Effect of Different Concentration of Gibberellic Acid and Auxin on Germination of Onion Seed

Abstract

Onion (Allium cepa L.) is the oldest bulbous vegetable crop having high nutritive as well as market value. Short viability and low quality of onion seeds are the reasons for slow and asynchronous germination. Therefore, the study was carried out to find the appropriate growth regulator and its concentration that enhances the germination of Red Creole variety of onion seed. The experiment was conducted in Agronomy lab of IAAS, Lamjung Campus during the period fromDecember 30, 2016, to January 12, 2017. The design of experiment was Complete Randomized Block Design (CRD) with nine Treatments 10ppm, 50ppm, 100ppm and 150ppm of auxin and 10ppm, 50ppm, 100ppm and 150ppm of gibberellic acid and control. Seeds treated with the same volume of respective concentration and kept in germination at temperature 20±2°C. Onion seeds were evaluated for germination percentage, vigor index, root length, shoot length, seedling length, fresh weight, and dry weight. Three replication of each treatment with 50 seeds per replication were arranged in Petri-plate containing blotting paper. From the experiment, highest germination perocentage (69%) was at 100ppm of GA3, which was significantly different from GA3 at 50ppm (65%), GA3 at 10ppm (64.67%) and auxin at 50ppm (55%). Auxin at higher concentration viz. 50ppm, 100ppm, and 150ppm inhibited the germination. Comparative study of auxin and GA3 at the different concentration on root length, shoot length, seedling length, fresh weight, and dry weight revealed that GA3 and auxin were highly effective. Thus, GA3 at 100ppm promotes the viability and quality of onion seeds, which enhances its germination.