Multifoliate alfalfa: its causes and influence

An increase in the leafiness of protein-rich alfalfa (Medicago) is possible not only through selection to change the size of the leaf blade. Some of the first reports on the study of the phenomenon of the formation of additional leaves, afterwards called multifoliate, date back to the 30 years of the XX century. This review article mentions the main articles related to the study of the trait. The structure of the leaf is described and information is collected on the correlations of multifoliate with height, internodes, day length and temperature. The influence of germplasm and research methods on obtaining contradictory data is indicated. The assumptions initially put forward by researchers about the atavistic nature of the manifestation of the trait, and later about the presence of a recessive mutation with 2 additive genes regulating expression, are considered. The method of finding the index of evaluation of the expression of multifoliate proposed by Craig Sheaffer and confirming the strong character of inheritance of the trait in classical selection through recurrent selection is shown. In conclusion, the most significant genes and gene families that directly or indirectly affect the manifestation of multifoliate, including PALM1 and KNOX, are collected.