Heterogeneous plastid genomes in anther culture-derived albino rice plants

Large-scale deletions in the plastid genome of albino plants derived from anther culture of japonica rice have in previous studies been detected by Southern blot analysis. In the present study, PCR was applied to detect large-scale deletions in the plastid genome of albino and green plants generated from the anther culture of japonica-indica hybrid-derived DH lines. The rice plastid genome (134.5 kbp) was separated into seven regions and each one (approximately 20 kbp) was amplified by long PCR. The plastid sequences of all 22 albino and 19 green plants were amplified at all the seven regions, indicating that large-scale deletions in the plastid genome were not detected by long PCR. The concentrations of two plastid genome regions were measured by competitive PCR. Four of 29 albino plants analyzed showed different concentrations between the two regions, indicating that both deleted and complete plastid molecules were present in each of the four albino plants. Such plastid genome heterogeneity was not detected in 17 green plants.