Molecular cytogenetical and biochemical studies on some Lupinus species

Abstract

Background Lupins are cultivated as human consumption grains and forage legumes. The chromosomes of lupins are too small to be karyotyped by conventional techniques, because they reveal a general lack of distinctive cytological features. In the current study, Fluorescence in situ Hybridization (FISH) was used to locate 5S and 45S ribosomal gene sites on the chromosomes of Lupinus albus ssp albus, Lupinus albus ssp graecus, Lupnus termis (all with 2n = 50), and Lupinus polyphyllus lindl var. polyphyllus (2n = 48), FISH together with seed storage protein electrophoretic patterns were used to find out the relationship among these species. Results The double-target FISH on the chromosomes of the studied species with rDNA probes revealed that the two types of rRNA genes are located on different chromosomes. The detected loci of rRNA genes partially reflected the taxonomical similarity among the two Lupinus albus subspecies and L. termis. Lupinus polyphyllus lindl var. polyphyllus was exception by having unique large chromosome mostly is covered by one signal of 45S rDNA, whereas its homologous chromosome seems to be normal-sized and have the other 45S rDNA locus. The similarity matrix among the Lupinus species as computed according to Jaccardʼs Coefficient from the SDS-PAGE, showed that L. albus ssp. Albus and L. albus ssp. Graecus are the most similar species (~ 97%), and then comes L. termis, and L. polyphyllus lindl var. polyphylus has been placed in separate clade and still the most related species to it among the studied species is L. termis (~ 70%). Conclusion It could be postulated from FISH and seed storage protein electrophoretic patterns that the relationships among the studied species is as follows, Lupinus albus ssp albus, is the most related species to Lupinus albus ssp graecus then comes Lupnus termis and Lupinus polyphyllus lindl var. polyphyllus at a distal position.