Rice Genotypes Research Articles

Endosperm structure and Glycemic Index of Japonica Italian rice varieties.

Given that rice serves as a crucial staple food for a significant portion of the global population and with the increasing number of individuals being diagnosed with diabetes, a primary objective in genetic improvement is to identify and cultivate low Glycemic Index (GI) varieties. This must be done while ensuring the preservation of grain quality. 25 Italian rice genotypes were characterized calculating their GI "in vivo" and, together with other 29 Italian and non-Italian genotypes they were studied to evaluate the grain inner structure through Field Emission Scanning Electron Microscopy (FESEM) technique. Using an ad-hoc developed algorithm, morphological features were extracted from the FESEM images, to be then inspected by means of multivariate data analysis methods. Large variability was observed in GI values (49 to 92 with respect to glucose), as well as in endosperm morphological features. According to the percentage of porosity is possible to distinguish approximately among rice varieties having a crystalline grain (< 1.7%), those intended for the preparation of risotto (> 5%), and a third group having intermediate characteristics. Waxy rice varieties were not united by a certain porosity level, but they shared a low starch granules eccentricity. With reference to morphological features, rice varieties with low GI (<55) seem to be characterized by large starch granules and low porosity values. Our data testify the wide variability of Italian rice cultivation giving interesting information for future breeding programs, finding that the structure of the endosperm can be regarded as a specific characteristic of each variety.

&lt;em&gt;In Vitro&lt;/em&gt; Effect of PEG and Proline on Callus Growth and Minerals Values in Basmati Rice (&lt;em&gt;Oryza sativa&lt;/em&gt;)

Purpose: Drought is a universal issue that disturbs photosynthetic system, adversely affecting quality and crop yield. The study was conducted to determine response of polyethylene glycol (PEG) as stressing agent alone or combination with proline on four fine rice genotypes for callus components as well as biochemical parameters like Chromium (Cr), Magnesium (Mg), Manganese (Mn), Iron (Fe), Phosphorus (P).Research Method: Callus was induced on media having 4.43g/L MS + 4mg/L 2, 4-D (2, 4-dichlorophenoxy acetic acid) + 30g/L sucrose + 1.76g/L phytagel with different levels of PEG “1.25g/L and 2.5g/L” with and without 1ml/L proline.Findings: Callus was used for different analyses after 30 days and results showed that PEG treatments have a negative effect on callus fresh weight, callus dry weight, days to callus induction, callus percentage, and mineral nutrients like K, Cr, Mg, Mn, Fe, P. PEG 2.5g/L showed a greater decrease as compared to PEG 1.25g/L. Proline significantly raises callus growth alone or in combination with PEG but less than control whereas callus dry weight, K, and Ca contents increased more than control when proline applied alone or with PEG combination.Originality/value: Exogenous proline application improves callus growth rate as well as macro- micro elements by mitigating the effect of PEG.

Fractionation of rice seed storage proteins in two rice genotypes

Fractionation of rice seed storage proteins in two rice genotypes

Identification of biochemical indices for brown spot (Bipolaris oryzae) disease resistance in rice mutants and hybrids.

Brown spot caused by Bipolaris oryzae is a major damaging fungal disease of rice which can decrease the yield and value of produce due to grain discoloration. The objectives of the current study were to investigate and understand the biochemical indices of brown spot disease resistance in rice. A total of 108 genotypes (mutant and hybrid) along with Super Basmati and parent RICF-160 were evaluated against brown spot disease. The genotypes exhibiting resistant and susceptible responses to brown spot disease according to the IRRI standard disease rating scale were screened and selected. To study the biochemical response mechanism, forty five selected genotypes along with Super Basmati and RICF-160 were analyzed using the biochemical markers. The physiological and biochemical analysis provided valuable insights and confirmed the resistance of rice hybrids and mutants against brown spot disease. Positive correlations were observed among stress bio-markers and disease response. Rice genotypes i.e. Mu-AS-8, Mu-AS-19, Mu-AS-20 and Mu-AS-35 exhibited moderate resistant response while Hy-AS-92, Hy-AS-98, Hy-AS-99, Hy-AS-101, Hy-AS-102 and Hy-AS-107 showed resistant response to brown spot disease. Brown spot resistant rice genotypes had lesser values of malondialdehyde and total oxidant status and higher antioxidant activities i.e. superoxide dismutase, peroxidase, total phenolic content and lycopene. The selected resistant rice genotypes had resistance capacity against Bipolaris oryzae stress. In conclusion, identified resistant mutants i.e. Mu-AS-8, Mu-AS-19, Mu-AS-20 and Mu-AS-35 and hybrids i.e. Hy-AS-92, Hy-AS-98, Hy-AS-99, Hy-AS-101, Hy-AS-102 and Hy-AS-107 could be used in rice breeding program to achieve sustainable rice production by coping the emerging challenge of brown spot disease under variable climate conditions.

Genetic and Phenotypic Screening of Different Rice Genotypes According to the Functional Marker Related to the Semi-Dwarfing Sd1 Gene

Genetic and Phenotypic Screening of Different Rice Genotypes According to the Functional Marker Related to the Semi-Dwarfing Sd1 Gene

Marker-assisted breeding accelerates the development of multiple-stress-tolerant rice genotypes adapted to wider environments.

Rice, one of the major staple food crops is frequently affected by various biotic/abiotic stresses including drought, salinity, submergence, heat, Bacterial leaf blight, Brown plant hopper, Gall midge, Stem borer, Leaf folder etc. Sustained increase of yield growth is highly necessary to meet the projected demand in rice production during the year 2050. Hence, development of high yielding and multiple stress tolerant rice varieties adapted to wider environments will serve the need. A systematic MAB approach was followed to pyramid eight major QTLs/genes controlling tolerance to major abiotic/biotic stresses viz., drought (qDTY1.1 and qDTY2.1), salinity (Saltol), submergence (Sub1), bacterial leaf blight (xa13 and Xa21), blast (Pi9) and gall midge (Gm4) in the genetic background of an elite rice culture CBMAS 14065 possessing high yield and desirable grain quality traits. Two advanced backcross derivatives of CBMAS 14065 possessing different combinations of target QTLs namely #27-1-39 (qDTY1.1+qDTY2.1+Sub1+xa13+Xa21+Gm4+Pi9) and #29-2-2 (qDTY1.1+qDTY2.1+Saltol+Xa21+Gm4+Pi9) were inter-mated. Inter-mated F1 progenies harboring all the eight target QTLs/genes were identified through foreground selection. Genotyping of the inter-mated F4 population identified 14 progenies possessing all eight target QTLs/genes under homozygous conditions. All the fourteen progenies were forwarded up to F8 generation and evaluated for their yield and tolerance to dehydration, salinity, submergence, blast and bacterial leaf blight. All the 14 progenies exhibited enhanced tolerance to dehydration and salinity stresses by registering lesser reduction in their chlorophyll content, relative water content, root length, root biomass etc., against their recurrent parent Improved White Ponni/CBMAS 14065. All the 14 progenies harboring Sub1 loci from FR13A exhibited enhanced survival (90 - 95%) under 2 weeks of submergence /flooding when compared to their recurrent parent CBMAS 14065 which showed 100% susceptibility The inter-mated population showed a enhanced level of resistance to bacterial leaf blight (Score = 0 to 2) against blast (Score - 0) whereas the susceptible check CO 39 and the recurrent parent CBMAS 14065 recorded high level of susceptibility (Score = 7 to 9). Our study demonstrated the accelerated development of multiple stress tolerant rice genotypes through marker assisted pyramiding of target QTLs/genes using tightly linked markers. These multiple stress tolerant rice lines will serve as excellent genetic stocks for field testing/variety release and also as parental lines in future breeding programs for developing climate resilient super rice varieties.

Analysis of genotypic and phenotypic correlations and path coefficients in 40 genotypes of rain-fed upland rice (Oryza sativa L.) in Oyo and Ogun States regions of Nigeria

Analysis of genotypic and phenotypic correlations and path coefficients in 40 genotypes of rain-fed upland rice (Oryza sativa L.) in Oyo and Ogun States regions of Nigeria

Assessing weed competitive abilities of rice genotypes in direct-seeded rice using purple rice as model weed

Assessing weed competitive abilities of rice genotypes in direct-seeded rice using purple rice as model weed

Deciphering the interactions between genetic elements and environmental factors in rice (Oryza sativa L.) genotypes: Valuable perspectives unveiled through AMMI modeling and GGE biplots analysis

Deciphering the interactions between genetic elements and environmental factors in rice (Oryza sativa L.) genotypes: Valuable perspectives unveiled through AMMI modeling and GGE biplots analysis

Resistance of traditional rice (Oryza sativa L.) genotypes against Asian gall midge (Orseolia oryzae wood-mason) in TBP command area

Resistance of traditional rice (Oryza sativa L.) genotypes against Asian gall midge (Orseolia oryzae wood-mason) in TBP command area

Correlation coefficient analysis of grain yield and yield related traits in rice (Oryza sativa L.) genotypes under alkalinity condition

Correlation coefficient analysis of grain yield and yield related traits in rice (Oryza sativa L.) genotypes under alkalinity condition

Exploring genetic diversity in traditional rice genotypes (Oryza sativa L.) through cluster analysis of qualitative and quantitative traits

Exploring genetic diversity in traditional rice genotypes (Oryza sativa L.) through cluster analysis of qualitative and quantitative traits

Creation of rice doubled haploids with low amylose content using in vitro anther culture.

In vitro androgenesis is a unique model for producing homozygous doubled haploid plants. The use of haploid biotechnology accelerates to obtain of doubled haploid plants, which is very important in rice breeding. The purpose of this work is to improve the production of doubled haploids in rice anther culture in vitro and selection of doubled haploid plants with valuable traits. The study the influence of nutrient media on the production of calli and plant regeneration processes in anther culture of 35 rice genotypes was revealed a significant influence of nutrient media on callus production. It was shown that the addition to culture medium phytohormones ratio with high level of cytokinin (5.0 mg/L BAP) and a low level of auxin (0.5 mg/L NAA), supplemented with amino acid composition promotes high production of green regenerated plants (68.75%) compared to albino plants (31.25%). As a result, doubled haploid lines of the glutinous variety Violetta were selected, which characterized by a low amylose content variation (from 1.86 to 2.80%). These doubled haploids are superior to the original variety in some yield traits and represent valuable breeding material.

Phenotyping of experimental rice population in accelerated breeding of new varieties with valuable grain quality traits

The study of the consumer advantages of rice samples was carried out in connection with the development of an effective breeding methodology for developing rice genotypes based on an accelerated breeding process. The aim of the research was to study the protein and amylose content in rice grain samples of the parent white-grain and red-grain forms and generations of BC2. In the program of developing varieties based on the use of modern postgenomic and cellular technologies, BC2 and their parent forms - samples of the USI “Collection of the FSC of rice” belonging to various groups by the grain form, white-grained, served as the research material. The crop was grown on the experimental plot of Federal Scientific Rice Centre. As a result of the work carried out, samples with an unpainted pericarp were isolated for large-scale genotyping. Phenotyping of the studied rice samples was carried out by protein and amylose content in rice grains. The assessment on the basis of “protein content” was carried out using a universal infrared express analyzer “Multicheck Plus”, InfraLUM FT 6, the amylose content in starch of rice grain varieties – according to GOST ISO 6647-2-2015 Fig. BC2 groups with a high protein content, more than 8.8% and amylose content 1 – 16.0-19.0 %, 2 - amylose content 20.0-22.0%, 3 - amylose content 22.1-27.0% were identified in BC2 grain combinations.

Accumulation patterns of anthocyanin and γ-oryzanol during black rice grain development.

Pigmented rice, especially black rice, is gaining popularity as it is rich in antioxidants such as anthocyanins and γ-oryzanol. At present, knowledge about temporal control of biosynthesis and accumulation of antioxidants during grain development is limited. To address this, the accumulation patterns of anthocyanins and γ-oryzanol were assessed in two distinct black rice genotypes over the course of grain development, and the expression of known regulatory genes for anthocyanin biosynthesis was examined. The results indicated that total γ-oryzanol content increased continuously throughout grain development, while total anthocyanins peaked at dough stage (15 to 21 days after flowering) followed by a decline until grain maturity in both genotypes. However, the rate of decrease in anthocyanin content differed between genotypes, and a more prominent decline in cyanidin 3-O-glucoside (C3G) relative to peonidin 3-O-glucoside (P3G) was observed for both. Anthocyanin content was closely linked with the expression of key regulatory genes in the MBW (MYB-bHLH-WD40) complex. This improved knowledge of the genotype-specific biosynthesis (anthocyanins only) and accumulation patterns of anthocyanins and γ-oryzanol can inform subsequent research efforts to increase concentrations of these key antioxidants in black rice grains.

Principal component analysis of rice genotypes grown under normal and flash flood environments

Principal component analysis of rice genotypes grown under normal and flash flood environments

Impact of salinity on protein metabolism and enzyme activities in salt-tolerant and susceptible rice genotypes

Impact of salinity on protein metabolism and enzyme activities in salt-tolerant and susceptible rice genotypes

Identifying key determinants of rice yield potential through multiple statistical techniques

Grain yield is complex traits, influenced by genetics and the environment, posing challenges for prediction. The goal of the present study was to identify key traits that contribute to rice yield by applying seven statistical techniques. The study examined twenty-four rice genotypes following a randomized complete block design (RCBD) with three replications. Pearson's correlation analysis revealed several traits exhibiting significant positive correlations with grain yield (r≥0.60), including thousand-seed weight (r = 0.63), filled seeds/panicle (r = 0.74), and number of panicles/m2 (r = 0.70). Multiple linear regression identified significant predictors as the number of panicles/m2 (R=0.01) and thousand-seed weight (Coefficient=0.12). Stepwise linear regression suggested key yield indicators viz. the number of panicles/m2 (R=0.01), filled seeds/panicle (R=0.02), thousand-seed weight (R=0.11), and panicle length (R=0.13). Bayesian linear regression found similar traits with a Bayes factor of 995.2 and an R-squared value of 0.77. Exploratory factor analysis showed grain number/panicle, filled seeds percentage, filled seeds/panicle, thousand-seed weight, grain width, and panicles/m2 are highly influenced grain yield and explained 61.9% total variance. Principal components analysis revealed the first three components explaining 79.1% of yield variation, with thousand-seed weight, grain width, and panicle number/m2. Path analysis demonstrated the number of panicles/m2, filled seeds/panicle, thousand-seed weight, and panicle length have large and significant positive direct effects on grain yield. These findings strongly suggest that selecting breeding materials with traits like high panicle density/m2, larger panicle size, more filled seeds/panicle, and higher thousand-seed weight, can significantly increase the rice yield.

Assessment of mutant rice genotypes on growth cycle length and response to reduced water availability

Assessment of mutant rice genotypes on growth cycle length and response to reduced water availability

Effective protocol for rice phenotyping based on grain quality: Ranking of rice samples from a segregating BC2 population

The physical properties of rice backcross samples were studied in connection with the development of an effective breeding methodology for creating rice genotypes based on an accelerated breeding process. The purpose of the research was to study the traits of size, vitreousity, and fracturing of samples of the segregating population of BC2 reseedings from the 2022 and 2023 yield. As part of the program for developing varieties based on the use of modern post-genomic and cellular technologies, BC2 samples were used; as parent forms – samples of the USI “Collection of Federal Scientific Rice Centre” of various groups according to the shape of the grain. The crop was grown in artificial climate chambers under controlled conditions of light and air temperature and on the growing site of Federal Scientific Rice Centre. In the study, white grain samples from the segregating BC2 population were isolated for large-scale genotyping. The cultivation of parental forms for hybridization and the crossing process were carried out in artificial climate chambers. Hybridizations were performed using pneumocastration, which included cutting off the flower scales by 1/3 and then removing the anthers using a vacuum compressor. White grain BC2 samples were isolated for research. Seeds were sown on the growing area in containers with 6 kg of soil and Pryanishnikov’s mixture as the main fertilizer. After ripening, the seeds were manually harvested. Plant phenotyping of experimental populations was carried out basing on grain quality traits using certified equipment in accordance with the instructions for the devices and GOST standards. For 15 combinations, samples with the best characteristics of grain quality were selected. In connection with the indicators of physical grain quality traits, BC2 samples were classified into three groups with indicators for each trait: high, medium, low.