In tropical climes, the sensitivity of pea (Pisum sativum L.) to high temperatures as well as its underlying genotypic potential with regard to high-temperature ambient/tolerance at field scale remain unknown. The fraction of the hybrids' (F₁) means values that increase or decrease relative to those of their best and middle parents is known as heterosis. "Heterobeltiosis" is the term used to describe how an F1 hybrid has improved over its superior parent. The selection of parental genotypes benefits from an understanding of general combining ability (GCA), specific combining ability (SCA), narrow-sense heritability (h2 n.s.), and broad-sense heritability (h2 b.s.). A significant improvement in salinity tolerance may be attainable through selection by the order of high heat stress tolerance values in the pea (Pisum sativum L.). The selection of parental genotypes benefits from an understanding of general combining ability (GCA), specific combining ability (SCA), narrow-sense heritability (h2 n.s.), and broad-sense heritability (h2 b.s.). The Pea (Pisum sativum L.) has high heritability values of the type that confer heat stress resistance, which suggests that a significant improvement in heat stress tolerance may be attainable by selection under conditions of intense selection pressure. Pisum sativum L. characteristics were mostly regulated by the additive and non-additive (dominance) gene activity under both normal conditions and heat stress.