In this study, we evaluated crop productivity and physiology during the hydroponic cultivation of medium-sized and cherry tomato crops, using two experimental greenhouses. Of the greenhouses, one used dye-sensitized solar cell (DSSC) technology for covering material, whilst the other, a conventional one (CONV), was covered using diffusion glass as a control. The effect of the colored lighting that resulted from the DSSC glass filtering on the physiological response of the crops was examined by measuring the plant transpiration rate and leaf chlorophyll content. Furthermore, we evaluated potential differences in the concentration of phytochemical compounds, such as ascorbic acid, lycopene, and quality characteristics. Tomato plants in the DSSC greenhouse presented lower early and total yields, as well as lower chlorophyll content, stomatal conductance, photosynthetic rate, and transpiration rate values, especially in the medium-sized fruits, as compared to the CONV greenhouse. The DSSC greenhouse showed significantly higher values of bioactive compounds for both the cherry and medium-sized tomato, with increases in the ascorbic acid, lycopene, β-carotene, and total carotenoids concentration, which ranged from 6% to 26%. Finally, for both the hybrids, the 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) tests showed circa 10% and 5% increase, respectively, in the DSSC greenhouse.

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ABSTRACT. The ability to discriminate all species is the ultimate target in barcoding. The Mediterranean basin is a center of origin for legumes and thus they have played a key role in feeding the Mediterranean population. It is also a region with important protected designation of origin and protected geographical indication legumes that provide income in rural areas. We evaluated the use of two chloroplast regions, trnL and rpoC1, and a nuclear internal transcriber region, ITS2, for their efficiency to barcode the main Mediterranean leguminous crops. Twenty-five legume species were studied. Plant material of pasture and legumes was obtained from the Greek GenBank and the Fodder Crops and Pastures Institute (National Agricultural Research Foundation). DNA was extracted with the Qiagen DNeasy plant mini-kit and PCR amplification was performed using the Kapa Taq DNA polymerase using primers amplifying the chloroplast trnL and rpoC1 regions or the ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 11 (3): 2548-2558 (2012) DNA barcoding of leguminous crops 2549 nuclear region ITS2. PCR products were sequenced and the sequences were aligned using CLUSTAL W. Species identification based on the sequence similarity approach was performed using the GenBank database. In order to evaluate intraspecific and interspecific divergence in legumes we used Molecular Evolutionary Genetics Analysis 5 and for pairwise Kimura 2-parameter distance calculations for all 3 DNA regions (2 chloroplast regions, trnL and rpoC1, and the nuclear region ITS2). Four tree-based methods (neighbor joining and maximum parsimony, maximum likelihood, and Bayesian inference analyses) were used to exhibit the molecular identification results to represent differences as an uprooted dendrogram. Additionally, the sequence character-based method was used with DnaSP and the information from each site was treated as a character to distinguish the species from one another. The DNA regions trnL and ITS2 successfully (100%) discriminated the Mediterranean crop legume species used, while rpoC1 identified only 72% of them. Furthermore, the use of the trnL region enabled the discrimination of even very closely related species, like Phaseolus lunatus and P. coccineus or Vicia faba subsp major with V. faba subsp minor, which are so closely related that even in NCBI they were both referred as Phaseolus vulgaris and V. faba, respectively. We conclude that trnL and ITS2 are efficient DNA barcoding target regions in order to discriminate Mediterranean leguminous crops and provide a reliable and efficient tool for the scientific, agricultural and industrial community.

The negative relationship between the yield potential of a genotype and its competitive ability may constitute an obstacle to recognize outstanding genotypes within heterogeneous populations. This issue was investigated by growing six heterogeneous wheat landraces along with a pure-line commercial cultivar under both dense and widely spaced conditions. The performance of two landraces showed a perfect match to the above relationship. Although they lagged behind the cultivar by 64 and 38% at the dense stand, the reverse was true with spaced plants where they succeeded in out-yielding the cultivar by 58 and 73%, respectively. It was concluded that dense stand might undervalue a landrace as potential gene pool in order to apply single-plant selection targeting pure-line cultivars, attributable to inability of plants representing high yielding genotypes to exhibit their capacity due to competitive disadvantage. On the other side, the yield expression of individuals is optimized when density is low enough to preclude interplant competition. Therefore, the latter condition appears ideal to identify the most promising landrace for breeding and subsequently recognize the individuals representing the most outstanding genotypes.

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