The effect of seed freezing on morphological characteristics of four pink species

The effects of nondeep (?10°C) and deep (?196°C) seed freezing on the morphological characteristics of four pink species were studied. As a rule, various regimes of seed freezing weakly affected plant growth and development. Relatively stable traits (flower diameter, the number of stem nodes, and root length) did not change. Reproductive shoots became slightly shorter, and the pattern of their distribution changed. The number of variable traits (the number of vegetative shoots and the number of flowers) was reduced. However, in the following year, the number of flowers was restored. Characteristics valuable for cryopreservation (the number of fruits and seed germinability) were essentially unchanged. Some stimulatory effects of seed freezing were noted: enhanced seed germination under unfavorable conditions and an increased upper limit of some indices, including the number of reproductive organs.