No abstract

Feoli-Chiapella, L. & Cristofolini, G. 1981. Serological contributions to the systematics of Ulex (Genisteae -Fabaceae) and allied genera. -Nord. J. Bot. 1 : 723-729. Copenhagen. ISSN 01074SSX.Seven UIex species were compared serologically with 21 species of related genera. Seed proteins were employed to immunize rabbits; immune sera to 17 species were produced. The presence or absence of differential characters (spurs) was detected in immunodiffusion experiments and recorded in a square matrix for each antiserum. The interspecific correlation was then computed, and an ordination on principal components was obtained. The results suggested that: ( 1 ) Ulex L. should include sect. Pseudogenista (= genus Nepa Webb) and sect. Stauracanthus (= genus Stauracanthus Link); (2) sect. Stauracanthus is closer to sect. Ulex than to sect. Pseudogenista; (3) Ulex is markedly dissimilar from any other genus, its highest similarity being to Genista sect. Phyllobotrys and to Chanzaespartium; (4) Ulex behaves like other derived genera and can be regarded as an extremely derived form within the Genista evolutionary line; (5) Echinosparturn seems a primitive genus, it is not closely related to Ulex but rather to Cytisanthus and allied genera. There is a good agreement between these results and morphological, phytogeographical and caryological evidence. A general outline of evolutionary relationships within the Genisteae is presented.

A karyological analysis of the so-called primitive genera of Genisteae has shown that they have a relatively homogeneous chromosome complement: all species tend to have a somatic chromosome number 2n = 48, which can increase to 2n = 52, presumably as a result of hyperaneuploidy. Karyological data suggest that Argyrocytisus, Cytisophyllum and Petteria may be considered as distinct genera rather than being assigned to Cytisus, with 2n = 52 for the first of these and 2n = 50 for the other two genera. They may be interpreted as relict monotypic genera as a result of the presence of a stabilized aneuploidy. Karyological characters exclude a recent origin of Genisteae from Thermopsideae. On the contrary, they are consistent with the hypothesis that Genisteae and Thermopsideae are independently derived from a basic papilionoid stock, of which present day Sophoreae are the remainder. At least two lines would lead from Sophoreae to the taxa of the 'genistoid alliance', one to Thermopsideae and the other 'podalyrioid alliances' (Podalyrieae and Mirbelieae), with the prevailing basic number of x = 9, and the other to Genisteae, with a basic number of x = 12 persisting in some present day genera, including Cytisus s.l. From this lineage, a wide range of secondary basic numbers has been formed, mostly by descending aneuploidy.

The storage proteins extracted from the seeds of five species of the genus Adenocarpus and of four subspecies or varieties of the type species A . complicafus were studied serologically and compared with the homologous proteins extracted from 20 other species of Genisteae and allied tribes. All taxa of Adenocarpus reacted strongly with an antiserum to A . complicatus ssp. complicatus; only slight differences were observed between subspecies and between species. Adenocarpus was shown to be isolated from all other Genisteae. However, it was more similar to the Genisteae than to species of other tribes. The highest similarity toward Adenocarpus was presented by Argyrolobium, by some primitive unspecialized genera (Laburnum, Cytisophyllum), and by such isolated genera as Cytisanthus, Spartium, Echinospartum. Retama and Lupinus were most dissimilar. It is concluded that Adenocarpus, a very uniform and isolated genus, belongs to the Genisteae; it shares many characters with the bulk of primitive genera of the Genisteae; its evolutionary line is independent from all others, but is not very distant from that of Argyrolobium.G . Cristofolini, 1st.