Abstract

GONZALEZ, Marie et al. Effect of nitrogen source in the culture medium in vitro on growth cocuy (Agave cocui Trelease). Bioagro [online]. 2012, vol.24, n.1, pp.39-44. ISSN 1316-3361.

The cocuy (Agave cocui Trelease) is a species that supports a large number of families in the semiarid area of Northwestern and Northern Venezuela. This study aimed to evaluate the effect of in vitro culture medium and nitrogen source on the plant growth through: A) Evaluation of the means of Murashige and Skoog (MS) and Knudson (K), alone or modified by incorporating a source of N-NH4+ (from ammonium sulfate or urea), and a source of N-NO3 (from calcium nitrate), for a total of eight treatments, and B) Evaluation of the concentration of MS salts, with four treatments: ¼ MS, ½ MS, ¾ MS and MS full. After six months of cultivation, the dry matter accumulation was higher in the shoots grown in the original MS medium compared to the original K. Overall, there was larger growth in the MS medium than in K medium, while the growth was lowest in the media with N-NH4+ coming from ammonium sulfate. In the media with N-NO3 there was a higher number of roots. The highest shoot length and the smallest number roots and root length were recorded in full MS medium, while the concentration of total and reducing sugars tended to increase as the strength of MS medium decreased. Since the plant had higher growth in MS medium than in K, and that there was more root growth and sugar accumulation in MS of low concentration. It is concluded that the ¼ MS could be very useful in facilitating the process of acclimatization of rooted shoots of cocuy plants.

Keywords : Ammonium; nitrate; semiarid.