Exogenous Supplementation of Growth Regulators and Temperature Improves Germination of Dormant Jerusalem Artichoke (Helianthus tuberosus L.) Seeds under in vitro and in vivo Conditions

Abstract

Jerusalem artichoke (Helianthus tuberosus L.) is an important tuber crop but the seed germination is one of the major limiting factors in propagation due to the dormancy of the seeds. To find a solution, we investigated whether exogenous application of the hormones 6benzylaminopurine (BAP) and gibberellic acid (GA) as well as chilling (4 ºC) alone or in combination can be used to alleviate the problem of dormancy under in vitro and in vivo conditions. In the present study, JA102xJA89 control seeds showed only 11.7 and 13.3% of germination rate under aseptic and greenhouse conditions, respectively. Exogenous supplementation of 8 ppm BAP for seven and two days scored the highest germination rate of 91.7 and 85.0% under aseptic and greenhouse conditions, respectively. In the presence of BAP it was not necessary to chill the seeds or add GA3 to increase germination, and, in the presence of chilling, it was not necessary to add GA. In addition, no variation was observed in germination percentages of different Jerusalem artichoke genotypes when supplemented with 8 ppm of BAP. Two weeks after germination under aseptic conditions the seedlings had the highest survival rate when transplanted under greenhouse conditions which could be applicable for further genetic characterization

Keywords

• Benzylaminopurine, cytokinin, gibberellic acid, chilling, dormancy, germination, Jerusalem artichoke