Screening of large numbers of seed families of Pinus strobus L. for somatic embryogenesis from immature and mature zygotic embryos

Abstract

The somatic embryogenic process was investigated using immature and mature zygotic embryos originating from 13 open-pollinated seed families selected for their embryogenic capacity from over 128 seed families of Pinus strobus. In a first step, intact megagametophytes with precotyledonary embryos from these families were placed on modified Litvay medium. Embryogenic tissues (ETs) were obtained for 12 of them, with initiation rates varying from 2.6% to 23%. On average, 14% of the ETs (36/258) formed stable embryogenic cell lines (ECLs) after 4–6 months of subculture. Mature somatic embryos were produced for 30 out of 52 cell lines, and plants were regenerated. Later, initiation of ETs from mature zygotic embryos was also tested for the selected families. ECLs were obtained for five of them, with a maximum initiation rate of 2.7%, and plants were produced for four ECLs.