Nomenclatura botánica de los cítricos

La frecuencia de mutaciones espontáneas y la facilidad de aparición de híbridos naturales u obtención de hibridos artificiales como resultado de cruzamientos interspecificos, ha dado origen a un elevadísimo número de variedades de cítricos, con mayor o menor interés comercial, que reciben nombres locales distintos y cuya identificación resulta con frecuencia complicada. El presente trabajo pretende facilitar la asignación de nombres botánicos a las variedades de cítricos más conocidas. Para ello nos hemos basado en gran parte en el trabajo de Carpenter y Reece (1969), que hace un amplio estudio crítico de las principales publicaciones sobre clasificación de los Aurantioideas. Para la denominación de especies se han seguido los criterios del «Código Internacional de Nomenelatura Botánica » (Voss, 1983), adoptados por el 139 Congreso Botánico Internacional. Asimismo se han tenido en cuenta las indicaciones y comentarios de Lawrence(1951) a las «Reglas Internacionales de Nomenclatura Botánica»

La selección clonal del limonero en España

La superficie dedicada al cultivo del limonero (Citrus limon (L.) Burm. f.) en España ha experimentado una gran expansión en los últimos veinte años, pasando de 10.000 ha en 1960 a 38.661 ha en 1980. En lo que concierne a las variedades cultivadas en España, la producción se basa en los cultivares autóctonos, siendo muy escasa hasta la fecha la importancia de las variedades extranjeras. Los limoneros "Verna" y "Fino" representan el 95% del total de producción (fig. 1). Otras variedades autóctonas como "Real", "Comunes", "Cuatro Estaciones" etc. están en franca regresión

Aberrant Citrus Plants obtained by Somatic Embryogenesis of Nuceli Cultured Invitro

Virus-free plants of 8 monoembryonic cultivars of Citrus clementina Hort ex Tan. were obtained by somatic embryogenesis of the nucellus cultured in vitro. Twenty-nine percent of them had abnormal phenotypic characters that were maintained for 7 years in the greenhouse, and by budwood propagation on different rootstocks. Electrophoretic studies of the proteins disclosed differences in band intensity and distribution between normal and abnormal plants, indicating the possibility of genotypic variations. Alternative methods to obtain virus-free citrus plants are advised to reduce the high percentage of abnormalities

Changes in the Bark Proteins of Sour Orange Rootstock Induced by Citrus Tristeza Virus

The effect of citrus tristeza virus (CTV) infection on bark proteins of several citrus rootstocks was studied by polyacrylamide gel electrophoresis (SDSPAGE). A protein band (P6) from bark of sour orange grafted with sweet orange, grapefruit or clementine scions had lower intensity in CTV-infected than in CTV-free trees. Decrease of P6 intensity was more conspicuous in trees infected with a severe CTV isolate than in those infected with a mild isolate. No difference was observed between bark proteins of CTV infected and CTV-free sour orange sprouts. Protein profiles of healthy and tristeza-infected Troyer citrange or Cleopatra mandarin, grafted with navel orange, were also indistinguishable. Finally, protein patterns of sour orange grafted with navel orange, severely declined from Phytophthora sp. or psorosis, were similar to those of non-declined controls. Thus, decreased intensity of P6 seems to be specifically associated with tristeza in citrus trees grafted on sour orange

Observaciones cariológicas en Vicia amphicarpa sensu lato

Cytological studies were carried out on twenty four amphicarpic wild populations of Vicia sativa group from different sites (19 from Spain, 4 from Syria and 1 from Turkey). Morphologically, 19 accessions can be attributed to taxonSe estudian cariológicamente 24 poblaciones anficárpicas silvestres pertenecientes al grupo Vicia sativa, de distinta procedencia (19 españolas, cuatro de Siria y una de Turquía). Se encuentran diferencias en los números cromosomáticos y en los cariótipos. Diecinueve poblaciones presentan 14 cromosomas y cariotipo como el observado por otros autores, constituido por un pequeño cromosoma metacéntrico y seis acrocéntricos, uno de ellos con satélite. Éstas corresponden a V. amphicarpa Dorthes. Las otras cinco, con 2n = 12 y cariotipo con tres cromosomas grandes, uno de ellos submetacéntrico, otro con satélite, y otros tres mucho más pequeños, corresponden a V. angustifolia subsp. pseudoangustifolia (Rouy) Tardío. Esta anterior se propone como combinación nueva. Por lo tanto, dentro de Vicia existen, al menos, dos táxones anficárpicos claramente diferenciados, tanto en su morfología externa como en el cariotipo

The Major Citrus Cultivars in Spain

Most of the citrus fruit are grown in two regions of Spain: a) the Levante area, which extends along the East coast and includes the provinces of Castellon, Valencia, Alicante, and Murcia, with about 80% of the total plantations; and b) the Andalusian area, with plantings both along the Guadalquivir river in the provinces of Cordoba and Sevilla, and near the coast, mainly in the provinces of Huelva, Malaga, and Almería, the area representing about 15% of the country’s total (4). The rest of citrus area is scattered in many other provinces of Spain (4), mostly near the coast (Fig. 1). Plantings of citrus by varietal groups are listed in Table 1 (5). With respect to the location of production of citrus fruits by groups of varieties (Table 2), most of the sweet oranges and mandarins are grown in the Valencia region (Valencia, Castellon, and Alicante provinces), while lemons are produced mainly in Murcia. The total production is over 3 x 106 1 (8)

Comparative-Study of Agrobacterium Biotypes 1, 2 and 3 by Electrophoresis and Serological Methods

A comparative study by electrophoresis and serology of strains representing the three Agrobacterium biotypes was carried out. Thirteen Spanish isolates and strains from international collections were included. Ten antisera were prepared by using strains from the three biotypes and different types of antigens. The strains were studied by immunodiffusion, indirect immunofluorescence and indirect ELISA. Serological relationship among all the strains was observed, although serological heterogeneity within each of the biotypes occurred. Biotype 3 appears as serologically related to biotypes 1 and 2, having an intermediate position. This observation is in agreement with their biochemical characteristics. Electrophoretic analysis of the three biotypes showed that there was high variability. Three main bands appeared in the six strains studied. One specific band occurred in the biotype 1 strains and another in the biotype 3 strains