Genetic advance, heritability and character association of component of yield in some genotypes of tomato Lycopersicon esculentum (Mill.

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1 Academia Journal of Biotechnology 2(1): , January 2014 DOI: ISSN: Academia Publishing Research Paper Genetic advance, heritability and character association of component of yield in some genotypes of tomato Lycopersicon esculentum (Mill.) Wettsd Accepted 5 th November, 2013 ABSTRACT Oluwatoyin Sunday Osekita* and Adedolapo Tomi Ademiluyi Department of Plant Science and Biotechnology, Adekunle Ajasin University, PMB 01, Akungba-Akoko, Ondo State, Nigeria. *Corresponding author. damtobest@yahoo.com, oluwatoyinosekita@gmail.com Five genotypes of tomato Lycopersicon esculentum (Mill.) Wettsd were grown during the growing seasons of 2011 and 2012 to study the interrelationship among quantitative traits; days to 50% flowering, plant height (cm), number of branches per plant, days to first fruit set, number of fruit per plant, number of cluster per plant, number of fruit per cluster, average fruit weight (g), pericarp thickness (cm), number of locules per fruit and fruit shape index. The quantitative traits were subjected to statistical analysis to determine the extent of variability of the component traits, the analysis of variance were significant at (p>0.05) and the highest coefficient of variation (66.56%) in average fruit weight. Phenotypic and genotypic coefficients of variation PCV and GCV were determined to show the degree of inherent traits or heritable variation on the component traits. The traits showed wide variability hence, they can be exploited by direct selection for improving yield in tomato. Key words: Quantitative traits, variability, genotypic, phenotypic, tomato. INTRODUCTION Tomato (Lycopersicon esculentum (Mill.) Wettsd) is an important vegetable crop grown widely all over the world. Ripe fresh fruit is consumed fresh as salads, in cooked form in stew and utilized in the preparation of various forms of processed products such as paste, powder, ketchup, sauce and canned whole fruits. Unripe green fruits are used for preparation of pickles and chutney. Tomatoes are important source of lycopene (an antioxidant), ascorbic acid and -carotene. Tomato is an important condiment in most diets and a very cheap source of vitamins A, C and E, and minerals that are very good for the body and protect against diseases (Taylor, 1987). It also contains a large quantity of water, calcium and niacin all of which are of great importance in the metabolic activities of man. However, the major producing areas in Nigeria lie between latitudes 7.5 N and 13 N, and within a temperature range of C (Vilareal, 1980). The areas include most states of northern Nigeria especially, Bauchi, Benue, Bornu, Kaduna, Kano, Plateau, Sokoto and some southern states of Delta, Kwara and Oyo (Denton and Swarup, 1983). Genetic advance is a product of heritability and infers the potentiality of selection intensity; genetic advance when considered along with heritability gives resemblance assessment of the resultant effects of selection in breeding populations (Johnson et al., 1955). Yield is a complex character controlled by a large number of contributing characters and their interactions. A study of correlation between different quantitative characters provides an idea of association that could be effectively exploited to formulate selection strategies for improving yield. Commercial F 1 hybrids are common in tomato and selection of new parents for higher heterosis is a continuous process. Generally, diverse plants are expected to give high hybrid vigour (Harrington, 1940). Hence, it necessitates the study of genetic divergence, among the existing varieties and germplasm collection for identification of parents for hybridization programme. The information on genetic divergence of various traits particularly of those that contributes to yield and quality would be most useful in planning the breeding programme. The significance of this

2 Academia Journal of Biotechnology; Osekita and Ademiluyi. 007 Table 1. Analysis of variance and coefficient of variation for quantitative traits in tomato. S/N Characters Treatment Coefficient of variation (%) 1 Days to 50% flowering ** Plant height 26.21** Number of branches per plant 1.06 ns Number of fruit per plant 0.49 ns Number of cluster per plant 0.81 ns Number of fruit per cluster 5.93* Average fruit weight 0.42 ns Pericarp thickness 0.50 ns Number of locules per fruit 1.00 ns Fruit shape index 5.92* **Significant at 1%, *Significant at 5%, ns: Not significant. vegetable crop in our diet and economy is evident from the given facts. Therefore, it is imperative to focus on the efforts needed to further expand its production to meet the ever growing domestic needs of people, exports and to achieve sustainability and stability of tomato production in every ecological zone of Nigeria. for different traits of five tomato genotypes were separated using least significant difference (LSD) test at 5% probability level as described by Steel and Torrie (1980). Analysis for components of variance was computed according to the methods of Lush (1940) and the PCV and GCV of the pooled estimate following the procedure of Burton (1952). MATERIALS AND METHODS Tomato germplasm for the study were collected from NIHORT and NACGRAB both in Ibadan, Oyo State. Nigeria. To study genetic variation for days to 50% flowering, plant height, number of branches per plant, number of fruits per cluster, number of cluster per plant, average fruit weight, pericarp thickness, number of locules per fruit and fruit shape index. The experiment was designed and conducted during the growing seasons of 2011 and 2012 in an open field beside the screen house of Plant Science and Biotechnology, Adekunle Ajasin University, Akungba- Akoko, Ondo State, Nigeria. Five tomato genotypes; NG/DE/MAR/09/019, NG/OA/10/11/047, TROPIMECH, TIMA and UC82B were raised in the nursery for 30 days. The seedlings were transplanted in randomized complete block design (RCBD) in triplicates. Each genotype was sown in three rows in plot size of 3.0 m 2. The row to row and plant to plant distance was 30 cm. The field was well ploughed and pulverized before transplanting, cultural and standard agronomic practices such as weeding, rouging and staking were carried out during the growing season. Data was collected from two central rows on days to 50% flowering, plant height, number of branches per plant, number of fruits per cluster, number of cluster per plant, average fruit weight, pericarp thickness, number of locules per fruit and fruit shape index. Statistical analysis The data were statistically analyzed using MStat-C software recommended for randomized complete block design. Mean RESULTS The mean sum of squares due to various sources of variation for ten (10) characters namely; days to 50% flowering, plant height, number of branches per plant, number of fruits per plant, number of clusters per plant, number of fruit per cluster, average fruit weight, pericarp thickness, number of locules per fruit, fruit shape index and coefficient of variation are presented in Table 1. The number of days to 50% flowering and Plant height was highly significant and shows least coefficient of variation of 0.67 and 2.30% respectively. However, number of branches per plant, number of fruits per plant, number of cluster per plant, average fruit weight, pericarp thickness and number of locules per fruit were non-significant. The coefficient of variation for the traits ranged from to 66.56% which is on the high side. The number of fruits per cluster and fruit shape index were only significant at p<0.05 with 9.31 and 32.60% coefficient of variation respectively. Number of days to 50% flowering ranged from 49.7 to 66.1 (Table 2). Minimum days to 50% flowering were observed by the genotype TROPIMECH (49.7 days) and the genotype UC82B with 66.1 days. The remaining genotypes ranged between 52 and 63 days. TROPIMECH perform better in yield component compared to the other genotypes with highest number of fruits per cluster (45.7), number of cluster per plant (8.6) and number of fruit per cluster (23.2). The plant height is moderate with branches vigorous enough to sustain the fruit clusters. The pooled mean values for all the traits were reported in Table 3; Number of days to 50% flowering was (58 days)

3 Academia Journal of Biotechnology; Osekita and Ademiluyi. 008 Table 2. Mean value for days to 50% flowering, plant height, number of branches per plant, number of fruits per plant, number of clusters per plant, number of fruit per cluster, average fruit weight, pericarp thickness, number of locules per fruit, fruit shape index. Genotypes DFF PH NBP NFP NCP NFC AFW PT NLF FSI NG/DE/MAR/09/ NG/OA/10/11/ TROPIMECH TIMA UC82B LSD 5% Significant at 0.05% probability level. Key: DFF: Days to 50% flowering; AFW: Average fruit weight; NBP: Number of branches per plant; PH: Plant height; NFP: Number of fruits per plant; PT: Pericarp thickness; NCP: Number of clusters per plant; NLF: Number of locules per fruit; NFC: Number of fruits per cluster; FSI: Fruit shape index. Table 3. Different genetic parameters for ten quantitative traits in tomato. Character Mean Vp Variance Vg PCV GCV h 2 Days to 50% flowering Plant height Number of branches per plant Number of fruits per plant Number of cluster per plant Number of fruits per cluster Average fruit weight Pericarp thickness Number of locules per plant Fruit shape index and the fruit yield components; number of fruits per cluster (39.25), number of cluster per plant (7.61), number of fruits per cluster (27.01) and average fruit weight (0.66 g). The estimate of heritability among the genotypes ranges from low to moderate and high as the case may be, number of cluster per plant had the lowest heritability estimate (2.60%) and the highest estimate of (99.68%) in days to 50% flowering. The phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) for all the traits were also recorded with the wide differences in number of fruits per plant (PCV 52.40) and (GCV 19.11), number of cluster per plant (PCV 44.08) and (GCV 7.08), number of locules per plant (PCV 27.27) and (GCV 9.64), the remaining traits did not differ greatly. The genotypic correlation coefficient analysis for the ten quantitative traits studied in tomato was presented in Table 4. Positive and highly significant correlation for number of fruits per plant (0.6661) and fruit shape index (0.5739) were observed, and highly significant and negative correlation were observed in average fruit weight The number of fruits per plant had highly significant and positive association with number of fruit per cluster (0.8843) but showed highly significant negative correlation with plant height ( ) and number of branches per plant ( ). The fruit shape index showed positive and highly significant correlations with days to 50% flowering (0.5739), Plant height (0.7607) and pericarp thickness (0.4919). It also showed negative significant correlations with number of cluster per plant (0.5233) and number of locules per fruit (0.4502). Number of cluster per plant was negatively and highly significantly correlated with plant height ( ) and number of branches per plant ( ). DISCUSSION The most important main objectives of any breeding programme were to produce high yielding and better quality lines for release as cultivars to farmers. The prerequisite to achieve this goal is the presence of sufficient amount of variability in which desired lines are selected for further manipulation to achieve the target. The present study was conducted to evaluate the performance of five genotypes of tomato in order to assess the presence of variability for desired traits and a significant amount of variation for different parameters. For better performance of the tomato genotypes the environment is better varied such that too much rainfall is avoided so that the number of days to flowering is reduced and more fruit yield enhanced.

4 Academia Journal of Biotechnology; Osekita and Ademiluyi. 009 Table 4. Genotypic correlation coefficient analysis among ten quantitative traits in tomato. Traits DFF PH NBP NFP NCP NFC AFW PT NLF FSI DFF * ** * ** * * ** PH ** ** ** ** * ** NBP ** ** NFP ** NCP ** ** NFC * AFW * ** * PT ** NLF ** FSI - **significant at 1% level of probability, *significant at 5% level of probability. Key: DFF: Days to 50% flowering; PT: Pericarp thickness; PH: Plant height; NLF: Number of locules per fruit; NBP: Number of branches per plant; FSI: Fruit shape index; NFP: Number of fruits per plant; NCP: Number of clusters per plant; NFC: Number of fruits per cluster; AFW: Average fruit weight. This scenario was manifested in Tropimech which has shorter days to flowering and performs better than the other genotypes in terms of yield. Similar results have been reported by Dhankhar and Dhankhar (2006). Minimum height was recorded in Tropimech while maximum plant height was recorded in NG/DE/MAR/09/019, other genotypes falls in between range, it is observed that Tropimech is the spreading type while others are erect as a result produces more fruit than the other genotypes. Consequently, too much rainfall affected the height of the plant and consequently brings about reduction in yield through flower abortion thereby preventing more fruit set. Singh et al. (2000) obtain similar results in his research work. The yield is a complex character that is controlled by quite a number of factors. Hence, the degree of association of these complex characters formed the basis for yield evaluations and correlation coefficient analysis measures the extent of closeness of the component traits. Positive and highly significant correlation of plant height with number of branches per plant and fruit shape index was observed. However, highly significant and negative correlations were observed in number of fruit per plant, number of cluster per plant and number of fruit per cluster. The genotypic and phenotypic coefficient of variability was high for plant height. Similar observations were made by Nandapuri et al. (1977), Reddy and Gulshanlal (1987). These characters also showed high heritability according to the findings obtained by Nandapuri (1977) and Bora et al. (1993). The strong association exhibited by the yield component indicated that selection for the trait will be good indexes for fruit production in a breeding programme. Dhankar et al. (2001) reported the average fruit weight under normal condition showed the highest positive effect on yield. This indicated that early flowering genotypes are higher yielding in terms of average fruit weight; this may be partly due to the considerable decline in rainfall relatively in the early season, a condition that placed the early flowering genotypes at a relative advantage in terms of productivity. This is supported by the findings of Shashikanth (2008). Conclusions and recommendations The overall results show that Tropimech was early maturing among the genotypes, with moderate plant height, number of branches per plant, number of fruit per plant and number of fruits per cluster, therefore, selection for average fruit weight, fruit shape index, number of fruits per plant and number of fruits per cluster is important for improvement of fruit yield. Other genotypes showed promising traits that could be improved upon in subsequent breeding work. ACKNOWLEDGEMENT The authors were grateful to the Head of Department Dr. O. F. Olotuah for providing for providing the facilities and to NIHORT and NACGRAB both in Ibadan Nigeria for the planting materials. The general support of colleagues in the Department is also acknowledged. REFERENCES Bora GC, Shadeque A, Bora LC, Phookan AK (1993). Evaluation of some tomato genotypes for variability and bacterial wilt resistance. Veg. Sci. 20(1): Burton GW (1952). Quantitative interaction in grasses. In: Proc. 6th Inter. Grassland Congr. 1: Denton OA, Swarup V (1983). Tomato cultivation and its potential in Nigeria. Acta. Horticul. 123: Dhankar SK, Dhankar BS, Sharma NK (2001). Correlation and path analysis in tomato under normal and high temperature conditions. Haryana J.Hort. Sci. 30(1-2):89-92.

5 Academia Journal of Biotechnology; Osekita and Ademiluyi. 010 Dhankhar SK, Dhankar SS (2006). Variability, heritability, correlation and path coefficient studies in tomato. Haryana J. Hort. Sci. 35(1&2): Harrington JB (1940). Yielding capacity of wheat crosses as indicated by balk hybrid tests. Canadian J. Res. 18: Johnson HW, Robinson HF, Comstock RE (1955). Estimates of genetic and environmental variability in soybean. Agron. J. 47: Lush JL (1940). Inter size correlation and regression of offspring on dams as a method of estimating heritability of characters. Proceed. Am. Soc. Anim. Prod. 33: Nandpuri KS, Kanwar JS, Roshanlal (1977). Variability path analysis and discriminate function selection in tomato (Lycopersicon esculentum Mil1.). Haryana J. Hort. Sci., 6: Reddy MLN, Gulshanlal R (1987). Genetic variability and path coefficient analysis in tomato (Lycopersicon esculentum Mill.) under summer season. Progr. Hort. 19(3-4): Shashikanth P (2008). Genetic variability studies in tomato (Solanum Lycopersicon (Mill.) Wettsd). Msc.(Agric.) Thesis, University of Agricultural Sciences, Dharwad. Singh JP, Singh DK, Gulshanlal S (2000). Variability pattern in Agromorphological characters in tomato (Lycopersicon esculentum Mill.) Pro. Hort. 32(1): Steel RGD, Torrie JH (1980). Principles and procedure of statistics. McGraw Hill Book Company Inc., New York. N.Y pp Taylor JH (1987). Text of lectures delivered at the national workshop on fruit and vegetable seedlings production held at NIHORT Vilareal RL (1980). Tomato in the tropics. West view Press Boulder, Colorado, sp.174 Cite this article as: Osekita OS and Ademiluyi AT (2014). Genetic advance, heritability and character association of component of yield in some genotypes of tomato Lycopersicon esculentum (Mill.) Wettsd. Acad. J. Biotechnol. 2(1): Submit your manuscript at