Paljundus

Paljundus is an Estonian term with two broad meanings depending on context: multiplication in mathematics and reproduction or propagation in biology and horticulture. In both senses it denotes producing new units from existing ones, either numbers or organisms.

In mathematics, paljundus refers to the operation of multiplication. It combines two numbers into a product; properties include commutativity, allowing a × b = b × a; associativity, enabling (a × b) × c = a × (b × c); and distributivity over addition. Repeated paljundus forms the basis of exponentiation, where a × a × ... × a (n times) yields a^n. The symbol × or · is commonly used to denote the operation.

In biology and botany, paljundus denotes asexual reproduction or vegetative propagation, producing new individuals without genetic recombination. Mechanisms include binary fission in single-celled organisms; budding in yeasts and some animals; and vegetative propagation in plants via cuttings, runners, tubers, bulbs, layering, or tissue culture. These methods often produce clones of a parent organism, preserving desirable traits.

Paljundus is central in agriculture, horticulture, and forestry for cloning desirable traits, achieving rapid establishment, and maintaining uniform varieties. It can, however, reduce genetic diversity and may propagate pathogens if not managed carefully. The concept also supports laboratory methods such as micropropagation, enabling mass production of uniform plant material.

Etymology traces paljundus to Estonian paljundama, meaning to multiply or reproduce, a term widely used in academic and educational contexts to describe both mathematical multiplication and biological reproduction.