Relationship between different fasciated lines of pea

Abstract

Although data on genetic control of fasciation in pea (Pisum sativum L.) appeared together with genetics itself (5), some aspects of it remain unclear. Until recently, even the number of genes involved in the development of this trait was under discussion: the hypothesis of monogenic control (5) was in controversy with one proposing the existence of two polymeric genes (2). At present, the former seems more probable, being supported by numerous experiments (4). The Fa locus proposed to be identical to that studied by Mendel, is localized on linkage group (LG) IV (2). Nevertheless, a few additional genes are known to cause fasciation: Fas(LG III, 1), Fa2 (LG V, 12), Nod4 (LGV, 8), and Sym28 (no linkage data, 7).The two latter also take part in the nodulation process.