Identification and characterization of somatic chromosomes of red rice (Oryza sativa subsp. japonica var. sylvatica) by means of a computerized chromosome image method (CHIA-EA)

The infesting habit of the red rice (Oryza sativa subsp. japonica var. sylvatica, 2n=24) and its diffusion have become a serious problem in rice cultivation because of seed shattering, which reduces rice yield and grain quality. The purpose of this work is to characterize red rice chromosomes and to reveal any differences from the karyotype of cultivated rice Loto (Oryza sativa subsp. japonica) used as reference. The first results, obtained by using a detailed chromosome analysis by means of a chromosome image method (CHIA-EA), showed that in the red rice various translocations occur which always involve a chromosome of the first pair together with other elements of the set. Occasional aneuploid cells with 23 (2n-1) and 25 (2n+1) chromosomes were also observed.