Micelles of two nonionic surfactants (Triton X-114 and Neodol 91) were shown by gel filtration chromatography to solubilize nondissociated NAA molecules in aqueous solutions. Micelle solubilization of nonpolar active ingredients in aqueous spray systems alters the distribution of the chemical in the spray solution and may influence chemical deposit formation and penetration characteristics. Chemical names used: 2-(1-naphthyl)acetic acid (NAA), octylphenoxy polyethoxylate-7.5 POE (Triton X-114), linear alcohol (C9-11) polyethoxylate-6 POE (Neodol 91).
Antonio Heredia and Martin J. Bukovac
Aurora Díaz, Antonio Martín, Pilar Rallo and Raúl De la Rosa
Previous analyses of olive (Olea europaea L.) crosses have revealed an important degree of pollen contamination. For this reason, the authors tested the paternity of a set of progenies coming from crosses among different cultivars within the olive breeding program of Córdoba, Spain, using four polymorphic microsatellites. They found that the expected pollen sired 141 (83.4%) of the 169 samples analyzed. The contamination rate was either almost total or almost null within each particular cross considered, not being comparable between different crosses. In a second experiment the authors evaluated the influence of several factors on the success of olive crosses, the type of isolation bag, the timing and number of pollinations, and the cross-compatibility of the parents in a multifactorial assay in 2003. They observed no differences in the type of pollination bag used or the number and timing of pollen additions when they analyzed 145 seeds. The main factor affecting the success of the crosses seems to be the intercompatibility among cultivars, because it had a significant influence on the rate of contamination. In the failed crosses, the authors clearly detected the contribution of more than one cultivar to the paternity. The results obtained here indicate that some knowledge of cross-compatibility relationships in olive is required to design crosses in olive breeding programs effectively. To achieve this objective, the progeny parentage analysis could be of great help because of the high level of pollen contamination found among those studied here.
Xabier Barandiaran, Nieves Martín, María Fernanda Rodríguez-Conde, Antonio Di Pietro and Jesus Martín
The influence of different callus induction media on the regeneration process in garlic was tested. The auxin 2,4 dichlorophenoxyacetic acid frequently used in garlic tissue culture was found to be detrimental when used at the levels described in the literature. However, combinations of growth regulators commonly used for dicot tissue culture produced high levels of callus induction and regeneration that could be used efficiently in a transformation program.
Aurora Díaz, Antonio Martín, Pilar Rallo, Diego Barranco and Raúl De la Rosa
We studied the self-incompatibility of two main Spanish olive (Olea europaea L.) cultivars, `Picual' and `Arbequina', by testing the selfing of the seeds with microsatellites. For this purpose, we used a rapid single-seed DNA extraction method and four highly polymorphic microsatellites. We analyzed seeds produced in branches bagged for selfing from mono- and multi-cultivar orchards in 2002 and 2003. We did not find any seed coming from selfing in the bagged branches, for either cultivar, in the two types of orchards. Additionally, we tested seeds coming from free pollination in mono-cultivar orchards from different locations. In the case of `Picual' olive, only three seeds out of the 70 collected were the product of selfing, although they came from mono-cultivar orchards located in areas where the cultivar used as the female parent was predominant. From the 20 seeds of `Arbequina' olive harvested in the middle of two high-density plantations, not one was a product of selfing. According to this, olive would behave as an allogamous species in mono-cultivar growing conditions and the pollen coming from long distances would be able to produce a normal bearing. Therefore, there is strong evidence to support the idea that the cultivars studied could be self-incompatible. Future experiments in self-compatibility should include a paternity check of the possible self seeds obtained.
Maria do Rosário G. Oliveira, António M. Calado and Carlos A. Martins Portas
Tomato (Lycopersicon esculentum Mill.) root distribution was evaluated by the trench profile wall method at four trickle irrigation regimes (irrigation at soil water potential -10, -20, -40, and -60 kPa) in a 2-year field trial. Total root length intensity (m·m-2), final yield (t·ha-1) and fruit size (g/fruit) decreased with decrease in amount of water applied. In both years, tomato water use efficiency (kg·ha-1·mm-1) was significantly lower with irrigation at -10 kPa than with any other irrigation regime studied. The largest proportion of tomato roots, 88% for 1989 and 96% for 1990, was found in the top 40 cm of the soil and rapidly decreased with depth. The high concentration of roots in the 30 to 40 cm layer was attributed to an horizon with high soil bulk density values, immediately below 40 cm, impeding deeper root penetration. Most roots occurred in the emitter area, close to the plant. In rows 1.5 m apart, between 12% and 21% of total root length was found more than 0.5 m from the stem, which may have resulted from the interpenetration of roots from plants of adjoining rows.
Raúl De la Rosa, Angjelina Belaj, Antonio Muñoz-Mérida, Oswaldo Trelles, Inmaculada Ortíz-Martín, Juan José González-Plaza, Victoriano Valpuesta and Carmen R. Beuzón
In the present work, a set of eight new hexa-nucleotide simple sequence repeats (SSRs) is reported in olive (Olea europaea L). These SSRs loci were generated on the basis of expressed sequence tag (EST) sequences in the frame of an olive genomic project. The markers showed a high level of polymorphism when tested on a set of cultivars used as genitors in the olive breeding program of Córdoba, Spain. The long-core repeat motif of these markers allows a wider separation among alleles, thus permitting an accurate genotyping. Besides, these markers showed comparable levels of polymorphism to di-nucleotide SSRs, the only ones so far reported in olive. Selected on the basis of their discrimination capacity, four of the eight SSRs were used to test their ability for paternity testing in a total of 81 seedlings coming from 12 crosses. The paternity testing showed that seven crosses matched the alleged paternity and the remaining five were products of illicit pollinations. These results exactly matched with previous paternity testing performed with di-nucleotide SSR markers. These results demonstrate the usefulness of the developed hexa-nucleotide repeated motifs for checking the paternity of breeding progenies and suggest their use on variability studies.