International Research Journal of Plant Science (ISSN: 2141-5447) Vol. 2(7) pp. 191-200, March, 2011 Available online http://www.interesjournals.org/IRJPS Copyright © 2011 International Research Journals Full length Research Paper Correlation, path-coefficient and genetic diversity in lentil (Lens culinaris Medik) under rainfed conditions Sunil Dutt Tyagi and Mudasir Hafiz Khan Division of Plant Breeding and Genetics KPG College, Ghaziabad (UP) Accepted 21 March, 2011 An experiment was carried out during winter (rabi) season of 2007 and 2008 to assess the correlation, path coefficient and genetic diversity in 30 morphological diverse accessions of lentil (Lens culinaris Medik) under rainfed conditions. Days to 50% flowering, biological yield/plant, seed yield/plant and 100-seed weight showed significant differences and wide variations during both years. Low differences between phenotypic coefficient of variability and genotypic coefficient of variability were observed for all the descriptors during both years. Pods/plant, days to 50% flowering, biological yield/plant, seed yield/plant and 100-seed weight in both the years showed high heritability coupled with high genetic advance (per cent of mean) signifying the influence of additive gene effects. The characters viz., biological yield/plant and number of primary branches/plant showed positive and significant correlations with seed yield/plant and exerted positive and high direct effects on seed yield/plant for both years. D2 analysis groped accessions into three clusters having 16, 10 and 4 accessions. The highest genetic diversity was observed between cluster I and III. Hence, accessions belonging to cluster I and III can be used as parents for hybridization programme for the development of high yielding lentil genotypes under rainfed conditions. Key words: Correlation, cluster analysis, lentil, path coefficient, variability. INTRODUCTION Among pulses, lentil (Lens culinaris Medik) with 2n = 14, is one the most important legume crops in India. It is one of the principal crops cultivated in semi arid regions of the world, particularly in the Indian sub-continent, and the dry areas of Middle East. Globally, lentil shows only 5-6% of the total area under pulses. It is predominantly grown in Asia which accounts for 80 – 95% global area and production (Malik, 2005), respectively. However, even now over 2/3rd of the cultivated area is un-irrigated *Corresponding author Email: kmudasirhafiz@yahoo.com and productivity in these areas can only be increased by the development of crops that are well adapted to dry conditions. Genetic variability is a pre-requisite for any crop improvement programme. The knowledge of genetic diversity and association of characters with yield is of great importance to the breeder for making an improvement in a complex character like seed yield which showed little response to direct selection. Path analysis is used to determine the amount of direct and indirect effects of the causal components on the complex component (Guler et al., 2001). The relationships between yield and plant characters affecting 192 Int. Res. J. Plant Sci. yield and in between these characters are usually neglected and often reported as meaningless (Sing et al., 1973). Ghafoor et al. (1990) found positive direct effect of harvest index and biological yield on yield. According to path analysis, there were strong direct effects of the biological yield, harvest index and number of seeds per plant on the seed yield (Ciftci et al., 2004). Yadav et al. (2003) reported that seed yield/per plant showed a positive and significant association with biological yield/per plant and harvest index. Biological yield/per plant had the positive direct effect on seed yield. Kakde et al. (2005) found that seed yield/plant was positively correlated with harvest index but it was negatively correlated with pods number/per plant. Harvest index and biological yield showed direct relationship with seed yield. However, days to maturity and pods/per plant had direct effect on seed yield/per plant. Bicer and Şakar (2008) reported that total biological yield and number of clusters and pods per plant had high positive direct effects on seed yield. Younis et al. (2008) explained that days to flowering, plant height, number of primary branches, biological yield, harvest index and hundred seed weigh had positive direct effects on seed yield. Biological yield, hundred seed weigh and harvest index also had positive and highly significant genotypic and phenotypic correlation with seed yield. Hence, these traits could be used in breeding for seed yield in lentil. Cluster analysis helps to understand the genetic relation among the accessions and also to facilitate the selection of genetically diverse parents in hybridization programme resulting in considerable amount of heterosis and wide range of segregation. Genetic divergence has been studied in lentil (Kumar et al., 2004; Sirohi et al., 2007; Solanki et al., 2000 and Sultana et al., 2005) legumes (Ghafoor and Ahmad, 2005) . Hence, the study was taken to investigate the extent of genetic diversity, association of seed yield/plant with other quantitative characters and to estimate the direct and indirect effects of various characters on seed yield in lentil under rainfed conditions. MATERIALS AND METHODS Experimental material Seeds of thirty accessions of lentil viz., P-32225, L-412, L-4661, L4677, L-415, L-3 96, L-4676, L-4618, L-386, L-381, L-4594, L-¸ L4598, L-2147, L-4596, L-414, L-4597, L-416, L-417, L-310, L-307, L-4595, L-4674, L-308, L-306, L-309, L-4671, L-395, L-4672 and L- 4620 were obtained from National Bureau of Plant Genetic Resource, New Delhi, India. Experimental layout The experimental was laid in a randomized block design during winter (rabi) 2007 and 2008 under rainfed conditions at Experimental Farm of Kisan (PG) College, Simbhaoli, Ghaziabad (UP), India. In each of the four experiments (2 sowing dates x 2 years), each genotype was assigned to a single row/plot of 3 mt length in each replication. The row to row and plant to plant distance was kept at 25 and 10 cm, respectively. During experiment only pre-sowing irrigation was applied to ensure proper seed germination. The total rainfall during the growth period was 30-35 cm which was sufficient to maintain moisture stress condition under field conditions. Recording of data The data were recorded from 20 randomly selected plants from each treatment on eleven distinct morphological characters namely days to 50% flowering, day to maturity, number of primary branches, number of secondary branches, pods plant-1, plant height, seeds pod-1, seed yield (g), biological yield (g), 100-Seed weight (g) and harvest index (%). Statistical analysis Statistical analysis was performed on quantitative characters for each year and pooled analysis was carried out when the errors were homogeneous. Phenotypic and genotypic coefficients of variations were calculated according to Burton (1952). Heritability (bs) and expected genetic advance were estimated according to Burton (1952) and Burton and Devane (1953), respectively. The estimates of direct and indirect contribution of various characteristics to seed yield were calculated through path coefficient analysis as suggested by Wright (1921) and elaborated by Dewey and Lu (1959). The quantitative diversity of genotypes was grouped into different clusters following Toucher’s Method (Rao, 1952). RESULTS Analysis of variance and coefficient of variability The analysis of variance for different characters is presented in Table 1. The critical perusal of table revealed that highly significant genotypic differences were observed for all the characters under study. The genotypic coefficient of variability (GCV) and phenotypic coefficient of variability (PCV) for various characters studied are presented in Table 2. It was observed that the genotypic coefficient of variation for biological yield/plant, seed yield/plant, 100-seed weight, and days to 50% Tyagi and Khan 193 Table 1. Pooled (2007 and 2008) analysis of variance for quantitative characters Source variation of Environment (E) Replication (R) ExR Genotypes (G) ExG Error df Day to maturity 3 Days to 50% flowering 525.42** Number of Second 5.30** Pods plant-1 564.00** Number of Primary 1.26** Seeds pod-1 seed yield (g) 432.33** Plant Height (cm) 156.04** 2 100Seed weight 2.71* Harvest index (%) 245.37** Biologica l yield (g) 27.37** 0.18** 128.75** 4.25 0.05 0.02 10.38 40.97** 0.02 3.95 0.51 0.05 0.72 6 42.33** 8.75* 0.20 0.46 28.58 4.44 0.02 6.39 0.44 0.03 1.99* 29 4049.84** 709.16** 1.67** 5.34* 2445.15** 103.33** 0.29** 270.97** 30.29** 14.37** 4.79** 87 232 14.89 11.99 21.68** 3.84 0.09 0.10 0.26 0.37 32.61 60.81 5.69 7.77 0.01 0.02 5.86 7.69 0.51 0.79 0.10** 0.04 3.23** 0.72 Table 2: Variability, heritability and expected genetic advance for quantitative characters Source of variation Days to 50% flowering Day to maturity Number of Primary branches Number of Secondary branches Pods plant-1 Plant height Seeds pod-1 Seed yield (g) Biological yield (g) 100-Seed weight (g) Harvest index (%) Yea r Range I II I II I II I II I II I II I II I II I II I II I II 45.50-106.17 44.00-105.00 126.50-151.00 125.00-151.00 3.34-5.05 3.52-5.22 6.20-8.67 6.60-8.92 52.95-400.33 52.32-100.67 26.62-37.19 26.09-38.37 1.30-1.88 1.33-1.89 9.29-30.14 10.10-29.87 3.02-10.15 3.25-9.79 2.74-7.94 2.63-7.84 31.27-34.92 29.37-33.89 Parameters Mean GCV % PCV % 85.38 85.67 143.36 142.47 4.18 4.24 7.47 7.70 81.65 83.30 32.04 32.50 1.62 1.68 20.12 21.63 6.59 6.93 5.04 5.02 32.76 31.99 21.64 21.32 5.46 5.68 7.91 9.04 7.31 8.98 16.19 17.32 7.87 8.96 9.54 8.62 22.50 21.82 22.94 22.59 21.88 21.84 2.86 3.11 22.21 21.50 5.68 5.79 11.69 11.07 11.63 11.15 20.12 18.25 13.14 10.86 12.66 10.62 27.48 23.69 27.55 24.48 22.30 22.07 4.06 3.96 Heritabili ty 94.90 98.35 92.25 96.25 46.35 67.55 41.50 65.70 65.85 90.20 39.50 67.80 57.70 66.40 68.85 84.90 70.55 85.40 96.30 97.95 51.50 61.40 Expected advance 43.43 43.18 10.79 11.66 11.15 14.02 9.68 13.92 27.01 30.81 10.46 15.19 15.20 16.38 38.22 38.60 39.59 39.48 44.27 42.68 4.37 5.04 genetic 26.29** 194 Int. Res. J. Plant Sci. flowering was high during both years , 2007 and 2008 with the values of 22.50 and 21.82; 22.94 and 22.59; 21.88 and 21.84 and 21.64 and 21.32, per cent, respectively. However, moderate genotypic coefficient of variation was observed for pods/plant, number of primary branches, number of secondary branches, seeds/pod and plant height with the values of 16.19 and 17.32; 7.91 and 9.04; 7.31 and 8.98; 9.54 and 8.62 and 7.87 and 8.96 per cent, respectively. However, the rest of the characters showed low values of genotypic coefficient of variation. On the other hand, phenotypic coefficient of variation also exhibited similar trend of high, moderate and low variations with slightly higher values. Heritability and expected genetic advance The estimates of heritability in broad sense and expected genetic advance for various characters studied are presented in Table 2. The estimates of heritability in broad sense were high for days to 50 per cent flowering (94.90 and 98.35), days to maturity (92.25 and 96.25), 100-seed weight (96.30 and 97.95), seed yield per plant (70.55 and 85.40), biological yield per plant (68.85 and 84.90) and pods per plant (65.85 and 90.20). Moderate heritability estimates were observed for seeds per pod (57.70 and 66.40), harvest index (51.50 and 61.40), number of primary branches (46.35 and 67.55) and number of secondary branches (41.50 and 65.70). Low heritability was observed for plant height (39.50 and 67.80) Highest value of expected genetic advance, expressed as per cent of mean during both years, 2007 and 2008 was obtained for days to 50 per cent flowering (43.43 and 43.18), 100-seed weight (44.27 and 42.68) seed yield per plant (39.59 and 39.48) and biological yield per plant (38.22 and 38.60), while the rest of the character showed moderate to low values of genetic advance as per cent of mean. Correlation and path coefficient analysis The results pertaining to correlation coefficients are presented in Table 3. The seed yield/plant was positively and significantly associated with number of primary branches, secondary branches, pods/plant, plant height, biological yield/plant and 100-seed weight. Number of seeds/pod showed negative and significant correlation with 100-seed weight in both years. Primary branches and secondary branches/plant showed positive and significant correlation with pods/plant, plant height and biological yield/plant during both years of experiment. Pods/plant showed significant and positive association with plant height and biological yield/plant. The results pertaining to path analysis are presented in Table 3. It can be noticed from the table that out of 11 characters four exhibited positive direct effect on seed yield/plant during both years, whereas three characters showed positive direct effect during first year and negative direct effect during second year. Days to maturity exhibited negative direct effect during both years of experiment. Indirect effects on seed yield/plant were also estimated and it was found that biological yield/plant showed maximum indirect effect via number of primary branches and plant height while the indirect effect of plant height was also positive via number of primary branches and biological yield/plant. Similarly, pods/plant showed positive indirect effect via number of primary branches, plant height and biological yield, while harvest index exhibited positive indirect effect via primary branches, plant height, biological yield and 100-seed yield. Genetic divergence 2 On the basis of D values, all the 30 genotypes were grouped in 3 clusters (Table 4). The maximum number of genotypes (16) was grouped in cluster II followed by cluster III (10) and cluster I (4). The intra and inter-cluster distance among the genotypes was of varying magnitude (Table 5). The maximum intra- cluster distance was observed in cluster III (2.896) followed by cluster I (2.643) and cluster II (2.309). The maximum inter-cluster distance was observed between cluster III and I (5.155) followed by cluster III and II (3.467) and cluster II and I (3.233). The cluster mean for each character is presented in Table 6. Highest mean value for days to 50% flowering (94.10) and days to maturity (146.87) was observed in cluster III, while least mean values for these characters were observed in cluster I. Cluster I exhibited the highest mean values for number of primary branches (4.49), number of secondary branches (8.30), pods/plant (96.62), plant height (34.94), biological yield/plant (24.29) and seed yield/plant (8.00).Cluster II consisted of seeds/pod (1.69), 100-seed weight (5.22) and harvest index (33.15) genotypes while, least mean values for these character were observed in Tyagi and Khan 195 Table 3. Direct (bold) and indirect effects of characters on seed yield/plant and correlation coefficients (in parenthesis) between characters. Character s Year Days to 50% flowering Day to maturity Primary branches Secondary branches Pods plant-1 Plant height (cm) Seeds pod-1 Biological yield (g) 100-Seed weight (g) Harvest index (%) seed yield (g) Days to 50% flowering I 0.020 0.025 Day to maturity I 0.014 II 0.017 -0.008 I -0.006 0.011 -0.073 (-0.296) -0.112 (-0.322) 0.080 (-0.326*) -0.121 (-0.348*) 0.246 II -0.008 0.003 0.348 I -0.002 0.013 0.211 0.006 (-0.086) 0.010 (-0.103) 0.028 (-0.379*) 0.021 (-0.211) -0.062 (0.859**) -0.081 (0.807**) -0.073 II -0.003 0.002 0.281 -0.100 I -0.005 0.013 0.168 --0.053 -0.046 (-0.241) 0.067 (-0.257) -0.074 (-0.389*) 0.091 (-0.348) 0.130 (0.682**) -0.188 (0.722**) 0.139 (0.727**) -0.174 (0.666**) 0.191 II -0.006 0.003 0.251 -0.067 -0.261 I -0.005 0.008 0.142 -0.034 0.160 -0.004 (-0.256) -0.023 (-0.285) -0.004 (-0.247) -0.022 (-0.269) 0.009 (0.575**) 0.050 (0.614**) 0.008 (0.462*) 0.046 (0.562**) 0.014 (0.836**) 0.062 (0.755**) 0.017 -0.020 (-0.138) 0.043 (-0.193) 0.015 (0.100) -0.003 (0.012) 0.049 (0.336*) -0.059 (0.267) 0.033 (0.229) -0.036 (0.164) 0.027 (0.183) -0.071 (0.320) -0.015 -0.135 (-0.250) -0.231 (-0.258) -0.146 (-0.271) -0.306 (-0.342) 0.521 (0.965**) 0.839 (0.938**) 0.468 (0.867**) 0.674 (0.753**) 0.374 (0.692**) 0.617 (0.690**) 0.222 (0.412*) 0.014 0.055) -0.021 (0.081) -0.009 (-0.035) 0.008 (-0.032) 0.101 (0.309*) -0.061 (0.239) 0.073 (0.282) -0.040 (0.156) -0.034 (-0.132) 0.063 (-0.245) -0.032 (-0.122) 0.006 (-0.114) 0.011 (0.042) 0.011 (-0.218) 0.006 (0.024) -0.020 (0.400*) 0.090 (0.360) -0.006 (0.129) 0.133 (0.532**) -0.008 (0.151) 0.120 (0.480**) -0.023 (0.459*) -0.255 II -0.023 (0.699**) -0.006 (0.681**) -0.033 0.258 0.475** Number of primary branches Number of secondary branches Pods plant-1 Plant height (cm) Seeds pod-1 Biological yield (g) 100-Seed weight (g) Harvest index (%) (-0.100) II -0.007 0.002 0.213 -0.056 -0.197 0.082 I -0.003 -0.003 0.083 -0.017 0.035 -0.002 -0.073 (0.331) 0.146 II 0.005 0.000 0.093 -0.063 -0.083 0.027 -0.221 I -0.005 0.009 0.238 -0.063 0.132 0.007 0.025 0.569 (0.636**) 0.093 (0.172) -0.017 (-0.019) 0.540 II -0.006 0.003 0.326 -0.075 -0.180 0.052 0.004 0.895 I 0.001 0.001 0.096 -0.020 -0.025 -0.002 -0.075 0.256 0.035 (-0.135) -0.134 (-0.514**) 0.182 (-0.709**) 0.123 (0.474**) -0.116 (0.453*) 0.260 II 0.002 0.000 0.083 -0.016 0.064 -0.011 0.157 0.405 -0.257 I -0.002 0.007 0.099 -0.009 0.029 0.008 0.022 0.098 0.057 0.048 (0.192) -0.007 (0.148) 0.066 (0.263) -0.009 (0.350) 0.088 (0.219) -0.011 (-0.022) -0.006 (-0.022) -0.050 II -0.001 0.000 0.125 -0.053 -0.125 0.16 -0.058 0.313 0.006 0.251 -0.238 -0.028 -0.317 0.980** 0.933** 0.865** 0.783** 0.687** 0.712** 0.441* 0.616** 0.191 0.025 0.997** 0.990** 0.481** 0.422* 196 Int. Res. J. Plant Sci. Table 4. Distribution of 30 genotypes in various clusters Cluster I Number genotypes 4 Cluster II 16 Cluster III 10 Cluster of Genotypes included P-32225, L-412, L-4661, L-4677 L-415, L-3 96, L-4676, L-4618, L-386, L-381, L-4594, L-¸ L-4598, L-2147, L4596, L-414, L-4597, L-416, L-417, L-310 L-307, L-4595, L-4674, L-308, L-306, L-309, L-4671, L-395, L-4672, L-4620 Table 5. Average inter and intra-cluster (bold values) distances among different cluster in lentil Cluster Cluster I Cluster II Cluster III Cluster I 2.643 3.233 5.155 Cluster II Cluster III 2.309 3.467 2.896 Table 6. Cluster means for different clusters in lentil Characters Days to 50% flowering Day to maturity Number of Primary branches Number of Secondary branches Pods plant-1 Plant height -1 Seeds pod Seed yield (g) Biological yield (g) 100-Seed weight (g) Harvest index (%) Cluster I 55.42 128.00 4.49 8.30 96.62 34.94 1.59 24.29 8.00 5.09 32.98 Cluster II 90.71 146.67 4.41 7.85 90.46 34.44 1.69 23.96 7.93 5.22 33.15 Cluster III 94.10 146.87 3.83 7.08 66.46 30.17 1.60 16.05 5.31 5.18 33.07 cluster I. Cluster III was found as the low seed yields among the three clusters. The low mean values for pods/plant, plant height and biological yield/plant were found in cluster III. Overall results indicated that maximum mean values for most of the yield contributing characters were found in cluster III. of lentil. It will provide an effective means to assess the extent of available variability, which will be useful for selecting superior genotypes on the basis of their phenotypic expression so as to use them in breeding programme to improve the commercially important characters. DISCUSSION Variability, heritability and genetic advance The aim of the present investigation was to study the genetic divergence in 30 genotypes on eleven characters The mean sum of squares due to genotypes was significant for all the characters indicating that the Tyagi and Khan 197 variation was genetic. Though variability in population is an indispensable prerequisite for any improvement, it cannot be the only criterion for deciding, as to which trait is showing the highest degree of variability. Phenotypic and genotypic variances and coefficient of variation can help in this regard. Maximum variation (phenotypic and genotypic) was exhibited by biological yield/plant, seed yield/plant, 100-seed weight, and days to 50% flowering. Similar results on variability for different characters were reported by Chakraborty and Haque (2000), Kishore and Gupta (2002), Rathi et al. (2002), Bicer and Sakar (2004), Haddad (2004) and Singh et al. (2005). However, low variability for other yield contributing traits was reported by Ayaz et al. (2004) and Singh et al. (2004). The minimum variation was recorded for number of primary branches per plant, harvest index, days to maturity and number of seeds per pod. Results on these aspects were reported by El-Attar (1991) and Chakraborty and Haque (2000). Genetic variability is very important for the improvement of crop plants. The more the variability in the population, the greater is the chances for producing desired plant types. Heritability estimates and genetic advance in a population provides information about the expected grain in the following generations. The most important functions of heritability estimates in the genetic studies of quantitative characters is their predictive role. Possible advance through selection based on phenotypic values can be predicted only from knowledge of the degree of correspondence between phenotypic and genotypic values. Thus, it is clear that a character with high GCV and high heritability will have high genetic advance. It can be stated that high heritability for a trait does not necessarily mean that it will also show high genetic gain, unless it is coupled with high GCV. The heritability, which is a ratio of genotypic and phenotypic variance, is mainly due to the additive gene effects in narrow sense, but in the broad sense it includes both additive as well as non-additive gene effects. The heritability values estimated in the present study are expressed in broad sense. Broad sense heritability, however, gives only a rough estimate. Moreover, broad sense heritability and narrow sense heritability are generally negatively correlated (Kempthorne, 1957). If heritability was mainly due to additive effects, it would be associated with high genetic gain and if it is due to non-additive, genetic gain would be low (Panse, 1957). Only six characters namely, days to 50 per cent flowering, days to maturity, 100-seed weight, seed yield per plant, biological yield per plant and pods per plant showed high heritability. The high heritability indicated that the characters were less influenced by the environment. Singh (1999), Chakraborty and Haque (2000), Kishore and Gupta (2002), Rathi et al. (2002), Bicer and Sakar (2004), Singh et al. (2005) also estimated high heritability for important morphological traits. Table 2 reveals that days to maturity showed high heritability, did not show equally high genetic advance. Johnson et al. (1955) suggested that characters with high heritability coupled with high genetic advance would respond to selection better than those with high heritability and low genetic advance. The characters like days to 50% flowering, 100-seed weight, seed yield/plant, biological yield/plant and pods/plant showed both high heritability as well as high genetic advance which could be improved through either pure line selection or simple mass selection. Moderate heritability and medium genetic advance was observed for seeds per pod number of primary branches and number of secondary branches. It indicates that these parameters are governed by additive gene action and could be equally improved through selection. On the other hand, harvest index exhibited moderate heritability with low genetic advance indicating that this character was governed by non-additive genes and selection would not be effective for this character. Days to 50% flowering, biological yield per plant, seed yield/plant and 100-seed weight showed high GCV, heritability and genetic advance (as percentage of mean). This indicated that these characters were governed by additive gene effects and can be improved through selections effectively. On the other hand, days to maturity exhibited low GCV and genetic advance with high heritability indicating non-additive gene effects and for improving this character heterosis breeding or recurrent selection should be followed. Genotypes which exhibited both high variability and heritability along with high genetic advance for certain characters may be evaluated in multi-location trials and isolated as donors for these characters or used as parents in hybrid development programme. Correlation and path coefficient analysis Seed yield is a complex quantitative character governed by large number of genes and is highly influenced by the environment. Studies on correlation provide an 198 Int. Res. J. Plant Sci. opportunity for critically assessing the relationship of these characters with seed yield. The correlation over the wide range of environments is likely to give true picture about the relationship, which will help the breeder to formulate strategies for indirect selection. Therefore, it is always possible to bring in improvement by resorting to indirect selection for one or more of its component characters. From this point of view, the information on correlation of seed yield with related traits is the prerequisite to form an effective selection strategy aimed at its improvement. Agarwal et al. (2001) elaborated the fact that positive correlation with seed yield and cluster per plant was consistent. This positive association was earlier reported Chauhan and Singh (2001). Moreover, positive association of pods per plant, biological yield/plant, plant height and 100-seed weight was additionally supported by Hamdi et al. (2003) and Luthra asnd Sharma (1990). High positive correlation of pods plant-1 with seed yield may be attributed to the increased sink strength (Nakaseko, 1984). So these characters may be considered as important selection criteria for making significant gain in seed yield. Changes in direction and magnitude of correlation coefficient observed between the years may be ascribed to significant genotype x environment interaction. This is confirmed by treatment x year interaction (Table 1). Knowledge of correlation alone is often misleading as the correlation observed may not be always true. Two characters may show correlation just because they are correlated with a common third one. In such cases, it becomes necessary to study a method which takes into account the causal relationship between the variables in addition to the degree of such relationship. Path coefficient analysis measures the direct influence of one variable upon the other and permits separation of correlation coefficients into components of direct and indirect effects. Partitioning of total correlation into direct and indirect effects provides actual information on contribution of characters and thus forms the basis for selection to improve the yield. Path coefficient analysis (Table 3) for seed yield revealed that the traits like biological yield, number of primary branches and plant height and showed highest positive direct effect on seed yield. It means a slight increase in any one of the above traits may directly contribute towards seed yield. Similar results have also been reported by Solanki (2006), Yadav et al. (2005) and Joshi et al. (2005). Positive direct effect of biological yield and plant height and indirect positive effect via number of primary branches were the main reason for strong positive correlation of these characters with seed yield (0.997** and 0.990** and 0.441** and 0.616**, respectively). Similar results were reported by Dixit and Dubey (1984). The path coefficient analysis revealed that direct and indirect contribution of biological yield, plant height, number of primary branches and pods plant-1 was maximum on seed yield. The above findings revealed that whatever may be the character chosen for increasing the seed yield, the improvement could be achieved mainly through these traits. The residual effect was found to be moderate which indicates that there may be some more components that are contributing towards seed yield. Genetic Divergence Genetic divergence (D2) is the basis of variability and helps to craft the designed genotypes as per the requirement. The present study aims at analyzing the genetic divergence of 30 genotypes of indigenous and exotic origin using D2 statistics. The pattern of clustering in respect to lentil genotypes depicted very interesting picture. By and large, there were 3 distinct clusters encompassing all genotypes. The clustering pattern also revealed that the groups of genotypes which were together in a cluster also indirectly proved their stable performance. Another important observation was the presence of an exclusively separate cluster of lentil genotypes, which suggested that geographical background also plays an important role in constellation. The exclusive distinct cluster by the lentil genotypes included in the studies proves that there is a clear relationship between clustering pattern and geographical distribution. Jeena and Singh (2002), Kumar et al. (2002), Haddad (2004), Sarker et al. (2005), Sirohi (2007) and Solanki (2007) also studied the genetic divergence in lentil. 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