Rice Varieties Research Articles

Impact of saline water irrigation on growth, yield and quality of rice (Oryza sativa L.) varieties

Impact of saline water irrigation on growth, yield and quality of rice (Oryza sativa L.) varieties

Effect of critical limit of saline water irrigation in suitable rice (Oryza sativa L.) varieties

Effect of critical limit of saline water irrigation in suitable rice (Oryza sativa L.) varieties

Rapid Screening of Traditional Rice Cultivars against Drought Using Tolerance Indices of Seedlings

Aim: To screen the traditional cultivars of rice based on the tolerance indices of seedling characteristics. Study Design: The experimental plan used was Complete Randomized Design with 59 treatments (genotypes) and two replications. Place of Study: P.G. Laboratory, Department of Seed Science and Technology, Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar district, West Bengal, India. Methodology: Seedling was raised in glass in two sets- PEG-mediated drought and normal conditions. Results: All the seedling characters showed highly significant differences among the varieties, different culture conditions as well as interaction between varieties and environment. Most of the cultivars exhibited reduction in number of primary roots per plant, root length, root fresh weight, root dry weight, shoot length, shoot fresh weight and shoot dry weight. Finally the cultivars were grouped under three categories- tolerant, semi-tolerant and susceptible based on mean tolerance index (MTI). The cultivars having ≥ 90.00, MTI Kashiya binni, Jhagri kartik and Garu Chakua were considered as tolerant. Among those three cultivars, Kashiya binni was found to be highly tolerant to drought as its MTI was ≥ 100.00 (114.96). Subsequently 22 cultivars were classified as semi-tolerant. In conclusion, the tolerance indices of seedling traits and subsequently the MTI can be used for rapid screening of rice genotypes for water stress.

Unraveling the genetic diversity in selected rice cultivars released in the last 60 years using gene-based yield-related markers

Unraveling the genetic diversity in selected rice cultivars released in the last 60 years using gene-based yield-related markers

Genome-wide association study reveals the genetic basis of rice resistance to three herbicides.

Crop resistance to herbicides is crucial for agricultural productivity and sustainability amidst escalating challenges of weed resistance. Uncovering herbicide resistant genes is particularly important for rice production. In this study, we tested the resistance to three commonly used herbicides: glufosinate, glyphosate and mesotrione of 421 diverse rice cultivars and employed genome-wide association studies (GWAS) to unravel the genetic underpinnings of resistance to these three herbicides in rice. We discovered that cultivated rice exhibited rich variation in resistance to the three herbicides, and the differences among subpopulations were significant. Six identified associations harboring candidate genes for resistance to these herbicides were significant. Among them, RGlu6 and RGly8 were the major QTL for resistance to glufosinate and glyphosate, respectively. The favorable alleles of RGlu6 and RGly8 were primarily present in japonica cultivars that originated from Europe, highlighting the geographic and genetic diversity of herbicide resistance and emphasizing the localized selection pressures in European rice varieties. Moreover, our findings might suggest that traditional target genes may not contain tolerant alleles in nature, and alternative mechanisms with novel loci associated with resistance may work. By mapping the genes for herbicide resistance, our results may help develop new strategies to combat the dual challenges on effective weed management and herbicide sustainability.

Variability of soil chemical properties and rice productivity in salt-affected soil in the north coastal rice field of Central Java, Indonesia

A coastal rice field is generally characterized by salt-affected soil and low soil quality for rice cultivation. Identifying soil chemical properties in these areas is necessary to determine soil management options for rice production. Therefore, soil samples were collected from 33 sampling points in the Wedung Sub-district of Demak Regency in the late dry season of 2021 to evaluate the variation among soil chemical characteristics in a coastline rice field. Soil samples were obtained beneath the topsoil (0-20 cm soil depth) and observed for electrical conductivity, exchangeable potassium, sodium, calcium, magnesium, and cation exchange capacity. Soils in the research field were categorized as slightly salty (0.75-2 dS m-1) to lightly salty (2.0-4.0 dS m-1) with very high sodium (>2 cmol(+) kg-1). Exchangeable potassium was dominated by moderate (0.3-0.7 cmol(+) kg-1) and low categories (0.2-0.3 cmol(+) kg-1). Based on soil calcium-to-magnesium ratios, around 6% of all samples were classified as calcium-deficient. The range of soil cation exchange capacity was 22-30 cmol(+) kg-1 and classified as high soil cation exchange capacity. Rice productivity in the salt-affected soil was around 4 t ha-1. Strategies for soil and controlling plants, such as soil amelioration and salt-tolerant rice cultivars, should be pursued to support plant growth and enhance rice productivity in the salt-affected soil, particularly in the coastal area.

Selection of Standard Rice Cultivars for Evaluating Cracking Resistance and Finding a Novel QTL Responsible for It

Selection of Standard Rice Cultivars for Evaluating Cracking Resistance and Finding a Novel QTL Responsible for It

Individual and concurrent effects of heat and drought stress on the growth and yield of two Malaysian rice cultivars

Individual and concurrent effects of heat and drought stress on the growth and yield of two Malaysian rice cultivars

Tolerance of local gogo rice sprouts under salinity stress conditions

The expansion of rice planting areas in the future needs to be carried out outside Java, as fertile land in Java is shrinking due to land conversion. Most of the land outside Java consists of marginal land, such as areas with high salinity. High salinity levels in the soil cause a decrease in plant germination, growth, and production. The research aimed to examine the tolerance of each cultivar at each level of NaCl concentration, to obtain cultivars that were tolerant to salinity stress, and to determine the NaCl concentration that suppresses the germination of local upland rice. The research was structured using a completely randomized design with a two-factor factorial pattern. The first was the six upland rice cultivars, namely, dongan, jahara, Pulu Konta, pomegranate, kalendeng, and pulu tau leru, while the second factor was the NaCl concentration consisting of 0%, 0.2%, 0.4%, 0.6%, 0.8% and 1%. Thus, there were 36 experimental units, which were repeated three times so that there were 108 experimental units. The results of the research showed that there was no interaction with all germination variables; cultivar and concentration had a significant effect on maximum growth potential, germination capacity, germination time, plumule length, radicle length and dry weight of sprouts, while cultivar affected the wet weight of sprouts. Kalendeng has a high salinity tolerance. The use of NaCl concentrations of up to 0.6% has been able to reduce the germination capacity of local upland rice. The conclusion of the research showe that there was no interaction between all germination variables.

New persistent plant RNA virus carries mutations to weaken viral suppression of antiviral RNA interference.

Persistent plant viruses are widespread in natural ecosystems. However, little is known about why persistent infection with these viruses may cause little or no harm to their host. Here, we discovered a new polerovirus that persistently infected wild rice plants by deep sequencing and assembly of virus-derived small-interfering RNAs (siRNAs). The new virus was named Rice tiller inhibition virus 2 (RTIV2) based on the symptoms developed in cultivated rice varieties following Agrobacterium-mediated inoculation with an infectious RTIV2 clone. We showed that RTIV2 infection induced antiviral RNA interference (RNAi) in both the wild and cultivated rice plants as well as Nicotiana benthamiana. It is known that virulent virus infection in plants depends on effective suppression of antiviral RNAi by viral suppressors of RNAi (VSRs). Notably, the P0 protein of RTIV2 exhibited weak VSR activity and carries alanine substitutions of two amino acids broadly conserved among diverse poleroviruses. Mixed infection with umbraviruses enhanced RTIV2 accumulation and/or enabled its mechanical transmission in N. benthamiana. Moreover, replacing the alanine at either one or both positions of RTIV2 P0 enhanced the VSR activity in a co-infiltration assay, and RTIV2 mutants carrying the corresponding substitutions replicated to significantly higher levels in both rice and N. benthamiana plants. Together, our findings show that as a persistent plant virus, RTIV2 carries specific mutations in its VSR gene to weaken viral suppression of antiviral RNAi. Our work reveals a new strategy for persistent viruses to maintain long-term infection by weak suppression of the host defence response.

Influence of various organic nutrient management technologies on microbial abundance, growth, and yield of rice (Oryza sativa L.) under field conditions

A field study (three years) was carried out to evaluate the outcome of various organic nutrient management technologies including farmyard manure (FYM) and poultry manure (PM) integrated with chemical fertilizers for microbial dynamics and growth and yield of rice at Experimental Farm of Nuclear Institute of Agriculture (NIA), Tandojam, Sindh, Pakistan. The most broadly grown rice variety, NIA-Shandar was selected for this study. The experiment involved integrating organic technologies, specifically Farm Yard Manure (FYM) and Poultry Manure (PM), each applied at 10 tons per hectare. These organic technologies were combined with varying levels of inorganic fertilizers: half (60 kg N ha-1 and 45 kg P2O5 ha-1) and full (120 kg N ha-1 and 90 kg P2O5 ha-1) recommended doses. Additionally, zinc was applied at 10 kg ha-1. The study employed a randomized complete block design (RCBD) with three replications to assess treatment effects. Both organic technologies perform better for microbial dynamics and rice growth and yield enhancement either alone technology or combined with chemical fertilizers during three rice seasons. The maximum general microbial abundance (9.70 log10 CFU g soil-1), N2 fixing (7.37 log10 CFU g soil-1), P solubilizing (7.97 log10 CFU g soil-1) and Zn solubilizing(6.75 log10 CFU g soil-1) population was recorded in FYM alone or with half N and P2O5 fertilizer application. The highest plant height (106 cm), tiller numbers(17.10), panicle numbers (26.53), panicle length (26.32 cm), one thousand grainweight (26.53 g) and rice grain yield (7.92 t ha-1) were perceived in FYM with full rate N and P2O5 fertilizer application. Both technologies along with chemical fertilizer induced soil properties and soil nutrients which reflected to increase soil microbial abundance and growth and yield of rice however, FYM showed higher potential than poultry manure during the three years rice cultivation seasons. Hence, it was indicated that a significant contribution to the development of sustainable agricultural technologies that prioritize soil health,environmental stewardship, and food security.

Performance evaluation of climate resilient rice varieties in Lakhimpur district of Assam

Performance evaluation of climate resilient rice varieties in Lakhimpur district of Assam

The metal tolerance protein OsMTP11 facilitates cadmium sequestration in the vacuoles of leaf vascular cells for restricting its translocation into rice grains

Rice (Oryza sativa) provides >20% of the consumed calories in the human diet. However, rice is also a leading source of dietary cadmium (Cd) that poses a serious threat to human health. Deciphering the genetic network that underlies the grain-Cd accumulation will benefit the development of low-Cd rice to mitigate the effects of Cd accumulation in the rice grain. In this study, we identified a QTL-gene, OsCS1, that is allelic to OsMTP11 and encodes a protein sequestering Cd in the leaf during vegetative growth and preventing Cd from being translocated to the grain after heading in rice. OsCS1 is predominantly expressed in leaf vascular parenchyma cells, where it binds to a vacuole sorting receptor protein OsVSR2 and is translocated intracellularly from the trans-Golgi network (TGN) to pre-vacuolar compartments (PVCs) and then to the vacuole. In this trafficking process, OsCS1 actively transports Cd into the endomembrane system and eventually sequesters it in vacuoles. There are natural variations in the promoter of OsCS1 between the indica and japonica rice subspecies. Duplication of a G-box-like motif in the promoter region of the superior allele of OsCS1 from indica rice enhances the binding of the transcription factor OsIRO2 to the OsCS1 promoter, thereby promoting OsCS1 expression. Introgression of this allele into commercial rice varieties could significantly lower grain-Cd levels compared to the inferior allele present in japonica rice. Our findings fill a gap in the genetic control of leaf-to-grain Cd translocation and provide a novel gene and its superior allele for the genetic improvement of low-Cd variety in rice.

Partial replacement of inorganic fertilizer with organic inputs for enhanced nitrogen use efficiency, grain yield, and decreased nitrogen losses under rice-based systems of mid-latitudes

In the rice-based system of mid-latitudes, mineral nitrogen (N) fertilizer serves as the largest source of the N cycle due to an insufficient supply of N from organic sources causing higher N losses due to varying soil and environmental factors. However, aiming to improve soil organic matter (OM) and nutrients availability using the best environmentally, socially, and economically sustainable cultural and agronomic management practices are necessary. This study aimed to enhance nitrogen use efficiency (NUE) and grain yield in rice-based systems of mid-latitudes by partially replacing inorganic N fertilizer with organic inputs. A randomized complete block design (RCBD) was employed to evaluate the effects of sole mineral N fertilizer (urea) and its combinations with organic sources—farmyard manure (FYM) and poultry compost—on different elite green super rice (GSR) genotypes and were named as NUYT-1, NUYT-2, NUYT-3, NUYT-4, NUYT-5, and NUYT-6. The study was conducted during the 2022 and 2023 rice growing seasons at the Rice Research Program, Crop Sciences Institute (CSI), National Agricultural Research Centre (NARC), Islamabad, one of the mid-latitudes of Pakistan. The key objective was to determine the most effective N management strategy for optimizing plant growth, N content in soil and plants, and overall crop productivity. The results revealed that the combined application of poultry compost and mineral urea significantly enhanced soil and leaf N content (1.36 g kg− 1 and 3.06 mg cm− 2, respectively) and plant morphophysiological traits compared to sole urea application. Maximum shoot dry weight (SDW) and root dry weight (RDW) were observed in compost-applied treatment with the values of 77.62 g hill− 1 and 8.36 g hill− 1, respectively. The two-year mean data indicated that applying 150 kg N ha⁻1, with half provided by organic sources (10 tons ha⁻1 FYM or poultry compost) and the remainder by mineral urea, resulted in the highest N uptake, utilization, and plant productivity. Thus, integrated management of organic carbon sources and inorganic fertilizers may sustain the productivity of rice-based systems more eco-efficiently. Further research is recommended to explore root and shoot morphophysiological, molecular, and biochemical responses under varying N regimes, aiming to develop N-efficient rice varieties through advanced breeding programs.

Factors influencing yield gap of rice varieties in the districts of South Kerala

Factors influencing yield gap of rice varieties in the districts of South Kerala

Characteristics of Rice Varieties for Commercial Use and Livestock Feed and Their Cultivation Technology in the Cold Region of Japan

Characteristics of Rice Varieties for Commercial Use and Livestock Feed and Their Cultivation Technology in the Cold Region of Japan

A comprehensive multivariate approach for GxE interaction analysis in early maturing rice varieties.

The genotype evaluation process requires analysis of GxE interactions to ascertain the responsiveness of a genotype to various environments, including the development of early maturing rice. However, the concept of interaction is relatively specific to grain yield. In contrast, grain yield is highly polygenic, so assessment should be carried out with multivariate approaches. Therefore, multivariate assessment in evaluating GxE interactions should be developed, especially for early maturing rice genotypes. The study aimed to develop a comprehensive multivariate approach to improve the comprehensiveness and responsiveness of GxE interaction analysis. The study was conducted in Bone and Soppeng districts, South Sulawesi, Indonesia, in two seasons. The study used a randomized complete block design, where replications were nested across two seasons and locations. Two check varieties and five early maturing varieties were replicated three times in each environment. Based on this study, a new approach to GxE interaction analysis based on multiple regression index analysis, BLUP analysis, factor analysis, and path analysis was considered adequate, especially for evaluating early maturing rice. This approach combined days to harvest, biological yield, and grain yield in multiple linear regression with weighting based on the combination of all analyses. The effectiveness of the GxE interaction assessment was reflected by high coefficient of determination (R2) and gradient (b) values above 0.8 and 0.9, respectively. Inpari 13 (R2=0.9; b=1.05), Cakrabuana (R2=0.98; b=0.99), and Padjajaran (R2=0.95; b=1.07) also have good grain yield with days to harvesting consideration, namely 7.83ton ha-1, 98.12 days; 7.37ton ha-1, 95.52 days; and 7.29ton ha-1, 97.23 days, respectively. Therefore, this index approach can be recommended in GxE interaction analysis to evaluate early maturing rice genotypes. Furthermore, Inpari 13, Cakrabuana, and Padjajaran are recommended as adaptive early maturing varieties.

A Sustainable Methodological Approach for mitigation of Salt Stress of Rice Seedlings in Coastal Regions: Identification of Halotolerant Rhizobacteria from Noakhali, Bangladesh and their impact

Salinity hinders the growth of many crops common in the diet, such as rice, wheat and maize when cultivated in coastal salinity areas. Given the limited availability of cultivable land and the increasing growth of the population, it is necessary to enhance productivity. In this paper, we present an innovative approach to adopting Halotolerant Plant Growth Promoting Rhizobacteria (HPGPR) to enhance salt-tolerant rice varieties to solve salinity stress and enhance crop production. HPGPR has functions to overcome plant growth and development and is the most efficient bioinoculant for rice in saline environments. This approach can be considered a potential method because of the cost-effective and environmentally friendly impacts in agricultural production, which involves salt-affected areas.

Development and Validation of an SNP Marker for Identifying Xanthomonas oryzae pv. oryzae Thai Isolates That Break xa5-Mediated Bacterial Blight Resistance in Rice.

Xanthomonas oryzae pv. oryzae (Xoo) is a pathogenic bacterium responsible for bacterial blight (BB) disease in rice, primarily mediated by the interaction between the plant and pathogen. The virulence mechanism involves the activation of the Sugars Will Eventually be Exported Transporter (SWEET) gene family in rice by transcription activator-like effectors derived from Xoo. The BB resistance gene xa5 has been identified as one of the most effective genes against Thai Xoo isolates, but xa5-mediated resistance-breaking Xoo strains have emerged. This study aimed to develop a single nucleotide polymorphism (SNP) marker for precise identification of xa5-mediated resistance-breaking Xoo. Comparative genomics of Thai Xoo isolates Xoo16PK001 and Xoo16PK002, which were incompatible and compatible with rice variety IRBB5 carrying xa5, respectively, identified eight SNP positions for the development of an SNP marker. The SNP marker XooE6 yields a specific 1,143 bp PCR product unique to Xoo16PK002. Screening 61 Thai isolates using XooE6 identified two positives: Xoo20PL010 and Xoo20UT002. Inoculation tests on rice varieties IRBB5 and IRBB13 demonstrated compatibility with IRBB5 and incompatibility with IRBB13, which bears Xa5 and xa13. Xoo16PK001 (XooE6-negative) showed different virulence. Inoculation on IRBB21 harboring Xa5, Xa13, and Xa21 resulted in partial resistance to both XooE6-positive and -negative strains. XooE6-positive strains up-regulated SWEET11 and suppressed SWEET14 in IRBB5, while Xoo16PK001 slightly induced SWEET11 but activated SWEET14 in IRBB13. This highlights the potential of XooE6 to identify xa5-mediated resistance-breaking Xoo strains and elucidate their pathogenic mechanisms through the upregulation of SWEET11.

Effect Of Animal And Plant Organic Fertilizers On Growth And Yield Of Rice In Tana Delta, Kenya

Rice is the 3rd most consumed cereal in Kenya while production is merely 20% of the demand making the country a net importer of the commodity. With increased global concern on healthy foods, producing more rice to contribute to achieving food secure nation while conforming to environmental sustainability remains a subject of concern in the country. In this case, good agricultural practices are needed to strike the balance. This study was carried out during rice growing season (February – June, 2024) to investigate the effect of basal organic fertilizers; Rich Farm (RF), Han Daebak (BK) and Han Yoobak (MK) on growth and yield of AT054 and Komboka rice varieties in Tana Delta Irrigation Project-Rice (TDIP-R) Scheme during the trial Phase undertaken by Agri All Africa (AAA) in preparation for a Public Private Partnership (PPP) project programme. The study was conducted in a Randomized Complete Block Design (RCBD). Rich Farm (RF) at 200 Kg/Ha, Han Daebak (BK) at 200 Kg/Ha and Han Yoobak (MK) at 200 Kg/Ha were applied as basal fertilizers. Conventional fertilizers (200 Kg/Ha DAP + 120 Kg/Ha MOP) was applied as the positive standard check (CF). Data collected was subjected to analysis of variance (ANOVA). The basal application of Rich Farm, Han Daebak and Han Yoobak organic fertilizers had significant positive effects on grain yield. Among the tested basal fertilizers, Rich Farm performed better at 4.9 and 5.3 ton/ha, followed by Han Yoobak at 4.7 and 4.1 ton/ha and Han Daebak at 4.3 and 3.9 ton/ha in AT054 and Komboka variety, respectively. Therefore, Rich Farm and Han Yoobak can be recommended as basal organic fertilizers in both AT054 and Komboka varieties, while Han Daebak can be used in AT054 variety for rice production. Further studies are of need to investigate the effects on these organic fertilizers on the soil properties of the area, as well as evaluating the optimal rates for higher rice production