Avena magna : An Important New Tetraploid Species of Oats

Abstract

Avena magna is a new tetraploid species morphologically similar to the hexaploid A. sterilis, having a high concentration of protein, large caryopses, and outstanding resistance to crown rust. One genome in A. magna appears homologous to the As genome present in hexaploid, tetraploid, and one group of diploid species. Avena magna is a possible ancestor of cultivated oats.

Domestication of the protein-rich tetraploid wild oats Avena magna and A. Murphyi

“…Several cultivars were crossed to the two wild tetraploid oats . The pentaploid F 1 hybrids were sterile due to meiotic irregularities of a magnitude similar to that already published (MURPHY et al ., 1968 ;RAJHATHY & SADASIVAIAH, 1969 ;LADIZINSKY, 1971b) . While male sterility was complete, a few seeds were obtained by pollinating the hybrids with normal pollen from the tetraploid parental species .…”

Cytogenetic Analysis of Diploid Avena L. Species Containing the As Genome

“…The data accumulated so far make it possible to assume that only one tetraploid species, A. macrostachya , is an autopolyploid [6,7], while the other species result from hybridization of different diploid ancestors. According to the genome composition, the allotetraploid species are divided into two main groups, AB ( A. abyssinica, A. vaviloviana , and A. barbata ) and AC ( A. maroccana, A. murphyi , and A. insularis ) [1,6,[8][9][10][11][12][13][14]. The genome formula of the hexaploid Avena species is ACD [8,14].…”

An important new diploid Avena species discovered on the Canary Islands

“…1) suggests a miniature A. magna (see Fig. 1 of Murphy et al 1968). The fine pattern of the cuticle of the glumes, i.e.…”

“…A new species of oat, which by its mode of dispersal and bidentate lemma tips resembles the hexaploid A. sterilis L. and the tetraploid A. imgna Murphy et Terrell (Murphy et al 1968), was detected by one of us (B.R.B.) while examining a 120-year-old collection from the Canary Islands obtained on loan from the Webb Herbarium of the Institute of Botany, Florence, Italy.…”