Genetic variability, heritability and genetic advance in tomato (Solanum lycopersicon L.).

Tomato (Lycopersicon esculentum L.) is an annual crop belonging to the family Solanaceae. The genus Lycopersicon consists of annual or short-lived perennial herbaceous plants. Tomato is a typical day neutral plant and is mainly selfpollinated, but a certain percentage of cross-pollination also occurs [1]. It is a warm season crop reasonably resistant to heat and drought and grows under wide range of soil and climatic conditions. Although tomato has a good potential to be cultivated every location in the universe but it confronts many abiotic stresses in which, high temperature is a crucial problem now a days [2]. It is known as protective vegetable due to its nutritional values, which protects human body from several ailments. It is also most extensively used vegetable in processing industry. Tomato ranks first in canned vegetables. Ripe fresh tomato fruit is consumed fresh as salads and consumed after cooking and utilized in the preparation of range of processed products such as puree, paste, powder, ketchup, sauce, soup 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 b-carotene and valued for their color and flavor. The area and production of tomato has been increasing constantly over the years. India is the second largest producer of tomato next to China [3]. The basic key to bring about genetic improvement to a crop is to utilize the available or created genetic variability. If the variability in the population is largely due to genetic cause with least environmental effect, the probability of isolating superior genotype is possible [4]. The variability available in the population can be partitioned into heritable and non-heritable component viz., phenotypic and genotypic coefficients of variation, heritability and genetic advance on which selection can be effectively carried out [5]. Heritability denotes the proportion of phenotypic variation due to genotypes thus help the breeders to select the elite variety for a character. However, heritability indicates only the effectiveness in which selection of a genotype can be based on phenotypic performance but it fails to indicate the expected genetic progress in one cycle of selection. High heritability alone is not enough to make efficient selection in segregating generations, unless information is accompanied for substantial amount of genetic advance. Genetic advance denotes the improvement in the mean genotypic values of selected families over base population and thus helps the breeder to select the progenies in the earlier generation itself [3]. Abstract The experiment was conducted during Autumn-Winter Season, at the Vegetable Research Area, Bihar Agriculture University, Sabour, Bhagalpur (Bihar). Genotypic variability, heritability and genetic advance for biochemical and biochemical contributing characters were studied on 29 tomato genotypes (including cultivated and wild species). Data were recorded on seven characters viz., Total Soluble Solids, Titratable acidity, Ascorbic acid content, Lycopene content, Total carotenoids content, Total phenolics content and Total antioxidant capacity. Very little differences were observed between genotypic coefficient of variation and phenotypic coefficient of variation for all the characters. Total Antioxidant Capacity showed the highest genotypic and phenotypic variance (33.98% and 34.01%) whereas TSS showed the lowest (6.84% and 7.48%). Higher GCV and PCV were recorded for most of the characters indicating higher magnitude of variability for these characters. The highest heritability (broad senses) estimates were observed for Titratable Acidity (100%) and Total Antioxidant Capacity (100%) while the lowest was for the TSS (84%). Highest genetic advance as percent of mean was recorded for (69.93%) and lowest for TSS (12.90%). The exploration of genetic variability in the available germplasm is a prerequisite in a breeding programme for effective selection of superior genotype of tomato.