scholarly journals Genetic Variability and Divergence Studies on Yield under Delayed Sowing Conditions in Rice (Oryza sativa L.)

Author(s):  
S. Vanisri ◽  
V. Ishwrya Laxmi ◽  
K. Charles Wesly ◽  
B. Priyanka ◽  
M. Sreedhar ◽  
...  

Timely sowing is a critical factor in realizing the yield as it ensures the vegetative growth to crop up during a period of satisfactory temperatures and fits the cultivar maturity length and growing season. In the present investigation, 38 cold tolerant rice genotypes were studied under delayed sowing conditions at College Farm, Professor Jayashankar Telangana State Agricultural University, Hyderabad. The genotypes were evaluated for yield attributing traits with a view of understanding the extent of variability and diversity present among the genotypes that could be suitable for delayed sowing conditions with cold tolerance. Analysis of variance (ANOVA) indicated significant differences for all the characters with high genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) values for tillers per plant, spikelet fertility, filled grains per panicle and seed yield per plant. High heritability coupled with high genetic advance as percent of the mean was observed for plant height, spikelet fertility, filled grains per panicle with higher variability indicating the presence of fixable gene action which may suggest a reliable crop improvement through selection of these traits. As association analysis could help the breeder to design selection strategies to improve grain yield, correlation studies were carried out which revealed the trait to be having positive relation with all the traits except panicle exertion and panicle length. Path coefficient analysis showed all the traits except panicle exertion and test weight to be exhibiting a direct positive effect on yield, selection for which should be emphasized on these positively associated traits for yield enhancement. Principal component analysis and D2 analysis together determined plant height, grain yield, panicle exertion, panicle length and yield per plant having higher contributions to the total variability, which could be taken into consideration in rice breeding programmes for further improvement in production.

Author(s):  
Danish Mushtaq ◽  
Bupesh Kumar ◽  
Praveen Singh ◽  
Manmohan Sharma ◽  
Ashish Sheera

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.


2021 ◽  
Vol 22 (2) ◽  
pp. 92
Author(s):  
Sashi Lamichhane ◽  
Nav Raj Adhikari ◽  
Bishwas K.C. ◽  
Sapana Thapa

<p>Rice is an essential staple food in Nepal but researches and varietal improvement programs are rarely carried out due to inadequate variability study. The field study was carried to diagnose the influence of genetic and environmental factors on yield traits to aid future rice breeding programs. Twelve genotypes were arranged in randomized complete block design with three replications from July to November 2019 at the research field of the Institute of Agriculture and Animal Science, Tribhuvan University, in the hilly area of Nepal. Analysis of variance showed significant difference for days to 50% booting, days to 50% flowering, plant height, panicle length, flag leaf area, filled grains per panicle, unfilled grains per panicle, fertility percentage, effective tillers m<sup>-2</sup>, straw yield, grain yield, 1000-grain weight, and harvesting index indicating the presence of variation in genotypes. LPN BR-1615 was the most promising genotype in grain yield. The values of Phenotypic Coefficient of Variation (PCV) were higher than Genotypic Coefficient of Variation (GCV) for each trait and low difference between them was found for days to 50% booting, days to 50% flowering, plant height, panicle length, grain yield, thousand-grain weight, fertility percentage, and harvesting index. Plant height, effective tillers m<sup>-2</sup>, and grain yield showed high heritability (i.e. 93.2%, 60.5% and 92.6%, respectively) and higher genetic advance as percentage of mean (i.e. 46.5, 34.6 and 50.1, respectively) . Thus, the experiment revealed that selections favoring plant height, effective tillers m<sup>-2</sup>, and grain yield would help in effective breeding programs of rice in future.</p>


Author(s):  
Anjani Kumar ◽  
D. N. Singh ◽  
Krishna Prasad ◽  
Avinash Pandey

This study performed to determine the correlation, their comparison and path coefficients of yield and yield contributing characters by using F2 (BPT-5204 /IR-64Drt1) their two parents separately and the joint parental populations. In this study, the computations for testing the significance of the difference between the 15 traits of different populations of rice determined from 324 F2, 9 IR-64Drt1 (P1), 9 BPT-5204 (P2) and 18 joint parental population. Results showed that the correlation of F2 indicated that the number of total tillers per plant, number of panicles per plant, plant height, panicle length, biomass, harvest index and yield per panicle were positive and significant association with yield per plant. Correlation of IR-64Drt1 stated that the plant height, panicle length, biomass and harvest index were positive and significant association with yield per plant. Correlation of BPT-5204 shown that the secondary branches per panicle and hundred-grain weight exhibited positive and significant association with yield per panicle. Correlation of the joint parent indicated that the plant height, panicle length, grain length, grain width, hundred-grain weight, biomass, harvest index and yield per panicle had exhibited positive and significant association with yield per plant. Path coefficient analysis indicated that harvest index had the highest direct positive effect (0.582) on yield per plant in the F2 population. However, the panicles per plant had the highest direct positive effect (1.481) on yield per plant IR-64Drt1 population. The total tillers per plant had the highest direct positive effect (1.821) on yield per plant in BPT-5204 population. In the joint population of BPT-5204 and IR-64Drt1, path analysis of yield components revealed that the biomass had the highest direct positive effect (0.658) on yield per plant. Information obtained in this study revealed that traits, the harvest index, biomass and panicles per plant are suggested as selection indices for grain yield improvement at segregating populations of rice.


2007 ◽  
Vol 20 (1) ◽  
pp. 39-45
Author(s):  
Khaleda Akter ◽  
S. H. Habib ◽  
M. K. Bashar ◽  
A. M. Nurunnabi

Thirty advanced breeding lines of deep-water rice were evaluated during T. Aman season (rainfed ecosystem) with a view to finding out variability and genetic association for grain yield and its component characters. All the tested characters showed significant variation. The highest genetic variability was obtained in filled grains/panicle followed by plant height. Panicles/plant, filled grains/panicle and grain yield had high genetic coefficient of variation and heritability in broad sense coupled with high genetic advance in percentage of mean. Panicle length, panicles/plant, plant height, filled grains/panicle and harvest index showed significant positive association with grain yield. Path coefficient analysis also revealed maximum positive and direct contribution of filled grain to grain yield followed by panicles/plant, 1000-grain weight and flag leaf area. Moreover, plant height had the highest indirect effect on grain yield through filled grains/panicle. Flag leaf area, harvest index and panicle length also had higher positive indirect effect on grain yield through filled grains/panicle.DOI: http://dx.doi.org/10.3329/bjpbg.v20i1.17024


2018 ◽  
Vol 1 (1) ◽  
pp. 149-160 ◽  
Author(s):  
Bhim Nath Adhikari ◽  
Bishnu Prasad Joshi ◽  
Jiban Shrestha ◽  
Naba Raj Bhatta

This study was conducted during summer 2015 at Regional Agriculture Research Station, Dipayal, Doti, Nepal to estimate the genotypic and phenotypic variability, heritability, genetic advance and correlation on grain yield and yield associated traits using 26 advance genotypes of lowland irrigated rice. Analysis of variance revealed the existence of significant difference for days to flowering, maturity, plant height, panicle length, thousand grain weight and grain yield. High heritability was estimated for days to flowering (0.88), maturity (0.79), thousand grain weight (0.48) and plant height (0.43) suggesting these traits are under high genetic control. High phenotypic variation was observed for grain yield (24.87%), number of grains/panicle (22.45%), number of panicles/m2 (20.95%) and straw yield (20.75%) while grain yield had medium (12.02%) and remaining traits showed low genotypic coefficient of variation (<10%). High phenotypic coefficient of variation estimated as compared to genotypic coefficient of variation showed environmental influence on the expression of traits. Grain yield (11.98) and days to flowering (10.32) showed medium and remaining traits sowed low genotypic advance as percent of mean. High to low heritability with moderate to low genotypic advance as percent of mean suggested these traits were governed by non additive gene thus direct selection is not beneficial. Further improvements on yield potentiality and yield traits on these genotypes are suggested by creating variation and selection. Panicle length (r = 0.230), days to flowering (r = 0.247), effective tillers (r = 0.488) and straw yield (r = 0.846) manifested significant positive association with grain yield indicating that yield can be increased if selection applied in favor of those yield components.


2015 ◽  
Vol 12 (2) ◽  
pp. 40-51 ◽  
Author(s):  
R Khare ◽  
AK Singh ◽  
S Eram ◽  
PK Singh

High heritability coupled with high to moderate phenotypic and genotypic coefficient of variation and genetic advance as per cent of mean was recorded for grain yield per plant, plant height, test weight, fertile spikelet per panicle, total grains per panicle and number of effective tillers per plant. Positive and significant association were observed for days to 50 per cent flowering, days to maturity, plant height, panicle length, fertile spikelet per panicle, total grains per panicle and spikelet fertility with grain yield per plant at both genotypic and phenotypic level, while highest positive direct effect on grain yield was recorded by fertile spikelet per panicle, total number of grains per panicle, plant height and days to 50% flowering. Based on ten quantitative traits the accessions were clustered into seven groups, the cluster III contained highest 14 accessions, followed by clusters I comprised 11 accessions and cluster VI, VII, V, IV and II have 9, 8, 7, 6 and 5 accessions, respectively. The first four principal components accounted for 77.13% of total variation of all the traits. DOI: http://dx.doi.org/10.3329/sja.v12i2.21915 SAARC J. Agri., 12(2): 40-51 (2014)


2020 ◽  
Vol 12 (4) ◽  
pp. 301-311
Author(s):  
G. Gerema ◽  
D. Lule ◽  
F. Lemessa ◽  
T. Mekonnen

Abstract. The present study was conducted to assess the nature and magnitude of genetic variability and traits association of bread wheat genotypes for yield and related traits. A total of 180 genotypes were evaluated in alpha lattice design with three replications in 2017/18 cropping season. Data for 10 quantitative traits were collected and subjected to analysis of variance. The result from the analysis of variance revealed highly significant variability observed among genotypes for all traits studied. Phenotypic coefficient of variation (PCV) is superior over genotypic coefficient of variation (GCV) for most traits but narrow variations were found between PCV and GCV for most of the traits. Heritability in broad sense and genetic advance as percent of the mean (GA%) were relatively higher for Kernels per spike and grain filling period. Grain yield showed positive and highly significant (p≤0.01) association with number of tillers, kernel per spike and plant height both on genotypic and phenotypic levels.The path coefficient analysis showed that spike length, plant height and kernels per spike had positive direct effect on grain yield on both genotypic and phenotypic levels. Divergence analysis (D2) grouped the total test germplasm into 10 clusters. Among those, clusters IV and IX showed the highest genetic distance and thus the possibility to develop segregating populations upon the crossing of widely related genotypes in those clusters. The results could help researches to utilize the most promising wheat genotypes of this study in future breeding programmes for enhancing desirable traits.


2021 ◽  
Vol 12 (5) ◽  
pp. 496-505
Author(s):  
M. Vennela ◽  
◽  
B. Srinivas ◽  
V. Ram Reddy ◽  
N. Balram ◽  
...  

The present investigation was carried out at Regional Agricultural Research Station, Polasa, Jagtial, Telangana state, India to study the correlation and path coefficient analysis towards yield, physical and chemical quality traits in 46 genotypes including two checks in Randomized Block Design with two replications during kharif, october, 2019. Association of yield and yield components and among grain yield characters makes us to understand their relationship towards selecting a high yielding and good quality varieties. The result from the study revealed that all the nineteen characters studied has shown a great range of variation for correlation and path analysis. The character association studies in this experiment revealed that the trait grain yield plant-1 had showed significant positive correlation with plant height, spikelet fertility, 1000 grain weight, milling %, hulling %, kernel length and kernel breadth whereas it showed negative and non-significant association with days to 50% flowering. The path analysis studies revealed that kernel length was the major contributor for grain yield plant-1 followed by plant height, spikelet fertility, number of grains per panicle, 1000 grain weight, milling %, gel consistency, amylose content and alkali spreading value. These characters showed direct positive effects for grain yield plant-1. From the study it can be concluded that the above characters can be used directly as the selection criteria in any rice yield improvement breeding programmes.


2020 ◽  
Vol 57 (2) ◽  
pp. 108-115
Author(s):  
D Shoba ◽  
S Robin ◽  
P Jeyaprakash ◽  
M Arumugam Pillai

Twenty six genotypes and four check varieties were studied for drought tolerance in rice. The experiment was conducted under both irrigated and stress regimes. Ten different drought tolerant contributing traits were evaluated under stress regime and five yield contributing traits were evaluated under irrigated regime. Among the studied genotypes, IR 87651-26-1-1-3 possessed desirable mean performance under stress for grain yield with other studied traits except number of panicles per plant. Under irrigated regime, the genotypes IR 87753-13-1-1-3, IR 87638-10-1-1-3, IR 87759-5-2-1-3 and IR 83381-B-B-137-3 were advantageous for grain yield and other studied traits except number of panicles per plant. From the variability studies under stress, the traits viz., leaf rolling, leaf senescence, leaf drying, panicle exsertion and grain yield exhibited high genetic advance indicated additive gene action and selection is desirable for these traits. High heritability with advantageous genetic advance was recorded for plant height and grain yield under non-stress regime. From the association analysis, grain yield had positive correlation with plant height, number of panicles per plant and panicle length and negative correlation with days to fifty per cent flowering, leaf rolling, leaf senescence, leaf drying and panicle exsertion under stress. Grain yield was positively correlated with days to fifty per cent flowering, plant height and panicle length under non stress. The desirable genotypes recognized from this study may be utilized as donors and the desirable traits identified may be exploited for drought tolerance rice breeding programs.


2016 ◽  
Vol 41 (1) ◽  
pp. 173-182 ◽  
Author(s):  
S Begum ◽  
A Ahmed ◽  
SH Omy ◽  
MM Rohman ◽  
M Amiruzzaman

Twenty-two maize hybrids were evaluated to find out their variability, character association and path coefficient of grain yield and its component characters. Significant differences were found among the genotypes for the characters studied. Ear length and grain yield (t/ha) had moderate genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV), but the had the low environmental co-efficient of variation (ECV). The heritability for all the characters was high. The characters viz. plant height, ear height and 1000-grain weight, showed high heritability along with high genetic advance. Ear length, ear diameter and kernel per row had highly significant positive correlation with grain yield. However, the deviations between genotypic and phenotypic correlation and magnitude of environmental correlation suggested considerable influence of growing environment in expressing almost all the characters. Path coefficient analysis revealed that plant height (0.659), ear length (0.934) and kernel-rows per ear (0.715) had highly significant positive direct effect on grain yield suggesting their importance during selection. Simultaneous restricted selection should be done for number of kernel rows per ear.Bangladesh J. Agril. Res. 41(1): 173-182, March 2016


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