Molecular markers : An important tool to assess genetic fidelity in tissue culture grown long-term cultures of economically important fruit plants

Abstract

India with its wide diversity in climate and soil is bestowed with a variety of ecosystems. It produces a large number of fruits commercially in various agroclimatic zones. India is the second largest producer of fruits with a production of 49 million tons and contributes 10 per cent share in global food production. India occupies first place in production of mango, banana, litchi, papaya, pomegranate and sapota (Anonymous, 2007). It has higher national average productivity in banana and sapota compared to world average productivity. India accounts for an area of 4.96 million hectare under fruit crops with a production of 49.29 million ton. Among states, Maharashtra ranks first in area and production of fruits and contributes 27 per cent and 21.5 per cent, respectively (Anonymous, 2007). Fruits occupy an important place in human diet as they provide a wide variety of nutrients essential for good health and happiness. Fruits contain carbohydrates (source of energy), minerals, dietary fibres, vitamins and some enzymes which are necessary not only for proper body functions but also for providing protection against diseases (Singh, 1969). The fruit plants are propagated both by sexual (seeds) and asexual (vegetative) methods. In sexual method the plants are raised from seeds producing seedlings. In asexual or vegetative propagation of plants, a vegetative part (leaf, stem or root) is placed in such an environment that it develops into a new plant. Conventionally, fruit plants are generally propagated by the vegetative or asexual methods. They involve no change in genetic makeup of the new plant. All the characteristics of the parent plant are reproduced in the daughter plants due to exact duplication of chromosomes during cell division. Thus, the plants are true-to type in growth, ripening, yield and fruit quality. The conventional methods of propagation are generally slow, labour intensive and requiring large number of propagules. Besides this, vegetatively propagated crops are often infested by pests and diseases which cause severe production loss. Most of the fruit plants are woody perennials and take several years to bear. Therefore, propagation of the Molecular markers : An important tool to assess genetic fidelity in tissue culture grown long-term cultures of economically important fruit plants