Karyotypes and morphological characteristics of some species in the genus Lathyrus L.

Abstract

In order to gain a better understanding of the genetical relationship among species of the genus Lathyrus, investigations on the morphological characteristics as well as karyotypes of the plants were carried out. Twenty four strains from twenty annual and perennial species representing the main sections of the genus were used. All the species analyzed had chromosome numbers of 2n=14 except fcr one strain (No.1)of L.pratensis with 2n=28. Karyotypic differences among species involved the shape and size of satellite chromosomes, the length of the arm with satellite, the ratio of the satellite chromosome length to the total length of all the chromosomes, the length and arm ratio on the individual chomosomes. The karyotypes were classified into six types A, B, C, D, E and 4X. The karyo type A was commonly observed in all the sections studied, while the others were all modified karyotypes and detected in a limited number of sections. Morphological characteristics such as configuration of stems, leaves, leaflets, veins, stipules, racemes, styles, pods and sutures were similar to those previously reported by DAVIS (1970) and MEIKLE (1977). Itappears that morphological changes from the primitive to the advanced form, based on the characters of this genus described by BASSLER(1966) and SIMOLA (1968), might correspond to karyotypic changes from the common to the modified type, as suggested by STEBBINS (1971).