赤かび病耐病性およびデオキシニバレノール産生抑制型品種の育成状況 Progress in improvement of Fusarium head blight resistant wheat varieties with low mycotoxin accumulation
<i>Fusarium</i> head blight (FHB) or scab is one of the most serious disease for the wheat production in Hokkaido, the northern most part of Japan. Wheat production in Hokkaido accounts for about 60% of domestic wheat in Japan and yield losses resulting from rain damage, pre-harvest sprouting and FHB, are estimated at 10–20% of total production. Since some <i>Fusarium</i> produce mycotoxins, the government applied guideline levels of 1.1 mg/kg for DON in raw cereals for human consumption and feed material, 1.0 mg/kg in feed for various animal species and 4.0 mg/kg for cattle older than 3 months in 2002. <br>Unlike Honshu district, there is no rainy season, humidity is usually low in the grain filling season except near the seashore or the river in Hokkaido. But it has become more frequent for wheats to be exposed to continuous rain during the maturing stage and the resistance to FHB of Hokkaido varieties is moderate to weak, not sufficient to avoid a contamination with DON. Selection and evaluation of FHB resistance are conducted by several methods, such as inoculation of a suspension of Fusarium spores onto wheat heads or inoculation by oat cultures with mist irrigation and a single floret injection method. Developing resistance lines, we also use Asian materials, such as Sumai 3, Japanese landrace and breeding materials developed at Kyushu agricultural research center, Brazilian varieties and European materials. Every materials have many inferior characters for Hokkaido conditions. Low yield potential, long culm, low qualities, susceptiveness to cold, snow molds and pre-harvest sprouting. Breeders and pathologists are actively screening and developing good resistance varieties and genetic material with excellent resistance to FHB. And DON accumulation of these material are low. The yield potential of these breeding lines are lower than'Hokushin', a leading variety in Hokkaido and they are still inferior in some traits, snow molds resistance, culm strength and quality. The improvement of these traits is being investigated.
マイコトキシン 56(1), 17-23, 2006-01-31
Japanese Society of Mycotoxicology