The Korean Journal of Crop Science ISSN:0252-9777(Print) 2287-8432(Online) 한국작물학회지

The purpose of this study was to know the seed longevity of rice (Oryza sativa L.) germplasm for effective viability monitoring. The longevity was determined via germination tests of 3,066 accessions of rice germplasm from the National Agrobiodiversity Center, Rural Development Administration, Korea. The rice germplasm accessions have been conserved at a mid-term storage (4°Csealed metal can on either sides for 25~26.5 years. The final germination percentages of 3,066 rice germplasm accessions of 6.5±1.0% seed moisture content with 94% initial germination stored at 4°C for 26.5 years declined to 47% while at -18°C for 25 years maintained high germinability as 93%. Germination time courses, which represent the average performance of rice ecotypes stored at 4°C and 30% RH, were fitted regression equation, to calculate the time at which germination characteristically declined to 50% (P₅₀). These P₅₀ values of Indica, Japonica, Javanica and Tongil type in rice were 39.9, 22.9, 25.4 and 31.8 years, respectively. The rice germplasm stored at 4°C could be clustered in 4 groups using quartile of final germination after 26.5 years storage. The seed longevity (P₅₀) of each group was estimated by regression equation of changed germination percentages according to storage periods. The P₅₀ values of group Ⅰ, group Ⅱ, group Ⅲ and group Ⅳ were 21.1, 23.6, 30.0 and 75.7 years.