In the Moscow region for two years of the 2020-2021 sowing season. a field experiment was carried out to assess the implementation of the seed productivity of Aflatun onion ( Allium aflatunense B. Fedtsch.) from the biocollection of VNIIO - a branch of the Federal State Budget Scientific Institution of the Federal Scientific and Scientific Center for Education. Aflatun onion is a perennial bulbous ephemeroid plant, endemic of the Tien Shan, xeromesophyte. Under the conditions of the culture of the Moscow region, the fruit set was 80.4%, the real seed productivity was 2.76 g per plant, the weight of 1000 seeds was 5.12 g, the insemination rate was 4.56 pcs/fruit. The formation of up to 4.11 seeds per fruit was noted, the average - 4.42, the upper one - 5.16 seeds per fruit. The reproductive potential under culture conditions is commensurate with that in natural populations; therefore, seed renewal of artificial populations is possible. The species must be kept in a living collection of onions and seeds to preserve the gene pool and as an insurance fund to maintain and restore natural populations in the event of their complete or partial extinction in nature.