I review the current knowledge on molecular markers for Eucalyptus species, with particular emphasis on individual identification and the prevention of escape of transgenes from transgenic Eucalyptus. Species-specific bands have been found in inter simple sequence repeat (ISSR) markers. Microsatellites are highly polymorphic genetic regions that allow precise discrimination of closely related individuals. Random amplified polymorphic DNA (RAPD) markers are also very useful for individual identification and map construction, although they have limited transferability because they are dominant markers with only two alleles. The amplified fragment length polymorphism (AFLP) technique facilitates the production of high-coverage parental maps in interspecific crosses of eucalypts. Genetic diversity in the continuously distributed Eucalyptus species has been investigated using nuclear restriction fragment length polymorphism (RFLP) loci. Chloroplast DNA, 5S rDNA genes, and ITS regions have proven to be useful in phylogenetic, population, and evolutionary studies of Eucalyptus. Genetic association studies using SNPs are in progress with several Eucalyptus species. Furthermore, microarray technology holds the promise of parallel analysis of thousands of markers in Eucalyptus. Early screening of hybrids with transgenic Eucalyptus using DNA markers will be important to prevent escaping transgenes.
To investigate the relationship between cell size and sucrose accumulation in melon fruit in response to mechanical restriction, some fruits were subjected to mechanical restriction by enclosing them in spherical acrylic acid resin cages with a radius of 5 cm (designated as the enclosed fruits). The mean weight of the enclosed fruit at 50 days after anthesis was 1,493 g less than that of the control (1,963 g). The mean cell size of the enclosed fruit was 153 μm, which was 162 μm smaller than the mean cell size of the control. The diameter of cells in 50-day-old control fruit varied markedly (100 μm to 600 μm) centering 315 μm, whereas cells of the enclosed fruit were distributed over a narrow range (50 μm to 350 μm) centering 166 μm. Mean sucrose content of the enclosed fruit was 3 g·1−1, one-twenty fifth of the mean sucrose content of the control, and glucose content decreased by restricting fruit growth, but fructose content was almost the same in the two plots.
There are many methods for sensing water condition in Sunagoke moss Rachomitrium canescens. The direct measurement of canopy is considered to be relatively inefficient and destructive to the plant. One alternative is the use of indirect measurement and non-destructive techniques such as machine vision. This study investigated the use of machine vision for monitoring water content in Sunagoke moss. The goal of this paper was to propose and investigate a combined genetic-neural algorithm to find the most significant image features or the sets of image features suitable for predicting Sunagoke moss water content. We extracted 50 features consisting of color, textural (Gray Level Co-occurrence Matrix and RGB Color Co-occurrence Matrix textural features) and morphological features. Ten textural features were calculated, including Entropy, Energy, Contrast, Homogeneity, Sum Mean, Variance, Correlation, Maximum Probability, Inverse Difference Moment and Cluster Tendency. The specificity of this problem was that we were not looking for single feature but several associations of features that may be involved in determining water content. The genetic algorithm was able to select features with 27 selected features and artificial neural network was able to predict water content according to the selected features with minimum error of MSE 0.0021.
Single-truss and high density cultivation of tomato plants (Lycopersicon escultentum Mill.) has great advantages in controlling the plants and stable production. In this cultivation, an effective application of short-term salt stress for high quality tomatoes was examined by analyzing mass transport to fruits via phloem. Tomato plant were grown by soil-less culture with non-woven fabric system for single-truss and high density cultivation, where short-term salt stress was induced for just 2 weeks at the stage of rapid fruit growth by adding the concentrated deep seawater to the standard nutrient solution (electric conductivity (EC), 1.2 dS m−1) to increase EC by 13.5 dS m−1. Although fresh weight of the fruits was restricted by salt stress, dry matter ratio of the fruits was increased. Soluble solid concentration and flux in the phloem sap was accelerated not only during the short-term salt stress but also after the removal. Concentrations of Na+, K+, and Mg+ in the phloem sap were also enhanced by the concentrated deep seawater. Consequently, sugar concentration of the fruits was significantly increased by short-term salt stress. These results may contribute to stable and high production of high quality tomatoes in single-truss and high density cultivation.
In the present study, to establish a novel improved method for the sawdust-based cultivation of shiitake mushroom, high-temperature and water-filling treatments of mycelial block were applied for controlling the flushing portion. In the improved method, fruit bodies flushed only from the upper portion of mycelial blocks. Number and fresh weight of fruit bodies flushed from the mycelial block cultivated by improved method showed almost constant value during the flushing period (180 days). From the results obtained in this study, it is concluded that improved cultivation method makes it possible to give a continuous flushing of fruit bodies with heavy fresh weight, leading to reduce the cost and labor for budding and cropping operation of fruit bodies.