Importance of in vitro storage root development for the successful transfer of micropropagated asparagus plants to greenhouse conditions

Abstract

The importance of in vitro storage root development for the growth and survival of micropropagated asparagus (Asparagus cfficinalis L.) plants under greenhouse conditions was assessed in four genotypes ('CRD047', 'CRDlOO', 'CRDlOl', and 'CRD222'). Plants with greater development of in vitro storage roots exhibited higher survival rates and took less time for the initiation of new shoot growth during acclimatisation in a humidity tent immediately following transfer out of culture. They also had higher survival rates and greater shoot growth on an open greenhouse bench 9 weeks following transfer from in vitro culture. An ideal micropropagated asparagus plant for greenhouse establishment consists of an in vitro minicrown supporting 4-6 shoots and 3-4 storage roots (3-4 em long). Such plants typically develop on a high-sucrose rooting medium.