Morphology and viability of five native seed species from the altiplano

Abstract

The native grasses of the Altiplano: Bromus catharticus (cebadilla), Hordeum muticum (mousetail), Adesmia spinosisima (añahuaya), Trifolium amabile (layu layu) and Suaeda foliosa (q′auchi), are staple foods of domestic and wild high altitude animals. They produce and are propagated by sexual seed. To establish monocultures or associated, it is necessary to know the percentage that remain alive, and the physical dimensions, and their relationship with their structural components. In the laboratory of the Patacamaya Experimental Station, the following were determined: the size, with a Kamasa digital calibrator (0-150mm/0-6), the weight of 1 000 seeds in a precision balance, the internal structure, morphological characteristics with a stereoscope and photographic machine, and the viability with treatments of three tetrazolium solutions: 1, 0.5 and 0.1 %. The average viability of the five species was 78.67 %, ranging from 15 to 95 %. The average viability of cebadilla was 91.50 %, similar to 91.33 % of mousetail and higher than 84.67, 73.33 and 52.50 % of añahuaya, layu layu and q′auchi, respectively. The treatment effect on seed viability and non-viability in all five species were highly significant (p≤0.01). For concentrations of 1, 0.5 and  0.1 % tetazolium solution the averages of viable seeds were 84.65, 79.40 and 72.05 %, and for non-viable seeds 15.95, 20.55 and 27.45 % respectively. The smallest and lightest seeds in relation to their weight 1.77 and 1.52 g, corresponded to mousetail and q′auchi. This last species in external cover is harder and thicker than layu layu and añahuaya, which have layers impermeable to the effect of the environment, compared to mousetail and cebadilla; however, four of the seeds except q′auchi had high percentages of viability.