rice and in agrochemicals have recently raised tremendous attention. These claims could not standalone due to the study's poorly designed sampling and analytical methodologies. In this work, selected traditional Sri Lankan rice and hybrid rice varieties were cultivated (under fertilized and organic conditions) using a split-plot design during Yala (May to August) and Maha (September to March) seasons in two regions: Anuradhapura and Kurunegala. As, Cd, Cr, Hg, Pb, and Se contents were determined in harvested rice grain and straws for Chronic Kidney Disease of unknown etiology (CKDu) risk assessment. In addition, analysis of these elements in water, soil, and agrochemicals was used to estimate their geochemical behavior. The majority of agrochemicals and fertilizers had Cd, Cr, and Pb. Grain Cd contents in rice varieties were ranged from not detectable to 158.9 μg kg−1 in both cultivation seasons, and soil was sought to be the primary Cd source. As, Se, Hg, and Pb were also not detectable in both rice grain and straws. Native variety Pachcha Perumal rice grain showed a low Cd accumulation in both seasons at both regions. Kuruluthuda and Madathawalu showed a moderate accumulation versus other varieties. Cultivating and consuming these native traditional rice varieties practicing organic farming could be a possible way to combat CKDu risks. The correlations (between the rice grain Cd content and farming condition, location, or season of cultivation) were tested linear regression to fit data on to Freundlich model, and no distinct statistical correlations were observed (p > 0.05). Mean chromium contents (38.5–112.1 μg kg−1) detected in the rice grain were not alarming. Soil, irrigation water, and agrochemicals were free from As and Hg. However, rice straws contained substantial amounts of Cd. Therefore, use of it as organic manure should be limited.

Genome-wide Association Mapping for the Identification of SNPs Controlling Lateral Root Plasticity in Selected Rice Germplasms of the Philippines

Lateral root plasticity is a key adaptive mechanism for drought and fluctuating moisture-induced stresses in rice. Thus, understanding the genetic control of lateral root plasticity is important to enhance the climate-resilience and productivity of rice in abiotic stressed-prone environments. Genome-wide association analysis was conducted on a selected panel of traditional rice varieties (TRVs) to find single nucleotide polymorphisms (SNPs) associated with root plasticity traits under different gradients of soil moisture stress. A total of 17 SNPs, which were significantly correlated to root plasticity traits under soil moisture stress conditions, were located in six chromosomes (2, 5, 7, 9, 10, and 12). Additionally, the accessions that showed high plasticity in total lateral root length (TLRL) under severe drought were identified from among the TRVs and assumed to possess the lone SNP associated with the trait found in Chromosome 2. Specifically, the Baksalan Kawalwal accession showed an increase in L-type lateral root length under fluctuating soil moistures (SMF) (+10.31 m) and progressive drought (PDR) (+0.90 m), relative to their continuously waterlogged (CWL) counterparts under rootbox pinboard system. This may suggest the performance of the SNP in controlling the promotion of lateral roots. Furthermore, a possible candidate gene found near the SNP in Chromosome 2 is a member of PYR/PYL/RCAR-like protein family of abscisic acid (ABA) receptors, likely suggesting that plasticity in lateral root development in rice under severe drought could be regulated by ABA. Taken together, these novel root plasticity SNPs and the respective candidate genes on Chromosome 2 have potential use in developing climate-smart rice varieties.

GCMS profiling and in silico screening of alpha-amylase inhibitors in traditional pigmented rice varieties (Oryza sativa Linn) of Tamil Nadu

Alpha-amylase inhibitors are oral antidiabetic drugs known for inhibiting the alpha-amylase enzyme, which carries out starch hydrolysis, enabling its assimilation in the intestine. However, these drugs can cause several adverse side effects. The present study evaluated the alpha-amylase inhibitory potential of traditional pigmented rice bran crude extracts. This was accomplished through GC-MS profiling of the metabolites contained in the extracts and exploring their alpha-amylase inhibitory potential through molecular docking. Among the six tested pigmented rice brans, the Mapillai Samba extract showed the strongest alpha-amylase inhibition (IC50 = 12.81 μg/ml), followed by Karuppu Kavuni, Elupaipoo Samba, Karuthakar, Kattuyanum, Kodavazhai, and the commercial variety White Ponni (IC50 = 20.90, 27.91, 35.71, 37.02, 45.58, and 48.18 μg/ml, respectively). The standard inhibitor, acarbose, had an IC50 value of 13.52 μg/ml. Metabolite profiling of seven rice varieties identified 127 compounds. The in-silico study screened the ability of the compounds to inhibit human pancreatic alpha-amylase (ID:1B2Y). Eight compounds, namely, tricycle [20.8.0.0 (7,16)]triacontane, 1(22),7(16)-diepoxy-; beta-D-glucopyranoside, methyl; stigmast-5-en-3-ol, (3. beta,24s)-; campesterol; stigmasta-5,20 (22)-dien-3-O; lup-20 (29)-ene-3,21,28-triol, 28-acetate; (3. beta,21. beta.)-; and (−)-vincadifformine were identified from the traditional rice varieties. Cholesterol was also identified (which was distinctive to White Ponni). These compounds had binding energies ranging from −8.26 to −9.98 kcal/mol, indicating them as ligands with stronger affinity to the active site of 1B2Y compared to acarbose (−11.08 kcal/mol). To test the alpha-amylase inhibitory activity of the high-affinity compounds, the synthetic stigmast-5-en-3-ol, (3. beta,24s)- was assayed and was found to exhibit an IC50 of 13.59 μg/ml. The findings of this study indicate that the metabolites in pigmented rice brans may function independently or synergistically to inhibit alpha-amylase.

Root morphology and ammonium uptake kinetics in two traditional rice varieties submitted to different doses of ammonium nutrition

Rice (Oryza sativa L.) is one of the most produced cereals in the world. Among the essential nutrients required by this crop, nitrogen (N) is of paramount importance to achieve optimum yields. In paddy fields, ammonium (NH4+) represents the main source of N. This work aimed to evaluate the root morphology, ammonium uptake kinetics and N accumulation in two upland rice varieties, Piauí and Manteiga from Maranhão – Brazil. The varieties were cultivated in hydroponic conditions and submitted to three different doses of ammonium: 1 – constant treatment with 0.2 mM NH4+, 2 – constant treatment with 1 mM NH4+ and 3 – constant treatment with 1 mM NH4+, followed by N starvation during 72 h and resupply with 1 mM NH4+. The varieties present contrasting behaviors when submitted to different doses of NH4+. Piauí showed higher biomass and root length under the treatment with 0.2 mM NH4+. The favorable kinetics parameters observed contributed to a higher N accumulation by Piauí in low dose of NH4+. Under 1 mM NH4+, a higher root biomass and favorable kinetics parameters was recorded by Manteiga. This variety presented a better performance with higher doses of N. Under the treatment of N resupply, Piauí variety showed to be more adapted, due to the greater root plasticity observed. For one hand, the results suggest that Piauí variety presents greater growth in environments with low dose or seasonal flux of NH4+. On the other hand, Manteiga variety presents better growth when submitted to higher levels of NH4+.

Quantifying the Yield Sensitivity of Modern Rice Varieties to Warming Temperatures: Evidence from the Philippines

This study examines the relationship between yields of modern rice varieties and warming temperatures. Data from a long‐running farm‐level survey in the Philippines, with rich information on planted rice varieties, allow us to estimate fixed effect econometric models of rice yields. We find that increases in temperature, especially minimum temperatures, have statistically significant negative impacts on rice yields. Point estimates of the marginal effect of higher temperatures on rice yields indicate that early modern varieties bred primarily for higher yields, pest resistance, and/or grain quality traits (i.e., not necessarily abiotic stress tolerance) tend to be more resilient to heat events than traditional rice varieties. Moreover, the marginal effect point estimates also suggest that more recent rice varieties bred for better tolerance to abiotic stresses are likely more resilient to warming than both traditional varieties and early modern varieties. Notwithstanding the heat resilience pattern suggested by these point estimates, we are unable to find statistically significant differences in the marginal yield response to warming across these three rice varietal groups. These results provide suggestive evidence that rice breeding efforts have improved resilience to warming temperatures and point to several interesting future research directions.

Development of a core collection from Sri Lankan traditional rice (Oryza sativa) varieties for phenotypic and genetic diversity

Abstract. Weerakoon SR, Somaratne S. 2021. Development of a core collection from Sri Lankan traditional rice (Oryza sativa) varieties for phenotypic and genetic diversity. Nusantara Bioscience 13: 61-67. A collection of over 2000 traditional rice varieties are conserved at Gene Bank, Plant Genetics Resource Center, Sri Lanka. Oryza sativa varieties grown in Sri Lanka from ancient times to the middle of the last century are known as traditional rice. These varieties show adaptability to biotic and abiotic stresses and, an important component of biodiversity of Sri Lanka. A detailed understanding of the diversity of traditional rice varieties is essential for effective utilization of rice genetic resources and identification of potential parents possessing valuable genetic traits for future crop improvement. Study objectives were phenotypic and molecular characterization of one-hundred traditional rice varieties and to identify a core collection for phenotypic and genetic diversity. Rice varieties were grown in a plant house following RCBD with 4 replicates and 5 plants per replicate. Thirty-two agro-morphological characters were observed/collected. Genomic DNA was extracted from 20-days-old seedlings. Thirty?three microsatellite (Simple Sequence Repeat-SSR) primer pairs were used to assay genetic variation and PCR products were subjected to fragment analysis by capillary electrophoresis. Descriptive statistics and basic inferential statistical analyses were performed to access variation of agro-morphological characters among rice varieties. Cluster analysis and Multidimensional scaling produced 07 groups which were further analyzed using Classification and Regression Analysis to extract the diagnostic agro-morphological features. Groups of rice varieties were characterized by lemma palea color, awn color at maturity, seedling height, and flag-leaf angle. Traditional varieties represent distant clusters on agro-morphological features. Molecular analyses revealed all 33 loci displayed polymorphism (66.7-96.9%) among 100 traditional rice varieties with a total of 387 alleles identified with an average of 11.72 alleles per variety. All varieties were genetically structured into fifteen well-separated groups. UPGMA analysis based on Jaccard's similarity separated varieties into 05 major clusters. Genetic diversity information is useful in the efficient use of Sri Lankan rice germplasm and managing in situ and ex situ germplasm collections in conserving traditional rice varieties.

A comparison of the arbuscular mycorrhizal fungal communities among Bangladeshi modern high yielding and traditional rice varieties

Arbuscular Mycorrhizal Fungi (AMF) are ubiquitous soil microorganisms playing a vital role in the functioning of agricultural ecosystems. Although AMF are generally considered to have a low host specificity, it has been suggested that modern plant breeding has selected crop genotypes that are more selectively associated with AMF, possibly resulting in modern high yielding varieties (HYV) having a lower AMF diversity than traditional crop varieties. Whether this is true for paddy rice varieties under field conditions is not known so far. Here, we aimed at comparing differences of AMF communities among modern HYV and traditional rice varieties. We collected root and soil samples of five Bangladeshi rice varieties (two traditional and three modern HYV) from 40 different rice fields and quantified AMF richness, diversity and community composition through high throughput amplicon sequencing of the small subunit (SSU) of the ribosomal RNA cistron. Overall, 75 AMF OTUs, distributed over six AMF families with Glomeraceae as predominant family were found. After accounting for differences in soil conditions, we found that AMF diversity significantly differed among the five varieties and was higher in the traditional than modern varieties. The composition and structure of the AMF communities were distinct between the traditional and modern varieties. An indicator species analysis detected 9 OTUs significantly associated with traditional rice varieties, whereas no indicator OTUs were found for the modern HYV. We conclude that modern breeding coupled with high fertilizer application rates provide a plausible explanation for the reduced AMF diversity and the different AMF community composition between Bangladeshi modern HYV and traditional varieties.

Physicochemical and cooking characteristics of pigmented traditional rice varieties

Traditionally, every variety of rice has had agricultural and food significance. The particularities of the varieties do not end with the paddy plants, duration, seasonality, etc. The grains also have their unique features. They have specific nutritive, cooking and eating qualities. To study the physicochemical and cooking characteristics of traditional rice popular brown rice varieties were collected from Pudukkottai, Sivagangai (Karaikudi) and Perambalur districts of Tamil Nadu. From the collected samples, five rice varieties namely Kaatuyaanam, Karuppukavuni, Karunguruvai, Mapillaisamba and Kuruvaikalanchiyam were selected for the study. Certain unique features of the rice were characterized out by the physical, thermal and cooking characteristics of brown rice varieties. Physical characteristics such as test weight, kernel length, and breadth and L/B ratio, seed grade were assessed. Thermal characteristics such as water uptake, volume expansion ratio and alkali spreading value were also assessed. The traditional rice varieties were found to exhibit good Phyico-chemical and thermal characteristics revealing their high grain quality.

Genetic Diversity of Local Rice Accessions Cultivated in Guinea Based on Agro-Morphological Traits and Identification of Sources of Tolerance to Iron Toxicity

In Guinea, traditional rice varieties are the most widely cultivated in rural areas despite their low yield and high susceptibility to iron toxicity. Moreover, the introduction of new improved varieties tolerant to iron toxicity poses a serious threat to the preservation of the genetic resources of these traditional varieties, whose genetic diversity remains poorly known. The present study therefore aims at a better valorisation of these local rice cultivars through the evaluation of their agromorphological diversity and the identification of genotypes potentially tolerant or resistant to iron toxicity. Thus, 90 accessions collected in the regions of Kindia and Macenta and six controls susceptible or resistant to iron toxicity (AZUCENA, BOUAKE 189, CK 73, IR64, NERICAL 19 and AURYLUX 6) were evaluated in three replicate alpha lattice designs in two sites (Seredou and Kilissi) using 16 agromorphological traits. The results showed significant agromorphological variability of the traditional accessions at both sites for all qualitative and most quantitative traits studied. In addition, 30 local cultivars expressed similar or higher grain yields than the resistant or tolerant controls at both sites, of which 12 were found to be stable at both sites. Of the 12 cultivars identified, five were resistant and seven tolerant to iron toxicity. These 12 accessions could be used in the varietal improvement of lowland rice in Guinea Conakry.

Water Availability, Crop Choices and Profitability of Farming: A Case Study of Mahakanumulla Tank Village

Village Tank Cascade Systems (VTCSs) were built in ancient Sri Lanka as self-reliant and climate-resilient agro-ecological systems. This study examined crop choices and profitability of farming under alternative rainfall regimes in a well-functioning tank village system in Mahakanumulla VTCS in Anuradhapura district. A Linear Programming (LP) model was developed to represent farming activities in the tank village for the 2018-19 Maha and 2019 Yala seasons using data gathered from secondary sources and a key informant survey. The baseline equilibrium was calibrated treating farmers as profit maximisers cultivating four types of land (uplands and lowlands in Maha and Yala seasons), two types of labour (hired and family), and twelve-monthly water constraints. The model was simulated under alternative rainfall regimes and technological interventions. The optimal crop mixes, farm profits, and shadow prices of resources associated with the baseline scenarios were compared with those of counterfactual scenarios. The results of the analysis indicated that the success of an intervention is determined by the rainfall regime. The analysis further showed that the introduction of a short-aged rice variety helps more in mitigating drought in a Maha season and the introduction of a traditional rice variety helps more in drought during Yala season. The positive effects of desiltation is quite large when a traditional rice variety is introduced in a Maha drought. Provision of seasonal weather forecasts, which will enable farmers to choose appropriate technological interventions, is recommended.

Colour based nutraceutical potential of some traditional rice (Oryza sativa L. ssp. indica) varieties of India

Consumption of unpolished grain, rather than polished grain has become a modern trend and consumers are mainly putting their thoughts and effort to consume products with more antioxidant capacity. Rice is the main staple food and apart from being considered as the main source of energy, it contains many nutraceutical properties because of its enriched secondary metabolites. This study is an effort to bring back the indigenous traditional rice landraces that almost disappeared from the farm fields after the advent of the Green Revolution in India. This article focuses on colour-based nutritional properties of six coloured and four non-coloured indigenous rice varieties based on antioxidant potential, total phenol and flavonoid content along with secondary metabolites profiling by high performance liquid chromatography. The biochemical uniqueness of these varieties has been explored that opens the gate for the conservation of more indigenous rice varieties for food security, as a cheap source of nutritional food and to construct a better niche for public health in developing country like India.