03483naa a2200169 a 450000100080000000500110000800800410001902200140006010000110007424501030008526000090018852028890019765300230308665300190310965300210312877301640314910841302012-03-27       2000    bl uuuu     u00u1 u    #d  a1415-47571 aEpagri  aGenetic characterization of Bromus auleticus Trinius accesses through allozymic and RAPDs markers.  c2000  aThe natural fields of the South of Brazil come along the years. serving as alimentary base for the cattle. However, this natural resource are not appropriately managed for its better conservation. The Bromus aufeticus Trinius is a perennial native species that is part of this ecosystem and it has been showing potential for good forage and quality. It is a characteristic plant of the Southern plateau of Brazil, with wide, but discontinuous dispersion, with few ind??v??duos and seemingly, it adapts in environments with some soil limitations. The improvement of this species could allow its cultivation not only in natural habitats but also in areas already degraded by the agricultural activity or excessive grazzing, providing great forage volume with considerable nutritional value. The objective of this work was to characterize the genetic variability among Bromus auleticus accesses existent in the Experimental Station of Lages (EPAGRI S.A.) through of allozymic and RAPD rnarkers.The allozymic analyses were made through elec??trophoresis in starch gel of maize penetrose (13%), using nine enzymatic systems: PCI, SKDH, IDH, PRX-1, PRX-2, PRX-3, PRX-4, PRX-5, NADHDH, MDH-1, MDH-2, MDH-3, PGM, 6PGDH and a-EST with tris-citrate buffer pH 7.5. The RAPD analysis was accomplished by PCR reactions with 1 U of Taq DNA Polimerase, 1.5 mM of MgCI2, 0.22 dNTPs mM, 0.6 primer mM and 9 ng of genomic DNA, in a final volume of 13 ??l. The reactions were submitted to 92oC by one minute, 35oC for one minute, 72oC for two minutes, being this cycle repeated 39 times. One more cycle of 72oC for 5 minutes, for complementation of the reaction were performed afterwards. The enzymatic analysis detected 15 apparent loci with 73.3 % of polymorphic loci and average of 2.1 alleles for loci. The observed heterozigosity was 0.345 and the expected was 0.340. In comparison with other species, the levei found can be considered high. To evaluate the amplification quality and the polymorphism with RAPD markers, 44 primers were tested. From them, 13 (29.5%) amplified visible fragments, revealing 67 bands, 34 of wich were polymorphic. The average of polymorphic bands for each polymorphic primer was 2.61. Eleven Bromus auleticus accesses were evaluated with 7 primers, wich detected 44 bands, of the which 27 were polymorphic. The analyses of genetic similarity were made with BIOSYS-1 and NTSYS programs, using Nei's coefficient (1978) and [accard, for isozymes and RAPD, respectively. In the dendrogram similar genetic groups can be distinguished. RAPDs markers, when compared with isozymes presented larger capacity of polymorphism detection. The high level of genetic variability exhibited by the accesses and it characterization will facilitate the parentaI choosing for the species improvement program, with maintenance of a wide genetic base. Support financial: EPAGRI S. A. /UFSC.  aGenetic similarity  aHeterozigosity  aPolymorphic loci  tIn: CONGRESSO NACIONAL DE GEN??TICA, 46., 2000, Aguas de Lindoia, SP. [Proceedings...]. Ribeirao Preto, SP: Sociedade Brasileira de Genetica, 2000. p. 538-539.