Rhizomatous Lotus corniculatus L.: I. Taxonomic and Cytological Study

Abstract

Wild, putative Lotus corniculatus L. accessions from Morocco differ distinctly from domesticated L. corniculatus in that they produce rhizomes. Rhizomes may be useful in increasing stand persistence of domesticated L. corniculatus. The objective of this study was to identify to species the wild Lotus accessions from Morocco (G31272, G31273, G31276, G31298, and G31317) that present rhizomatous growth. Comparative morphological and cytological analyses and intercrossing with L. corniculatus were used in this study. Six morphological characters that distinguish L. corniculatus and L. uliginosus Schkuhr. (the only species in the genus Lotus recognized as producing rhizomes) were used to categorize taxonomically the Moroccan accessions. The Moroccan accessions were morphologically similar to L. corniculatus with the exception of the rhizome trait. The accessions were tetraploid with 2n = 4x = 24 somatic chromosomes. Karyotype analyses detected more similarities than differences between the Moroccan accessions and Norcen. Progeny were produced from intercrosses between L. corniculatus cvs. Norcen and AU Dewey and the Moroccan accessions. Hybridity of progeny was verified by morphological and random amplified polymorphic DNA (RAPD) analyses. A sample of reciprocal F1 progeny were tetraploid, fertile, and consistent in their production of rhizomes. A combination of morphological, chromosome, and karyotype analyses confirmed accessions G31272, G31273, G31276, G31298, and G31317 as L. corniculatus. This is the first description of L. corniculatus with rhizomes.