Plant Breeding for Developing Resistance to Insect Pests

Insects and pests are another major cause of crop and produce loss on a large scale. A plant's resistance to insect attack can come from morphological, biochemical or physiological characteristics.

Examples of natural resistance

• Hairy leaves in several plants deter insect pests — for example, resistance to jassids in cotton and to the cereal leaf beetle in wheat.
• Solid stems in wheat discourage the stem sawfly from attacking.
• Smooth-leaved, nectar-less cotton varieties are less attractive to bollworms.
• High aspartic acid, low nitrogen and low sugar content in maize confers resistance to maize stem borers.

Breeding for pest resistance

The steps involved in breeding for insect-pest resistance are the same as those used for any other agronomic trait, such as yield or quality. Sources of resistance genes may come from cultivated varieties themselves, from germplasm collections, or from wild relatives of the crop. Some released crop varieties bred by hybridisation and selection specifically for insect-pest resistance are listed below.

| Crop | Variety | Insect pests | …