Asian wheat may offer novel genes for shoring up the defenses of U.S. varieties against Fosarium garminearum fungi that cause Fusarium head blight disease. USDA's Agricultural Research Service is looking at the FHB resistance found in today's U.S. wheat varieties and it's primarily based on the Chinese wheat variety Sumai 3 and a few other sources, according to a release issued by the agency.
There is a concern that FHB causing species of F. graminearum will overcome these resistant sources. In susceptible varieties, the fungus infects the wheat heads, causing kernels to shirivel up and turn chalky white. The fungus can alos produce mycotoxins that reduce kernel value and quality.
Working with Kansas State University scientists, ARS researchers are seeking new sources of FHB resistance from exotic wheat lines from China, Korea and Japan. These lines include "landrace" populations, which are domesticated plants that have changed little since the advent of modern plant breeding.
Of 87 total Asian landrace accessions tested in greenhouse trials, 26 showed high levels of FHB resistance. And grain evaluations showed that 15 of those had exceptionally low levels of mycotoxin contamination, which is produced during disease development.
Six of those accessions possessed genes for different forms of FHB resistance known as types I, II and III. Some of the genes appear unrelated to Sumai 3, which would suggest Asian landraces could broaden the genetic pool of resistance now available to U.S. breeders.
This genetic research offers hope for continued advancement in the breeding of resistant wheat varieties.