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.
‘Friar’ (1968) and ‘Blackamber’ (1980).] Burbank said he used ‘Simon’ to breed many plum cultivars including ‘Bartlett’, ‘Chalco’, ‘Challenge’, ‘Climax’, ‘Combination’, ‘Eldorado’, ‘Late Shipper’, ‘Maybard’, ‘Royal’, ‘Santa Rosa’, and ‘Wickson’ ( Howard
Amino acids, a major fraction of the low-molecular-weight organic nitrogen in soil, act as signaling molecules that indicate the presence of nutrient-rich patches to the roots. To characterize the effects of amino acids on root growth, we used seedlings of habanero pepper (Capsicum chinense), one of the most widely cultivated annual spice crops in the world. We tested the effect of L-glutamate, L-aspartate, and glycine on the primary root of seedlings grown aseptically under different conditions of pH and light. L-glutamate and L-aspartate did not inhibit the root growth of habanero pepper. In contrast, glycine inhibited the growth of roots, stimulated root hair growth, and induced a significant accumulation of starch grains in the root apex. The use of aminoethoxyvinylglycine, an inhibitor of ethylene biosynthesis, and the evaluation of 1-aminocyclopropane-1-carboxylic acid oxidase expression provided evidence of a role for ethylene in the root responses to glycine. We suggest that these changes in the root apex in response to exogenous glycine could be an important adaptive response that allows plants to efficiently access the fluctuating availability of nutrients in the soil.
A winter gibberellic acid (GA3) spray consistently reduced flower formation, but had a variable effect on the amount of first-grade fruit in the early harvest of `Clausellina' satsuma (Citrus unshiu Marc.), and in the long term these applications had no significant effect on the value of the crop. Auxin applications increased the amount of first grade-early harvested fruit, and increased crop value as compared to hand-thinned trees. No significant differences in yield or fruit grade could be found among the different auxin applications tried, namely an application of 20 mg·L-1 2,4-dichlorophenoxyacetic acid (2,4-D) at flowering, or applications of 25 mg·L-1 naphthaleneacetic acid (NAA), or 50 mg·L-1 2,4-dicholorophenoxypropionic acid (2,4-DP) at the end of fruitlet abscission. Apart from their effect on size, the auxin applications had only a marginal effect on fruit quality.
Reusing irrigation water has technical, environmental, and financial benefits. However, risks are also associated with the accumulation of agrochemicals, in addition to ions, plant and food safety pathogens, and biofilm organisms. In this project, we measured the concentration of paclobutrazol (a persistent and widely used plant growth regulator) in recirculated water in greenhouses producing ornamental plants in containers. Solutions were collected from catchment tanks at nine commercial greenhouses across seven states in the United States in Spring and Fall 2014. Paclobutrazol was detected in all samples, with differences observed by season, greenhouse operation, paclobutrazol application method, and irrigation method. Across operations, the residual concentration of paclobutrazol was higher in spring for most greenhouses (ranging from 0 to 1100 µg·L−1) compared with the fall (ranging from 0 to 8 µg·L−1). The spray-drench application method resulted in the highest residual concentrations (up to 35 µg·L−1), followed by substrate drench (up to 26 µg·L−1) and foliage spray (concentrations under 3 µg·L−1). Residual concentrations were higher with overhead irrigation (up to 35 µg·L−1) compared with subirrigation systems (up to 15 µg·L−1). Our results indicate that paclobutrazol is likely to be a growth retardant risk in greenhouse operations recirculating water. A clear understanding of the risks associated with recirculated water intends to support the development and implementation of risk management strategies to ensure and promote safe use of recirculated water in greenhouses. Overall, the most effective preventative strategy is to ensure the use of the minimum amount of the a.i. necessary per unit of space and time.
Biolistic genetic transformation of plants with viral genes is a method for controlling plant virus diseases; however, optimization of the particle bombardment parameters according to the transformation system is a key factor for an appropiate transgene expression and, therefore, a stronger resistance mechanism in transgenic plants. In order to optimize biolistic parameters, somatic papaya (Carica papaya L.) cv. Maradol embryo masses were bombarded with the CAMBIA 1301 plasmid construction that contains the coat protein gene (CP) of the papaya ringspot virus isolate of Colima, Mexico, driven by the double constitutively CaMV 35S promoter and flanked for the GUS and hygromycin (hpt) resistance genes. Particle bombardment protocol was carried out using the Helios™ Gene Gun device (BioRad) and the manufacturer's instruction manual. Helium pressure (50, 100, and 150 psi) and gold particle size (0.6, 1.0, and 1.6 μm) were evaluated. Five days after bombardment, somatic embryo clusters were used for GUS transient expression and, during 2 months, were selected into 50, 75, and 150 mg·L-1 hygromycin-containing media to its later CP-PCR detection. Results showed that 50 psi and 1.0 μm were the two optimal values for the assayed analyses. This is the first report of genetic transformation of papaya using the Helios™ Gene Gun device as a new tool compared to conventional PDS-1000/He.
Palms (Arecaceae) are perhaps the most important tropical plant family for human use, both for utility and ornamental horticulture. The wide diversity of palm species with different seed germination characteristics necessitates tailoring horticultural practices to the needs of each. This is crucial for production and conservation horticulture. In this study, wild-collected seeds of yarey palm (Copernicia berteroana) and buccaneer palm (Pseudophoenix sargentii) were germinated in a variety of organic (standard nursery container mixes) and inorganic substrates. The yarey palm seeds were sown at two different depths, 0.5 inch and at the surface (seed half exposed). Mean maximum germination across all treatments for yarey palm was 79% and for buccaneer palm 60%. The standard nursery mixes generally fostered the best germination and long-term survival. This is likely due to a combination of the lower water availability at the surfaces of the more porous inorganic substrates (sand and perlite) and greater difficulty for coarse palm roots to penetrate the denser inorganic substrates, including fired ceramic, which otherwise had similar water-holding capacity (WHC) and even lower air space than the organic substrates. Difficulty of penetration caused roots of some seedlings to either dry up early in germination as in the surface sown yarey palm, or to “push up” the seed (buccaneer palm) rather than penetrating the substrate and this was often fatal. Thus, inorganic substrates are not recommended for germination and early seedling growth of these palm species and planting the seeds slightly below the surface may be preferable to surface sowing. For conservation horticulture of wild-collected palm seeds, this information can help prevent further genetic bottlenecks while under protective cultivation.
authors thank Bill Suyeyasu Wholesale Florist and Consorcio Quitoflores S.A., Quito, Ecuador, for donating some of the plant material used in this research. We gratefully acknowledge the skilled technical assistance of Linda Dodge and Rosa Valle. Reference
production in Bulgaria is based on Rosa damascena Mill. f. trigintipetala Dieck, currently known as the ‘Kazanlak rose’ after the town of Kazanlak, which is situated in the Rose Valley in Bulgaria. It is still a moot point whether the Kazanlak rose is a
Field trials were conducted in two locations in Spain to determine the effect of methyl bromide (MBr) alternatives on soilborne diseases and nematodes, and strawberry (Fragaria ×ananassa) yields under high-tunnel conditions. Fumigant treatments were applied to the same plots each year. Treatments were MBr + chloropicrin (Pic) (50:50, v/v) at a rate of 400 kg·ha−1; 1,3-dichloropropene (1,3-D) + Pic (65:35, v/v) at 300 kg·ha−1; Pic at 300 kg·ha−1; dimethyl disulfide (DMDS) + Pic (50:50, v/v) at 500 kg·ha−1; propylene oxide at 550 kg·ha−1; dazomet at 400 kg·ha−1; and calcium cyanamide (Ca-cyanamide) at 700 kg·ha−1. A nontreated control was also included. Fumigation with MBr + Pic, 1,3-D + Pic, Pic, and DMDS + Pic consistently improved early and total marketable strawberry yields in both locations. This response was caused by successful soilborne fungus and nematode control, improving strawberry growth and development, which resulted in increased plant canopy diameters and higher strawberry early and total yield.