Genetic Analysis of Avocado (Persea americana L.) Genotypes for Fruit and Nutritive Traits

Abstract

Avocado (Persea americana Mill.) or butter fruit is one the important nutritious sub tropical fruit native to Central America. Fruits are rich in nutrients, vitamins and phytochemicals. Fruit pulp is rich in fat and low in sugar content. Avocado exhibits wider variability due to protogyny nature of flower. However exploitation of this variability is very meager. The present study was conducted at Horticultural Research Station, Tamil Nadu Agricultural University, Thadiyankudisai to study and to find out suitable genotypes for further crop improvement programme. A field survey was conducted in Lower Pulney hills area and identified more than 100 genotypes and subjected to fruit characterization by using IPBGR descriptor. Sixteen genotypes were selected out of 100 genotypes based on the fruit characters and did nutritive analysis. Among the sixteen genotypes the avocado genotype TKDPA 93 recorded higher values for fruit length, fruit diameter, peduncle length, peduncle diameter and fruit weight. The genotype TKDPA 87 showed overall superior performance for nutritive traits viz. fat, dietary fibre, carbohydrate, carotene, vitamin C, calcium and phosphorus. The estimates of genetic parameters showed that the highest phenotypic variance was observed with the traits fruit weight, phosphorus content, fat content and peduncle length. Similarly the highest genotypic variance was observed with fruit weight, peduncle length and fat content. The maximum phenotypic co efficient of variance was noted with fruit weight, peduncle length, peduncle diameter, carotene content and pedicle length. The maximum genotypic co efficient of variance was noted with fruit weight, peduncle length, peduncle diameter, carotene content and pedicel length. GCV: PCV values were near unity for the traits fruit weight, peduncle length, peduncle diameter, carotene content, pedicel length and fruit diameter suggested that these traits are less influenced by the environment and can be used as a selection indices for avocado genetic improvement programme.