Thomas, R. R. | Search bioRxiv

bioRxiv2026

Enhancing Germination and Assessing the Longevity of Native Plants' Seeds with Dormancy through Different Priming Techniques

Vachellia pachyceras and Convolvulus oxyphyllus are native species of arid and semi-arid desert regions, including Kuwait. They are inherently adapted to extreme conditions characterized by high temperature, prolonged drought and limited rainfall. They contribute significantly, to restore the ecosystem by providing food and shelter for wildlife. Despite their ecological importance, seed germination in both species is constrained by dormancy, and natural recruitment of seedlings is limited by narrow and unpredictable rainfall windows, severely restricting opportunities for establishment. In this context, seed priming is an effective pre-sowing technique that enables uniform and rapid germination within the short window of favorable conditions. This study aims to identify the optimal seed-priming techniques for these two keystone native species and to assess the effect of priming on seed longevity. The seeds were scarified to remove the physical dormancy prior to priming treatments. Relative seed longevity was measured for primed seeds through artificial ageing and analyzed using probit analysis and analysis of variance. Results showed that hormonal priming [(mechanical scarification + 100 ppm gibberellic acid (GA3)] for six hours and hydropriming (mechanical scarification + soaking in water) for 8 hours (h) were effective treatments among the tested priming treatments for V. pachyceras. The estimated p50 value (i.e., number of days to lose seed viability to 50%) was 22 days for hormonal priming and 21 days for hydropriming. Mechanical scarification followed by one and half hour of hydropriming was the most effective in C. oxyphyllus (p50 = 74 days). Based on these results, the longevity of V. pachyceras and C. oxyphyllus could be considered medium. Further studies are needed to determine the effectiveness of seed priming on additional ecologically and economically important native species to achieve success in revegetation programs.

ecology↗

bioRxiv2025

Decoding hidden goal-directed navigational states and their neuronal representations using a novel labyrinth paradigm and probabilistic modeling framework

Goal-directed navigation involves a sequence of planned actions aimed at achieving long-term goals through reinforcement, but detecting hidden states that support this process and their neuronal substrates remains a fundamental challenge. To address this, we developed a complex labyrinth test that mimics naturalistic foraging and implemented a novel hierarchical probabilistic modeling framework, Cognitive Mapping of Planned Actions with State Spaces (CoMPASS). This framework infers a nested state structure, comprising short-term surveillance-ambulation states (Level 1) and long-term goal-oriented navigational states (Level 2). Using CoMPASS, we show that successful navigation in wild-type mice is marked by increased recruitment of both surveillance and goal-oriented states specifically at decision nodes, revealing how sequential behavioral decisions culminate in long-term goals. In contrast, the humanized AppSAA mouse model of Alzheimers disease (AD) exhibited navigational impairments marked by diminished surveillance during decisions, reduced goal-directed states, and increased navigation stochasticity. Importantly, we show that gamma oscillations in the posterior parietal cortex (PPC), a region involved in spatial navigation planning, encode these CoMPASS behavioral states and their dynamic operating modes linking spatial locations to long-term goals. Our findings provide a novel paradigm for assessing hidden goal-directed navigational states and identify gamma oscillations in the PPC as their neural substrates.

neuroscience↗