National Rice Research Institute Research Articles

Multi-environment evaluation of rice genotypes: impact of weather and culm biochemical parameters against sheath blight infection.

Sheath blight caused by Rhizoctonia solani is one of the major diseases of rice, causing widespread crop losses. The use of semi-dwarf rice varieties in the ongoing nutrient-intensive rice cultivation system has further accentuated the incidence of the disease. An ideal solution to this problem would be identifying a stable sheath blight-tolerant genotype. A multi-environment evaluation of 32 rice genotypes against sheath blight infection was conducted over six seasons across two locations (Agricultural Research Farm, Institute of Agricultural Sciences, Banaras Hindu University (28.18° N, 38.03° E, and 75.5 masl), for four years during the wet seasons (kharif) from 2015 to 2018 and two seasons at the National Rice Research Institute (20°27'09" N, 85°55'57" E, 26 masl), Cuttack, Odisha, during the dry season (rabi) of 2019 and the kharif of 2019, including susceptible and resistant check. Percent disease index data were collected over 4 weeks (on the 7th, 14th, 21st, and 28th day after infection), along with data on other morphological and physiological traits. The resistant genotypes across seasons were the ones with a higher hemicellulose content (13.93-14.64) and lower nitrogen content (1.10- 1.31) compared with the susceptible check Tapaswini (G32) (hemicellulose 12.96, nitrogen 1.38), which might explain the resistant reaction. Three different stability models-additive main effect and multiplicative interaction (AMMI), genotype + genotype x environment (GGE) biplot, and multi-trait stability index (MTSI)-were then used to identify the stable resistant genotypes across six seasons. The results obtained with all three models had common genotypes highlighted as stable and having a low area under the disease progress curve (AUDPC) values. The ideal stable genotypes with low disease incidence were IC 283139 (G19), Tetep (G28), IC 260917 (G4), and IC 277274 (G10), with AUDPC values of 658.91, 607.46, 479.69, and 547.94, respectively. Weather parameters such as temperature, rainfall, sunshine hours, and relative humidity were also noted daily. Relative humidity was positively correlated with the percent disease index.

Rapid production of novel beneficial alleles for improving rice appearance quality by targeting a regulatory element of SLG7.

Rapid production of novel beneficial alleles for improving rice appearance quality by targeting a regulatory element of SLG7.

Effect of Low Light Stress on Plant Height, Tiller Number, Panicle Number, Leaf Area and Yield of Long Duration Rice (Oryza sativa. L) Varieties

The purpose of this study was to determine the impact of low light stress on the morphological parameters and yield of long duration rice genotypes. The experiment was carried out in the field of National Rice Research Institute, and the field layout was done as per the split plot design, with the light in the main plot and the varieties in the sub-plot. During Kharif 2019, the experiment was carried out at plot-4, V-block under the Department of Crop Physiology and Biochemistry at the National Rice Research Institute (NRRI), Cuttack. The experiment was carried out with three different light intensities, namely 100% light as treatment-I (Control), 75% light as treatment-II, and 50% light as treatment-III. Eleven long duration rice varieties were chosen based on yield to investigate the effect of low light on their morphology and yield. It was observed that at 50% flowering stage in 75% and 50% light intensities, plant height and leaf area increases but tiller number, panicle number and yield reduces. At 50% light intensity, yield reduction was significantly greater than 75% light intensity. Among the varieties Nasati Sali, Nalini Sali and Swarnaprabha was recorded highest grain yield in 100% (5.10 t ha-1), 75% (4.27 t ha-1) and 50% light intensity (3.05 t ha-1) respectively.

Conversion of Mangroves Into Rice Cultivation Alters Functional Soil Microbial Community in Sub-Humid Tropical Paddy Soil

Conversion of mangrove vegetation into rice cultivation is considerably enhanced nowadays which adversely affects ecological sustainability. Soil microbial community is one of the key indicators to monitor soil health in mangroves. Studies on the variations in the microbial community within mangroves are plenty, whereas reports in mangrove-converted paddy soils are scarce. Therefore, Biolog® eco-plate-based technique was used in this study to assess soil microbial community in the Bhitarkanika (MB) and Sundarban (MS) sub-humid tropical mangroves-converted paddy soil. The results showed that significantly lower soil microbial biomass carbon and enzyme activities were recorded in MB and MS compared to the NRRI (National Rice Research Institute) paddy soil where continuous rice cultivation is being practiced conventionally since 1946 under the sub-humid tropical region. Biolog®-based average well color development (AWCD) was found significantly lower in MS and MB compared to NRRI. Shannon–Weaver and McIntosh indices followed the similar trends of AWCD. A biplot analysis indicated the positive correlation of pH, available phosphorus, actinomycetes population, and phenolic compound utilization under MS, whereas EC and phosphate-solubilizing bacteria were positively correlated under MB. Compared to MS and MB, NRRI paddy soil harbored more carbohydrate-utilizing microbes and showed a positive correlation with fluorescin-diacetate, dehydrogenase, and acid phosphatase. Overall, the present study suggested that the conversion of the Sundarban and Bhitarkanika mangroves into rice cultivation adversely affected the microbial diversity, thereby altering natural sustainability.

Effect of elevated carbon dioxide on biology and morphometric parameters of yellow stem borer, Scirpophaga incertulas infesting rice (Oryza sativa)

An experiment was conducted at Research Farm, National Rice Research Institute, Cuttack, Odisha, India to quantify the effect of elevated carbon dioxide (CO2) concentrations on the biology and morphometric parameters of yellow stem borer (Scirpophaga incertulas, Pyralidae, Lepidoptera). Yellow stem borer is one of the major pest of rice in the whole rice growing regions of South East Asia. The effect of three carbon dioxide concentrations i.e. 410 ppm (ambient), 550 ppm and 700 ppm on the duration of the developmental period as well as morphometric parameters of each stage of the lifecycle of the pest was analysed. It was found that, there was an increase in the duration of the developmental period of each stage of life cycle as the concentration of CO2 increases. However, the life span of the adult moth was significantly lower under the elevated CO2 concentrations when compared with ambient CO2 concentration. Morphometric parameters viz., mean length, width and weight of each larval instar, pupa and adult were found to be significantly higher in elevated concentrations of CO2 as compared to ambient concentration.

Major Fungal Diseases of Rice: A Case Study

Disease screening and evaluation is a major parameter for measurement of host resistance of various rice germplasm and this study will facilitate for genetic mapping of resistance genes for researchers. The survey work was carried out on rice fields in National Rice Research Institute, Cuttack, to evaluate the distribution of different fungal diseases on various rice cultivars. Disease occurrence percentage was calculated as the proportion of cultivars showing the symptoms of a particular disease, out of total number of cultivars assessed. Fourteen different cultivars were namely CG (2090/226), Dhalaswarna, Tapaswini, TRB 1949, TRB 1156, TN1, BA115, BA90, BA13, Ajay 2006, Pradhandhan, M313 and aerobic variety assessed based on disease prevalence. Six different diseases were observed during the study period viz., sheath rot, sheath blight, false smut, blast, brown spot and bakane. Identification of these diseases was based on the specific morphological symptoms on leaves and other infected parts of these rice cultivars. Methods of isolation of casual organism and their colony character were also observed during survey in department of plant pathology. It was found that in the month of October four fungal diseases are most prevalent. These are blast, sheath blight, sheath rot and Bakanae. At the end of November false smut and brown smut symptoms were found. Among these diseases, leaf blast was found as the most prevalent disease at vegetative growth stage as it affected highest number of cultivars. Among these, blast is found to be more prevalent disease with 35.71% of occurrence which is caused by fungus Magnoporthe oryzae followed by sheath blight and sheath rot. Brown spot and bakane disease was found each with least percentage of occurrences.

Herbicide mixture mediated soil environment analysis in wet direct-sown rice

Direct-sown rice is the possible alternative to the conventional puddled transplanted rice as it saves resources viz. water, labour and time. Pre-germinated (sprouted) seeds are sown on puddled soil in wet direct-sown rice. But weed infestation is the major yield compromising factor under this environment as the weeds emerge simultaneously with the rice and compete from the beginning. Among the weed control methods, herbicide-based weed control is the most effective and efficient method. However single herbicide application in a long run leads to weed flora shift and development of herbicide resistance in weeds. In contrast, herbicide mixtures with different mode of action are the possible alternative to reduce the herbicide resistance and to broaden the weed control spectrum season long. But soil environment aspect is important for sustainable rice farming using herbicide mixtures. This investigation was done in Research farm of ICAR – National Rice Research Institute, Cuttack, Odisha in wet season of 2016. The experiment was laid out in randomized complete block design with nine treatments viz. herbicide mixture florpyrauxifen-benzyl + cyhalofop-butyl in four doses i.e. 120, 150, 180 and 360 g/ha; florpyrauxifen-benzyl in two doses i.e. 25 and 30 g/ha; bispyribac-sodium at 30 g/ha; weed free and weedy check; replicated thrice. Soil environment parameters viz. microbial-biomass carbon, FDA hydrolase activity, dehydrogenase activity and urease activity were studied before, 4, 10, 20 and 30 days after herbicide treatments. The herbicide mixture florpyrauxifen-benzyl + cyhalofop-butyl at 150 g/ha (4.91 t/ha) was found to be the most effective herbicide showing no detrimental effect on soil environment of wet direct-sown rice after 10 days of application and yielding at par with the weed free (5.27 t/ha).

Performance of Drought Tolerant Rice Varieties in Malkangiri District of South Eastern Ghat Zone of Odisha

Drought is the major problem in India and occurrence at the time of critical growth stages, reduce crop yield significantly. The National Rice Research Institute, Cuttak, Odisha has developed so many drought tolerance rice varieties to reduce the economic loss due to drought. Krishi Vigyan Kendra, Malkangiri introduced NRRI released two rice varieties i.e. Sahbhagi Dhan and Satyabhama at framers' field to evaluate the performance of these drought tolerant varieties in South Eastern Ghat Zone of Odisha. The highest plant height was observed with the rice variety Satyabhama (104.1 cm). But, overall performance of Sahbhagi Dhan was better as compare to Satyabhama and local check verity (Khandagiri). Sahbhagi Dhan gave highest yield of 36.5 q/ha, which was statistically differed from others. Correlations study for Sahbhagi Dhan was assessed and observed the positive correlation for grain yield with all studied characters except plant height. For economic point of view, Sahbhagi Dhan recorded highest net return of Rs.19, 925/- per ha along with B:C ratio of 1.6 as compared to the rest two varieties.

Submergence tolerance in relation to some metabolic changes and anti-oxidant enzyme activities of submerged rice (Oryza sativa L.)

The experiment was conducted to find out the effect of plant spacing (15×10 and 20×15 cm) with two varieties i.e. IR64 (submergence susceptible) and IR64-Sub1 (submergence tolerant) under conventional and submerged condition at the National Rice Research Institute (NRRI),Cuttack Odisha during the Rabi season of 2018. Different planting densities were maintained using different spacing's. These include (S1) 15 cm × 10 cm, (S2) 15 cm × 20 cm. The experiment was laid out in a randomized complete block design with 3 replications. Spacing of 15 cm × 10 cm has maximum survival rate in submerged condition on IR64-Sub1 rice cultivar, this result suggests that higher planting density (15cm×10cm) rather than increased number of seedling hill-1 is necessary for getting higher yield of IR-64Sub1 rice cultivar in continuous submerged condition. (Where V1=IR 64, V2=IR-64 Sub1, S1=15cm×10cm, S2=20cm×15cm).

Addition of Pulses, Cooking Oils, and Vegetables Enhances Resistant Starch and Lowers the Glycemic Index of Rice (Oryza sativa L.)

AbstractRice exhibits relatively high glycemic index (GI) value compared to other carbohydrate rich foods. Eating rice as a staple food and leading sedentary life style may lead to obesity and type‐II diabetes. National Rice Research Institute (ICAR‐NRRI), Cuttack, India released varieties were analyzed for low GI and high resistant starch (RS) content. Large variations were observed in the GI (57.5–76.4) and RS content (0.28–2.94%) among the varieties. The rice Shaktiman had the lowest GI (57.50) with relatively high RS content (2.11%) while Gayatri had the highest RS (2.94%) with relatively low GI (60.31) value. Addition of pigeon pea to rice resulted in lowering of GI and increased RS content compared to other pulses. Addition of ghee (clarified butter) to rice during cooking resulted in lowering of GI and increase in RS content. The effect was not so pronounced with vegetable oils. Addition of vegetables like fenugreek and cauliflower to rice caused much more lowering of GI as compared to other vegetables. The findings emphasize the importance of identifying and developing rice with low GI and high RS content. This also highlights the importance of formulating food combinations of rice with other edible commodities that suit diabetics.

Improvement in anaerobic germination potential and grain yield of rice (oryza sativa) through seed priming

A field experiment was conducted during the dry season of 2014 and 2015 at National Rice Research Institute (NRRI), Orissa, India, (20.5ºN, 86°E, and 23.5 meters above mean sea level). Seed priming was employed to enhance the anaerobic germination potential in two near isogenic rice lines (IR64 and IR64-Sub1). Under natural field condition, oxygen concentration in floodwater never dropped to zero. It varied from 3.0 to 5.2 mg L-1. Seed priming with calcium peroxide and seed soaking with water followed by sun drying showed greater beneficial effects as compared to potassium nitrate. Seed priming with sodium peroxide found deleterious. Cultivar IR64-Sub1 responded well due to seed priming as compared to cultivar IR64 under submergence. To improve anaerobic germination potential in rice, seed soaking with water followed by sun drying found economicalas compared to other methods of seed priming as this technique was not linked with additional investment in chemicals and was more environments friendly.
 SAARC J. Agri., 17(1): 37-48 (2019

Candidate screening of blast resistance donors for rice breeding

Rice blast is one of the most serious diseases in the world. The use of resistant cultivars is the most preferred means to control this disease. Resistance often breaks down due to emergence of new races; hence identification of novel resistance donors is indispensable. In this study, a panel of 80 released varieties from National Rice Research Institute, Cuttack was genotyped with 36 molecular markers that were linked to 36 different blast resistance genes, to investigate the varietal genetic diversity and molecular marker-trait association with blast resistance. The polymorphism information content of 36 loci varied from 0.11 to 0.37 with an average of 0.34. The cluster analysis and population structure categorized the 80 National Rice Research Institute released varieties (NRVs) into three major genetic groups. The principal co-ordinate analysis displays the distribution of resistant and moderately resistant NRVs into different groups. Analysis of molecular variance result demonstrated maximum (97%) diversity within populations and minimum (3%) diversity between populations. Among tested markers, two markers (RM7364 and pi21_79-3) corresponding to the blast resistance genes (Pi56(t) and pi21) were significantly associated and explained a phenotypic variance of 4.9 to 5.1% with the blast resistance. These associated genes could be introgressed through marker-assisted to develop durable blast resistant rice varieties. The selected resistant NRVs could be good donors for the blast resistance in rice crop improvement research.

Technological interventions to enhance rice productivity and profitability in rainfed lowlands of Asom

Improved technological interventions are important to sustain production and productivity of rice. A study was conducted by Regional Rainfed Lowland Rice Research Station, ICAR–National Rice Research Institute, Gerua, Kamrup in four districts of lower brahmaputra valley and north bank plains agro-climatic zones of Asom during boro seasons from 2012–13 to 2016–17 to enhance productivity of boro rice through introduction of latest rice varieties and application of improved production technology. Performance of open-pollinated varieties, viz. Naveen, Chandrama and CR Dhan 909, and hybrids, viz. Ajay and Rajalaxmi under application of improved production technology were demonstrated. At all the locations, application of improved technologies showed superior results in terms of growth, yield attributes, productivity and profitability over local checks under farmers’ practice. Rice varieties with application of improved production technologies, increased mean grain yield by an average of 38.8% and extra earning of `18137/ha over existing farmer’s practice with only `3632/ha extra expenditure on inputs. The mean gap indices,viz.extension gap (1.56 t/ha), technology gap (0.96 t/ha), technology index (14.5%) and mean B:C (4.99) clearly indicated the superiority of technological demonstrations over farmers’ practices. The study also lays emphasis on the framing intensive technology transfer programmes like technological demonstrations on field to motivate the farmers for higher adoption rate of improved rice production technology.

Effect of Plant Spacing on Growth and Yield of Rice (Oryza sativa L.) under Submerged Condition

The experiment was conducted to find out the effect of plant spacing on the performance of rice variety IR-64 and IR64-Sub1 under conventional and Submerged condition at the National Rice Research Institute (NRRI), Cuttack, Odisha during the Rabi season of 2018. Different planting densities were maintained using different spacing's. These include (S1) 15 cm × 10 cm, (S2) 15 cm × 20 cm. The experiment was laid out in a randomized complete block design with 3 replications spacing of 15 cm × 10 cm with produced the highest grain yield of 350 gm-2 in submerged condition on IR64-Sub1 rice cultivar, which was significantly higher than the yield with recommended density (15 cm × 10 cm with IR64 Sub1). This yield was increased due to higher number of panicles m-2. This result suggests that higher planting density (15 cm×10 cm) rather than increased number of seedling hill-1 is necessary for getting higher yield of IR-64Sub1 rice cultivar in continuous submerged condition (where V1=IR 64, V2=IR-64 Sub1, S1=15 cm×10 cm, S2=20 cm×15 cm).

Determination of amylose content and expression analysis of the Granular-Bound Starch Synthase I (GBSS1) gene in rice grains

The study determined amylose content and expression level of GBSS I gene in rice grain. A total of eighteen (18) rice ( Oryza sativa L) cultivars of Indica varieties were collected from the National Rice Research Institute (NRRI) Cuttack and screened for their percentage amylose contents. Three cultivars namely Bindli, Naveen and Pooja which had contrasting characters in percentage amylose were then planted and used for the expression analysis. In the first stage of grain filling Bindli had 0.27 fold expression while Pooja and Naveen had 1.72 and 1.44 respectively. There was dramatic increase in the expression levels of the gene in the middle stage of grain filling in all the three cultivars with relative folds of 10.97, 42.71 and 27.34 recorded in Bindli, Pooja and Naveen respectively. However, at the last stage of grain filling, GBSS1 expression was low compared to the second stage with expression folds of 7.12, 7.55 and 1.67 in Bindli, Pooja and Naveen cultivars respectively. On the whole, Bindli cultivar showed lowest expression of the gene (GBSS1) when compared to Pooja and Naveen. Key words: rice gene, amylose, expression analysis, GBSS1

Simultaneous mapping of multiple QTLs & complex traits in rice: Association mapping-indispensable for effective molecular breeding

Association mapping or linkage disequilibrium mapping is extensively used in dissecting the genetic nature of many human diseases and now extended to plant system for mapping the complex loci. Association Mapping is a method used to detect QTLs controlling traits based on correlating genotype with phenotype. The main advantage of association mapping is the use of natural variability, relatively less expensive and less time requiring for mapping. The lead lecture includes linkage disequilibrium (LD), its assessment, mapping and generalized scheme for association mapping involving basic steps in mapping a complex trait. The talk also includes the association mapping study on cold stress tolerance, high temperature stress tolerance, early seedling vigour, grain protein content and grain Fe and Zn content in rice performed at National Rice Research Institute, Cuttack, Odisha, India.

Does ecology has an impact on seed dormancy???

About 91 varieties of different ecology released from National Rice Research Institute (NRRI), Cuttack were screened for duration of seed dormancy harvested after 25, 30 and 35 days of heading. The varieties harvested after 25 days of heading showed 0–37 days of dormancy with Lunishree was observed as strongly dormant with 37days of dormancy duration. Moderate dormancy (≥20days) was observed in Jayanti, Kamesh, Jayantidhan, Nua chinikamini, Nua kalajeera, and Lunisree harvested at 30days after heading. The varieties that were collected after 35 days of heading showed 0–20 days of dormancy and were mostly non dormant and weakly dormant at this stage of sampling. Varieties Jayanti, Nua chinikamini, and Lunisree identified with moderate seed dormancy (.15 days) may be useful for breeding programme. Highest duration of dormancy was observed in the varieties developed for coastal salinity followed by deep water ecology. Variation in duration of dormancy of the variety Luna Sampad grown in two different ecologies strengthen the influence of ecology on seed dormancy.

Net house evaluation of resistance in rice genotypes against white backed plant hopper, Sogatella furcifera (Horvath)

Fifty one rice varieties including checks, were evaluated as per Standard Evaluation System for their resistance against white backed plant hopper Sogatella furcifera (Horvath) under net house condition at National Rice Research Institute, Cuttack during 2011 and 2012. Result of the experiment revealed that five varieties i.e. PS3, Satabdi, Radhi, Kalinga 1 and Hazaridhan were found resistant (Score 1) against WBPH during both the year under study and can be used as donor for varietal development programme. Thirteen varieties i.e. Annada, Satyakrishna, Virendra, Sadabahar, Heera, Varsadhan, Jogen, Neela, Khanish, Tara, ASD-16, CSR-4 and PR113 were moderately resistant (Score 3) and thirty one varieties were under susceptible to highly susceptible category (score ≥ 5).

Screening of red rice accessions for resistance to brown planthopper Nilaparvata lugens Stal.

Red rice is the reservoir of large amount of phytochemicals such as carotenoids, phenolics, alkaloids, nitrogen and organosulfur containing compounds, possesses antioxidant properties, richer source of protein, zinc and have nutritive and medicinal value. Present study examines the utility of red rice accessions for their resistance against Brown planthopper (BPH), a damaging insect pest of rice. A total of 215 red rice accessions along with susceptible check TN1, resistance checks PTB-33 and Salkathi were evaluated under greenhouse condition of the National Rice Research Institute (NRRI), Cuttack. Accessions were screened using standard seed box technique for mass screening followed by replicated screening for the confirmation of resistant reaction. Only four accessions, namely, matameher, manipuri black sonahanan and hormonona were found to be highly resistant (score-1) while eleven showed resistant reaction (Score-3) and 13 were moderately resitant (Score-5) to BPH. Mechanism of resistance was studied in the resistant accessions through the method of antixenosis or nymphal preference to plants. Matameher and manipuri black showed least nymphal preference as compared to the susceptible check TN1. Resistant genotypes identified and confirmed in the present study can be grown as resistant varieties in BPH endemic areas and also can be utilised in resistance breeding programme to develop BPH-resistant varieties with other desired traits.

Identification and fine mapping of a new gene, BPH31 conferring resistance to brown planthopper biotype 4 of India to improve rice, Oryza sativa L

BackgroundRice (Oryza sativa L.) is the staple food for more than 3.5 billion people, mainly in Asia. Brown planthopper (BPH) is one of the most destructive insect pests of rice that limits rice production. Host-plant resistance is one of the most efficient ways to overcome BPH damage to the rice crop.ResultsBPH bioassay studies from 2009 to 2015 conducted in India and at the International Rice Research Institute (IRRI), Philippines, revealed that the cultivar CR2711–76 developed at the National Rice Research Institute (NRRI), Cuttack, India, showed stable and broad-spectrum resistance to several BPH populations of the Philippines and BPH biotype 4 of India. Genetic analysis and fine mapping confirmed the presence of a single dominant gene, BPH31, in CR2711–76 conferring BPH resistance. The BPH31 gene was located on the long arm of chromosome 3 within an interval of 475 kb between the markers PA26 and RM2334. Bioassay analysis of the BPH31 gene in CR2711–76 was carried out against BPH populations of the Philippines. The results from bioassay revealed that CR2711–76 possesses three different mechanisms of resistance: antibiosis, antixenosis, and tolerance. The effectiveness of flanking markers was tested in a segregating population and the InDel type markers PA26 and RM2334 showed high co-segregation with the resistance phenotype. Foreground and background analysis by tightly linked markers as well as using the Infinium 6 K SNP chip respectively were applied for transferring the BPH31 gene into an indica variety, Jaya. The improved BPH31-derived Jaya lines showed strong resistance to BPH biotypes of India and the Philippines.ConclusionThe new BPH31 gene can be used in BPH resistance breeding programs on the Indian subcontinent. The tightly linked DNA markers identified in the study have proved their effectiveness and can be utilized in BPH resistance breeding in rice.