Immunological Affinities Among Subfamilies of the Poaceae

Abstract

Immunological affinities were investigated among twenty taxa belonging to the grass subfamilies Pooideae, Chloridoideae, Panicoideae, Oryzoideae, and Bambusoideae. Antisera were raised to the prolamin fraction of seed proteins from species of eleven grass genera (Hordeum, Bromus, Festuca, Phleum, Elensine, Panicum, Pennisetum, Tripsacum, Dendrocalamus, and Oryza) and reacted with their homologous antigens and nineteen different heterologous antigens in Enzyme‐Linked Immunosorbent Assay (ELISA). The immunological cross‐reactivity among the eleven taxa whose prolamin was used for antisera production was analyzed quantitatively by generating matrices of averaged cross‐reactivities, Q correlation and distance. The averaged cross‐reactivity matrix was calculated from averaging reciprocal immunological reactions while the two other matrices were computed by considering each antiserum as a character and antigens as OTUs. The three matrices were subjected to clustering by the Unweighted Pair Group Method using Arithmetic Averaging (UPGMA). The phenogram based on the averaged similarity matrix showed some distortion, while the other two phenograms were similar in topology and were informative. A phenon line at r = 0.17 divided the phenogram based on Q correlation into four major groups: Pooideae, Oryzoideae, Bambusoideae, and Chloridoideae‐Panicoideae. The two subfamilies in the Chloridoideae‐Panicoideae group clustered at a correlation coefficient of 0.22. Within the Pooideae, the tribes Aveneae and Agrostideae were closely grouped together (r = 0.85), but they were quite distinct (r = 0.16) from the tightly clustered (r = 0.84–0.85) Bromeae, Poeae, and Triticeae. The Oryzoideae and Bambusoideae showed low immunological similarity (r = –0.07). The two tribes of the Panicoideae, Paniceae and Andropogoneae, displayed extensive immunological similarity clustering tightly at r = 0.84–0.86. The immunological data revealed a possible trend in grass evolution encompassing the chloridoid‐panicoid groups and provided insights into the phylogenetic affinities of the bambusoid and oryzoid grasses. The results also underscored the heterogeneity of the taxa within the Pooideae.

Genetic Markers and Plant Genetic Resource Management

“…The technology of producing monoclonal antibodies to specific antigens (e.g., a diagnostic bacterial cell wall component) has enabled ELISA to become a standard tool for disease diagnosis (Clark 1981;Catello et al 1988). ELISA has also been enlisted in systematic studies of suprageneric taxa (Esen and Hilu 1989), maize (Zea mays L.) racial diversity (Yakoleff et al 1982), and maize inbred lines .…”