Rice Quality Traits Research Articles

Study of Variability and Correlation for Yield Attributing and Grain Quality Characters in Aromatic Short Grain Rice

This study was conducted in kharif, 2023 at the Indian Institute of Rice Research, Hyderabad, it involved 42 breeding lines and 3 checks in an Augmented Randomized Block Design. This study evaluates genetic variability, heritability, and genetic advance as percent of mean were recorded for all the traits, that revealed high PCV (22.16%) and GCV (20.96%) were recorded by grain yield per plant. Significant variability was observed in traits such as plant height, grain yield per plant, and kernel length, while high heritability coupled with genetic advance as percent of mean were noted for traits like plant height (96.20%;25.44%) and grain yield (89.48%;40.91%), indicating these characters could be improved through selection. Correlation analysis revealed that grain yield per plant shows a positive association with days to 50% flowering, plant height, panicle length, number of productive tillers, 1000 grain weight, hulling percentage, head rice recovery, kernel L/B ratio and amylose content suggesting importance should be given to these characters, during selection for improving yield and quality traits of aromatic short grain rice.

Assessment of Genetic Variability and Character Association for Morpho-physiological and Quality Traits in Rice under Aerobic Conditions

Assessment of Genetic Variability and Character Association for Morpho-physiological and Quality Traits in Rice under Aerobic Conditions

Genetic Variability and Character Association Studies on Yield Attributing and Grain Quality Traits in Rice (Oryza sativa L.)

Genetic Variability and Character Association Studies on Yield Attributing and Grain Quality Traits in Rice (Oryza sativa L.)

Influence of Nitrogen Fertilization on Quality Parameters and Heat Use Efficiency of Basmati Rice

ABSTRACT Physical, milling, cooking, and chemical qualities of basmati cultivars had great concern for researchers, producers, traders, and consumers as instability index of production is higher. Quality may be enhanced by good N optimization to responsive basmati varieties. Therefore, a field experiment was conducted for two consecutive years under split-plot design. Results revealed that application of 120 kg N ha−1 improved heat use efficiency (4.85 & 4.91 kg ha−1 degree-day−1), milling quality traits, physical quality, and chemical quality while aroma score (up to 2.50) improved only up to 60 kg N ha−1. Highest protein (7.79 & 7.77%) and least amylose (21.88 & 22.24%) content were recorded with highest N rates while highest protein yield (414.18 & 402.66 Kg ha−1) reported at 120 Kg N ha−1. Basmati varieties, HUBR 10–9 and HUBR 2–1, were superior in most of quality traits along heat use efficiency (4.62–4.70 kg ha−1 degree-day−1). However, short-grained aromatic variety HUR 917 recorded higher head rice recovery (64.34 & 63.21%), protein (7.61 & 7.63%), and amylose content over others. Most important trait, i.e. aroma (1.83–2.38) score, was higher with basmati varieties. Overall, basmati (HUBR 10–9 and HUBR 2–1) grown with 120 kg N ha−1 proved superiority. This study achieved better heat use efficiency along with improved quality of basmati rice which found to be positively correlated with most quality traits of basmati rice. The low amylose in basmati is preferable, and amylose found to be negatively correlated with heat use efficiency.

Elucidation of nutritional properties and cooking quality traits of under-exploited pigmented rice (Oryza sativa L.) landraces

The present study assessed five pigmented rice (Oryza sativa L.) landraces along with two commercial varieties. Protein (9.57 ± 0.18–12.46 ± 0.01%), zinc (19.9 ± 0.5–27.6 ± 0.4 μg/g) and iron content (10 ± 0.2–15.7 ± 0.2 μg/g) of the pigmented landraces were higher thanvarieties. With a high breakdown value, highest peak viscosity and low amylose, Norungan was classified as a high-quality cooking rice.Bold-type grains possessed higher amylose and resistant starch (RS) content compared to slender types. Karun Kuruvai recorded thehighest RS content (7.0 ± 0.3%), which lowers the glycemic index. Therefore, there is a need to unravel these nutritional properties todevelop a therapeutic variety

OsEXPA7 Encoding an Expansin Affects Grain Size and Quality Traits in Rice (Oryza sativa L.)

BackgroundYield and quality are the two most important traits in crop breeding. Exploring the regulatory mechanisms that affect both yield and quality traits is of great significance for understanding the molecular genetic networks controlling these key crop attributes. Expansins are cell wall loosening proteins that play important roles in regulating rice grain size.ResultsWe investigated the effect of OsEXPA7, encoding an expansin, on rice grain size and quality. OsEXPA7 overexpression resulted in increased plant height, panicle length, grain length, and thousand-grain weight in rice. OsEXPA7 overexpression also affected gel consistency and amylose content in rice grains, thus affecting rice quality. Subcellular localization and tissue expression analyses showed that OsEXPA7 is localized on the cell wall and is highly expressed in the panicle. Hormone treatment experiments revealed that OsEXPA7 expression mainly responds to methyl jasmonate, brassinolide, and gibberellin. Transcriptome analysis and RT-qPCR experiments showed that overexpression of OsEXPA7 affects the expression of OsJAZs in the jasmonic acid pathway and BZR1 and GE in the brassinosteroid pathway. In addition, OsEXPA7 regulates the expression of key quantitative trait loci related to yield traits, as well as regulates the expression levels of BIP1 and bZIP50 involved in the seed storage protein biosynthesis pathway.ConclusionsThese results reveal that OsEXPA7 positively regulates rice yield traits and negatively regulates grain quality traits by involving plant hormone pathways and other trait-related pathway genes. These findings increase our understanding of the potential mechanism of expansins in regulating rice yield and quality traits and will be useful for breeding high-yielding and high-quality rice cultivars.

Generation mean analysis for yield and quality traits in basmati rice (Oryza sativa L.)

Generation mean analysis for yield and quality traits in basmati rice (Oryza sativa L.)

Nature of gene action and combining ability effects for grain yield and quality traits in rice (Oryza sativa L.)

Nature of gene action and combining ability effects for grain yield and quality traits in rice (Oryza sativa L.)

Detection of consensus genomic regions and candidate genes for quality traits in barley using QTL meta-analysis.

Improving barley grain quality is a major goal in barley breeding. In this study, a total of 35 papers focusing on quantitative trait loci (QTLs) mapping for barley quality traits published since 2000 were collected. Among the 454 QTLs identified in these studies, 349 of them were mapped onto high-density consensus maps, which were used for QTL meta-analysis. Through QTL meta-analysis, the initial QTLs were integrated into 41 meta-QTLs (MQTLs) with an average confidence interval (CI) of 1. 66 cM, which is 88.9% narrower than that of the initial QTLs. Among the 41 identified MQTLs, 25 were subsequently validated in publications using genome-wide association study (GWAS). From these 25 validated MQTLs, ten breeder's MQTLs were selected. Synteny analysis comparing barley and wheat MQTLs revealed orthologous relationships between eight breeder's MQTLs and 45 wheat MQTLs. Additionally, 17 barley homologs associated with rice quality traits were identified within the regions of the breeder's MQTLs through comparative analysis. The findings of this study provide valuable insights for molecular marker-assisted breeding and the identification of candidate genes related to quality traits in barley.

QTL Detection and Candidate Gene Identification for Eating and Cooking Quality Traits in Rice (Oryza sativa L.) via a Genome-Wide Association Study.

The eating and cooking quality (ECQ) directly affects the taste of rice, being closely related to factors such as gelatinization temperature (GT), gel consistency (GC) and amylose content (AC). Mining the quantitative trait loci (QTLs), and gene loci controlling ECQ-related traits is vital. A genome-wide association study on ECQ-related traits was conducted, combining 1.2 million single nucleotide polymorphisms (SNPs) with the phenotypic data of 173 rice accessions. Two QTLs for GT, one for GC and five for AC were identified, of which two were found in previously reported genes, and six were newly found. There were 28 positional candidate genes in the region of qAC11. Based on a linkage disequilibrium (LD) analysis, three candidate genes were screened within the LD region associated with AC. There were significant differences between the haplotypes of LOC_Os11g10170, but no significant differences were found for the other two genes. The qRT-PCR results showed that the gene expression levels in the accessions with high ACs were significantly larger than those in the accessions with low ACs at 35d and 42d after flowering. Hap 2 and Hap 3 of LOC_Os11g10170 reduced the AC by 13.09% and 10.77%, respectively. These results provide a theoretical and material basis for improving the ECQ of rice.

Identification of RILs for agronomic and grain quality traits in rice through Intraspecific crosses

Identification of RILs for agronomic and grain quality traits in rice through Intraspecific crosses

The OsGAPC3 mutation significantly affects grain quality traits and improves the nutritional quality of rice.

The glycolytic enzyme cytoplasmic glyceraldehyde-3-phosphate dehydrogenase (GAPC3) is involved in multiple biological processes in plants, including transcriptional regulation, and material metabolism. However, the relationship between OsGAPC3 and the quality traits of rice is poorly understood. Here we identify OsGAPC3 mutations that enhance the protein content and grain nutritional quality of rice by regulating the OsAAP6 gene expression. The number and volume of type-II protein bodies in the endosperm of the OsGAPC3 mutants, and GPC increase significantly. We report significant increases in chalkiness area and degree, and decreases for starch content, gel consistency, and taste value. Results of proteomic detection and analysis reveal that OsGAPC3 affects the major storage substances (proteins and starch) metabolism in rice, and the accumulation of proteins and starch in the endosperm. Additionally, the OsGAPC3 mutation significantly decreases the rice-seedling salt tolerance. Therefore, OsGAPC3 affects multiple quality traits of rice, participates in regulating rice-seedling salt-stress response. These data can be used to design better-quality and stronger salt-resistant rice varieties.

Exploration of quality variation and stability of hybrid rice under multi-environments

Improving quality is an essential goal of rice breeding and production. However, rice quality is not solely determined by genotype, but is also influenced by the environment. Phenotype plasticity refers to the ability of a given genotype to produce different phenotypes under different environmental conditions, which can be a representation of the stability of traits. Seven quality traits of 141 hybrid combinations, deriving from the test-crossing of 7 thermosensitive genic male sterile (TGMS) and 25 restorer lines, were evaluated at 5 trial sites with intermittent sowing of three to five in Southern China. In the Yangtze River Basin, it was observed that delaying the sowing time of hybrid rice combinations leads to an improvement in their overall quality. Twelve parents were identified to have lower plasticity general combing ability (GCA) values with increased ability to produce hybrids with a more stable quality. The parents with superior quality tend to exhibit lower GCA values for plasticity. The genome-wide association study (GWAS) identified 13 and 15 quantitative trait loci (QTLs) associated with phenotype plasticity and BLUP measurement, respectively. Notably, seven QTLs simultaneously affected both phenotype plasticity and BLUP measurement. Two cloned rice quality genes, ALK and GL7, may be involved in controlling the plasticity of quality traits in hybrid rice. The direction of the genetic effect of the QTL6 (ALK) on alkali spreading value (ASV) plasticity varies in different cropping environments. This study provides novel insights into the dynamic genetic basis of quality traits in response to different cropping regions, cultivation practices, and changing climates. These findings establish a foundation for precise breeding and production of stable and high-quality rice.

Molecular basis of genetic improvement for key rice quality traits in Southern China

Grain qualities including milling quality, appearance quality, eating and cooking quality, and nutritional quality are important indicators in rice breeding. Significant achievements in genetic improvement of rice quality have been made. In this study, we analyzed the variation patterns of 16 traits in 1570 rice varieties and found significant improvements in appearance quality and eating and cooking quality, particularly in hybrid rice. Through genome-wide association study and allelic functional nucleotide polymorphisms analysis of quality trait genes, we found that ALK, FGR1, FLO7, GL7/GW7, GLW7, GS2, GS3, ONAC129, OsGRF8, POW1, WCR1, and Wx were associated with the genetic improvement of rice quality traits in Southern China. Allelic functional nucleotide polymorphisms analysis of 13 important rice quality genes, including fragrance gene fgr, were performed using the polymerase chain reaction amplification refractory mutation system technology. The results showed that Gui516, Gui569, Gui721, Ryousi, Rsimiao, Rbasi, and Yuehui9802 possessed multiple superior alleles. This study elucidates the phenotypic changes and molecular basis of key quality traits of varieties in Southern China. The findings will provide guidance for genetic improvement of rice quality and the development of new varieties.

Genetic analysis of zinc rich landraces for yield, quality and nutritional traits in rice (Oryza sativa L.)

Aim: To study genetic variability, correlation, path and Principal Component Analysis (PCA) in a set of 100 zinc rich rice landraces along with four checks. Methodology: The study was carried out at the Regional Agricultural Research Station (RARS), Maruteru, during Rabi season, 2020-2021 in an Augmented Randomized Block Design. Results: Grain yield per plant, grains per panicle, productive tillers m-2 and test weight showed moderate genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) coupled with high heritability and genetic advance as per cent mean. These traits also had positive and significant association coupled with high positive direct effect on grain yield per plant. They also contributed maximum variance to the total variability indicating the effectiveness of direct phenotypic selection for these traits for improving the grain yield per plant. Further, cluster analysis grouped the zinc rich rice landraces along with checks into three clusters. Cluster II had the highest genotypes (42), while Cluster I had 32 genotypes and Cluster III consisted of 30 zinc rich landraces along with three check varieties. Interpretation: Grains per panicle, productive tillers and test weight were identified as effective selection criteria for the improvement of grain yield towards development of high yielding zinc-rich rice varieties to curtail micronutrient malnutrition in areas with rice as staple food. Key words: Cluster analysis, Landraces, Oryza sativa, Path analysis, PCA, Zinc

Genetic Divergence Analysis for Yield and Quality Traits in Rice (Oryza sativa L.) Germplasm under Irrigated Conditions

The present investigation was carried out to conduct genetic divergence analysis for yield and quality traits in rice (Oryza sativa L.) germplasm under irrigated conditions. The experiment was conducted at crop research farm, Department of Genetics and Plant Breeding, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences. Prayagraj. The experiment was performed with 40 rice genotypes with 13 quantitative characters and 8 qualitative characters. Analysis of variance revealed that all the genotypes showing significant at 1% level of significance for all the characters. According to mean table Shiats dhan-7, Shiats dhan-2 show greater mean in grain yield per plant. Genetic parameters show PCV greater than GCV in all the characters, the traits Grain yield per plant and biological yield exhibits greater in both GCV and PCV. Heritability showing high range of estimates in all the characters as Days to maturity, Days to 50% flowering exhibit greater among all the characters. Number of spikelets per panicle, biological yield shows highest among the characters in Genetic advance. According to D2 analysis, the total genotypes are divided into five clusters, Cluster II showing greater in Intra cluster distance, Cluster V and Cluster I combination showing greater in Inter cluster distances. The Cluster IV showing highest among the clusters in the mean of Grain yield per plant. According to percentage contribution Grain yield per plant showing highest among the characters. Quality analysis had done on 35 genotypes, based upon quality characters Hulling percentage showing genotype Ajaya greater and genotype MTU-2032 shows greater in Kernel elongation ratio.

Integrated genome-wide differentiation and association analyses identify causal genes underlying breeding-selected grain quality traits in japonica rice

Improving grain quality is a primary objective in contemporary rice breeding. Japanese modern rice breeding has developed two different types of rice, eating and sake-brewing rice, with different grain characteristics, indicating the selection of variant gene alleles during the breeding process. Given the critical importance of promptly and efficiently identifying genes selected in past breeding for future molecular breeding, we conducted genome scans for divergence, genome-wide association studies, and map-based cloning. Consequently, we successfully identified two genes, OsMnS and OsWOX9D, both contributing to rice grain traits. OsMnS encodes a mannan synthase that increases the white core frequency in the endosperm, a desirable trait for sake brewing but decreases the grain appearance quality. OsWOX9D encodes a grass-specific homeobox-containing transcription factor, which enhances grain width for better sake brewing. Furthermore, haplotype analysis revealed that their defective alleles were selected in East Asia, but not Europe, during modern improvement. In addition, our analyses indicate that a reduction in grain mannan content during African rice domestication may also be caused a defective OsMnS allele due to breeding selection. This study not only reveals the delicate balance between grain appearance quality and nutrition in rice but also provides a new strategy for isolating causal genes underlying complex traits, based on the concept of “breeding-assisted genomics” in plants.

Estimation of combining ability and heterosis for grain yield, yield components, and some grain quality traits in rice under water deficit conditions

Estimation of combining ability and heterosis for grain yield, yield components, and some grain quality traits in rice under water deficit conditions

Correlation among Quality Characteristics in Medium-Grain Rice

Rice (Oryza sativa L.) grain attributes, such as grain length and shape, milling quality, and physicochemical quality, are crucial for varietal development and subsequent farm adoption. Thus, it is crucial to comprehend the phenotypic range of these grain attributes and how they relate to one another. Therefore, this study analyzed the main grain quality traits in medium-grain rice, namely the amylose content (AC), gelatinization temperature (GT), gel consistency (GC), ratio of head rice (HR), and percentage of chalkiness (PC). Correlations among the major quality characteristics were then calculated through Pearson correlation matrix analysis. The results showed that AC was highly connected with GC, and PC and HR (GC) showed a strong correlation. The correlation between GT and GC was average. The other quality traits did not correlate significantly. The phenotypes of the grain quality traits provide a basis for improving the quality of medium-grain rice populations.

Nitric oxide confers cadmium tolerance in fragrant rice by modulating physio-biochemical processes, yield attributes, and grain quality traits

Cadmium (Cd) stress causes serious disruptions in plant metabolism, physio-biochemical processes, crop yield, and quality characters. Nitric oxide (NO) improves the quality features and nutritional contents of fruit plants. However, how NO confers Cd toxicity in fragrant rice plants, is sparse. Hence, the present study investigated the effects of 50 µM NO donor sodium nitroprusside (SNP) on physio-biochemical processes, plant growth attributes, grain yield, and quality traits of fragrant rice under Cd stress (100 mg kg−1 soil). The results revealed that Cd stress diminished rice plant growth, impaired photosynthetic apparatus and antioxidant defense system, and deteriorated the grain quality traits. However, foliar application of SNP mitigated Cd stress by improving plant growth and gas exchange attributes. Higher electrolyte leakage (EL) was accompanied with elevated levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2) under Cd stress; however, exogenous application of SNP reduced them. The activities and relative expression levels of enzymatic antioxidants; superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) and non-enzymatic antioxidants, glutathione (GSH) contents were reduced by Cd stress, while SNP application regulated their activity and transcript abundances. SNP application improved fragrant rice grain yield and 2-acetyl-1-pyrroline content by 57.68 % and 75.54 % respectively, which is concomitant with higher biomass accumulation, photosynthetic efficiency, photosynthetic pigment contents, and an improved antioxidant defense system. Collectively, our results concluded that SNP application regulated the fragrant rice plant physio-biochemical processes, yield traits and grain quality characters under Cd-affected soil.