The mixed-mating model is a mathematical model that describes the

mating system A mating system is a way in which a group is structured in relation to sexual behaviour. The precise meaning depends upon the context. With respect to animals, the term describes which males and females mate under which circumstances. Recognised ...

of a plant population in terms of degree of

self-fertilisation Autogamy, or self-fertilization, refers to the fusion of two gametes that come from one individual. Autogamy is predominantly observed in the form of self-pollination, a reproductive mechanism employed by many flowering plants. However, species o ...

. It is a fairly simplistic model, employing several simplifying assumptions, most notably the assumption that every fertilisation event may be classed as either self-fertilisation, or

outcrossing Out-crossing or out-breeding is the technique of crossing between different breeds. This is the practice of introducing distantly related genetic material into a breeding line, thereby increasing genetic diversity. Outcrossing can be a usefu ...

with a completely

random In common usage, randomness is the apparent or actual lack of pattern or predictability in events. A random sequence of events, symbols or steps often has no order and does not follow an intelligible pattern or combination. Individual ra ...

mate. Thus the only model

parameter A parameter (), generally, is any characteristic that can help in defining or classifying a particular system (meaning an event, project, object, situation, etc.). That is, a parameter is an element of a system that is useful, or critical, when ...

to be

estimated Estimation (or estimating) is the process of finding an estimate or approximation, which is a value that is usable for some purpose even if input data may be incomplete, uncertain, or unstable. The value is nonetheless usable because it is der ...

is the probability of self-fertilisation. The mixed mating model originated in the 1910s, with

plant breeders Plant breeding is the science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals. The goals of plant breeding are to produce cro ...

who were seeking evidence of

contamination of self-pollinating crops, but a formal description of the model and its parameter estimation was not published until 1951. The model is still in common use today, though a number of more complex models are also now in use. For example, a weakness of the model lies in its assumption that

inbreeding Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders and o ...

occurs only as a result of self-fertilisation; in reality, inbreeding may also occur through outcrossing between closely related individuals. The

effective selfing model The effective selfing model is a mathematical model that describes the mating system of a plant population in terms of the degree of self-fertilisation present. Overview It was developed in the 1980s by Kermit Ritland, as an alternative to the ...

relaxes this assumption by seeking also to estimate the degree of shared ancestry of outcrossing mates.

References

Plant sexuality Mating systems Mathematical modeling {{botany-stub