Showing 42 results for Correlation
A. Dehdari, M. Mobli, A. Rezai,
Volume 5, Issue 4 (1-2002)
Abstract
In order to determine the relationships among the different traits of onion and to study the direct and indirect effects of these traits on bulb and seed yield, an experiment was conducted in 1998 at the research farm of Isfahan University of Technology. Results showed that phenotypic and genotypic correlations were similar and bulb weight showed the highest and lowest coefficients of correlation with bulb diameter and number of days to emergence, respectively. Results of stepwise regression analysis showed that leaf width at 25% of its length from the neck, leaf length, and leaf dry weight were the best estimators for leaf area bulb diameter, bulb length, plant height and number of days to maturity were the most important determining characters for bulb yield variation. Number of fertilized florets was the best determinator of seed yield and bulb weight, while diameter and volume were the best describing characters for the number of meristems on the basal plate. Path-coefficient analysis revealed that bulb diameter showed the highest direct positive effect on bulb yield and the indirect effect of plant height through bulb diameter on it was of prime importance. Number of fertilized florets per plant and number of inflorescence per plant through the number of fertilized florets showed the highest direct and indirect effects on seed weight, respectively.
H. Alipour, A. Rezai, S. A. M. Meibodi, M. Taheri,
Volume 5, Issue 4 (1-2002)
Abstract
This experiment was conducted to study genetic variation for electrophoretic seed protein patterns and their relations with some seed characteristics such as protein and oil percentages, chemical compositions and 100-seed weight among 270 soybean (Glycine max L. Moench) genotypes.
Among different electrophoresis procedures examined, 10% and 4.5% concentrations of acrylamide for resolving and stacking gels, respectively, 13.5 mg/ml concentration of protein buffer extraction, injection of 10 microlitre sample injection into gel hollows, 2.5 miliamper and 2-hours staining period were determined as the best combination to achieve clear bands and good separation. Based on relative mobility on gel, 30 protein bands were observed, of which only 5 varied among genotypes. In general, 8 electrophoretic patterns were recognized. Cluster analysis based on qualitative evaluation of patterns grouped the genotypes in 8 clusters and classified different bands in three groups. Simple concordance (matching) coefficients between protein bands with relative mobilities of 2.5% and 49.5% were zero, which is an indication of their independent occurrence. Probably, these bands are coded with one gene that in dominant and recessive homozygous genotypes appear as a single band at different positions on the gel. Analysis of variance revealed significant differences (P<0.05) among protein patterns for protein and oil percentages. Correlation coefficients between variable protein bands and studied traits showed a positive and significant relation (P<0.05) of bands with relative mobility of 3.5 and 49.5 with protein and phosphorous contents of the seeds, respectively. Protein patterns having band with relative mobility of 49.5 had the highest phosphorous content. Black hilum color of seeds was related to protein band with relative mobility of 52.
G. Saeidi,
Volume 5, Issue 4 (1-2002)
Abstract
Flax (Linum usitatissimum L.) is an oilseed and widely adapted crop. Oil of regular genotypes of flax is used in industry because of its unique fatty acid profile. New, mutant genotypes of flax have oils similar to sunflower oil which can be used as edible oil. This experiment was conducted to investigate the genetic variation of agronomic traits and productivity in different edible and industrial oil genotypes of flax in Isfahan. The genotypes were evaluated in augmented design.
Based on the results, the average numbers of seedling/m2 in edible and industrial oil genotypes were 178 and 367 with variation coefficients of 70 and 10%, respectively. Maturity also showed variation and varied between 89 to 116 days in edible oil genotypes and between 89 to 128 days in industrial oil genotypes. Plant height varied between 57 to 86 and 49 to 73 cm in edible and industrial oil genotypes, respectively. Seed yield also had considerable variations and varied between 429 to 2651 and 779 to 2389 kg/ha with variation coefficients of 35 and 25 in edible and industrial oil genotypes, respectively. Seed yield per plant showed a high and positive correlation with basal branches (r=0.77**) and bolls per plant (r=0.93**), but high and negative correlation with stand (r=-0.66**). Regression analysis revealed that approximately 96% of the variation in seed yield per plant was attributed to variation in bolls per plant, seeds per boll and seed weight and they were determined as the major yield components, respectively. Bolls per plant was the most important yield component and contributed to 87% of the variation for seed yield per plant.
M. A. Edriss, M. Mostajeran, R. Ebadi,
Volume 6, Issue 2 (7-2002)
Abstract
To estimate the relationship between honey yield and some of the morphological characters, five queen-daughters from each of 30 queen-mothers were studied. The queen-mothers were selected randomly from the apiary of Research Center of Animal Science and Natural Resources in Isfahan Province. Summer honey yield was measured from the difference of honey comb before and after honey extraction while fall honey production was calculated from area of sealed honey combs. Morphological characters were recorded using a stereodissecting microscope fitted with a calibrated micrometer reticule according to Ruttner’s procedures.
The mean of honey yield for a year was estimated to be 10.05 kg. Phenotypic correlations between yearly honey production and summer and fall honey productions were estimated to be 0.49 and 0.88, respectively, while the correlation between summer and fall honey yields was low (0.019). There were significant correlations between summer honey yield with cubital-b index, tibia length and forewing width (0.28, 0.27 and 0.25, respectively). Also there were significant correlations between metatarus width with total and fall honey yields (0.22 and 0.23, respectively). Genetic correlations between metatarus length and cubital index with summer honey yield were negative (-0.75 and
-0.45, respectively). It may be concluded that due to the high correlation between summer honey production and total honey yield, one could improve yearly honey production by selecting on the basis of summer yield of colonies. Among morphological traits, metatarus length, forewing width and cubital index could be used in the breeding plan in order to increase honey yield.
F. Nourbakhsh, A. Jalalian, H. Shariatmadari,
Volume 7, Issue 3 (10-2003)
Abstract
Cation exchange capacity (CEC) is one of the most important chemical characteristics which influences soil quality from different aspects. At the same time, CEC is an input parameter of many computer models being applied in soil science and agriculture. Methods of CEC determination are always time-consuming and laborious. Therefore, developing a model for CEC estimation from other soil properties is essential. The objective of this study was to understand the associations between CEC (as a dependent variable) and sand, silt, clay, organic matter and pH (as independent variables). In this study 464 soil samples from A, B, and C horizons of different soils were used. Results revealed that CEC is negatively correlated with sand (r=-0.389***) and is positively correlated with organic matter (r=0.772***), clay (r= 0.391***) and silt (r= 0.233***). No significant correlation was observed between CEC and pH. Stepwise regression analysis showed that both organic matter and clay enter the model and that coefficients of determination (r2) for the multiple models are higher than those of simple linear correlations. Other parameters could not increase the r2 considerably. Correlation analysis on data from A, B, and C horizons revealed that the CEC of organic matter in different horizons are not the same. Separation of Aridisols could not increase the r2 of the model and the accuracy of the estimations. Correlation studies in acid soils showed that the contribution of organic matter in CEC is much higher than that of clays.
A. R. Hosseinpur,
Volume 8, Issue 3 (10-2004)
Abstract
Information about nonexchangeable potassium (NEK) release rate in Hamadan soils is limited. The objective of this study included an investigation of the dynamics of NEK in some soils from Hamadan Province by successive extraction with dilute citric acid over a period of 2500 h and determination of the correlation between the rate constants in this kinetic equation with soil properties. The results of this experiment showed that the initial NEK release rate was rapid which slowed down later on. The amount of NEK released after 2500 h ranged from 0.87 to 2.89 cmol kg-1. The amount of NEK released after 2500 h was significantly correlated with CEC, NEK, and soil separates. First order, parabolic diffusion law and power function equations described well the NEK release kinetics based on their highest determination coefficient and their lowest value of the standard error of the estimate. Release rate constant in the first order, parabolic diffusion law and power function equations ranged from 1.0×10-4 to 3.0×10-4, 1.7×10-4 to 10.6×10-4 and 2.75×10-1 to 4.6×10-1, respectively. In the correlation study the rate constants in the kinetic equations were correlated with some chemical properties and particle size distribution. The results of this experiment also showed that dilute citric acid can be used in the study of NEK release.
M. Khalili Mahani, B. Hatami, H. Seyedoleslami, A. M. Rezaei, B. Heidari,
Volume 8, Issue 4 (1-2005)
Abstract
Elm leaf beetle were reared under controlled conditions (25± 2 oC, 70± 5%R.H. and 16L: 8D) to determine relationship between biological traits and the number of eggs per female on different hosts and to evaluate correlation between traits. U. carpinifolia, U .c. var. umbraculifera, U. glabra var. pendula and Celtis caucasica were examined as hosts. The biological traits consisted of 1st, 2nd and 3rd larval developmental times first, second, and third larval percent mortality rates prepupal and pupal developmental times male and female longevity and pre-ovipositional period recorded during experiments. The relationships between traits and the number of eggs per female were determined by multiple regression (Foreward selection and stepwise). The correlation between traits was evaluated, too. The results showed that the number of eggs per female were mostly affected by certain special traits such as 2nd and 3rd larval developmental time, pre-ovipositional period and male longevity which are distinct in different hosts and seasons.
H. Sabori, A. Rezai, S. A. M. Mirmohammady Maibody, M. Esfahani,
Volume 9, Issue 1 (4-2005)
Abstract
An experiment was conducted at Rasht Rice Research Institute, in 2001 to study trait relationships and to determine the direct and indirect effects of different characteristics on grain yield of rice (Orgza sativa L.). A 9x2 factorial experiment in complete randomized block design with 3 replications was used. The two factors were 9 cultivars, namely: Hashemi, Ali Kazemi, Binam, Sepeedroud, Nemat, Khazar, Taichung, Chanto, and Usen, and 2 planting patterns (15x15 cm and 30x30 cm). Significant differences were detected among cultivars, between planting patterns, and their interaction effects. The direct effect of the number of panicles/m2 on grain yield was positive and significant in both planting patterns and their combined analysis. Heading date had a positive and significant direct effect on the number of panicles/m2 in both planting patterns and their combined analysis. Only in 30x30 cm planting pattern, a positive correlation was found between biomass at heading date and the number of panicles/m2. Grain weight per plant had a direct and positive effect on panicle weight in the 3 cases studied. Also, in all the cases studied, flag leaf area had positive direct effects on grain weight per plant. Grain filling rate and effective grain filling period increased in 30x30 cm planting pattern. Native cultivars demonstrated longer latent period. Grain filling rate and effective grain filling period showed positive direct effects on grain yield in both plantings. According to the results obtained, an increase in the number of panicles/m2, rate of grain filling, and effective grain filling period would enhance grain yield. Selection for heading date, grain yield per plant, and flag leaf area would also indirectly increase grain yield.
M. Moradi, A. Rezai, A. Arzani,
Volume 9, Issue 1 (4-2005)
Abstract
This study was conducted to analyze the correlation among grain yield, yield components, duration of vegetative and grain filling periods in twelve oat (Avena sativa L.) cultivars at the Research Farm of the College of Agriculture, Isfahan University of Technology, from 2001 to 2003. A randomized complete block design with three replications was used. The correlation coefficients among the grain yield/m2, fertile tiller/m2, grain number/panicle and the duration of grain filling period were positive and significant. Among yield components, the number of panicle/m2 and the number of grain/panicle had the largest direct effects on grain yield (0.68 and 0.30, respectively). Furthermore, the duration of the grain filling period had the highest direct effect on the number of grain/panicle and the grain weight (0.82 and 0.80, respectively), which were greater than its correlations with the number of grain per panicle (0.42) and 1000-grain weight (0.35). However, its negative indirect effects through other traits reduced the correlation coefficients. The results of path analysis indicated that the number of panicle/m2 and the number of grain/panicle had the largest direct effects on the grain yield. Considering the direct effects of grain filling duration on the number of grain/panicle and the 1000-grain weight, and also the fact that most of the dry matter in oat is produced in this period, it seems plausible to use these traits as a selection criterion in breeding programs for higher yields of cultivars of oat.
M. Eslami, S.a.m. Mirmohammady Maibody, A. Arzani,
Volume 9, Issue 3 (10-2005)
Abstract
To evaluate heritability, phenotypic and genotypic correlation coefficients, phenotypic and genotypic variances as well as relationships between some of the grain quality traits, an investigation was conducted in a randomized complete block design replicated three times in 2001, using four durum wheat genotypes PI40100, Dipper-6, Oste/Gata, Shova and their F2 and F3 progenies derived from their crosses. Grain quality characteristics including seed hardiness, protein content, SDS sedimentation volume and gluten content were evaluated. The results indicated that wet gluten content and dry gluten content had the highest coefficient of variation. Statistical analysis showed a significant difference between genotypes for all traits with the exception of SDS sedimentation volume. Dry gluten content had the highest heritability (90.4%) while SDS sedimentation volume had the lowest heritability (48.6%). Results of correlation analysis indicated that seed hardiness correlated significantly with protein content, SDS sedimentation and dry gluten content. Protein content had a positive correlation with wet and dry gluten content. Since dry gluten content showed a high correlation with protein content (quantity) and seed hardiness had a high correlation with SDS sedimentation volume, hence these two traits can be used as the selection criteria for improving quality of protein in durum wheat.
A. Abouzari Gazafrodi, R. Honarnegad, M. H. Fotokian, A. Alami,
Volume 10, Issue 2 (7-2006)
Abstract
In order to investigate path analysis and study correlations among 16 agronomic traits, 49 Iranian and foreign rice entries were evaluated in a simple lattice square as experimental design with 2 replications at research farm of Tonekabon agricultural college in 2001. Analysis of variance showed significant difference among genotypes for all the studied traits (p<0.05). Phenotypic and genotypic correlation analysis showed positive and significant correlation between grain yield and the number of productive tiller, total tillers and number of grain per panicle. Based on path analysis of the traits, the number of productive tillers had the highest direct effect on the grain yield. Furthermore, the number of grain per panicle and 100-grain weight had a high direct effect on the yield. Overall, the results are suggestive of the direct selection for grain yield in these genotypes through above - mentioned traits.
A. Siah-Marguee, M. H. Rashed-Mohassel, M. Nasiri-Mahallati, M. Banayan-Awal, H. Rahimiyan-Mashhadi,
Volume 10, Issue 3 (10-2006)
Abstract
This study was conducted in a sugar beet field at Collage of Agriculture Experimental Station, Ferdowsi University of Mashhad, Iran. In order to describe the pattern of spatial variations and density of Chenopodium album, Solanum nigrum, Amaranthus sp., Portulaca oleracea, Echinochla crus-galli, and Convulvulus arvense as the main prevalent annual and perennial weeds of sugar beet fields, geostatistic methods were used. Samples were taken by systematic method from the corners of (7m × 7m) grids, using (0.5m × 0.5m) quadrates in three stages (before application of herbicides, after herbicide treatment, and before harvesting sugar beets). The integrity of spatial variation of variables was determined by using variogram functions and distribution maps of species. The variograms indicated that variations of all variables did not happen by chance. The maximum and minimum ranges of variation were observed in Solanum nigrum (by 142.7m) and Portulaca oleracea (by 1.5m), respectively. Both maximum and minimum ranges of variations were related to pre herbicide application. The highest and the lowest spatial correlations were related to Amaranthus sp. (in the third sampling treatment) and Solanum nigrum (in the first stage of sampling), respectively. The spatial distribution maps confirmed the patchiness distribution of the weeds. The patch of weed was constructed from a dense point at the center, gradually tapering toward the edges. The patches were skewed across the rows and irrigation channels. The structure of patches altered during the growing season. Any information on the distribution of weeds in the fields can be useful to improve decision makings in relation to applying the herbicides, selecting the herbicide type or applying the amount of herbicide. Also it can be useful to better design of weed control programs.
M. Vatankhah, M. Moradi-Sharbabak, A. Nejati-Javaremi, S. R. Miraei-Ashtiani, R. Vaez-Torshizi,
Volume 10, Issue 3 (10-2006)
Abstract
In this study external fat-tail dimensions (upper, middle and lower width, length, length of gap, depth and upper circumference) and fat-tail weights collected on 724 Lori-Bakhtiari sheep were used to study external fat-tail dimensions and their relationships with fat-tail weights. Sheep were 3 months to 6 years old and slaughtered at the industrial slaughter house of Joneghan in Chaharmohal and Bakhtiari province in 2003. The mean of fat-tail dimensions were estimated as 15.83, 23.85, 24.73, 26.52, 14.96, 14.12 and 52.59 cm for upper width, middle width, lower width, length, length of gap, depth and upper circumference, respectively. Fat-tail weight varied from 0.10 to 20.60 with overall mean of 2.71 kg. Fat-tail percentage varied from 1.18 to 37.18 with overall mean of 11.87 percent. The effects of fixed factors of age, sex and body condition of sheep on all of traits were highly significant (p<0.0001). The least square means of all traits except fat-tail percentage were increased with increasing age of sheep. Lowest least square mean (± s.e) of 2.12 ± 0.25 kg fat-tail weight and 7.91 ± 0.72% fat-tail were observed for sheep having body condition score of 1 and the highest least square mean with fat-tail weight of 9.84 ± 0.56 kg and fat-tail percentage of 20.59 ± 1.63 were observed for sheep having body condition score of 5. Estimation of correlation coefficients among external fat-tail dimensions and fat-tail weight were positive and varied from 0.60 between upper fat-tail width and fat-tail weight to 0.83 between upper circomference of fat-tail and fat-tail weight. Upper circumference of fat-tail accounted for %69.5 of variation of fat-tail weight. This study showed that fat-tail weight in live sheep of Lori-Bakhtiari could be estimated using external fat-tail dimensions with very high accuracy (r = 0.904).
M. R. Jazayeri Nooshabadi, A. M . Rezai,
Volume 11, Issue 1 (4-2007)
Abstract
This research was conducted at Research Farm of Isfahan University of Technology to examine the relations among phonologic, morphologic and physiologic traits and their effects on grain yield of 20 oat (Avena sativa L.) genotypes. A randomized complete block design with three replications was used in each irrigation treatment (i.e. irrigation after 70±3, and 130±3 mm evaporation from class A pan). Grain yield had significant and positive correlations with harvest index and relative water content (RWC) in both irrigation treatments and with plant height at maturity in non-stress condition. Also, grain yield had significant and negative correlation with days to heading. Factor analyses resulted in three factors in each condition, which were named yield factor, phenologic factor and sink factor in both conditions. Based on stepwise regression, harvest index was the first character which entered the grain yield model in both conditions. At the next step, RWC and plant height entered the model, with harvest index explaining 66% and 64% of yield variation in stress and non-stress conditions, respectively. The results of path analysis in both conditions showed that harvest index had the highest positive direct effect on grain yield. The highest indirect negative effects through number of grain per panicle were obtained for the harvest index and panicle m-2 in stress and non-stress conditions, respectively.
M. Salehi, A. Haghnazari, F. Shekari, H. Baleseni,
Volume 11, Issue 41 (10-2007)
Abstract
In order to evaluate relationship between Different traits in lentils (lens culinaris Medik), a field study was conducted as an RCBD based design with 3 replications on Zanjan University Research Farm during spring of the year 2004. ANOVA analysis revealed significant differences for all characters except for the number of primery branches. Correlation analysis indicated positive and significant correlation between seed yield and harvest index, number of primery branches, pods/plant and biological yield, and grian yield. The result of the factor analysis also showed that the second factor including number of primery branches, pods/plant, grian yield, canopy width and seeds/plant was an important trait involved in the grian yield in lentil. In addition, cluster analysis helped divide the genotypes into four distance groups of large, medium, semi medium and low yields.
V. Narjesi, H. Zeinal Khaneghah, A. Zali,
Volume 11, Issue 41 (10-2007)
Abstract
Thirty soybean cultivars from different maturity groups were evaluated in a randomized complete block design with four replications in Research Station of College of Agriculture at Tehran University in Karaj in 2004. The purpose was to determine genetic relationship of some important agronomic traits related to seed yield. Analysis of variance showed that there were significant differences among varieties for the traits under study, indicating the existence of genetic variation among varieties. Number of pods/plant, number of seeds/plant and 100-seed weight, all of which are considered yield components, had the highest genotypic correlation with seed yield. Using stepwise regression analysis, 85.6 % of seed yield variation was attributed to four traits, including harvest index, biological yield, protein precent and number of seeds /plant. Harvest index was more important for predicting seed yield compared to other traits based on standardized ßs. Results of path analysis showed that the harvest index and protein precentage had the highest and lowest direct and positive effect (p=0.536), (p=0.008), respectively. Therefore, harvest index may be considered as a selection criteria to improve seed yield in breeding programs. Results of factor analysis showed five independent factors accounted for 80.2 % of total variations in data. The first principle determined 28.2 % of total variation and was designated as phenologic factor.
M. Yousofi Azar, A.m. Rezai,
Volume 11, Issue 42 (1-2008)
Abstract
This study was conducted at Research Farm of Isfahan University of Technology to evaluate drought tolerance potential of 23 F2:4 wheat lines derived from the cross of Virmarin (susceptible line) and Sardari (tolerant line). A randomized complete block design with three replications was used in each irrigation treatment (i.e. irrigation after 70±3 and 120±3 mm evaporation from class A pan for non-stress and stress conditions, respectively). Drought tolerance and susceptibility indices were calculated for yield, and principal components analysis was performed on the basis of indices. Rosielle and Hambline tolerance index and Fisher and Maurer stress susceptibility index had positive and significant correlation, but their correlations with drought yield and the first two principal components were negative. High value of these components indicates low sensitivity to drought. The first component had high and positive correlations with geometric mean productivity, stress tolerance index and harmonic mean. Lines number 4, 17, 11 and 14 with high yields in drought condition, showed high values for these indices. Line number 2 with high yield in non-stress condition and in spite of high sensitivity to stress, was a superior genotype based on these indices.
M. Sabokdast , F. Khyalparast,
Volume 11, Issue 42 (1-2008)
Abstract
This research was conducted in order to determine the relationship between grain yield and yield components, using 30 common bean varieties in a randomized complete block design with four replications at the Agricultural filed faculty of Agriculture,Tehran university In this study 18 traits were assessed on 10 random plants from each plot. The result showed that there were significant differences among varieties in terms of trait under study, indicating the existence of genetic variation among varieties. Also results showed that the grain yield had a positive and significant genotypic correlation with number of seed/pod, pod weight, number of pod/plant, biological yield, days to flowering and maturity. Stepwise regression analysis showed that the maximum variation in grain yield could be attributed to the number pod/plant, number seed/plant, 100 seed weight and pod length. The results of path analysis showed that the highest direct effect, being positive, was related to number seed/plant and the lowest direct effect, which was related to number pod/plant. Factor analysis resulted in three factors that accounted for 78/7% of total variation. The first factor accounted for 38.39% of total variation and was designated as yield and yield component factor. This factor is comprised of pod weight, biological yield, grain yield and number of pod/plant traits.
M. Ramazani, H.a. Samizadeh Lahiji, H. Ebrahimi Koulabi, A. Kafi Ghasemi,
Volume 12, Issue 45 (10-2008)
Abstract
In order to study agronomic and morphological traits in maize hybrids in Hammedan, two early (108 and 301), three medium (604, 647 and TWC647) and two late maturing (704 and 711) hybrids were evaluated in a randomized complete block design with three replications in Agricultural and Natural Resources Research Station in Hammedan in 2005. 33 morphological and phonological traits were recorded from 10 plants randomly selected from two central rows of each plot. The maximum and minimum grain yield was obtained from SC647 and SC301, respectively. The grain yield had the highest correlation with dehusked ear weight. Factor analysis of data after varimax rotation identified four factors that accounted for 98.03% of total variance. The scatter plot of hybrids based on the two first factors (the seed yield factor and phenological structure factor) showed that SC704 had the maximum forage yield and the best physiological characteristics and SC647 had the maximum grain yield, cob diameter and number of seed in row.
M. Bayat, B. Rabiei, M. Rabiee, A. Moumeni,
Volume 12, Issue 45 (10-2008)
Abstract
To study relationship between grain yield and important agronomic traits of rapeseed in paddy fields as second culture, fourteen varieties of spring rapeseed were grown in a randomized complete block design of experiment with three replications at Rice Research Institute of Iran, Rasht, during 2005-2006. Analysis of variance showed that there were significant differences between varieties for most of traits. Broad sense heritability ranged from 0.29 for pod length to 0.99 for days to maturity. Phenotypic and genotypic coefficients of variation for days to maturity and the number of pods in secondary branches were the lowest and highest, respectively. Moreover, genetic advance with 5% of selection intensity varied from 3.68% (0.25 cm) for pod length in main branch to 31.48% (915.58 Kg.ha-1) for grain yield. Results from genotypic correlation coefficients demonstrated that there were positive significant correlations between grain yield and the number of secondary branches, the number of pod in main and secondary branches, pod length in secondary branches, pod diameter in main and secondary branches, 1000-grain weight and oil percentage, and negative significant correlations between grain yield and days to 90% of flowering and days to maturity. Path analysis on genotypic correlations for grain yield as a dependent variable and the other traits as independent variables showed that the 1000-grain weight and the number of pods in secondary branches had the highest direct effects and days to 90% of flowering had low and negative direct effect on grain yield. Therefore, indirect selection for increasing 1000-grain weight and the number of pods in secondary branches are recommended for improving grain yield in rapeseed as second culture in paddy fields.
