Norin 10

Norin 10. It is a semi-dwarf wheat variety developed in Japan that became the foundational genetic source for modern high-yielding wheat cultivars worldwide. Its introduction of reduced-height genes revolutionized wheat breeding programs, most famously in the work of Norman Borlaug, leading to dramatic increases in grain production. This genetic material was pivotal to the Green Revolution, transforming agriculture across Asia and Latin America.

History and Development

The variety was developed by Gonjiro Inazuka and his colleagues at the National Institute of Agricultural Sciences in Japan. It was released in 1935, originating from a cross between the Japanese landrace Daruma and two American wheat varieties introduced to Japan. Following World War II, samples of the wheat were transferred to the United States Department of Agriculture (USDA) as part of Allied occupation efforts. Plant pathologist S. C. Salmon recognized its potential and provided seeds to Washington State University researcher Orville Vogel, who began incorporating its genes into Pacific Northwest breeding lines. This work directly enabled Norman Borlaug of the International Maize and Wheat Improvement Center (CIMMYT) to utilize the germplasm in his pioneering work in Mexico.

Genetic Characteristics

The primary genetic contribution of this wheat is its semi-dwarfing genes, specifically the reduced-height (Rht) alleles Rht-B1b and Rht-D1b. These genes, originating from the Daruma parent, inhibit the plant's response to the hormone gibberellin, resulting in shorter, sturdier stalks. This dwarfing characteristic provides superior resistance to lodging, even under high applications of nitrogen fertilizer. The variety also carried genes for photoperiod insensitivity, allowing for wider adaptation across different latitudes. Its genetic makeup represented a major departure from traditional tall wheat varieties, enabling a fundamental shift in plant architecture and harvest index.

Impact on Wheat Breeding

The incorporation of its dwarfing genes into international breeding programs marked a watershed moment in 20th-century agriculture. Norman Borlaug's team at CIMMYT used it to develop the famous Mexican dwarf wheat varieties, such as Sonora 64 and Lerma Rojo 64. These cultivars demonstrated unprecedented yields and were rapidly adopted across the Global South. The success spurred similar dwarfing gene transfers into rice breeding, exemplified by the work at the International Rice Research Institute (IRRI) with varieties like IR8. The breeding methodology pioneered using this germplasm became the model for the Consultative Group on International Agricultural Research (CGIAR) system, influencing crop improvement for maize, sorghum, and millet.

Agricultural Significance

The widespread adoption of derivatives led to the Green Revolution, dramatically boosting food security in nations like India, Pakistan, and Turkey. The shorter plants allocated more energy to grain production rather than stem growth, resulting in higher yields per hectare. This genetic improvement allowed for intensive farming practices, including increased use of irrigation and synthetic fertilizers, without the risk of crop failure from lodging. The production surges in Asia during the 1960s and 1970s, often termed the "Wheat Revolution," are directly attributed to the dissemination of semi-dwarf varieties stemming from this Japanese wheat.

Related Varieties and Derivatives

A vast number of modern wheat cultivars trace their pedigree to this variety. Key early derivatives include Gaines and Nugaines from Orville Vogel's program, which were critical for North America. Norman Borlaug's CIMMYT lines, such as the Veery series, spread globally. Notable national varieties incorporating its genes are Kalyan Sona and Sonalika in India, Mexipak in Pakistan, and Anza in the United States. Its genetic legacy continues in contemporary breeding through advanced lines developed by institutions like the John Innes Centre and CSIRO, ensuring its impact endures in modern agriculture. Category:Wheat varieties Category:Agricultural history Category:Green Revolution