Reproductive Isolation Barriers Within the Tall Fescue Complex
Hexaploid tall fescue (F. arundinacea Schreb., 2n = 6x = 42) is a widely adapted forage species which grows in various climatic, edaphic, and geographical regimes. Consequently, this grass has developed several ecotypes. Although most ecotypes (including those widely geographically isolated) are morphologically similar, have the same chromosome number (2n = 42), and are easily crossable, some of them are nevertheless reproductively isolated, as evidenced by the complete sterility of hybrids between them (Table 5.1, Fig. 5.1). Thus, so far as reproductive isolation is concerned, some ecotypes behave essentially as separate species (see Sect. 2.1). This is an enigmatic situation from the cytogenetic and breeding standpoints.
Unable to display preview. Download preview PDF.