Effects of plant population density on cabbage (Brassica oleracea var. capitata L.) crop

Com a finalidade de avaliar o efeito da densidade de população de plantas sobre a cultura de repolho (Brassica cleraoea var, capitata L.), foi realizado um experimento no Campo Experimental do Setor de Horticultura da Escola Superior de Agricultura "Luiz de Queiroz", Piracicaba, São Paulo, em um Latossol Roxo, Série Luiz de Queiroz, utilizando-se os espaçamentos de 0,60 mx 0,80 m; 0,60 m x 0,65 m; 0,60 m x 0,45 m; 0,60 m x 0,30 m e 0,60 m x 0,15 m. À medida em que se aumentou a densidade de população, houve as seguintes alterações na planta de repolho: mudança de for mato chato da "cabeça" para cônico, redução do numero de folhas, tamanho (peso, volume e diâmetros transversal e longitudinal) , aumento na densidade da "cabeça" (peso/volume) e aumento na porcentagem de plantas que não produziram "cabeça.In order to study the effects of plant population density on cabbage crop (Brassica oleracea var-. capitata), an experiment using different spacing (0,60 m x 0.80 m, 0.60 m x 0.65 m, 0.60mx0.45m, 0.60 m x 0.30 m, and 0.60mx 0.15m) was carried out. There were the following changes in cabbage plants due to increasing population density: plant head became conical: number and size (weight, volume and diameters) of leaves decreased; density (weight/volume) and percentage of plants forming no head increased

Efecto de una generación de endocría sobre caracteres vegetativos y productivos en dos estructuras familiares de alcaucil Effect of one generation of selfing over vegetative and productive traits in two family structures of globe artichoke

El alcaucil (Cynara scolymus L.) es una especie alógama cuyos cultivares no son aptos para ser propagados a través de semillas debido a su elevada heterocigosis. Para obtener materiales genéticamente homogéneos es necesario producir líneas endocriadas que pueden ser utilizadas directamente u obtener híbridos a través de ellas. Los objetivos del presente trabajo fueron evaluar el efecto de una generación de endocría sobre los caracteres tanto vegetativos como productivos y determinar la existencia de variabilidad genética entre las familias S1 a través de la estimación del Grado de Determinación Génico (G.D.G.) en dos estructuras familiares diferentes. Se utilizaron 2 conjuntos de familias S1 provenientes uno de ellos de cruzamientos dirigidos entre clones y el otro por cruzamientos al azar de los mismos clones. Se evaluaron, en plantas individuales, caracteres productivos y vegetativos. Los resultados obtenidos ponen de manifiesto la importancia del material de origen para la obtención de líneas con buen comportamiento agronómico. La generación S1 originada de plantas half-sibs no sería la más adecuada para la obtención de líneas ya que manifestaron una mayor depresión endogámica para la mayoría de los caracteres que las originadas de plantas full-sibs. Si bien los principales caracteres de interés selectivo manifestaron depresión endogámica, la variabilidad existente entre conjuntos, entre familias S1 y entre plantas dentro de familias permitiría elegir plantas individuales con buenas características agronómicas adecuadas para continuar el proceso de endocría o para ser propagadas clonalmente.<br>Globe artichoke (Cynara scolymus L.) is an allogamous species where vegetative propagated cultivars are not suitable for seed multiplication due to their high heterozigous condition. To obtain homogeneous materials, the inbreeding process is necessary. Inbred lines could be used as cultivars or in hybrid combinations. The effect of one generation of selfing over vegetative and productive traits were evaluated. The Genetic Determination Coefficient was estimated in two different family structures. Two sets of S1 families were originated: one from crosses between clones and the other through open pollination of the same clones. These assays were implanted in the field, in Zavalla, Argentina. The vegetative and reproductive characters were evaluated in a single plant. The importance of the starting material to obtain lines with adequate agronomic performance was demonstrated: S1 families originated from half-sib plants presented a strong endogamic depression in the majority of the traits in comparison to those obtained from full-sibs. Although all characters manifested endogamic depression after one generation of selfing, a genetic variability still remained among sets, among families and plants within families. As a consequence, it could be possible to select elite plants to continue the inbreeding process or to be vegetatively propagated as clones