Seed Germination Protocols (Standard, Accelerated Aging) and Plant Growth Traits for Wild Schoenocaulon texanum...

Green pesticides provide sustainable, biorational alternatives to synthetic pesticides. Sabadilla, Schoenocaulon, store alkaloids in their seeds; veratridine and cevadine are extracted with insecticidal activity. Wild, extant populations of native, N. American, S. texanum, are the focus of this research. The goal of this research was to determine soil constituents; alkaloid levels; quantify reproductive capacity for bulbs/plant, inflorescences/plant, seed capsules/plant, seeds/plant; seed dimensions, 100 seed wt.; standard and saturated salt accelerated aging (SSAA) percent seed germination of open-pollinated, untreated seed. We tested 10 genotypes and derived open-pollinated seed lots from five non-sympatric populations collected in Texas. Soil samples showed variation for all soil characteristics. Organic matter levels and micro-nutrients were low; pH = 7.8-8.2; heavy metals (Al, Cd, Cr, Ni, Pb) were detected. Seeds of S. texanum are smaller than S. officinale, but share appearance, hardness, color and shape. Alkaloid content was ~20% lower than S. officinale. Mean number of bulbs/clump was 2-12 with 1-8 flower stems/plant. Mean 100 seed weight = 0.45 g. No seeds germinated in weeks 1-2 (G1, G2) in standard or SSAA tests. Highest % germination in both tests was in G3-G4, declining precipitously in G5-G6. We establish initial seed germination standards of ≥70% for both standard and SSAA germination tests, based on total or adjusted final % germination of seed lots.