Biochemical and Molecular Analysis of Some Commercial Samples of Chilli Peppers from Mexico

The genusCapsicumprovides antioxidant compounds, such as phenolics and carotenoids, into the diet. In Mexico, there is a wide diversity of species and varieties of chilli peppers, a fruit which has local cultural and gastronomic importance. In the present study, the relationship of the carotenoid and phenolic profiles with the RAPD fingerprint of three different commercial cultivars of chilli peppers of seven regions of Mexico was investigated. Through RAPD, the species of chilli were differentiated by means of different primers (OPE-18, MFG-17, MFG-18, C51, and C52). The genetic distance found with OPE 18 was in the order of 2.6. The observed differences were maintained when the chromatographic profile of carotenoids, and the molecular markers were analyzed, which suggest a close relationship between carotenoids and the genetic profile. While the chromatographic profile of phenols and the molecular markers were unable to differentiate between genotypes of chilli peppers. In addition, by using infrared spectroscopy and statistical PCA, differences explained by geographic origin were found. Thus, this method could be an alternative for identification of chilli species with respect to their geographic origin.

Species identification in meat origin farm animals through DNA technology

RAPD fingerprint technique was used on several meat sources to identify the species. The tested meat species were: Buffalo, Cattle, Goat and Sheep. Eighteen primers as a single, short oligonucleiotides were used to detect the species by fingerprint and genetic similarity as band sharing (BS) among these four species. By comparison between all four species, the band sharing average values were [51.0, 45.0, 59.0, 41.0, 48.0 and 70.0%] respectively. In respect of comparison, the comparison between Goat and Sheep showed high similarities while between Cattle and Goat showed low similarities. The genetic similarity as BS values ranged from 41.0 to 70.0 % respectively. The results showed that RAPD analysis provided a rapid and effective method to detect the genetic variation of different species. Also the results showed that RAPD analysis produced clear fingerprints from the products analyzed for which the species could be easily identified.

Genetic and Morphological Analysis of the Origin and Identity of Perennial Lavatera (Malvaceae) Cultivars

Knowledge of the origin of Lavatera L. (tree mallows) cultivars helps to predict their cultural requirements. Eighteen accessions representing 15 cultivars, 14 accessions of 7 species, and 5 accessions of an F1 hybrid between the putative parents of the cultivars were sampled for morphological variation and for randomly amplified polymorphic DNA (RAPD) fingerprint variation. Species-specific molecular markers were identified from the RAPD profiles. Chimeral elements were not distinguishable by RAPD analysis. Principal component analysis identified the majority of the cultivars to be selections of hybrid origin, probably from a narrow genetic base. Two cultivars were derived directly from individual species. The resolving power of RAPD markers and morphology was similar although RAPD data offered greater ability to ascribe parentage while morphology offered optimal discrimination of cultivar selections.

Genetic Analysis of Isolates of Botrytis cinerea Sensitive and Resistant to Benzimidazole and Dicarboximide Fungicides

A total of 56 isolates of B. cinerea collected from ornamental crops from commercial greenhouses were examined by random amplified polymorphic DNA (RAPD) fingerprint analyses. Isolates were examined as two independent sets of 35 and 36 isolates, with 15 isolates common to both sets. The isolates had four phenotypes: 17 were sensitive to two commonly used fungicides, thiophanate-methyl (a benzimidazole) and vinclozolin (a dicarboximide) (STSV); 18 were resistant to both fungicides (RTRV); 16 were resistant to thiophanate-methyl but sensitive to vinclozolin (RTSV); and 5 were sensitive to thiophanate-methyl but resistant to vinclozolin (STRV). Relationships among the isolates were determined by cluster analyses of mean character differences using the unweighted pair group method using arithmetic average and cladograms were constructed. Isolates were clustered primarily by fungicide-sensitivity phenotype. In one set of greenhouse isolates, 6 of 10 STSV isolates clustered together with a bootstrap confidence value of 91%. In the other fingerprint set of greenhouse isolates, 9 of 11 STSV isolates clustered together and had a bootstrap confidence value of 98%. Isolates resistant to thiophanate-methyl, vinclozolin, or both fungicides usually were not clustered with other isolates or were clustered with isolates of the same phenotype. To further elucidate these relationships, variant isolates resistant to one or both fungicides were produced on fungicide-amended agar medium from 14 STSV greenhouse isolates. These 14 STSV parent isolates, 57 resistant variant isolates, and 11 resistant greenhouse isolates were analyzed as three independent RAPD fingerprint sets. Variants selected from eight STSV parent isolates were resistant to both thiophanate-methyl and vinclozolin even though parent isolates were exposed to only one of the fungicides. Isolates resistant only to vinclozolin (STRV) had fingerprint patterns similar to and clustered with those of parent isolates, while fingerprint patterns of isolates resistant to thiophanate-methyl (i.e., RTRV or RTSV), regardless of sensitivity to vinclozolin, clustered differently from both those of STSV parent isolates and those of STRV isolates derived from the same parent. RTRV and RTSV variant isolates derived from the same fungicide-sensitive parents only clustered with other variants having the same phenotype.