Highest Positive Direct Effect Research Articles

Studies on genetic variability, correlation and path coefficient analysis in fenugreek (Trigonella foenum graecum L.) genotypes

An experiment was carried out on fenugreek genotypes to study the genetic variability, and relationship among yield traits. Analysis of variance showed that the genotypes significantly differed in all the growth and yield parameters studied. The variability study indicated that PCV was higher than the GCV for all the traits and high genotypic and phenotypic coefficient of variation was recorded for the number of primary and secondary branches per plant, the number of pods per plant and seed yield per plant. High heritability was observed for all the studied characters. Correlation studies revealed that the seed yield was significantly and positively correlated both at the genotypic and phenotypic levels to pod length and the number of pods per plant. The highest positive direct effect on seed yield per plant was observed on the number of pods per plant (0.3467) followed by the number of secondary branches per plant (0.3259), the number of seeds per pod (0.2301) and pod length (0.1468). The information on these statistical parameters would be helpful to identify the genotypes having superior yield potential which can be utilized in the improvement of fenugreek. Key words: Genotypic variability, heritability, correlation, path coefficient analysis

Genetic variability and association analysis in the segregating population of extra early barnyard millet [Echinochloa frumentaceae (Roxb.) Link] involved crosses

An investigation was conducted to evaluate the F2 population of two crosses of barnyard millet viz., cross I, ACM-15-343 X IEC 82 and cross II, Co (Kv) 2 X IEC 107 for extra earliness. Genetic variability and association analyses were carried out for sixteen biometrical traits. In both the crosses, high PCV and GCV was observed for the width of flag leaf, length of a lower raceme, number of racemes and grain yield per plant. Low PCV and GCV was observed for days to maturity. The minimum difference between PCV and GCV was observed for all the traits in both crosses, indicating the negligible effect of environment on the expression of the characters. Moderate to high heritability with moderate to high genetic advance in all the traits revealed the predominance of additive gene action. A positive significant correlation was noted for grain yield with plant height, days to flowering, days to maturity, the number and length of nodes, the number of basal tillers, stem diameter and single ear head weight. Path analysis disclosed a high positive direct effect of the number of basal tillers and single ear head weight on yield. These results together help in the selection of superior segregants based on the number of basal tillers and single ear head weight in forwarding them to successive generations. Key words: Barnyard millet, F2, Variability, Association analysis

Trait relationship and path analysis under sodicity in Nagina 22 rice mutants

The present study was conducted for evaluating EMS induced mutants for sodicity tolerance in rice. A set of 402 Nagina 22 rice mutants along with three sodicity tolerant check varieties namely TRY2, TRY3 and TRY4 were screened at Anbil Dharmalingam Agricultural College and Research Institute, Trichy under sodic soil condition and also screened under hydroponics condition at the seedling stage. A total of 13 biometrical traits and salt injury scores were recorded and subjected to association analysis and path analysis. Correlation analysis showed that there was a significant and positive correlation observed for flag leaf length, flag leaf breadth, the number of total tillers per plant, the number of productive tillers for the plant, tillering efficiency percentage, panicle length, panicle weight, panicle harvest index and hundred seed weight and also showed significant and negative correlation for salt injury index and vegetative vigour. Both the scores at the field (vegetative vigour) and salt injury score showed a negative correlation with single plant yield. Path analysis revealed a high positive direct effect on the number of productive tillers per plant, panicle weight, hundred seed weight and panicle length and the remaining traits showed negligible effects on single plant yield. As a result, enhancing the correlating trait as well as reducing the effect of negative correlating trait leads to the development of better tolerant varieties. Key words: Nagina 22 mutants, correlation, path analysis, sodicity

Genetic Association and Path Coefficient Analysis for Grain Yield Characters in Elite Rice (Oryza sativa L.) Germplasm

The study was carried out to study the correlation and path coefficient analysis for grain yield characters in 36 rice genotypes including one check for 13 quantitative parameters. The experimental material was carried out during Kharif, 2020, in a randomized block design with three replications obtained from the Department of Genetics and Plant Breeding, SHUATS, Allahabad, U.P., India. Analysis of variance revealed that there is significant variability among the genotypes. Correlation coefficient analysis at genotype level and phenotypic level revealed that plant height, flag leaf length, flag leaf width, number of tillers per hill, number of panicles per hill, number of spikelets per panicle, biological yield, and harvest index, showed positive significant correlation with grain yield per plant. Path coefficient analysis at both genotypic and phenotypic levels revealed that flag leaf length, number of panicles per hill, days to maturity, biological yield, harvest index and test weight had positive direct effect on grain yield per hill. Biological yield per hill (0.8481) exerted high positive direct effect as well as high positive significant association (0.809**) with grain yield per hill thus this character resulted as most essential direct yield character.

Multivariate Analysis and Character Association Studies for Yield and Nutritional Characters in Swarna and Type 3 RIL Population of Rice (Oryza sativa L.).

The investigation was carried out in one hundred Swarna X Type 3 RIL population of rice to understand the association among yield, yield attributing and nutritional traits. Their direct and indirect effects on the grain yield using correlation and path analysis and the principal component analysis was assessed using multivariate analysis. Significant differences were observed among the RIL population for the traits studied. High values of heritability and genetic advance were observed for plant height, panicle weight, number of filled grains per panicle, panicle weight, 1000-seed weight, grain yield per plant, grain iron and zinc concentration. Character association for the yield attributing traits at both genotypic and phenotypic level revealed significant positive association of grain yield per plant with test weight and plant height. Path coefficient analysis revealed that test weight had highest direct positive effect on grain yield per plant followed by plant height and filled grains per panicle. PCA showed that a cumulative variance of 32.5% from PC1 attributed by grain iron, grain zinc, plant height and test weight would be beneficial in contributing to the total morphological diversity. RILs P45 and P57 have shown higher grain yield per plant with high iron and zinc concentrations. Thus, the trait test weight that showed positive and direct association with grain yield can be focused in selection and can be utilized for improvement in future breeding programmes.

Studies on the nature of relationships between grain yield and yield-related traits in durum wheat (Triticum durum Desf.) populations

This experiment was conducted at the Field Crops Institute, Agricultural Experimental Station of Setif (ITGC-AES), Eastern semi-arid areas of Algeria, during two successive cropping seasons, 2010/11 and 2011/12. The aim of the study was to evaluate the association of yield and yield-related traits and determine the direct and indirect effects of yield-related traits on grain yield. The plant materials consisted of 330 F3 and 174 F4 durum wheat lines along with their four parents and one control cultivar, which were evaluated under rainfed conditions in a semi-arid region. Data on nine agronomic traits were recorded. Sufficient genetic variability was observed among wheat traits as indicated by the minimum and maximum mean values and confirmed by the phenotypic and genotypic coefficients of variation that took intermediate and high estimates for most of the traits evaluated both in F3 and F4 generations. A high heritability (>60%) was observed for almost all the traits studied indicating the involvement of the additive action of genes in their genetic determinism. Results of stepwise regression and path analysis showed that biological yield, harvest index and number of spikes were the most determinant components of grain yield, exhibiting high positive direct effects (0.697, 0.683 and 0.293 in F3 vs 0.695, 0.205 and 0.560 in F4, respectively) coupled with positive and significant correlations (r=0.696*, r=0.778* and r=0.127* in F3 vs r=0.686*, r=0.628* and r=0.491* in F4, respectively) with this trait. These three yield-contributing traits can be considered as suitable indirect selection criteria to improve grain yield in the subsequent generation of the wheat breeding program.

Character Association and Path Analysis for Yield Components and Biochemical Traits in Maize (Zea mays L.) Genotypes

Background: Grain yield is a complex character so direct selection for yield as such can be misleading. Keeping in view, the present study aimed to assess the path coefficient analysis with correlation coefficient technique to establish the direct and indirect relationship between the yield and its component. Methods: The present investigation carried out during kharif 2019 at Centurion University of Technology and Management, Odisha in randomized complete block design with 3 replication involving 20 maize genotypes. Data were collected from five randomly selected plnts on 20 agromorphic and biochemical traits. All the biochemical analysis estimated from leaf sample following standard procedure. Result: The traits shelled grain weight, cob diameter, number of grains per cob and anthesis silking interval were found to possess significant association in disirable direction with five ear weight at both genotypic and phenotypic levels. None of the biochemical trairts establishing significant positive association with yield. Highest positive direct effect on 5 ear weight was noticed by shelled grain weight (1.108) followed by phenols (0.115), internodal length (0.106) and days to 50 percent anthesis (0.102) indicating that the selection for these characters were likely to bring about an overall improvement in grain yield directly.

Intergeneration correlation and parent-offspring regression in rust resistance derived F4 and F5 generations in bread wheat

The present investigation aimed to determine the intergeneration correlation and parent-offspring regression in F4 and F5 generations of two wheat crosses, WH 1105 × WH 711 and RAJ 3765 × WH 711 grown during the rabi 2015-16 and 2016-17 in research area of Wheat and Barley Section, CCS HAU, Hisar. Correlation studies indicated that grain yield/plant showed a significant positive correlation with almost all the yield attributing traits which may be considered as prime traits during selection. Biological yield/plant had the highest positive direct effect on grain yield/plant, followed by the harvest index. Almost all the characters had high indirect effects through biological yield/ plant and harvest index. The F4 generation progenies showed highly significant and positive values of intergeneration correlation and regression with F5 generation progenies for all the characters in both the crosses. Therefore, the performance of the plants in the F4 generation is a reliable indicator of the performance of their progeny in subsequent generations. Narrow sense heritability values were high for the number of grains/ear, grain weight/ear and grain yield/ plant while response to selection values were high for the number of grains/ear, biological yield/plant, plant height and number of spikelets/ear in the progenies of both crosses. Hence, improvement through selection can be based upon these traits in these crosses. Thus estimation of correlation and regression analysis among yield and yield components may provide effective selection criteria to improve wheat grain yield.

Character association and genetic gain of nine agronomic traits of F1 populations in onion (Allium cepa L.)

F1 populations of half diallel cross were considered for this investigation. Phenotypic component of variation (s2P) was higher than genotypic (s2G), interaction ((s2I) and within error (s2w) components of variation. Trait bulb weight showed the highest values for s2P, s2G, s2I and s2w. The noticeable amount of phenotypic, genotypic, interaction and within error covariation was found in the combination of BW×BY, possibly indicating wide scope of selection for this pair of characters. Genotypic correlations were higher than the respective phenotypic correlations. This situation was also marked in the path coefficient analysis. Bulb yield/plot showed highly significant and positive correlation coefficient with other characters both at phenotypic and genotypic levels. When all the nine characters were included in an index, it exhibited the highest genetic gain as percentage. When a combination of two or more characters was studied in a function, the efficacy was higher than that of direct selection for bulb yield. The combination of five, six, seven or eight characters showed higher percentage of expected gain. Due to significantly correlated with BY and having high positive direct effect at phenotypic level characters viz., LL, BW, PH and NLs is considered as primary yield components. Again combinations of these four characters gave the commendable expected genetic gain of 330.7290% may be considered as important selection index for this material.

Assessment of variability and association for seed yield and yield attributing traits among the interspecific derivatives of greengram x blackgram cross

The present investigation was carried out with 24 progenies in F4 generation of interspecific cross derivatives of Vigna radiata cv. VBN(Gg)2 x Vigna mungo cv. Mash 114 to study the variability and association among the yield and the yield component traits. A set of 24 F4 progenies from the interspecific cross between greengram (VBN(Gg)2) and blackgram (Mash 114) formed the basic genetic material for the present investigation. Variability studies recorded high Phenotypic Coefficient of Variation (PCV) and Genotypic Coefficient of Variation (GCV) for the traits viz., number of branches/ plant, number of clusters/ plant, number of pods/ plant and seed yield /plant. High heritability (h2) along with high genetic advance as per cent of mean (GAM) were recorded for the traits, plant height, number of clusters/ plant, number of pods/ plant and seed yield/ plant. Association studies revealed that the trait number of pods/ plant alone recorded high direct positive effect on seed yield/ plant. The results indicated that high magnitude of variability was present among the interspecific progenies for these traits. The high heritability and genetic advance might be due to presence of additive gene action. Hence selection based on these traits might be effective for genetic improvement among the interspecific progenies of Vigna radiata x Vigna mungo. The study indicates that the trait, number of pods / plant should be given due importance in selection programme for seed yield improvement in the interspecific progenies of greengram and blackgram.

Variability, Correlation, and Path Coefficient Analysis of Grain Yield and Yield-Related Traits of Facultative Barley Accessions Grown Under Rainfed Conditions

A study was conducted during the period of three concessive years from 2016/2017 to 2018/2019 in the experimental field of the Institute of Agriculture - Karnobat, Southeastern Bulgaria with the aim to investigate the variability, heritability, and correlation between grain yield and yield-related traits of breeding lines of facultative barley under rainfed conditions and to select lines with desirable agronomic traits for including in further breeding work for the development of facultative barley varieties for Bulgarian environments. The traits: number of days to heading, plant height, spike length, spikelet number per spike, grain number per spike, grain weight per spike, and grain yield were recorded. The analysis of variance indicated significant differences between 6-rowed facultative barley genotypes in the studied traits. Most of the traits under the study showed the relatively low phenotypic and genotypic coefficient of variation. The estimates for heritability in broad-sense were high for the number of days to heading, grain weight per spike, and 1000-grain weight and very high for plant height and spike length suggesting a possibility for improvement of those traits through selection based on phenotype. Whereas low heritability of grain yield was found indicating that the phenotypic selection could be ineffective under these specific conditions. Grain yield of facultative barley accessions showed a significant positive correlation with spike length, spikelet number per spike, grain number per spike and grain weight per spike. The traits with the highest positive direct effect on grain yield were grain number per spike and 1000-grain weight while days to heading had a highly negative direct effect on grain yield. A combination of high heritability and high direct on grain yield in 1000-grain weight and days to heading shows that those traits may be used in early-generation selection in breeding of high-yielding facultative lines. The accession TX01D236 had a significantly higher grain yield compared to check varieties and could be included in future breeding work.

Genetic variability, correlation and path coefficient analysis in segregating population of rice

A study was conducted to evaluate the genetic variability parameters, correlation and path coefficient analysis for eight yield related traits in segregating F2 population of an aerobic restorer AR 9-18 × YPK 198 (Donor for yield enhancing genes Gn1a and OsSPL14) at ICAR-IIRR, Hyderabad during the kharif, 2019. The results indicated that, productive tiller number, grain number per panicle and plant yield showed high PCV and GCV. Height of plant, productive tiller number, grain number per panicle and plant yield exhibited a high heritability and also high genetic advance as per cent of mean which indicates simple selection would be effective for enhancement of these traits. Correlation studies indicated that plant yield was associated significantly positive with height of plant, productive tiller number, length of panicle and grain number per panicle. High positive direct effect on plant yield was recorded by productive tiller number, grain number per panicle and height of plant. Key wordsRice, Variability, F2 segregating population, Correlation, Path analysis

Strategies for Selecting Early Maturing Maize Inbred Lines for Hybrid Production under Low Soil Nitrogen and Striga Infestation

Development, testing and selection of superior inbred lines is crucial for the success of a hybrid program targeting Striga-infested and low soil nitrogen (low-N) environments. The practical value of inbred lines is determined by multiple traits, most of which are inter-dependent. The main objective of this study was to identify early maturing inbred lines based on multiple traits under optimal, low-N and Striga-infested environments for hybrid development and population improvement. One hundred early maturing inbred lines were evaluated under artificial Striga-infestation, low-N and optimal growing environments for two years at Kwadaso and Nyankpala in Ghana. The inbred lines exhibited high levels of genetic variability for grain yield and other agronomic traits desirable for Striga resistance and low-N tolerance. Under optimal growing conditions, days to silking (DS), ears per plot (EHARV) and days to anthesis (DA) had high direct effects on grain yield (GYLD). Days to silking and ears per plant (EPP) had the highest positive direct effects on GYLD, while DA had the highest negative direct effect on grain yield in low-N environments. Under Striga-infestation, the highest negative direct effect on GYLD was obtained with EASP. All the measured traits previously identified to have direct influence on grain yield were associated with it and could be used for indirect selection for improved grain yield under the contrasting environments. Forty-eight of the 100 inbred lines studied were identified as low-N tolerant and forty-nine as Striga resistant.

Character association and path analysis studies in upland rice (Oryza sativa) genotypes

This study was conducted during 2019-20 at Prince of Songkla University, Hat Yai campus, Thailand to calculate the correlation coefficient, path analysis, direct and indirect effects of ten popular upland rice genotypes (Oryza sativa) to determine the nature of relation between grain yield with other yield contributing traits. The experiment was designed as a completely randomized block design with three replications with observations on the growth, grain yield, and yield components of rice. The result showed that plant height, effective tiller, panicle length, panicle number, flag leaf length, flag leaf width, harvest index, filled grain, unfilled grain, seed fertility, seed length and seed width was positively significant and phenotypically correlated with grain yield per genotypes (0.657, 0.166, 0.589, 0.778, 0.136, 0.538, 0.228, 0.816, 0.081, 0.424, 0.168 and 0.106, respectively). Path analysis indicated that plant height, effective tiller, panicle length, panicle number, internode length and filled grain exhibited positive direct effect on grain yield. Among these traits, filled grain, seed fertility, seed width, panicle number and effective tiller possessed high positive direct effects (10.96, 7.50,1.25, 0.4802 and 0.1665). Thus, selection of these traits like effective tiller, panicle number, filled grain, seed fertility can bring improvement yield performance of upland rice.

بررسی اثر سطوح مختلف نیتروژن و تراکم بر رشد و عملکرد Datura stramonium L.

Datura stramonium L. is one of the important medicinal plants in the pharmaceutical industry due to its alkaloid compounds. To investigate the effects of urea fertilizer at three levels (60, 120, and 180 kg.ha-1) and planting density at three levels (6, 10, and 14 plants.m-2) on the yield and yield components of this plant species, a factorial experiment was conducted in a randomized complete block design in the research farm of Isfahan Agricultural and Natural Resources Research and Education Center, Iran in 2018 and 2019 crop years. The main effects of density and urea on the traits including height, number of lateral branches, and 1000-seed weight and the interaction of different urea and density levels on the traits including seed yield, biological yield, number of capsules per plant, number of seeds per plant, and number of seeds per capsule were significant in both years. The highest seed yield (1282.37 and 1212.53 kg.ha-1, respectively in 2018 and 2019 years) was obtained in the urea fertilizer 180 kg.ha-1 and 6 plants.m-2 treatment. The causal analysis results showed that the highest direct positive effect at the different levels of density and urea was related to the number of capsules per plant. The results of this experiment showed that the application of 180 kg.ha-1 of urea and 6 plants.m-2 could play an important role in increasing the seed yield of medicinal plant D. stramonium.

Chemical and molecular scale speciation of copper, zinc, and boron in agricultural soils of the Canadian prairies

The general incidence of copper (Cu), zinc (Zn), and boron (B) deficiencies in soils of the Canadian prairies may be related to identifiable, highly variable, inherent soil attributes. The objective of this study was to investigate the variability of selected properties and their relationship with the bioavailability, forms, and distribution of Cu, Zn, and B in a range of prairie soils. The nature of these micronutrient distributions were evaluated by measuring extractable concentrations, supply rates, and by separation into various chemical pools through sequential extraction and spectroscopic speciation analyses. Soil pH was found to be the least variable property [coefficient of variation (CV) < 13%], whereas carbonate content was the most variable (CV > 130%). The Cu and B availability showed strong negative correlation with the sand content in all soils. Path coefficient results indicated that organic carbon had the highest positive direct effect on availability and supply of Cu and B in Grey soils. Extractable Zn was positively correlated with organic carbon content of Brown and Dark Brown soils. Overall, high sand content and low organic matter were identified as important soil properties contributing to the deficiency of Cu, Zn, and B. The major proportion of Cu, Zn, and B was found in the recalcitrant residual fraction (59%–88%), with the smallest proportions in labile soluble, exchangeable forms (2%–8%). The X-ray absorption near edge structure revealed that Cu and Zn associated with carbonate minerals were dominant forms of these micronutrients present in all soils. Chemisorption is likely a major process regulating the bioavailability of Cu and Zn in prairie soils.

Determination of agronomic properties of tobacco (Nicotiana tabaccum L.) voor-oogst on krosok production using path analysis

Tobacco is an important trade commodity in Indonesia because it supports the country’s economy through taxes and excise. The path analysis is used to measure the direct and indirect effects of agronomic character parameters that are strongly correlated with the results. The path analysis in this study aims to find the agronomic characteristics of tobacco that can be used as selection criteria to get high krosok production. The number of samples used was 50 plants. Observation parameters included plant height, stem diameter, number of leaves per plant, foot leaf length, foot leaf width, middle leaf length, middle leaf width, shoot leaf length, shoot leaf width, leaf wet weight, yield, heavyweight. The results showed the wet weight of the leaves can be used as direct selection criteria. The fresh weight of the leaves has a high positive correlation (Rx10y = 0.812), a high positive direct effect (Px10y = 0.924), and a contribution value of 75.007%.

Evaluation Yield of Okra with Associated Traits Using Analysis Correlation and Path

The study was conducted at the fields of the Department of Horticulture and Landscape Gardening, College of Agriculture Engineering Sciences, University of Baghdad. During the spring 2017. All the recommended practices were followed during experimentation. The experimental material consisted four Genotype it is Batraa, Btera, Mosulle, and local selection. The experiment was applied in Randomized Complete Block Design (RCBD). The objectives of Study were to estimate the some genetic parameters and path coefficient for some traits Okra, The results of statistical analysis for these genotypes were highly significant differences for all traits except the traits number of leaves, the number of main branches, the number of nodes before the first flower and Fruit length. Genetic analysis showed that the genetic variation for all traits was more than environment, High value of heritability was for yield per plant (95.4%) highly significant genotypic, phenotypic and environmental correlation between fruit number and plant yield (0.998, 0.990 and 0.905) respectively. The result of path coefficient the number of fruit had the highest positive direct effect (0.8551) followed by fruit width, fruit weight and plant high (0.0446, 0.0260 and 0.0106) respectively. It can be conclude the possibility of using the traits fruit weight yield per plant as criteria for selection to improve the yield of Okra.

Correlation and Path Coefficient Analysis of Fruit Yield Attributes in Forty Genotypes of Okra (Abelmoschus esculentus)

Farmers and plant breeders are often faced with the problem of selecting the best genotypes of okra as a result of lack of adequate knowledge of association among yield and its component characters which has led to the inefficiency of crop improvement. Efficient selection in any breeding programme will not only depend on yield alone but on yield together with other yield components. Based on this fact, this research was carried out on forty genotypes of okra to determine the association of different agronomic characters with pod yield and their direct and indirect effects on pod yield so as to select the best genotype for further breeding work. The seed of each genotype was sown in a plot laid out in randomised complete block design with three replications, and data were collected on fourteen agronomic characters and analysed. Pod yield per plant had highly significant and positive genotypic and phenotypic correlations with plant height, number of leaves, petiole length, internode length, plant height at flowering, peduncle length, fruit length, fruit diameter, number of seeds and number of pods, indicating that pod yield in okra could be a function of these traits. Highly significant, negative genotypic and phenotypic correlations were observed for pod yield per plant with days to 50% flowering and days to maturity, suggesting that early flowering and maturity are desirable traits for improved productivity in okra. Path coefficient analysis revealed that number of pod per plant had the highest positive direct effect on pod yield per plant with its largest indirect effect with days to 50% flowering and reduction in days to maturity. Due to close associations among these traits, they could be used as basis of selection when high yield is the breeding objective.

Correlation and path analysis studies on yield and yield components in brinjal (Solanum melongena L.)

An experiment on correlation and path analysis involving thirty F1 and six parents of brinjal (Solanum melongena L.) was carried during rabi, 2018 at Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore. The genotypic correlation coefficient was higher in magnitude than the corresponding phenotypic correlation coefficient for most of the characters. The fruit yield per plant had exhibited a highly significant and positive correlation with fruit length (0.837) and the number of fruits per plant (0.716). The genetic improvement of fruit yield thus can be obtained by selection for these yield components. Path coefficient analysis revealed that the characters viz., the number of fruits per plant (0.962), days to first harvest (0.922) and fruit girth (0.616) had a high positive direct effect on fruit yield per plant. Thus, the fruit yield per plant can be improved by making the selection of these traits in the yield improvement programme.