Selection of RAPD marker for growth of seedlings at low temperature in rice

We have developed a polymerase chain reaction (PCR)based assay that could e ffectively reduce the time period required to screen and select the cold to lerance gene of rice seedlings under field conditions. The two specific ran dom amplified polymorphic DNA (RAPD) fragments for the assay were identifie d on the basis of quantitative trait loci (QTL) analysis which were found t o be tightly linked to cold sensitivity. The two RAPD fragments, OPT8(600) in the cold sensitivity rice cultivar 'Dular (indica)' and OPU20(1200) in t he resistance rice cultivar 'Toyohatamochi (japortica)', were identified af ter screening 11 RAPD fragments using 2 random primers on the genomic DNAs of 'Dular' and 'Toyohatamochi', These primers, when used in a multiplexed P CR, specifically amplified a 0.6 kb and a 1.2 kb fragment in the sensitive and resistant rice cultivars, respectively, When this assay was performed o n the genomic DNAs of 16 japonica, 3 Tongil (indica/japonica), and 2 indica rice cultivars, the primers amplified a 0.6 kb fragment in all of the cold sensitivity rice cultivars or 1.2 kb fragment in all of the resistance one s. These markers can he of potential use in the marker-assisted selection ( MAS) for cold tolerance in rice seedling, As screening for resistance can n ow be conducted independent of the availability of low temperature, the bre eding of cold tolerance cultivars can be hastened.