Effect of pre-sowing treatments with chemical mutagens on seed germination and growth performance of jamun (Syzygium cuminiL. Skeels) under different potting substrates

Abstract

Introduction. Jamun, propagated through seed for raising rootstock, involves a lot of cost and risk for maintenance until attainment of graftable size. Use of suitable growing substrates is essential for production of quality nursery plants. Chemical mutagenesis is a simple approach to create mutation in plants for improvement of potential agronomic traits in rootstock materials. Materials and methods. Seeds originating from a single ‘elite’ tree were soaked in 0.1 and 0.5% ethyl methane sulfonate and colchicine solutions for 24 h prior to sowing in different propagation substrates (Arka fermented coco-peat and a mixture of sand, soil and farmyard manure). Morphological, physiological and biochemical analyses were performed after 3 months. Results and discussion. The Arka fermented coco-peat substrate resulted in earlier and higher seed germination, higher polyembryony, greater accumulation of photosynthetic pigments and total carbohydrates, and lower synthesis of stress-induced metabolites in leaves. These performances were probably due to a better balance between the water and air capacity than in the other growth substrate. Among different doses of chemicals, colchicine at 0.1% concentration was found to stimulate early seedling emergence, improve plant morphological characters and enhance production of total chlorophyll and total carbohydrates in leaves. Conclusion. The graftable stage can be attained rapidly if jamun seeds are treated with 0.1% colchicine and sown in Arka fermented coco-peat substrate.