Effect of Thiourea on Yield and Quality of Potato (Solanum tuberosum L.)

A field experiment was carried out to study the effect of five concentrations (0, 250, 500, 750 and 1000 mM) of thiourea application on mother tubers on yield and quality attributes of harvested potato, variety Spunta in the region of Chott-Mariem in Tunisia. Treated tubers (Ш = 50 mm) were planted in field after breaking dormancy at a spacing of 80 cm x 30 cm according to completely randomized design (CRD) in three replications. Quality attributes of potato tubers especially fresh matter and dry matter of plant, total reducing sugars in leaves, tuber yield, number and diameter of tubers per plant and number of sprouts per tuber was measured. Soluble proteins and starch content in potato tubers were also quantified.In general we noted that application of thiourea showed significant influence on yield and on quality of tubers comparing to control. Maximum tuber yield per plant, maximum number of tubers per plant and maximum starch content was recorded with 250 mM of thiourea. Moreover, highest dry matter of potato plant was found also at this concentration. While increasing dose of thiourea thereafter it showed slight significant improvement and do not affect significantly the diameter of tubers comparing to control

Effect of hydrogen peroxide and thiourea on fluorescence and tuberization of potato (Solanum tuberosum L.)

The aim of this study is to determine the effect of hydrogen peroxide and thiourea on potato crop (quantum yield (Fv/ Fm), chlorophyll content, tuber diameter, tuber number and total tuber yield). The concentrations of these two chemicals are hydrogen peroxide: 0, 20, 40, 60 and 80 mM, and thiourea : 0, 250, 500, 750 and 1000 mM. The experiment was conducted in the farm of Chott-Mariem Institute during three months using variety 'Spunta' and arranged in a completely randomized block with three replications. Results show that there is no significant difference in tuber diameter between treatments and among the same treatment. However, tuber yield is significantly increased by 20 % by thiourea (250 mM). Maximum total yield was obtained at this concentration (810 g/plant). In addition, application of thiourea (500 and 750 mM) results in a significantly higher number of tubers number (5.7 and 5.2 respectively). In contrast, treatment with hydrogen peroxide brings about similar tuber yields. Although, application of hydrogen peroxide at low concentration (20 mM), decreases chlorophyll content and stresses plants, application of thiourea increases chlorophyll content, and improve quantum yield especially when it is applied at 250 mM

The Multidimensional Work Motivation Scale: Validation evidence in seven languages and nine countries

Self-determination theory proposes a multidimensional conceptualization of motivation comprising autonomous and controlled forms. Whereas autonomous motivation relates positively to individuals’ optimal functioning (e.g., well-being, performance), controlled motivation is less beneficial. To be able to use self-determination theory in the field of organizational behaviour, the Multidimensional Work Motivation Scale was developed and tested using data from 3435 workers in seven languages and nine countries. Factorial analyses indicated that the 19-item scale has the same factor structure across the seven languages. Convergent and discriminant validity tests across the countries also indicate that the psychological needs for autonomy, competence, and relatedness as well as the theoretically derived antecedents to work motivation (e.g., leadership and job design) are predictably related to the different forms of motivation, which in turn are predictably related to important work outcomes (e.g., well-being, commitment, performance, and turnover intentions). Implications for the development of organizational research based on self-determination theory are discussed

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field