Evolution of rice improvement in Korea

Because of small size of rice farms and high production costs, international competitive power of Korean rice goods is still in the relatively inferior situation. At the present time, the Korean rice industries are confronted with strong pressure of opening ties for the world market of agricultural products. Here is the introduction of evolution in rice varietal improvement and perspective direction coming the 21st century for international society. Yield potential of japonica rice steadily increased during the last nine decades. From 1970s to 1980s, the breeding experience of Tongil-type rice improvement has greatly attributed to the improvement of japonica rice for short culum length and pest resistance as well as high yield potential since 1980. Major improvements are plant type and canopy architecture, resistance or tolerance to major pests and environmental stresses. Most cultivars distributed medium to late in maturity which constrain stable rice production before 1965. Diversification in maturity form very-early to medium-late promised not only stable rice production but also adaptability to various cropping system. As the result of developing economics, the grain quality of japonica rice cultivars was really improved in both grain appearance and palatability of cooked rice since 1980. Diversification of food-processing utility had realized the development of special rice such as large kernel, chalky endosperm, aromatic and colored rices since 1990. The first japonica rice cultivar resistant to stripe virus disease was developed in 1975 and since then, many rice cultivars resistance to stripe virus disease were continuously developed. Also, high-quality japonica rice cultivars were extensively improved for resistance to stripe virus and bacterial leaf bligt since 1992. But soon after severe occurrence of neck blast of the Tongil-type rice in 1978, the new blast-resistant varieties were developed and quickly substituted. Rice production in 1980 was sharply decreased by 3.6million ton, about 34% reduction of total rice production, due to low-temperature injuring when cold susceptible cultivars of Tongil-type (indica/japonica) released to be grown in the farmer's filed. In tolerance to environmental stresses the japonica rice cultivars were considerably improved in lodging and cold tolerance. The conventional breeding system such as pedigree and bulk mehtod were modified to the general breeding system accompanying the rapid generation advancement (RGA) scheme utilizing greenhouse or IIRI field during winter season. The haploid breeding using anther culture technique for shortening breeding periods was practically established in japonica rice since 1980s to meet socio-economic needs. The establishment of embryo rescue technique is useful for interspecific hybrid between different genomic wild species and cultivars, and to transfer resistant genes for diseases and insect pests from wild rice species to cultivars by recurrent backcross since 2000. Also the basic techniques to ensure the practical utilization of biotechnology in rice breeding is recently developing at the moment.

Bibliographic Details

Main Author:	Yang, Sae Jun
Format:	conference_item biblioteca
Language:	eng
Published:	CIRAD
Subjects:	F30 - Génétique et amélioration des plantes, Oryza sativa, amélioration des plantes, recherche, http://aims.fao.org/aos/agrovoc/c_5438, http://aims.fao.org/aos/agrovoc/c_5956, http://aims.fao.org/aos/agrovoc/c_6513, http://aims.fao.org/aos/agrovoc/c_4116,
Online Access:	http://agritrop.cirad.fr/510218/
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