Browsing by Author "Carrasco, Basilio"

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    Efficient protocols for the extraction of microbial DNA from the rhizosphere of hydrophilic forests in Chile
    (PONTIFICIA UNIV CATOLICA CHILE, FAC AGRONOMIA INGENIERIA FORESTAL, 2012) Caceres, Pablo; Cordero, Cecilia; Gonzalez, Gloria; Quiroz, Karla; Bobadilla, Juan C.; Bravo, Carmen; Caligari, Peter D. S.; Carrasco, Basilio; Garcia Gonzales, Rolando
    P. Caceres, C. Cordero, G. Gonzalez, K. Quiroz, J.C. Bobadilla, C. Bravo, P.D.S. Caligari, B. Carrasco, and R. Garcia-Gonzales. 2012. Efficient protocols for the extraction of microbial DNA from the rhizosphere of hydrophilic forests in Chile. Cien. Inv. Agr. 38(3): 585-592. A lysis buffer-based protocol (Protocol BA), a modified lysis buffer-based protocol (Protocol BA Mod) and a commercial extraction kit (Protocol PS Kit) (Power Soil, Mo bio Laboratories, CA USA) were each evaluated for their ability to produce high-quality DNA with yields sufficient to allow its use in biodiversity studies. Similarly, the effect of liquid nitrogen on the process of cell disruption in all of the protocols that were studied. DNA yields ranged from 12.4 ng g(-1) of processed soil to 9620 ng g(-1) using the modified lysis buffer and commercial extraction kit, respectively. The quality of the DNA was determined by the ability of the DNA to produce efficient and reproducible polymerase chain reaction (PCR) products, using primers for universal 16S and 18S ribosomal RNA regions from bacteria and fungi, respectively. High-quality DNA was obtained to run PCRs in all protocols, but the efficiency of the method depended on the dilution of the DNA prior to performing the PCR. The three extraction methods generated PCR products with 90% efficiency. The DNA produced with the commercial kit was able to produce the highest PCR efficiency (95%) when the 10(-1) dilution was used. The method based on the use of lysis buffer produced the highest efficiency (90%) using a 10(-2) dilution. Meanwhile, the modified lysis buffer-based protocol generated the highest efficiency of PCR products using the 10(-3) dilution factor with 95% of efficiency. For the first time, reliable and efficient DNA isolation from the rhizosphere of hydrolic forest is documented, enabling a wide range of applications for this technique.
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    Genetic structure of highland papayas (Vasconcellea pubescens (Lenn, et C. Koch) Badillo) cultivated along a geographic gradient in Chile as revealed by Inter Simple Sequence Repeats (ISSR)
    (SPRINGER, 2009) Carrasco, Basilio; Avila, Patricio; Perez Diaz, Jorge; Munoz, Patricio; Garcia, Rolando; Lavandero, Blas; Zurita Silva, Andres; Retamales, Jorge B.; Caligari, Peter D. S.
    In Chile Vasconcellea pubescens is cropped to produce canned fruit, juice, jam and processed sweets. Additionally this species produces latex with a high level of papain, an important and valuable proteolytic enzyme with industrial applications. In this investigation seven ISSR primers were used to study the level and organization of genetic diversity in 333 samples of V. pubescens. Out of the 114 bands recorded, 63 proved to be polymorphic (P = 55.3%). At the species level, the genetic diversity was rather low (h = 0.01 +/- A 6,80188E-05, Shannon's Index I = 0.16 +/- A 0,000148). The major portion of the genetic diversity was found within groups (65%). The genetic differentiation between the different groups was significant, as the AMOVA analysis suggested (I broken vertical bar(pt) = 0.35). When analysing the Northern area alone, the differentiation increased to I broken vertical bar(pt) = 0.40. When only the Southern area was analysed, I broken vertical bar(pt) decreased to 0.18, indicating greater genetic similarity among the samples. The results generated from Structure and Bayesian Analysis of Population Structure distinguished 8 genetically different groups, five of them located in the north and three in the south. The results are discussed in the light of the growers' practices.
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    Proximal causes of genetic variation between and within populations of raulí (Nothogafus nervosa).
    (2009) Carrasco, Basilio; Garnier, Maurice; Eaton, Lafayette; Guevara, Rafael; Carú, Margarita