Genetics and breeding of pea

Pea (Pisum sativum L; 2n=2x=14) also commonly known as English pea or green pea and is a commonly grown leguminous vegetable in the world. Pea is highly self – pollinated due to cleistogamous flower structure and has less than one percent out crossing. It is consumed as fresh vegetable or dry seed throughout the world. It is also one of the most popular vegetables grown for home use by home gardeners. The main emphasis in pea improvement has been on early maturity, yield, quality, and resistance to diseases and insect pests. Three single recessive genes, cry, la and le influence internode length and plant height. Each gene governs these characters along with other two genes. Similarly branching is controlled by two single recessive genes, fr and fru in presence of each other. A single recessive gene, ram is responsible for increasing the number of branches. The characters of leaves, leaflets, stipules and tendrils are governed by single recessive genes. Single dominant genes confer resistance to several diseases like Enation mosaic virus (en), Near Wilt, Fusarium oxysporum f. pisi race 2 (fnw), Fusarium wilt, Fusarium oxysporum f. pisi race 1 (fw), Brown root of peas, Fusarium solani f. sp. pisi, Rust, Uromyces fabae, Downy mildew Perenospora pisci and Bacterial blight. Pseudomonas syringe pv. pisi race 1. The resistance to Bacterial Brown spot of Pea, Pseudomonas syringe pv. pisi, is due to a complex system of inheritance. The highly heritable polygenic characters are plant height, earliness, number of pods per plant, pod length, seeds per pod and 100 seed weight. Seed yield per plant had additive genetic variance and positive epistatic gene action for seed yield per plant. Days to flowering showed non additive gene action with partial dominance and over dominance. Partial dominance or over dominance were also observed for plant height. Arkel and Bonneville must get priority on the part of vegetable breeders as a challenge to them.