Test-Retest Reliability and Validity of the Plank Exercise

Purpose: The plank exercise is a popular and widely used exercise to increase core strength. We previously established normative values for the plank exercise that may be used for fitness classification to identify gaps in core muscular strength and endurance. Whether the plank exercise can be confidently added to current fitness appraisal protocols will depend on its reliability and validity in the fitness testing environment. This study sought to examine test-retest reliability of the plank exercise and to compare plank performance with established normative values for the curl up test. The role of verbal encouragement cues during plank performance testing was also assessed. Methods: Collegiate male (n=14) and female participants (n=19) performed the plank exercise in two separate sessions separated by a minimum of 72 hr. Participants maintained the plank position until complete fatigue was reached. Verbal cues were given to half of the participants in one of the two sessions. Performance on the curl up exercise was measured in a third, separate session. Results: Intraclass correlation showed that mean time held in the plank position was not significantly different between the two plank testing sessions (108.15 + 49.38 versus 111.39 + 56.87 seconds, p=0.556). Verbal encouragement cues did not improve performance time (between group effect, p=0.940). The curl up test was not significantly correlated with either plank session (r=0.410 and 0.276 for plank session one and two, respectively). Surprisingly, the curl up test was positively correlated with participant height (r=0.578). Conclusion: This study suggests that the plank exercise is a reliable test; plank performance was comparable across testing sessions and not influenced by verbal encouragement. Further testing is needed to confirm validity of the plank exercise as a measure of core muscular endurance. We show here that plank performance was not correlated with the standard curl up test. However, the curl up test may not adequately measure core strength, given that increased body height was associated with higher curl up completion scores

Root vacuolar sequestration and suberization are prominent responses of Pistacia spp. rootstocks during salinity stress

Understanding the mechanisms of stress tolerance in diverse species is needed to enhance crop performance under conditions such as high salinity. Plant roots, in particular in grafted agricultural crops, can function as a boundary against external stresses in order to maintain plant fitness. However, limited information exists for salinity stress responses of woody species and their rootstocks. Pistachio (Pistacia spp.) is a tree nut crop with relatively high salinity tolerance as well as high genetic heterogeneity. In this study, we used a microscopy-based approach to investigate the cellular and structural responses to salinity stress in the roots of two pistachio rootstocks, Pistacia integerrima (PGI) and a hybrid, P. atlantica x P. integerrima (UCB1). We analyzed root sections via fluorescence microscopy across a developmental gradient, defined by xylem development, for sodium localization and for cellular barrier differentiation via suberin deposition. Our cumulative data suggest that the salinity response in pistachio rootstock species is associated with both vacuolar sodium ion (Na+) sequestration in the root cortex and increased suberin deposition at apoplastic barriers. Furthermore, both vacuolar sequestration and suberin deposition correlate with the root developmental gradient. We observed a higher rate of Na+ vacuolar sequestration and reduced salt-induced leaf damage in UCB1 when compared to P. integerrima. In addition, UCB1 displayed higher basal levels of suberization, in both the exodermis and endodermis, compared to P. integerrima. This difference was enhanced after salinity stress. These cellular characteristics are phenotypes that can be taken into account during screening for sodium-mediated salinity tolerance in woody plant species

Investigation of Salt Tolerance Mechanisms across a Root Developmental Gradient in Almond Rootstocks

The intensive use of groundwater in agriculture under the current climate conditions leads to acceleration of soil salinization. Given that almond is a salt-sensitive crop, selection of salt-tolerant rootstocks can help maintain productivity under salinity stress. Selection for tolerant rootstocks at an early growth stage can reduce the investment of time and resources. However, salinity-sensitive markers and salinity tolerance mechanisms of almond species to assist this selection process are largely unknown. We established a microscopy-based approach to investigate mechanisms of stress tolerance in and identified cellular, root anatomical, and molecular traits associated with rootstocks exhibiting salt tolerance. We characterized three almond rootstocks: Empyrean-1 (E1), Controller-5 (C5), and Krymsk-86 (K86). Based on cellular and molecular evidence, our results show that E1 has a higher capacity for salt exclusion by a combination of upregulating ion transporter expression and enhanced deposition of suberin and lignin in the root apoplastic barriers, exodermis, and endodermis, in response to salt stress. Expression analyses revealed differential regulation of cation transporters, stress signaling, and biopolymer synthesis genes in the different rootstocks. This foundational study reveals the mechanisms of salinity tolerance in almond rootstocks from cellular and structural perspectives across a root developmental gradient and provides insights for future screens targeting stress response

Charges for commercially applied pesticides

Published January 1958. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo

Pod indehiscence is a domestication and aridity resilience trait in common bean.

Plant domestication has strongly modified crop morphology and development. Nevertheless, many crops continue to display atavistic characteristics that were advantageous to their wild ancestors but are deleterious under cultivation, such as pod dehiscence (PD). Here, we provide the first comprehensive assessment of the inheritance of PD in the common bean (Phaseolus vulgaris), a major domesticated grain legume. Using three methods to evaluate the PD phenotype, we identified multiple, unlinked genetic regions controlling PD in a biparental population and two diversity panels. Subsequently, we assessed patterns of orthology among these loci and those controlling the trait in other species. Our results show that different genes were selected in each domestication and ecogeographic race. A chromosome Pv03 dirigent-like gene, involved in lignin biosynthesis, showed a base-pair substitution that is associated with decreased PD. This haplotype may underlie the expansion of Mesoamerican domesticates into northern Mexico, where arid conditions promote PD. The rise in frequency of the decreased-PD haplotype may be a consequence of the markedly different fitness landscape imposed by domestication. Environmental dependency and genetic redundancy can explain the maintenance of atavistic traits under domestication