Assessment of genetic instabilities induced by tissue culture in alkaligrass

Resumo

Alkaligrass (Puccinellia chinampoensis Ohwi), one of the important forage grasses in saline-alkalieroded grasslands, has been proved to be invaluable for improving saline-alkali soils. However, little is known of its genetic instabilities during in vitro culture for its artificial breeding. In this paper, a simple and efficient regeneration system of mature seed-induced calli in alkaligrass was established, and the somaclonal variation in the regenerated plants was assessed by inter-simple sequence repeat (ISSR) and retrotransposon-microsatellite amplified polymorphism (REMAP) markers. 18 randomly chosen regenerants were subjected to ISSR and REMAP analysis with the shoot from the same grain of seed as the control. ISSR analysis showed that of the 145 scored bands, 13 were polymorphic among the analyzed samples, giving rise to a genetic variation frequency of 8.97%. REMAP analysis revealed that 4 out of 127 scored bands were polymorphic, a genetic variation frequency of 3.15% occurred. Cluster analysis indicated that the genetic similarity index calculated on the basis of ISSR data or REMAP data among the 18 regenerated plants and the donor plant was 0.974 and 0.996 respectively. All the results confirmed that somaclonal variation was induced by tissue culture in alkaligrass at a higher frequency, and indicated that the regeneration system could be a viable option for genetic improvement of alkaligrass by biotechniques.