Genetic and morphological characterization of the endangered Austral papaya Vasconcellea chilensis (Planch. ex A. DC.) Solms

Caligari, PDS (Caligari, P. D. S.) Univ Talca, Ctr Plant Breeding, Talca, Chile; Univ Talca, Phen Ctr, Inst Ciencias Biol, Talca, Chile.-The Austral papaya (Vasconcellea chilensis) is an endangered species that has valuable characteristics for introgression into other papaya species. These characteristics include disease resistance, cold tolerance and latex with low proteolytic activity. It is a species that grows under extreme environmental conditions of drought, salinity and temperature; it is found growing naturally in Chile but today only as three remnant populations. The results presented here, using inter simple sequence repeat molecular markers, along with morphological trait analyses, suggest that these relict populations are the result of a relatively recent fragmentation. This implies that the fragmentation has not yet had its full effect on the genetic variation and so emphasises the need for clear and urgent conservation measures to preserve the remaining genetic variation, particularly for the most northern of the three populations which is presently unprotected

The genetic improvement of bananas and plantains (Musa spp.)

status: publishe

Morphometric and phytochemical characterization of chaura fruits (Gaultheria pumila): a native Chilean berry with commercial potential

Univ Talca, Inst Biol Vegetal & Biotecnol, Talca, Chile; Caligari, PDS (Caligari, Peter D. S.); Pico, J (Pico, Jose)Background: For the first time, a morphometric characterization of chaura (Gaultheria pumila) fruits has been conducted between natural populations growing in the Villarrica National Park, Araucania Region, Chile. Chaura is a native Ericaceae from Chile that produces aromatic and tasty fruits which could be of agricultural interest. Results: To influence the decision for a further domestication of G. pumila, both the fruit sizes (indicator of productivity) and the nutritional properties of the fruits have been determined from different subpopulations. Samples were a total of 74 plants and 15 fruits per plant which were randomly harvested following its natural distribution around the Villarrica volcano. Altogether, fresh weight, shape, color, diameter in the pole and the equatorial dimensions were determined as phenotypic traits of the G. pumila fruits. Meanwhile the total soluble solids, anthocyanin and pectin contents were calculated as nutritional traits of the Chaura fruits. Results showed a high phenotypic diversity between the sampled population with three main fruit shapes and three predominant colors. The round shapes were the most abundant, whereas a significant correlation was found among fruit size with weight and color. The highest fresh weight (597.3 mg), pole diameter (7.1 mm) and equatorial diameter (6.5 mm) were estimated in the pink color fruits. Conclusions: The total amount of anthocyanin was higher in red fruits, while the maximum pectin content was obtained in the round white fruits. Overall results must pave the way for a further domestication and introduction of the Chaura species in the agro-productive system in Chile

Competition of similar and non-similar genotypes

It has been well established that the fitness of a genotype is often a function of the presence and relative frequencies of other genotypes coexisting with it1-3. Facilitation or interference between individuals of like genotypes is suggested by some experiments4-9, and it is commonly accepted that competition is an important element in agricultural practice 10,11. However, most such studies, at least those that use Drosophila as the experimental organism, involve strains which carry different mutations or chromosomal rearrangements. Here we demonstrate that competition of similar as opposed to non-similar genotypes can be detected in a random mating population not subject to genetic manipulation. © 1982 Nature Publishing Group