Trompillo, angels or encyclia rabbit (Encyclia adenocaula (La Llave & Lex.) Schltr) is an endemic orchid of Mexico distributed in the states of Nayarit, Jalisco, Michoacán, Mexico, Guerrero and Oaxaca. In the state of Mexico it is in the municipalities of Temascaltepec, Tejupilco and Valley de Bravo (^{Ruiz et al, 2008}; ^{Szeszko, 2011}; ^{Téllez, 2011}), is one of the 188 species listed in NOM-059-SEMARNAT- 2010 (^{SEMARNAT, 2010}) in the "endangered". Because of its showy flowers (inflorescences 60 cm to a meter long, with 10 to 35 flowers) and its pleasant fragrance noon, the species has been very collected involuntarily causing considerable decrease in natural populations (^{Ruiz et al, 2008}; ^{Szeszko, 2011}), adding, climate change and forest disasters is suffering its ecosystem. It is important to conserve the species both in situ and ex situ conditions, a key strategy of the latter, is the implementation of genebanks (^{Lascurain et al., 2009}; ^{Sánchez and Jiménez, 2010}).

In Mexico the vast majority of genebanks are intended to conserve species of agrifood interest, although some banks responsible for collecting wild, priority species, with viability problems in some category of risk, etc. (^{Lascurain et al, 2009}). The efforts to preserve the Orchidaceae family have been exhaustive, by implementing plant germplasm banks under in vitro conditions by method of minimal growth or slow growth. However, as in gardens or living collections germplasm maintenance requires adequate facilities and specialized maintenance more expensive maintenance costs, conservation of germplasm from seed is a viable strategy to preserve the greatest genetic variability possible with lower costs and very tight spaces.

Determine the quality of stored seeds is an important factor in determining the success or failure of conservation in genebanks point. In the analysis of seeds should study physical and biological a lot to assign a value features, these tests should be performed in two stages: first, immediately after extraction and clean seed; and second, before being planted or used for any other destination and the main analyzes are, weight and size of seeds, viability, purity, moisture, etc (^{Raó et al., 2007}).

^{Ossenbach et al. (2007)}, they conducted feasibility tests on orchid seeds of 22 accessions of 10 different species and determined that pretreatment with Ca(OCl)₂ as a desiccant significantly affects the viability of the seeds and tetrazolium test it is a very valid to determine the viability of seeds of orchids method, however, they determined that the accuracy of these studies is affected by the ability of the analyst who interprets them.

There are several studies that evaluate the germination of orchid seeds, however, its main objective is to evaluate germination rates and germination rate in different media in order to set the protocol in vitro of each of the species propagation, only ^{Salazar-Mercado (2012)}, tested for germination tetrazolium comparing to demonstrate feasibility of Colombian tropical seeds.

The aim of this study was to analyze the physical and physiological quality of Encyclia adenocaula as model and priority species in the State of Mexico, for their conservation in a genebank seed.

The study was conducted at the laboratory of tissue culture and greenhouse 5 which houses the collection of orchids of the Faculty of Agricultural Sciences at the Autonomous University of the State of Mexico. The mature seeds capsules were used in a population of E. adenocaula pollinated in 2012 and collected in May 2013 from plants of the community called "El Peñon" in the town of Temascaltepec, Mexico, located UTM 14Q 381736 and 2106024 with 1789 masl; in the laboratory he proceeded to remove the remnants of flowers and placed in paper envelope until dehiscence at room temperature, once you open the capsules proceeded to completely open along the longitudinal lines on a glass surface. Once extracted all the seeds, we proceeded to remove foreign particles or debris capsule with forceps for further storage in amber bottle under refrigeration (10 °C) until use.

In the analysis of E. adenocaula seeds were taken into account aspects such as size, weight and structure of the seed and the viability of it. For size and structure of the seed sample that was placed on three slides using a light microscope (Leica Microsystems Ltd. Leica Application Suite V4) and the software package Image Tool 3.00 (UTHSCSA) took 300 seeds they were measured species data taking as long and wide seed and coverage areas structures seeds. To determine the weight, 0.0001 g of seed were taken in triplicate and counted, by rule of three weight and number of seeds per gram was obtained.

The seed viability was determined by two techniques: 1) Tetrazolium test (TDZ) is a rapid test and germination. In the first methodology followed Bohm (1996), cited in ^{Ossenbach et al, 2007}. A 0.0001 g was established design completely random with three replications, where four treatments, which consisted of immersing filter paper packages were evaluated seeds: T1) 24 h imbibition in distilled water, was then replaced by solution of Ca(OCl)₂ for two hours and subsequently 24 h in solution TDZ; T2) 24

hours in distilled water imbibition and 24 h in solution TDZ; T3) 24 h imbibition in distilled water, then was replaced with solution of Ca(OCl)₂ for two hours and subsequently 24 h in solution TDZ plus two drops of Tween 80 and T4) 24 hours of soaking in distilled water and 24 h Tetrazolium solution plus two drops of Tween 80.An analysis of variance and Tukey 5% was made using the statistical program SAS System for Windows 9.0; and 2) the germination test was used a completely randomized design with ten repetitions using the technique sowing of in vitro. The culture medium was ^{Murashige and Skoog (MS) (1962)} basal medium supplemented with glycine (2 mg L^-1), myo-inositol (100 mg L^-1), thiamine HCl (0.4 mg L^-1), pyridoxine (0.5 mg L^-1), nicotinic acid (2 mg L^-1), sucrose 30 mg L^-1 added as treatments: 1 g L^-1 charcoal (MS+CA); 10% ofbanana extract (MS+P); 10% coconut water (MS+AC); pH was adjusted to 5.7±1 with 6 g L^-1 agar. The cultures were incubated at 24 ± 2 °C, 18/6 h photoperiod at a light intensity of 27 μmol m^-2s^-1.

Germination was considered phenological stage called initial protocorm, this because it is easy to detect visually stage. Using a stereoscopic microscope, a camera and software package Image Tool 3.00 (UTHSCSA) images of a field repetition were obtained. An analysis of variance and Tukey test at 5% was performed with the help of The SAS System for Windows 9.0 statistical software.

After studies it was determined E. adenocaula presents filiform and long elongated seeds, with a length of 0.56±0.08 mm and a width of 0.09±0.01 mm, covering an area of 3.25±0.5 mm², these data were taken from whole seeds (embryo and testa) (Figure 1), results consistent with those reported for other species of orchids since 1992 by Arditti as well as Hagsater et al. (2005); Verdugo et al. (2007); ^{Tellez (2011)} and ^{Aguilar and López (2013)}, reporting seed sizes from 0.25 to 1.2 mm long and 0.09 to 0.27 mm wide.

Figure 1 Structure and dimensions of typical seed Encyclia adenocaula. Microphotography. 

The seed presented the two basic structures of seeds corresponding to the Orchidaceae family; an embryo lacking endosperm (reserve nutrients) with an approximate area of 0.01±0.01 mm². The approximate weight of a seed was 1.6±0.08 g, equivalent to approximately 63 500 seeds per gram. The viability of seeds to determine whether a seed is alive and has the ability to germinate (^{Ruiz, 2009}). According to feasibility testing, testing TDZ, called rapid test, statistically significant differences (p≤ 0.05) between treatments were recorded, showing no significant difference T2 (50.3%) and T4 (48.2%) treatments; i.e. that pretreatment with Ca(OCl)₂ directly affected the viability of the seeds, where this solution is used the percentages were lower corresponding to T1 and T3 with 24.1% and 48.2% respectively, results that agree with ^{Ossenbach et al. (2007)} for five species of orchids including Encyclia ochracea obtained where 95% viability without pretreatment with Ca(OCl)₂ and 85% with pretreatment.

^{Lallana and Garcia (2013)} report a viability of 90 and 85% in Trichocentrumjonesianum seeds, ^{Salazar-Mercado (2012)}, in Cattlella mendelii seeds with 93% viability and ^{Salazar and Cancino (2012)} reported 87.2 and 80.6% seeds feasibility of P. vespa y S. klotzcheana respectively with the same method. According to statistical analysis there was no any significant effect on the addition of drops of Tween 80 with respect to the loss of viability, however, with the addition of this product was achieved better observation on the coloration of the embryo.

The percentage viability assessment by the technique of in vitro germination, showed statistically significant differences (p≤ 0.05) between treatments as better treatment resulting MS+CA with 56.9% germination at 30 days, followed by medium MS+AC with 31.4% germination to 55.7 days, finally the MS + P medium with 23% to 59.1 days. Results consistent with those reported in ^{Ruiz et al. (2008}) for the same species 62.4% germination at 27 days, although the difference in percentages can be given mainly by the origin of the material established in experiments. However, it is noteworthy that germination in the work can be considered from the imbibition of seeds as they consider various authors to the presence of first leaves, this must be due perhaps to the objective of the work.

However, in the same treatment the seeds germinated asynchronously; i.e. in the same condition after two months of establishing the different stages of germination and growth in vitro of the species were observed: imbibition, presenting swelling and embryo took a pale green caused by water absorption (Figure 2A); green seed, the seeds showed a pronounced green coloration and the embryo begins to increase in size within 15 days after sowing (Figure 2B); germination, at 30 days the embryo breaks testa (Figure 2C), initial protocorm; 36 days cell complex very faint green formed, the leaf primordium (Figure 2D) appearing; protocorm late, the protocorm continued growth, being born at the apex a foliar primordium 40 days after the establishment (Figure 2E); leaf development; the leaf primordium continued to grow, protocorm body began to decrease and to differentiate the leaves to about 47 days (Figure 2F); root development, was presented to the 57 days or so, the root primordia developed near the base of the leaves white (Figure 2G); full seedling, roots and leaves perfectly (Figure 2H) distinguished; They were seen as stages coincided with that reported with ^{Flores et al. (2008}), ^{Salazar and Cancino (2012)}, ^{Aguilar and López (2013)} in some species of orchid.

Figure 2 Germination and in vitro development of Encyclia adenocaula. A. imbibition to ±7 days after sowing, scale bar 400 μm B. Green seeds, ± 15 days. Scale bar 1 mm. C. Germination, ± 30 days, 1 mm, scale bar. D. initial protocorm, ± 36 days, 1 mm, scale bar. E. protocorm late, ± 40 days, scale bar 1 mm. F. Development of leaves, ± 47 days, scale bar 1 mm. G. root development, ± 57 days, 1 mm, scale bar. H. Full seedling, scale bar 2 mm. Photomicrographs.