Ponderosa pine (Pinus ponderosa Dougl. ex Laws) is the main forest tree species cultivated in Patagonia without irrigation. Its productive potentiality and the surface available for afforestation with it indicate the species will continue to be among the first forest tree alternatives in the region, what makes essential to assure the availability of seeds with adequate genetic quality. In the last decade, a set of commercial stands acted as seed sources although they have never been genetically tested. The aim of the present study is to evaluate those stands by testing their progeny. In this first report we present the results at the nursery stage. We assayed 31 local seed sources in two sites. Total height and stem diameter at the root collar were measured in two-year-old seedlings. Provenance X site interaction was shown by means of ANOVA, and also differences among seed sources within each site. Rankings were subsequently built for each trial and trait separately. Pair-wise comparisons were performed, and homogeneous groups were built. Genotypic stability of each seed source was estimated by calculating their ecovalence. Results are still preliminary, however, finding significant differences at such an early age alert us about the importance of the seed source for commercial production. We expect these differences will increase with age, and field trials have already been planted in order to test this expectation.

El Pino Ponderosa (Pinus ponderosa Dougl. ex Laws) es la principal especie forestal implantada en secano en la Patagonia. Su potencialidad productiva y la disponibilidad de tierras para su cultivo permiten proyectar la continuidad de su uso en plantaciones comerciales, para lo que es indispensable asegurar la provisión de semillas de adecuada calidad genética. Las semillas utilizadas en la última década se produjeron en una serie de rodales mediante ensayos para evaluar su descendencia. El objetivo del presente trabajo es evaluar estos rodales ensayando su descendencia. En este primer reporte presentamos los resultados de una evaluación en etapa de vivero. Se ensayaron 31 procedencias locales seleccionadas (Áreas Productoras de Semillas, APS) en dos sitios, midiendo altura y diámetro a la altura del cuello en plantines de 2 años de edad. A través de análisis de la varianza se probó un claro efecto de interacción entre las APS y los sitios, y también diferencias entre las APS dentro de cada sitio. Seguidamente, se establecieron rankings de las APS por sitio y variable evaluada. A través de comparaciones de a pares se formaron grupos homogéneos. También se estimó la estabilidad genotípica de las APS por medio del cálculo de sus ecovalencias. Los resultados son aún preliminares, pero el haber probado diferencias en tan temprana edad nos alerta sobre la importancia de la procedencia de las semillas a utilizar para la producción comercial. Se espera que estas diferencias se acentúen en edades más avanzadas. Para probarlo, ya se han establecido ensayos de plantación.

The analysis of the genetic variation and evolutionary processes related to the conservation and use of forest genetic resources requires reliable tools. The aim of the present study is to determine the mode of inheritance of isozyme variants of Nothofagus antarctica, species of economic and ecological importance inhabiting the temperate forests of southern South America. Buds from 56 trees and their offspring were subjected to horizontal starch gel electrophoresis. Good resolution and consistent band patterns were obtained from five out of 15 enzyme systems surveyed. Expected equal number of heterozygous and homozygous seedlings of open pollination from a putative heterozygous mother was tested by the Chi-square test. Superoxide dismutase (SOD) revealed invariant electrophoretic patterns. Glutamate-oxalacetate transaminase (GOT) showed two zones of enzymatic activity, each one encoded by a gene locus with codominant expression and three alleles. Phosphoglucose isomerase (PGI) and phosphoglucomutase (PGM) showed two zones, the most anodal of which were invariant, and six and five alleles respectively in the variable zone. Four confident polymorphic gene markers are thus available for different population genetics studies on Nothofagus antarctica.

El análisis de la variación genética y de diversos procesos evolutivos en relación con la conservación y uso de los recursos genéticos forestales requiere la utilización de herramientas confiables. El objetivo del presente estudio es determinar el modo de herencia de variantes isoenzimáticas en Nothofagus antarctica, una especie de los bosques templados de Sudamérica de gran importancia tanto económica como ecológica. Las yemas de 56 árboles adultos y plántulas de su descendencia se analizaron electroforéticamente sobre gel horizontal de almidón. Se obtuvo buena resolución y patrones de bandas consistentes en cinco de los 15 sistemas enzimáticos ensayados. Mediante el test de Chi-cuadrado se puso a prueba la hipótesis esperada de igualdad entre las frecuencias de plántulas homocigotas y heterocigotas en la descendencia de polinización abierta de madres heterocigotas putativas. La enzima superóxido dismutasa (SOD) reveló un patrón electroforético invariable. Glutamato-oxalacetato transaminasa (GOT) mostró dos zonas de actividad enzimática, cada una codificada por un gen-locus codominante y tres alelos. También se observaron dos zonas en fosfoglucosa isomerasa (PGI) y en fosfoglucomutasa (PGM), invariables las más anódicas en ambos casos, y con seis y cinco alelos respectivamente en la zona variable de cada una de estas enzimas. De este modo se dispone de cuatro marcadores génicos polimórficos confiables para llevar a cabo diversos estudios genéticos en Nothofagus antarctica.

Plântulas de cravo (Dianthus caryophyllus) micropropagadas durante várias gerações pelo período de um ano, foram enraizadas in vitro com AIA, ANA e AIB nas concentrações de 0,0; 0,25; 0,5 e 1,0 mg/l, em fatorial do tipo 3 x 4, com todos os tratamentos promovendo a formação de raízes, mas não diferindo do controle. Foi confrontado em condição autotrófica, o desempenho entre plântulas enraizadas in vitro na presença e ausência do regulador AIA 0,5 mg/l e plântulas enraizadas ex vitro, sem nenhuma diferença quanto ao comprimento da parte aérea. Para a variável produção de massa de matéria seca os melhores resultados foram proporcionados pelas plantas que passaram pela fase de enraizamento in vitro, tendo o sistema radicular efeito sinergístico no crescimento da parte aérea.

Plantlets of carnation (Dianthus caryophyllus L.) micropropagated through several generations during one year, were observed with respect to rooting in vitro, in the presence of IAA , NAA and IBA, at the following concentrations: 0,0; 0,25; 0,5 and 1,0 mg/l. All treatments promoted root formation, however no differences were detected in comparison to control. As far as the lenght of the aerial part is concerned no difference was observed between in vitro rooting. in the presence or absence of IAA 0,5 mg/l, and ex vitro rooting. Plantlets which were rooted in vitro conditions showed higher production of fresh matter then those rooted ex vitro. The root system had a synergistic effect on the growth of the aerial part.

Baixos níveis de benziladenina (BAP), baixo potencial de água no meio e baixa umidade condicionada por tampas de algodão foram capazes de inibir a vitrificação de cravo (Dianthus caryophyllus L.) cultivado In vitro, mas essas condições implicaram no baixo desenvolvimento das plantas e da taxa de propagação. Elevados níveis de NH4NO3 demonstraram serem altamente promotores da vitrifícação assinalada pelo alto conteúdo de proteína, enquanto relação inversa foi constatada para altos níveis de CaCl2, aos quais seguiu-se aumento na atividade da peroxidase. Os resultados permitiram estabelecer um protocolo para controle da vitrificação do cravo, constituído de 4,0 g/1 de "Gelrite", 0,5 mg/1 de ácido naftalenoacético (ANA), 0,05 mg/1 de BAP, doses normais das soluções salinas do meio MS e vedação do tipo tampas de algodão para cultivo de ápices meristemáticos. Para a fase de multiplicação, este protocolo deve ser alterado para 0,5 mg/1 de BAP, 10,3 mM de NH4NO3 e 12,0 mM de CaCl2.

Low levels of benzyl adenine (BAP), low water potential of the growth medium and low humidity due to cotton covers, inhibited vitrification of carnation (Dianthus caryophyllus L.) in vitro. However, under these conditions, a low development of plants and a decrease in the multiplication ratio, were observed. High levels of amonium nitrate enhanced vitrification with an increase in the total soluble protein content. An inverse correlation was observed in the presence of high levels of calcium chloride. The latter was correlated to an increase in peroxidase activity. The results allowed the establishment of a protocol to control vitrification during carnation meristein growth, as follows: "Gelrite", 4 g/1; naphtalene acetic acid, 0.5 mg/l; BAP, 0.05 mg/l; normal dosis of MS salts; cotton covers. For in vitro multiplication the protocol should be altered to BAP, 0.5 mg/1; amoniuin nitrate 10.3 mM; calcium chloride 12.0 mM.