Between and within species variation in annual Medicago species
1996
Fyad-Lameche, F.Z. | Bellatar, G. | Bouabdallah, S. | Yahia, N. (Universite d'Oran-Es-Senia, Oran (Algeria). Laboratoire d'Amelioration des plantes)
Genetic variability of annual Medicago species was examined with respect to allozyme, SDS-PAGE seed storage proteins, pollen germination, seed coat hardness, heading date and cold hardiness one hundred accessions of ten species. The allozyme electrophoretic analysis leads us to the conclusion that all the species studied were very homogeneous. Only two cases of within species variation were clearly demonstrated. It concerned LAP system for M. scutellata species and the GOT system for M. Polymorpha. Hypothesis concerning the genetic control of enzymatic systems are formulated. The SDS-PAGE seed storage study showed few polymorphism but the number of bands is relatively high. The patterns were specific for each species, difference is rather qualitative which means that almost all the bands were different from one species to the other. The variation within species concerned minor bands with high molecular weight. Some cases of bands encoded by a single locus have been found. The data obtained on the pollen grain germination and viability rates showed a wide range of variation at all levels (species, populations of flowers under one plant). The seed coat hardness has been assessed by seed germination rates. Six seed morphological traits (weight, length, colour, width, seed coat and aspect) are suspected to be related to seed coat hardness have been measured and the data obtained showed a wide variation. The variation of heading date have been assessed by a randomised block design. Some growth traits have been measured on the plant for suspected interrelationships with heading date.
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