or bakanae disease (, , ), from the

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

for "foolish seedling", is a

disease A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

that infects the

rice Rice is the seed of the grass species ''Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima ''Oryza glaberrima'', commonly known as African rice, is one of the two domesticated rice species. It was first domesticated and grown i ...

plant. It is caused by the

fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...

Gibberella fujikuroi ''Gibberella fujikuroi'' is a fungal plant pathogen. It causes ''bakanae'' disease in rice seedlings. Another name is foolish seedling disease. It gets that name because the seeds can be infected, leading to disparate outcomes for the plant. Th ...

'', the metabolism of which produces a surplus of

gibberellic acid Gibberellic acid (also called gibberellin A3, GA, and GA3) is a hormone found in plants and fungi. Its chemical formula is C19H22O6. When purified, it is a white to pale-yellow solid. Plants in their normal state produce large amounts of GA3. It ...

. In the plant, this acts as a

growth hormone Growth hormone (GH) or somatotropin, also known as human growth hormone (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is thus important in h ...

, causing

hypertrophy Hypertrophy is the increase in the volume of an organ or tissue due to the enlargement of its component cells. It is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number.Updated by Linda J ...

. The affected plants, which are visibly etiolated and

chlorotic In botany, chlorosis is a condition in which leaves produce insufficient chlorophyll. As chlorophyll is responsible for the green color of leaves, chlorotic leaves are pale, yellow, or yellow-white. The affected plant has little or no ability to ...

, are at best infertile with empty

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...

s, producing no edible grains; at worst, they are incapable of supporting their own weight, topple over, and die (hence "foolish seedling disease"). Bakanae Disease sporulation JIRCAS

The earliest known report of ''bakanae'' is from 1828; it was first described scientifically in 1898 by

researcher Shotaro Hori, who showed that the causative agent was fungal.A Short History of Gibberellins
at Plant-Hormones.info The fungus affects rice crops in Asia, Africa, and North America. In epidemic cases yield losses may reach up to 20% or more. A 2003 publication from the

International Rice Research Institute The International Rice Research Institute (IRRI) is an international agricultural research and training organization with its headquarters in Los Baños, Laguna, in the Philippines, and offices in seventeen countries. IRRI is known for its wor ...

estimated that outbreaks of bakanae caused crop losses that were 20% to 50% in Japan, 15% in Thailand and 3.7% in India.

References

External links

The "Bakanae" Disease
Rice diseases {{plant-disease-stub