INTRODUCTION Curry leafis botanically as Murraya koenigii L. Sperg has a wide distribution throughout India, both in wild and cultivated forms. It is a perennial tree spice cum medicinal plant and is versatile in nature (Chittaragi et al., 2022). A number of ‘landraces’ of this species are widely found in homestead gardens, especially in southern India. They areunder-utilized and under explored spice crops in terms of efforts towards their genetic improvement and area under cultivation.Generally, genetic resource of any crop plant includes gene pools of both domesticated and wild species. They are the potential resource of useful genes, which could be of immense use for the genetic improvement of crops. Vavilo (1926) stated that about 160 species of domesticated plants have originated in India. Among these, the tree spice, curry leaf constitutes a minor group of plant, which had its origin in India. In plant breeding program, it is essential to maintain a germplasm collection or have access to new material in the gene pool from which potential attributes may be incorporated into the crop (Simmonds, 1979 and Nandi et al., 2021). Evaluating the genetic variation in the germplasm is the first step toward understanding the scope and utility of material in the collection (Marshall, 1990). Information obtained from the analyses of genetic variability and molecular systematics of crop species will allow the breeders to understand better the biogeographical distribution, variability and historical development of the crop germplasm with which they are working, and to facilitate more efficient use of the available variability for the crop (Harlan, 1992; Devi et al., 2021). Curry leaf in India has ample genetic variability. Grouping of the curry leaf genotypes and the presence of variation among them indicated the strong scope for breeding programme (Chittaragi et al., 2021). In Tamil Nadu, curry leaf is mainly grown in Coimbatore, Erode, Madurai, Salem and Tiruchirappalli districts. The plantis rich in the volatile properties as well as antioxidants and it isutilized in our traditional systems of medicine too (Xie et al., 2006; Chittaragi et al., 2021). Every household of Indian kitchen were not satisfied without curry leaves. Because they are used for culinary purposes as a condiment. Recent past this high-value low volume crops are gaining prime value in the nutraceutical industries. The growing demand from the emerging segment of nutraceuticals is driving the global consumption of Indian spices.The curry leaf has vast adaptability and distribution to the different soil, agroclimatic condition, and its nutraceutical value, there is a scope for searching genotypes for salt affected soil, which will be an alternate crop even for the salt affected soil. In addition to that curry leaf has natural variability in its growth, yield and biotic stress.In this connection, it is a time to find out the genotypes which could meet the need of domestic and industrial needs. In addition to that finding the variability among the population is vital for further breeding work in curry leaf. With this view, an experiment was conducted at HC&RI (W), TNAU, Trichy, Tamil Nadu between 2016-2019with thirteen genotypes used to assess the variability, heritability, genetic advance and inter relationships between traits and the direct and indirect effects of some quantitative parameters. MATERIAL AND METHODS The investigation was carried out to collect the different curry leaf genotypes across Tamilnadu between 2016-2019. Curry leafland races or genotypes collected from different locations were established at Horticultural College and Research Institute for Women, Tamilnadu Agricultural University, Trichy under sodic soil. The details of land races or genotypes collected were given in table 1. The plants were planted at a spacing of 1.5 × 1.5 m and all cultural practices were performed as per the standard package of practices. The research trial was laid out in randomized block design with three replications. The observations on growth and yield attributes viz., plant height (cm), plant girth (cm), internode length (cm), petiole length (cm), number of mature shoot per plant, number of compound leaf per plant, number of leaflet per compound leaf, leaf area and fresh yield per plant (g) were made in each replication. The mean data were used to assess the variability present among the population and subjected to correlation coefficient among the various traits observed in curry leaf. The data recorded for each character was subjected to analysis of variance (ANOVA) using randomized complete block design to test the variations among genotypes. The analysis of variance was calculated using the procedure suggested by Panse and Sukhatme (1985). The genotypic and phenotypic variation were calculated by using the mean sum of square from variance table (Lush, 1940). The Phenotypic Coefficient of Variation (PCV) and Genotypic Coefficient of Variation (GCV) were calculated as per the formula proposed by Burton (1954). Accordingly, the PCV and GCV of the genotypes were classified into three range of variations such as low (< 10 %), medium (10-20 %) and high (> 20 %) as suggested by Sivasubramanian and Menon (1973). Heritability was estimated as per the formula suggested by Lush (1940) and expressed in per cent. The range of heritability was categorized as low (0-30 %), medium (31-60 %) and high (> 60 %) as proposed by Johnson et al. (1955). Genetic advance was calculated as per formula proposed by Johnson et al. (1955) and characters were classified in to high (more than 20 %), medium (10 - 20 %) and low (less than 10 %). RESULT AND DISCUSSION In the present investigation analysis of variance was carried out for nine traits. The analysis of variance showed significant difference among the genotypes for all traits observed and reported that the genotype mean square for the traits observed were found to be significant (Table 2). The estimates of phenotypic variance, genotypic variance, phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) were depicted within the table 3. Genetic variance among the curry leaf population were from 0.27 for internodal length to 879.16 for plant height while, the phenotypic variance was ranged from 0.35 to 955.64 respectively for the internode length and plant height. Among the plant growth characters studied, plant height (879.16 and 955.64), leaf area (308.81 and 329.90) and number of mature shoots per plant (28.86 and 31.45) recorded the very best genotypic and phenotypic variances respectively. This result expressed that the existing curry leaf population reflected with large variability. Hence such genotypes might be utilized for the further crop improvement programmes. Similar results were reported earlier by Lal et al. (2001) Shoba et al. (2020); Chittaragi et al. (2022) in curry leaf. The result informed that those attributes were more viable for selection than the other characters and inferred that the presence of considerable genetic variability for the studied genotypes, which empowers the breeder to improve curry leaf production only through simple selection. Hence the selection among the genotypes may be based on these traits will be efficient. Generally genotypic coefficient of variation is a measure of genetic variability which provides means to compare with other characters facilitating the successful identification of desirable types under sodic soil. The range of GCV of the traits recorded was ranged from 13.83 % in leaflet per compound leaf, to 46.01 % for leaf area. Likewise, the PCV was ranged from 20.02 % for leaflet per compound leaf to 47.55% for leaf area (Table 3). According to the statement of Deshmukh et al. (1986), the PCV and GCV values greater than 20% are regarded as high and values between 10% and 20% to be medium, whereas values less than 10% are considered to be low. Accordingly, high PCV and GCV were registered for Leaf area (47.55 and 46.01), Number of mature shoot per plant (45.89 and 43.97), Plant girth (32.36 and 30.76) and Plant height (29.53 and 28.33) while traits with moderate GCV were recorded for the Internode length (19.88), Number of compound leaves (17.58) and Leaf let per compound leaf (13.83). The existence of substantial variability for the characters were indicated through high values of PCV and GCV and this will facilitate effective selection in the curry leaf population. In this study, the PCV was relatively greater than GCV for all traits observed, however, GCV was near to PCV for the characters like plant height and leaf area inferred that high contribution of genotypic effect for phenotypic expression of such characters. Similar result was reported by Selvakumari (2013), Sheetal and Maurya (2015); Shoba et al. (2020). The traits with wider gaps between estimate of PCV and GCV showed disparate contribution of environmental factors in addition to genotypic effect for expression of the traits (Karunakar et al., 2018). Generally, the genotypic coefficient of variance provides information on the genetic variability present in quantitative characters of the base population, but it is alone not possible to determine the amount of the variation that was heritable. The clear picture of the amount of genetic advance to be expected from selection was governed by the genetic coefficient of variance together with heritability estimates (Burton and Devane, 1953). Heritability estimates in the present study was ranged from 47.71 % in leaflet per compounds leaf to 93.61% for leaf area (Table 3). The heritability values are useful in the prediction of expected progress to be achieved through any selection progress as well as heritability in association with genetic advance would highlight a reliable index of selection value (Panse, 1957). The heritability values greater than 80% were very high, values from 60–79% were moderately high, values from 40– 59% were medium and values less than 40% were low (Singh, 2001). Accordingly, in the present study, the estimate of heritability of Plant height, Plant girth, Petiole length, Number of mature shoot per plant, Leaf area and Fresh leaf yield per plant were recorded with high heritability. This result revealed the relatively small contribution of the environmental factors to the phenotype and selection for such characters could be fairly easy due to the high additive effect. The results were in line with work of Raja and Bagle (2008); Selvakumari (2013); Sheetal and Maurya (2015); Shoba et al. (2020). Accordingto Jonhson et al. (1955) that the worth of genetic advance as percent of the mean is categorized as low (< 10%), moderate (10–20%) and high (> 20%). The GAM of leaflets per compound leaf was classified as moderate, whereas other characters were found to be high (Table 3). The high heritability estimates together with the high genetic advance as per mean is typically more helpful in predicting gain under selection than heritability alone. In the present investigation, among the curry leaf genotypes studied, the very high heritability alongwith high genetic advance as percent of the mean are exhibited by plant height, plant girth, Plant girth, Petiole length, Number of mature shoot per plant, Leaf area, and for fresh leaf yield per plant. The moderate high heritability along with high genetic advance as percent of the mean was expressed by the Internode length and Number of compound leaves which reflecting the presence of additive gene action for the expression of those traits which is fixable for next generations, and selection in next population based on this character would be ideal. Similar observation was recorded by Raja and Bagle (2008); Selvakumari (2013); Sheetal and Maurya (2015) in moringa, Shoba et al. (2020) and Chittaragi et al. (2022) in curry leaf. The traits having moderate values of heritability as well as moderate genetic advance as percent of the mean viz. leaf let per compound leaf, suggest that selection for improvement of those characters may also be rewarding. It also indicates a greater role of non-additive gene action in their inheritance. Similar results were also reported by Shoba et al. (2020); Indhumathi et al. (2020). Phenotypic and genotypic correlations of nine characters in all possible combinations were calculated to know the relationship among them (Table 4). In general, genotypic correlation coefficients were higher than corresponding phenotypic correlation coefficients for most of the traits. Fresh leaf yield per plant had significant and positive association with plant height (0.561 and 0.588), plant girth (0.821 and 0.808), internode length (0.651 and 0.596), petiole length (0.732 and 0.753), number of mature shoot per plant (0.647 and 0.665), number of compound leaves (0.455 and 0.544) and leaf area (0.455 and 0.544) may be considered as selection indices for yield improvement Similar results were also reported by Subha et al (2010); Indhumathi et al. (2020); Chittaragi et al.(2022) in curry leaf.