BIOCHEMICAL AND PHYSIOLOGICAL EFFECTS OF NEEM AND SHEESHAM EXTRACTS ON WHEAT SEED PRIMING

Abstract

The present research assessed the biochemical and physiological effects of Neem (Azadirachta indica) and Sheesham (Dalbergia sissoo) leaf extracts as seed priming agents on wheat (Triticum aestivum L.) under laboratory conditions at the Department of Botany, The Islamia University of Bahawalpur. Wheat seeds were primed with aqueous extracts of Neem and Sheesham at concentrations of 2.5% and 5%, along with distilled water (hydropriming) and unprimed seeds as control. Results showed a significant improvement in germination proportion, seedling vigor, and antioxidant enzyme activity. Maximum germination percentage (96.3%) was recorded in seeds primed with 5% Neem extract, significantly higher than control (80.3%). Mean germination time (MGT) was lowest (3.2 days) in 5% Neem extract, indicating faster germination. Seedling vigor index (SVI) increased markedly with 5% Sheesham extract (1345), compared to control (987). Antioxidant enzyme activities, comprising superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), were significantly enhanced. The highest SOD activity (11.6 U mg⁻¹ protein), CAT (9.4 U mg⁻¹ protein), and POD (8.3 U mg⁻¹ protein) were observed in 5% Neem extract treatment. Furthermore, total soluble proteins increased up to 3.28 mg g⁻¹ FW, while proline content peaked at 6.74 µmol g⁻¹ FW in 5% Sheesham extract. The results demonstrate that seed priming with Neem and Sheesham extracts effectively enhances germination traits and activates antioxidant defense mechanisms in wheat. This eco-friendly approach may serve as a promising seed enhancement strategy in sustainable agriculture.