Breeding Avenues in Fruit Crops for Imparting Resistance Against Insect Pests

Abstract

Insect pests cause huge losses to crops directly or indirectly, and fruit crops are not an exception to this statement. The application of insecticides for minimizing qualitative and quantitative losses in fruit crops is not only hazardous to consumers but also results in undesirable environmental and ecological consequences. The development of insect-resistant fruit varieties is an ecofriendly alternative to chemical control and is a durable solution to the menace of insect pests. The host plant resistance against insect pests is based on certain structural and biochemical features of the plants. The transfer of traits to the elite germplasm through conventional breeding is often limited by the long pre-bearing juvenile phase of the fruit crops. The genomics-assisted breeding, which is the integration of genomic tools with conventional breeding, can prove helpful in overcoming these shortcomings. Among the genomics approaches, biparental mapping, association mapping and genomic selection have direct relevance in genetic improvement of fruit crops. The biparental mapping helps in locating the gene/QTLs for insect pest resistance. Through this approach, the host plant resistance against leaf miner in citrus, woolly apple aphid and rust mite in apple, gall mite in black currant and aphid in raspberry has been mapped. Similarly, the use of genetic engineering-based approaches like transgenesis, cisgenesis, RNAi and other potential techniques, which could enhance the fruit crop resistance against insect pests, has been discussed in this chapter.