scholarly journals Genetic Variability and Association of Traits in Mutant Lines of Rice (Oryza sativa L.) for Submergence Tolerance

2019 ◽  
pp. 1-7 ◽  
Author(s):  
Nikita Kumari ◽  
Rajesh Kumar ◽  
Avinash Kumar
Keyword(s):  
Coefficient Of Variation ◽  
Oryza Sativa L ◽  
Crop Improvement ◽  
Shoot Elongation ◽  
Yield Potential ◽  
Submergence Tolerance ◽  
Rice Varieties ◽  
Survival Percentage ◽  
Ethyl Methyl ◽  
Mutant Lines

Present investigation was carried out with 240 mutant lines developed from different combination of gamma rays and ethyl methyl sulfonate on three rice varieties i.e FR13A, FR13B and Labella along with three untreated checks (FR13A, FR13B and Labella). These were evaluated for their survival percentage under submerged condition and yield potential along with 9 other morpho-physiological traits using Type 2 modified augmented design during Kharif season of 2017 in the agroclimatic region of north bihar, India. Analysis of variance revealed highly significant differences among the mutant lines for all morpho-physiological characters under study. Higher magnitude of phenotypic coefficient of variation (PCV), genotypic coefficient of variation (GCV), heritability (broad sense) and genetic advance as percentage of mean were observed for number of tillers per plant, number of fertile tillers per plant, relative shoot elongation and survival percentage, indicating that these traits could be used as selection indices for yield improvement and submergence tolerance. Association study revealed that number of tillers per plant and survival percentage had significant positive high to moderate direct association with grain yield per plant under submergence condition. Thus, these traits may be used as selection criteria in further crop improvement programmes for submergence tolerance.

Assessment of genetic variability for quantitative characters in rice (Oryza sativa L.) under post flood situation in sali

2021 ◽  
Vol 58 (1) ◽  
pp. 43-48
Author(s):  
Dalibha Pathak ◽  
Umesh Ch. Kalita
Keyword(s):  
Grain Yield ◽  
Coefficient Of Variation ◽  
Quantitative Traits ◽  
Oryza Sativa L ◽  
Block Design ◽  
Genetic Advance ◽  
Spikelet Sterility ◽  
Rice Varieties ◽  
Randomized Block Design ◽  
Spikelets Per Panicle

Sixteen genotypes of rice (including one check) were evaluated on 18 quantitative traits during sali (August), 2018 in a randomized block design with three replications at Instruction cum Research Farm, Department of Plant Breeding and Genetics, Assam Agricultural University, Jorhat to study the nature and magnitude of variability, heritability and genetic advance under delayed sown condition. The analysis of variance for 18 quantitative traits revealed the presence of significant differences for grain yield and its component characters. The highest genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) was observed for chaffs per panicle followed by grains per panicle, spikelet sterility (%), spikelets per panicle, grain yield (kg/ha). A high heritability coupled with high genetic advance was observed for plant height (cm), spikelets per panicle, spikelet sterility (%), chaffs per panicle, grains per panicle, grain yield (g/hill), grain yield (kg/ha), biological yield (kg/ha), straw weight (kg/ha) and harvest index (%) indicating that selection might be effective for improvement of these characters under delayed sown condition with low input. From the findings of this investigation, one genotype viz., Gandhari emerged as the outstanding genotype which yielded 4170 kg/ha and could be directly used for cultivation in delayed sown situation with low inputs. Some other promising genotypes that yielded higher than the check Manoharsali under delayed sown condition were JR 29, JR 16, Basundhara and JR 60 and could be utilized as potential parental material in the hybridization programmes designed to develop suitable rice varieties for delayed sown situation.

scholarly journals Genetic Variability, Character Association and Path Analysis in Boro Rice (Oryza sativa L.) Germplasm from Bangladesh

2019 ◽  
Vol 22 (1) ◽  
pp. 35-43
Author(s):  
MZ Islam ◽  
T Chakrabarty ◽  
N Akter ◽  
ESMH Rashid ◽  
M Khalequzzaman ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Coefficient Of Variation ◽  
Oryza Sativa L ◽  
Block Design ◽  
Crop Improvement ◽  
Leaf Length ◽  
Component Traits ◽  
High Heritability ◽  
Positive Significant Correlation ◽  
Boro Rice

The success of varietal development programmme largely depends on the nature and magnitude of genetic variability, heritability and characters association of the crop. The objective of the present study was to estimate the extent of genetic variability and relation between yield and related characters of rice. Forty Boro rice germplasm were evaluated in a randomised complete block design with three replications. Analysis of variance indicated significant differences among the genotypes for 14 quantitative characters. The presence of slightly higher phenotypic coefficient of variation than genotypic coefficient of variation indicated the negligible influence of environment on the expression of yield and its component traits. Leaf length, days to flowering, days to maturity and 1000 grain weight showed highly positive significant correlation present with yield hill-1. High heritability had been observed for yield contributing traits during the study, suggested that these traits would respond to selection owing to their high genetic variability and transmissibility. Therefore, a thorough understanding of the inheritance of traits, their heritability and relationship with other important characteristics is important for the choice of breeding and selection methods for crop improvement. Bangladesh Rice j. 2018, 22(1): 35-43

scholarly journals OsmiR396/Growth Regulating Factor modulate rice grain size through direct regulation of embryo-specific miR408

2021 ◽  
Author(s):  
Xiaofang Yang ◽  
Xiaoling Zhao ◽  
Zhengyan Dai ◽  
Feilong Ma ◽  
Xuexia Miao ◽  
...  
Keyword(s):  
Grain Size ◽  
Regulatory Networks ◽  
Oryza Sativa L ◽  
Indica Rice ◽  
Expression Patterns ◽  
Crop Improvement ◽  
Genetic Regulatory Networks ◽  
Rice Grain ◽  
Rice Varieties ◽  
Size Regulation

Abstract microRNAs (miRNAs) are promising targets for crop improvement of complex agricultural traits. Coordinated activity between/among different miRNAs may fine-tune specific developmental processes in diverse organisms. Grain size is a main factor determining rice (Oryza sativa L.) crop yield, but the network of miRNAs influencing this trait remains uncharacterized. Here we show that sequestering OsmiR396 through target mimicry (MIM396) can substantially increase grain size in several japonica and indica rice subspecies and in plants with excessive tillers and a high panicle density. Thus, OsmiR396 has a major role related to the regulation of rice grain size. The grain shape of Growth Regulating Factor8 (OsGRF8)-overexpressing transgenic plants was most similar to that of MIM396 plants, suggesting OsGRF8 is a major mediator of OsmiR396 in grain size regulation. A miRNA microarray analysis revealed changes to the expression of many miRNAs, including OsmiR408, in the MIM396 plants. Analyses of gene expression patterns and functions indicated OsmiR408 is an embryo-specific miRNA that positively regulates grain size. Silencing OsmiR408 expression (miR408KO) using CRISPR technology resulted in small grains. Moreover, we revealed the direct regulatory effects of OsGRF8 on OsMIR408 expression. A genetic analysis further showed that the large-grain phenotype of MIM396 plants could be complemented by miR408KO. Also, several hormone signaling pathways might be involved in the OsmiR396/GRF-meditated grain size regulation. Our findings suggest that genetic regulatory networks comprising various miRNAs, such as OsmiR396 and OsmiR408, may be crucial for controlling rice grain size. Furthermore, the OsmiR396/GRF module may be important for breeding new high-yielding rice varieties.

scholarly journals Mechanism of anoxic tolerance in backcross lines developed through Jyothi x Swarna-Sub 1 under submergence stress.

2020 ◽  
Vol 80 (04) ◽  
Author(s):  
Deepa John ◽  
K. S. Shylaraj
Keyword(s):  
Alcohol Dehydrogenase ◽  
Alcoholic Fermentation ◽  
Flash Flood ◽  
Pyruvate Decarboxylase ◽  
Shoot Elongation ◽  
High Survival ◽  
Rice Varieties ◽  
Survival Percentage ◽  
Submergence Stress ◽  
Donor Parent

Rice varieties adapted to flash flood exhibit submergence tolerance by maintaining reduced shoot elongation under submerged conditions. This study focuses on the two main physiological traits leading to flash flood tolerance- high survival percentage with reduced shoot elongation under submergence and increased rate of alcoholic fermentation. Sub1introgressed BC3F2 lines exhibited higher survival percentage with moderate shoot elongation under submergence stress for fourteen days similar to the donor parent Swarna- Sub1. Enzymatic activities of alcohol dehydrogenase and pyruvate decarboxylase were monitored for fourteen days under submergence stress. The developed Sub1 introgressed lines and the donor parent Swarna-Sub1 showed higher rates of alcohol dehydrogenase and pyruvate decarboxylase activities under submergence stress thereby maintaining optimum rates of alcoholic fermentation. The findings of this study confirmed the expression of tolerance mechanism in the Sub1introgressedJyothi Backcross Inbred lines under submergence stress.

scholarly journals Marker-assisted selection for transfer of submergence tolerance, bacterial blight resistance and yield enhancement in the rice backcross derivatives

2020 ◽  
pp. 1288-1294
Author(s):  
Shibani Mohapatra ◽  
Akshaya Kumar Bastia ◽  
Alok Kumar Panda ◽  
Sharat Kumar Pradhan
Keyword(s):  
Resistance Genes ◽  
Bacterial Blight ◽  
Rice Variety ◽  
Yield Component ◽  
Yield Enhancement ◽  
Yield Potential ◽  
Blight Resistance ◽  
Submergence Tolerance ◽  
Bacterial Blight Resistance ◽  
Rice Varieties

Achieving the demand and supply of rice for the increasing global population will be a challenging task beyond 2040. Therefore, the yield potential of popular rice varieties needs to be increased. The production from lowland rice can be enhanced by managing the major biotic and abiotic stresses faced in the ecology. In this work, we have developed the pipelines for gene stacking of submergence tolerance, bacterial blight resistance and yield component QTLs in the popular rice variety ‘Swarna’ by marker-assisted backcross breeding approach. Genotyping results of 796 BC1F1 backcross derived lines showed the presence of GW2, OsSPL14, SCM2 yield component QTLs, Sub1A for submergence tolerance and bacterial blight resistance genes xa5 and Xa21 in the progenies. The four stacked QTLs and two resistance genes were observed in six backcrosses derived progenies only. These progenies will be used in the next generation for further selection and evaluation for enhancing submergence tolerance, yield potential and bacterial blight resistance in Swarna rice variety background.

scholarly journals Exploring the Relationship between Yield and Yield Attributing Traits in Advanced Breeding Lines of Rice (Oryza sativa L.)

2021 ◽  
pp. 350-358
Author(s):  
Danish Mushtaq ◽  
Bupesh Kumar ◽  
Praveen Singh ◽  
Manmohan Sharma ◽  
Ashish Sheera
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Coefficient Of Variation ◽  
Oryza Sativa L ◽  
Association Studies ◽  
Block Design ◽  
Phenotypic Expression ◽  
Panicle Length ◽  
Rice Varieties ◽  
Breeding Lines

Aim: Present study endeavors to explore the genetic variability for various agro-morphological and quality traits as well as to delineate the association between grain yield and its yield attributing components Study Design: Randomized Complete Block Design Place and Duration of Study: Division of Plant Breeding and Genetics, She-e-Kashmir University of Agricultural Sciences and Technology of Jammu during kharif 2020. Methodology: A experiment was carried out to determine the association between grain yield and yield attributing components among advanced breeding lines of rice to establish a well grounded selection criteria for developing rice varieties with improved grain yield. Phenotypic coefficient of variation (PCV) was found to be relatively greater than the genotypic coefficient of variation (GCV) for most of traits indicating role of environment in the phenotypic expression of traits. Characters viz., plant height, total number of tillers per plant, number of effective tillers per plant, panicle length and grain yield per plant exhibited high heritability coupled with high genetic advance indicating their efficient inheritance from preceding generations. Results: Association studies indicated that characters viz., Plant height, total number of tillers per plant, number of effective tillers per plant, panicle length, 1000 grain weight and grain yield per plant had a significant positive relationship with grain yield per plot indicating their role in breeding rice varieties for higher grain yield. Conclusion: Cause and effect relationship revealed that traits viz., days to 50 per cent flowering, total number of tillers per plant, days to maturity, panicle length and grain yield per plant can be exploited for indirect selection for improving grain yield.

scholarly journals Genetic variability for grain yield and yield associated traits in transplant Aman rice (Oryza sativa L.)

2015 ◽  
Vol 2 (2) ◽  
pp. 207-213
Author(s):  
Mashtura Begum ◽  
Md Amir Hossain ◽  
Fakir Muhammad Munawar Hossain ◽  
Ahmed Khairul Hasan
Keyword(s):  
Grain Yield ◽  
Oryza Sativa L ◽  
Rice Variety ◽  
Crop Improvement ◽  
Genetic Advance ◽  
Improvement Program ◽  
Rice Varieties ◽  
Spad Value ◽  
Crop Varieties ◽  
Planting Materials

For any crop improvement program, it is imperative to assess the grain yield progress of the existing crop varieties to find the further avenue to out yield the existing superior ones. Therefore, an experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from July to December 2013 to find out the genetic variation for grain yield and their associated traits of transplant Aman rice varieties. The experiment consisted of 11 varieties viz. Bashiraj, Binadhan-7, BR10, BR11, BR22, BR23, BRRIdhan32, BRRIdhan39, BRRIdhan49, BRRIdhan57 and IR64. The high yielding Bangladeshi varieties were selected based on their releasing year with a local and one exotic T. Aman rice varieties. Among the varieties, BR10 produced the highest grain yield (3.83 t ha-1). Binadhan-7 rice variety recorded the highest chlorophyll content (39.93 SPAD value) at 29DAT, (44 SPAD value) at 39 DAT and (47.30 SPAD value) at 49 DAT. The highest phenotypic (1491.81) and genotypic (1147.26) variances and genetic advance (61.19) were obtained from spikelets panicle-1 and this parameter had greater ability to increase yield. Among the traits, the highest heritability was recorded by effective tillers hill-1 (87.91%) which influenced the grain yield. Therefore, it may be concluded that the variety BR10 of transplant Aman rice produced maximum grain yield, spikelets panicle-1, showed high phenotypic and genotypic variances and genetic advance. Bashiraj, BRRIdhan49 and BRRIdhan57 also can be considered as planting materials as their yield performance is close to BR 10. Therefore, the findings of the present study will help the breeders for further yield improvement of rice.Res. Agric., Livest. Fish.2(2): 207-213, August 2015

scholarly journals Agro-Morphological and Genetic Diversity Studies in Rice (Oryza Sativa L.) Germplasm Using Microsatellite Markers

2021 ◽  
Author(s):  
Shiraz Mehmood ◽  
Israr Ud Din ◽  
Izhar Ullah ◽  
Heba I. Mohamed ◽  
Abdul Basit ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Distance ◽  
Oryza Sativa L ◽  
Crop Improvement ◽  
Biodiversity Loss ◽  
Cadmium Content ◽  
Rice Varieties ◽  
Morphological Variations ◽  
Germplasm Collections ◽  
Rice Genotypes

Abstract Knowledge of the genetic diversity and population structure of germplasm collections is an important foundation for crop improvement. Rice production across a broad range of rice-growing environments results in a diverse array of local rice varieties. Many rice varieties have been lost as a result of biodiversity loss and are now grown in Pakistan. To protect the biodiversity of rice varieties, an experiment was carried out to check the genetic and morphological variations between 8 exotic and 7 local rice genotypes, using 5 different SSR markers, i.e, RM3, RM259, RM341, RM520, and RM11943. The analysis of morphological and quality traits of rice observed significant variation across genotypes. The results revealed that genotype Irri-Pak attained the highest plant height and primary branch plant-1, while genotype Mushkan produced a higher number of productive tillers and obtained a higher fertility factor (%). Similarly, the highest value for panicle length was observed for genotype Faker-e-Malakand, 1000-grains weight in genotype Calmochi, and maximum days to maturity was noticed in genotype Swati-2014. Moreover, the genotype Brio attained the highest value of stem diameter, while maximum seed length was noted in genotype Sug Dasi. The highest number of primary branches plant-1 in genotype Ibge-I and secondary branches plant-1 in genotype Calmochi were noticed. A higher concentration of sodium and potassium was observed for the genotype Marte, while the genotype Muskan attained the maximum content of copper. Moreover, the highest concentration of iron in genotype Originario, zinc in genotype JP-5, and cadmium content were noticed in genotype Ibge. Similarly, the dendrogram analysis for quantitative parameters showed three clusters at 74.13 % similarities. Whereas all the genotypes of European origin formed a separate cluster. A set of 5 SSR primers, covering four chromosomes, amplified a total of 14 alleles and showed 100% polymorphism with an average PIC value ranging from 0.39 to 0.91. The UPGMA cluster analysis separated the 15 rice genotypes into 3 main groups based on 32.5% similarities and the highest genetic distance (45.1%) was observed between two genotypes (Fakher-e-malakand and Musa), having different geographical origins. There was no genetic distance between genotype Marte and Brio, irrespective of having the same origin.

scholarly journals An Overview of Rice QTLs Associated with Disease Resistance to Three Major Rice Diseases: Blast, Sheath Blight, and Bacterial Panicle Blight

Agronomy ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 177 ◽  
Author(s):  
Seyedeh Soheila Zarbafi ◽  
Jong Hyun Ham
Keyword(s):  
Disease Resistance ◽  
Oryza Sativa L ◽  
Quantitative Resistance ◽  
Sheath Blight ◽  
Yield Potential ◽  
Burkholderia Glumae ◽  
Rice Varieties ◽  
Disease Resistant ◽  
Resistant Varieties ◽  
Panicle Blight

Rice (Oryza sativa L.) is one of the most important crops that are produced as human food, directly feeding people more than any other crop. Hence, it is important to increase the yield potential of rice through improving the disease resistance to prevailing rice diseases. Blast caused by the fungus Magnaporthe oryzae, sheath blight caused by the fungus Rhizoctonia solani Kühn, and bacterial panicle blight caused by the bacteria Burkholderia glumae and B. gladioli are serious rice diseases in many rice-producing regions. In spite of the chronic damages from these major diseases, the quantitative resistance to each of them is not known very well and any available disease-resistant varieties are rare or not stable. Although gene-for-gene resistance that is mediated by an R-Avr interaction has been intensively studied for blast, quantitative (or horizontal) resistance to a broad spectrum of races in M. oryzae is still poorly understood. Identification of the quantitative trait loci (QTLs) related to these diseases and using marker technology can facilitate marker-assisted selection to screen resistant traits in individual resources, which could ultimately lead to the development of novel disease-resistant rice varieties. This article is a summary of identified QTLs that are associated with rice diseases, including blast, sheath blight, and bacterial panicle blight that can be used in breeding programs.

scholarly journals Agro-Morphological Diversity (Qualitative Traits) of Oryza sativa L. Cultivated in Paiyunpata Village, Baglung, Nepal

2020 ◽  
Vol 19 (1) ◽  
pp. 9-15
Author(s):  
Hom Nath Pathak
Keyword(s):  
Morphological Traits ◽  
Oryza Sativa L ◽  
Crop Improvement ◽  
Germplasm Conservation ◽  
Morphological Diversity ◽  
Morphological Characters ◽  
Rice Varieties ◽  
Central Nepal ◽  
Qualitative Characters ◽  
Study Sites

 The study was carried out in Paiyunpata, Baglung-13, which lies in the southern part of Baglung Bazaar, Central Nepal. The main objective of the present study was to study the agro-morphological traits of rice varieties cultivated in the study area and make easy ways for germplasm conservation. Direct observation and measurements were carried out to collect primary data.Agro-morphological characters of 19 landraces of rice in the study sites were measured in terms of qualitative characters and made ways easy for germplasm conservation. Besides, the varied landraces may besuggested to breeding for crop improvement, but patents should be that of the community.

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