Fifty pineapple buds (cv. Red Spanish Pinar, donor) were collected from field-grown plants and cultured in vitro. Forty-three young pineapple shoots were obtained after 42 d of implantation. Shoots were micropropagated for 168 d to produce 24,768 shoots. Three hundred young leaves were randomly selected as explants for callus formation. Calli proliferated for 4 months. Five hundred calli were randomly selected and transferred to the plantlet regeneration medium. Four hundred twenty-seven in vitroplantlets were obtained and later hardened ex vitro. Then, 387 plantlets were transferred to the field environment and asexually propagated for two generations (30 months). Only two phenotype variants were identified: P3R5 and Dwarf. A more detailed study was carried out to compare these two variants with the donor plant. The variant P3R5 showed differences in the number of slips and suckers, and in the presence of thorns in the leaves and in the fruit crowns. The somaclonal variant Dwarf, was different from the donor plant in regard with the plant height; the peduncle diameter; the number of shoots, slips and suckers; the fruit mass with crown; the number of eyes in the fruit; the fruit height and diameter; the leaf color; the plant architecture; the length of plant generation cycle; and the fruit color and shape. Both somaclonal variants showed different AFLP banding patterns in comparison with the donor cultivar.

The Food and Agriculture Organization has highlighted pineapple as one of the most important tropical fruits. Since classical pineapple breeding is difficult, biotechnology has emerged as an attractive instrument. We obtained two new pineapple somaclonal variants derived from in vitro culture of cv. Red Spanish Pinar: P3R5 and Dwarf. The AFLP analysis revealed an existing genetic distance. So far 44 phenotype indicators selected due to their relation to a wide range of important agricultural, morphological and physiological processes have been evaluated. P3R5 differed from the donor in 19 variables (19/44; 43.18%), while Dwarf varied in 31 indicators (31/44; 70.45%). The number of shoots was significantly different among the three plant materials. Dwarf showed two shoots per plant while P3R5 and the donor did not form any shoots. We also observed that water use efficiency, chlorophyll b concentration, total chlorophyll concentration, transpiration rate, chlorophyll a concentration, thickness of leaf photosynthetic parenchyma, fruit mass with crown, content of free phenolics and superoxide dismutase specific activity were also very different among the three plant materials. The Euclidean distances of each somaclonal variant to the donor plant material taking into consideration the genotype (AFLP) and the phenotype evaluations were also calculated. Regarding the genotype information, P3R5 is separated from cv. Red Spanish Pinar by 2.83 units of Euclidean distance, and Dwarf by 3.00 units. However, the phenotype indicators revealed higher differences: 3.74 in P3R5 and 4.71 in Dwarf. To our knowledge, this is the first report of a comprehensive analysis of pineapple somaclonal variants

We previously reported a partial agricultural and amplified fragment length polymorphism (AFLP) characterization of two new pineapple somaclones (P3R5 and Dwarf) derived from in vitro culture of the donor cv. Red Spanish Pinar. Both somaclonal variants showed different AFLP banding patterns compared to the donor cultivar, although they were separated by less than 0.09 U of genetic distance. The present report shows data of various indicators of morphology and physiology of P3R5 and Dwarf D leaves. The stoma diameter, number of stomata per square millimiter, diameter of leaf vascular tissue, thickness of the leaf aquiferous parenchyma, and thickness of the leaf photosynthetic parenchyma were measured. The photosynthetic rate, the transpiration rate, the water use efficiency, the internal leaf CO 2 concentration, and the chlorophyll pigment contents were recorded as well. Between the somaclonal variant P3R5 and the donor genotype, statistically significant differences were recorded in all indicators with the exception of the stoma diameter and the photosynthetic rate. Comparing the somaclonal variant Dwarf and the cv. Red Spanish Pinar (donor), statistically significant differences were also recorded in all parameters except in the stoma diameter and in the transpiration rate. This investigation was performed to demonstrate that small changes in the pineapple DNA may result in relevant phenotypic modifications.

El monitoreo forestal es de gran interés para integrar bases de datos que permitan generar conocimiento y nuevas tecnologías para optimizar la producción, proteger los recursos y acrecentar el valor de los bosques, a través del manejo forestal sustentable. En el estado de Chihuahua, el monitoreo para el desarrollo de conocimiento científico relativo a estos ecosistemas se inició en 1950 con el establecimiento del primer Sitio Permanente, de Investigación Silvícola (SPIS), en el paraje conocido como “El Poleo”, el cual se ubica en el norte del municipio Madera. En la década de 1980-1990 se establecieron 234 parcelas en el área experimental del INIFAP, localizada en la región sur del ejido El Largo; de 1990 a 2000, se implementaron 48 parcelas en el municipio Bocoyna y 16 en el municipio Guachochi, como parte del proyecto: Bosque Modelo. Finalmente, entre 1998 y 2001 se delimitaron 48 parcelas en el municipio Guadalupe y Calvo con el apoyo del Programa de Desarrollo Forestal (Prodefor). Las parcelas localizadas en El Poleo, Madera, Llano blanco, así como Guadalupe y Calvo tienen datos de remediciones periódicas; las cuales muestran incrementos medios anuales superiores a 4 m3ha-1, con registros de hasta 16 m3ha-1 en el sur de la entidad. La información histórica y las bases de datos de los SPIS son un valioso antecedente para el seguimiento de los programas de monitoreo y el desarrollo de métodos silvícolas para el manejo sustentable de los bosques de la región.

El uso de polímeros retenedores de humedad es una técnica que se ha utilizado para incrementar la supervivencia en plantaciones de restauración forestal, sin embargo, escasos estudios han evaluado su efectividad. El objetivo del estudio fue evaluar el efecto de diferentes dosis de un polímero retenedor de humedad en la supervivencia de tres plantaciones de mezquite (Prosopis glandulosa Torr.), en dos sitios de zonas áridas del estado de Chihuahua, México. Se utilizó un polímero hecho a base de potasio en dosis desde tres hasta diez gramos por planta. Se midió la precipitación en cada sitio, la humedad del suelo en cada planta y los porcentajes de supervivencia de cada plantación en diferentes fechas a lo largo de un año. Los porcentajes de supervivencia después de un año fueron 34%, 59% y 83%. No se encontró efecto positivo de ninguna dosis de hidrogel en la supervivencia. La humedad en el suelo por efecto del polímero es muy corta en condiciones de poca precipitación y altas temperaturas, y los eventos de lluvia distanciados en tiempo no son suficientes para la rehidratación del polímero. Esto genera una igualdad de condiciones en términos de humedad del suelo para las diferentes dosis durante los meses críticos de sequía, en los cuales se registró la mayor mortandad de planta.