The study "Distance between rows and plants in two ecotypes of canihua (Chenopodium pallidicaule Aellen) in the northern Altiplano" was conducted during the agricultural period of 1999-2000 in the community of Achaca, Tiahuanaco canton, Ingavi province, department of La Paz, Bolivia. It was at 3854 meters above sea level, 16°35' South latitude by 68°41' West longitude. Precipitation was 474.6 mm and the soil was a loose sandy texture. The genetic material was composed of the ecotypes of yellow Lasta, red Lasta, yellow Saihua, and red Saihua, from the Belén Experimental Station, part of the Faculty of Agronomy, San Andrés Higher University. With the objective to evaluate the effect of distance between rows and between plants on the agronomic behavior of two ecotypes of Canihua in the northern Altiplano, planting took place on December 20, 1999, in rows 20, 40, and 60 cm apart, at a density of 4 kg/ha, all of it under a random block design with plots sub-subdivided. The principal plot set the distance between rows, the subplot set the distance between plants, and the sub-subplot the different ecotypes. Thirty-five days after planting the plants were thinned by hand, and with the use of a cord they were located at pre-established distances of 10, 20, and 30 cm between plants. The effects of the different distances on the ecotypes gave the following results and principal conclusions: The height and stem width of canihua was directly proportional to the different distances between plants and rows, and inversely proportional to the number of plants per area. The maximum values reached for height (21.4 cm) and diameter (2.5mm) occurred with 60 cm between rows and 101,852 plants per hectare. Also, the yellow Saihua ecotype was taller than the rest of the ecotypes at 19.1 cm. As for diameter, the ecotypes presented statistically similar behavior.

Cañahua (Chenopodium pallidicaule Aellen) is a poorly studied, annual subsistence crop of the high Andes of South America. Its nutritionally value (high in protein and mineral content) and ability to thrive in harsh climates (drought, extreme elevations, etc.) make it an important regional food crop throughout the Andean region. The objectives of this study were to develop genetic markers and to quantify genetic diversity within cañahua. A set of 43 wild and cultivated cañahua genotypes and two related species (C. quinoa and C. petiolare) were evaluated for polymorphism using 192 microsatellite markers derived from random genomic sequences produced by 454 pyro-sequencing of cañahua genomic DNA. In addition, another and 424 C. quinoa based microsatellite markers were evaluate as potential cross-species marker loci. A total of 48 polymorphic microsatellite marker loci were identified which detected a total of 168 alleles with an average of 3.5 alleles per marker locus and an average heterozygosity value of 0.47. A cluster analysis, based on Nei genetic distance, grouped the cultivated cañahua into a single dominant branch clearly separated from wild cañahua genotypes and the outgroup species. Within the cultivated genotypes, two dominant subclades were present that were further partitioned by AMOVA analysis into five model-based clusters. Significant correlations were found between genetic distance and morphological traits. The isolation by distance test displayed no significant correlation between geographic collection origin and genotypic data, suggesting that cañahua populations have moved extensively, presumably via ancient food exchange strategies among native peoples of the Andean region. The molecular markers reported here are a significant resource for ongoing efforts to characterize the extensive Bolivian and Peruvian cañahua germplasm banks, including the development of core germplasm collections needed to support emerging breeding programs.