The Chi-Square test (χ² test) is a family of tests based on a series of assumptions and is frequently used in the statistical analysis of experimental data. The aim of our paper was to present solutions to common problems when applying the Chi-square tests for testing goodness-of-fit, homogeneity and independence. The main characteristics of these three tests are presented along with various problems related to their application. The main problems identified in the application of the goodness-of-fit test were as follows: defining the frequency classes, calculating the X² statistic, and applying the χ² test. Several solutions were identified, presented and analyzed. Three different equations were identified as being able to determine the contribution of each factor on three hypothesizes (minimization of variance, minimization of square coefficient of variation and minimization of X² statistic) in the application of the Chi-square test of homogeneity. The best solution was directly related to the distribution of the experimental error. The Fisher exact test proved to be the “golden test” in analyzing the independence while the Yates and Mantel-Haenszel corrections could be applied as alternative tests.

The production and consumption of nuts are increasing in the world due to strong economic returns and the nutritional value of their products. With the increasing role and importance given to nuts (i.e., walnuts, hazelnut, pistachio, pecan, almond) in a balanced and healthy diet and their benefits to human health, breeding of the nuts species has also been stepped up. Most recent fruit breeding programs have focused on scion genetic improvement. However, the use of locally adapted grafted rootstocks also enhanced the productivity and quality of tree fruit crops. Grafting is an ancient horticultural practice used in nut crops to manipulate scion phenotype and productivity and overcome biotic and abiotic stresses. There are complex rootstock breeding objectives and physiological and molecular aspects of rootstock–scion interactions in nut crops. In this review, we provide an overview of these, considering the mechanisms involved in nutrient and water uptake, regulation of phytohormones, and rootstock influences on the scion molecular processes, including long-distance gene silencing and trans-grafting. Understanding the mechanisms resulting from rootstock × scion × environmental interactions will contribute to developing new rootstocks with resilience in the face of climate change, but also of the multitude of diseases and pests.

The Transylvanian region of Romania is a place of rich history since ancient times, where the original natural environment around architectural heritage sites or buildings has not been severely altered by urban development. Unfortunately, many such places are left by the authorities to degrade or totally collapse for lack of funds, vision or initiatives. The current paper addresses the potential of Unmanned Aerial Vehicles (UAVs) in the assessment of a viable and feasible prospect of restoration on a 19th century mansion that belonged to a nobiliary family. UAV use is rising in many industries and has become very popular in the last decade, but for survey engineering and related domains they represent a quantum leap in technology. Integrating UAV-acquired data and structure from motion software, has enabled modern techniques to obtain useful metrics from the field, accurate photorealistic 3D models for visual inspection, structural damage analyses, architectural rehabilitation-restoration, conservation and spatial analysis of the surrounding area. In this work a socio-cultural planning and design process is explored and presented to improve the local community and inclusion in a tourist circuit based on the regional potential, as well as an evaluation of accessibility derived from a vector-raster database that highlights the central position of the cultural heritage in regards to the axis of circulation between the important metropolitan areas and the local tourist attractions. This established workflow of modern topographic and construction measurements is fully integrable into the architectural process, building information modelling, heritage conservation and reconstruction.

Drought tolerance was evaluated in twelve cultivars of three ornamentalTagetesspecies (T. patula,T. tenuifoliaandT. erecta). A stress treatment was performed by completely stopping watering of plants maintained in controlled greenhouse conditions. After three weeks, several plant growth parameters (stem length (SL), fresh weight (FW) and water content (WC)), photosynthetic pigments (chlorophylls and carotenoids (Car)), osmolytes (proline (Pro), glycine betaine (GB) and total soluble sugars (TSS)), an oxidative stress maker (malondialdehyde (MDA)) and antioxidants (total phenolic compounds (TPC) and total flavonoids (TF)) were measured. Considerable differences in the evaluated traits were found among the control and drought-stressed plants. Drought stress generally caused a marked reduction in plant growth and carotenoid pigments, and an increase in soluble solutes and oxidative stress. For most cultivars, proline levels in stressed plants increased between 30 and 70-fold compared to the corresponding controls. According to the different measured parameters, on averageT. erectaproved to be more tolerant to drought thanT. patulaandT. tenuifolia. However, a considerable variation in the tolerance to drought was found within each species. The traits with greater association to drought tolerance as well as the most tolerant cultivars could be clearly identified in a principal components analysis (PCA). Overall, our results indicate that drought tolerant cultivars ofTagetescan be identified at early stages using a combination of plant growth and biochemical markers.

Several ornamental species have demonstrated adaptive features that could increase their resilience to the current climate emergency but could also be linked to invasiveness in non-native environments. The present review examines the responses of ornamental plants’ grown in the Mediterranean region to relevant abiotic stress conditions such as drought, salinity, extreme temperatures, heavy metal toxicity, and atmospheric N deposition, emphasising physiological and biochemical responses that allow them to adapt to unfavourable environments. These response mechanisms, although useful for landscaping under challenging climate change effects, would help non-native ornamental plants outcompete native flora, change ecosystem functioning, and ultimately contribute to a loss in biodiversity. Effective management practices for sustainable landscaping ensure the sensible use of native species and the development of non-invasive cultivars to minimise ecological risks. This review attempts to provide information on the ornamental and environmental functions of plants in landscape architecture through the relationships between aesthetic and ecological values under abiotic stress, including their negative environmental impact due to their invasive potential.

The Norway spruce (Picea abies), the most important tree species in European forests, is relatively sensitive to salt and does not grow in natural saline environments. Yet many trees are actually exposed to salt stress due to the common practice of de-icing of mountain roads in winter, using large amounts of NaCl. To help develop strategies for an appropriate use of reproductive seed material on reforestation sites, ensuring better chances of seedling survival in salt-affected areas, we have studied the responses of young spruce seedlings to salt treatments. The specific aim of the work was to identify the optimal salt stress biomarkers in Picea abies, using as experimental material seedlings obtained by germination of seeds with origin in seven populations from the Romanian Carpathian Mountains. These responses included general, conserved reactions such as the accumulation of ions and different osmolytes in the seedlings needles, reduction in photosynthetic pigments levels, or activation of antioxidant systems. Although changes in the contents of different compounds involved in these reactions can be associated to the degree of stress affecting the plants, we propose that the (decreasing) levels of total phenolics or total carotenoids and the (increasing) levels of Na⁺ or K⁺ ions in Picea abies needles, should be considered as the most reliable and useful biomarkers for salt stress in this species. They all show very high correlation with the intensity of salt stress, independently of the genetic background of the seeds parental population, and relatively easy, quantitative assays are available to determine their concentrations, requiring simple equipment and little amount of plant material.