Ioannis T. Tsialtas

Cation selectivity in cotton ( Gossypium hirsutum L.) grown on calcareous soil as affected by potassium fertilization, cultivar and growth stage

Background and aimsSelective uptake of K over Na has been proposed as a mechanism employed by plants to tackle high soil salinity. However, the impact of other dominant soil cations such as Ca and Mg and essentiality of higher K/Ca and K/Mg selectivity for plant performance under adverse growing conditions have been studied much less. We addressed this topic by looking at cation selectivity in cotton grown on calcareous soil supplemented by K.MethodsCation selectivity in leaves was determined as a ratio of two cations to the respective ratio in the soil over two growth seasons, three growth stages, and two cotton cultivars. Concurrently, instantaneous and long-term leaf traits related to CO2 assimilation, N and water use efficiency were assessed.ResultsPotassium addition did not affect on cation selectivity; growth stages and their interaction with years were allotted with the most of the variation found for cation selectivity and many of the physiological traits. Cultivar Carmen compared to Elina had higher K selectivity, was water conservative and had higher fiber quality. Elina took up Na selectively over Mg in an effort to sustain stomata open.ConclusionsThe reported results indicated an importance of improved cation selectivity to optimize K+ nutrition in plants grown on calcareous soils. Under conditions of low K+ availability, cotton cultivars took up selectively Na and Mg over Ca, to optimize its water relations and photosynthetic performance. Cation selectivity was largely affected by growth stages and was correlated with stomata functioning.

In the wild hybridization of annual Datura species as unveiled by morphological and molecular comparisons

BackgroundThe present work aimed to verify whether intermediate variants were natural crosses between Datura species (D. stramonium forms and D. ferox). Their existence has been long ago insinuated but has not been studied using morphological features and molecular tools. The variants differed in stem coloring, upper bearing forks, and fruit characters.ResultsPrincipal Components Analysis of 11 morphological characteristics showed that D. ferox and D. stramonium (forms stramonium and tatula) were quite different and the putative hybrids were intermittent. The D. ferox × D. stramonium f. tatula was closer to the latter of its parents. Sequencing analysis revealed identical amplified trnL intron in all variants and a 100% homology with D. stramonium accession number EU580984.1 suggested that this plastid cannot discern Datura variants. However, genomic analysis with URP markers indicated that the hybrids had >60% genetic makeup similarity with both parents suggesting that the intermediate variants were putative inter-specific hybrids. Moreover, the dendrogram stemmed from cluster analysis of the fingerprint profile of variants placed D. stramonium and D. ferox in different branches indicating their genetic differentiation from each other as well as from their hybrids.ConclusionsThe findings suggest that the natural hybridization of annual Datura species occurs. Extrapolating, this hybridization could be the first step for speciation. More possibly, it can alter population composition, its weediness and adaptability to local conditions.

Determination of Free and Total Underivatized Amino Acids Including L-Canavanine in Bitter Vetch Seeds Using Hydrophilic Interaction Liquid Chromatography

ABSTRACT A new hydrophilic interaction liquid chromatography method coupled with diode-array detector was developed for the determination of 17 underivatized amino acids including L-canavanine in bitter vetch [Vicia ervilia (L.) Willd.] seeds. Amino acids were extracted as free as well as total extracts after acid hydrolysis, followed by chromatographic separation on a Zorbax Rx-SIL column with a mobile phase of acetonitrile/potassium phosphate buffer (12.5 mM; pH 3.0) using gradient elution and detection at 190 nm. The method is characterized by a wide linear range (0.01–200 µg/mL, r > 0.9987), sufficient accuracy (relative error 86.3–109.1%), and suitable precision for the results (relative standard deviation <4.9% in the case of intra-day and <9.8% in the case of inter-day precision). The limits of detection and quantification for free amino acids ranged from 0.01 to 0.24 mg/g and 0.03 to 0.72 mg/g, respectively, whereas the total amino acids ranged from 0.02 to 0.47 mg/g and 0.07 to 1.43 mg/g, respectively. The mean recoveries of free and total amino acids in spiked samples exceeded 70.3% for most amino acids. The mean total content of free and total amino acids in bitter vetch seeds was 1.71 and 14.88 g/100 g seed, whereas the corresponding values for canavanine were 0.07 and 0.19 g/100 g seed, respectively.