An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Brandt J, Thordal-Christensen H, Vad K, Gregersen PL, Collinge DB.Brandt J, et al.Plant J. 1992 Sep;2(5):815-20.Plant J. 1992.PMID: 1302634Free article.