Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Effect of freezing stress on chlorophyll fluorescence of Malus sieversii (Ledeb.) M.Roem. histoculture seedlings: (a) Chlorophyll fluorescence induction curves of Malus sieversii (Ledeb.) M.Roem. histoculture seedling leaves in each treatment (CK, T12h, T36h, HF24h); (b) Y(NO) imaging; (c) Value of Y(NO). Means denoted by the same letters did not significantly differ at p < 0.05 (Duncan’s range test) on a given treatment.
