Storage procedures for yeast preservation: phenotypic and genotypic evaluation

The aim of this study was to evaluate the morphological and biochemical characteristics of yeasts during storage, Six Candida, spp. standard strains were stored in agarized medium with mineral oil in distilled water, frozen at -70 degrees C and freeze dried. Strains were phenotypically characterised before being stored and then periodically for up to 18 months. Randomly Amplified Polymorphic DNA (RAPD) was carried out in time zero, 6, 12 and 18 months of storage. The viability of all samples was preserved except for the strain of Candida dubliniensis after 12 months of storage with mineral oil. No phenotypic alterations were observed in any of the methods employed. However, variations were observed in some phospholipase or proteinase activities. Changes in the RAPD patterns were not detected. These results seem to indicate that the maintenance methods tested were able to preserve the stability of the yeast phenotypic and genotypic characteristics.57346146

Clonal stability of latex yield in eleven clones of Hevea brasiliensis Muell. Arg.

Eleven Hevea brasiliensis clones were evaluated for clonal stability of latex yield. A randomized complete block design was used with four replicates, two locations, seven years and three periods per year. Stability analysis was based on clone x year and clone x year x location interactions. Five stability parameters viz environmental variance, shukla's stability variance, regression of clonal latex yield on environmental index, variance due to regression and variance due to deviation from regression were applied. There was significant clone x environment effect at the two levels of interaction. Among the eleven clones, C 162 was outstanding for clonal stability and it can serve as donor parent for stability alleles. Three clones (C 76, C 150 and C 154) were also stable. The four stable clones (C 76, C 150, C 154 and C 162) are suitable for broad-spectrum recommendation for latex yield. Five clones (C 83, C 143, C 163, C 202 and RRIM 600) will require environment-specific recommendation because of their unstable phenotype. The stability feature of two clones (C 145 and C 159) was not clear and this will be investigated in subsequent studies