Production and characterization of a complete set of individual chromosome additions from Oryza officinalis to Oryza sativa using RFLP and GISH analyses

Abstract

Monosomic alien addition lines (MAALs) are valuable materials for comparative analyses of two distinct genomes, for elucidating introgression mechanisms, and for dissecting genes controlling complex traits. In the study reported here, MAALs of rice containing the complete genome of Oryza sativa and individual chromosomes of Oryza officinalis were produced. Interspecific hybridizations were made between O. sativa L. ssp. Japonica (CV, Hejiang 19, 2 n = 24, AA) and O. officinalis (Acc. HY018, 2 n = 24, CC). Two backcrosses were made to the cultivated rice to obtain BC2F1 plants. Through RFLP and GISH analyses, 25 MAALs (2 n = 25, AA + 1C) were identified and divided into 12 syntenic groups, designated MAALs 1-12. MAALs 1, 2, 3, 5, 7 and 10 were each represented by one plant, MAALs 8, 11 and 12 by two plants, MAALs 6 and 9 by four plants, and MAAL 4 by five plants. An ideogram of the C-genome of O. officinalis was constructed, based on GISH analysis of the interspecific hybrid and the MAALs. Comparative RFLP maps showed strong syntenic associations between the A-genomes and C-genomes. Chromosomal arrangements such as translocations and duplications were detected in different alien chromosomes of the MAALs. The complete set of O. officinalis MAALs generated here provides a novel manipulation platform for exploiting and utilizing the O. officinalis genome and carrying out genetic studies.

Simple sequence repeat analyses of interspecific hybrids and MAALs of Oryza officinalis and Oryza sativa

“…A previous study using RFLP markers in a complete set of MAALs demonstrated that chromosomes of the C-genome exhibited high synteny with their corresponding chromosomes of the A-genome (Tan et al 2005). In our study, the same set of MAAL plants was analyzed with 176 SSR markers, and 124 of these displayed O. officinalis-specific bands in the 12 MAALs.…”

“…Both the F 1 and BC 1 plants carry a full set of the 12 chromosomes of the O. officinalis C-genome. Each of the MAALs has a single chromosome from the Cgenome; these are referred to as MAAL1 to MAAL12, on the basis of RFLP analysis (Tan et al 2005). In this study we examined a complete set (12 individuals) of officinalissativa MAAL (BC 2 ) plants, the parental cultivated rice ZS97B and wild rice O. officinalis, each of the interspecific F 1 hybrids and the BC 1 plants used in the development of the MAALs.…”

“…For the development of a complete set of officinalis-sativa MAALs, the cultivated rice ZS97B was used as the female parent and the male parent was the wild rice O. officinalis. The hybrid F 1 was successfully backcrossed with cultivated rice to create BC 1 and then the MAAL plants (Tan et al 2005). In this study, a total of 396 SSR markers, distributed over all 12 chromosomes of cultivated rice were used to amplify genomic DNA samples prepared from cultivated rice ZS97B and wild rice O. officinalis.…”

“…O. officinalis is a diploid species with a C genome. The morphology of O. officinalis is quite different from that of cultivated rice, and many useful characters have been found in O. officinalis Tan et al 2005). The C genome of O. officinalis is considered to be the basic genome of the officinalis complex and is similar to the A genome of O. sativa (Aggarwal et al 1999;Vaughan et al 2003).…”

Drought-tolerant rice germplasm developed from an Oryza officinalis transformation-competent artificial chromosome clone

“…This indicated that genes that confer resistance to the brown planthopper and white-backed planthopper (Sogatella furcifera) are located on chromosome 6 of O. sativa (Jena and Khush, 1990). Tan et al (2005) also produced rice MAALs containing an individual chromosome of O. officinalis, and studied syntonic associations between the A genomes and C genomes using restriction fragment length polymorphism markers. Jena et al (1992) derived 52 introgression lines from the hybrids (BC 2 F 8 ) of two cultivated rice and five O. officinalis lines.…”