Effect of development stage of Pinus heldreichii megagametophytes on the induction of embryogenic tissue

Abstract

The potential of somatic embryogenesis induction was examined by in vitro growing of isolated ovules of Pinus heldreichii (Christ.) on nutrient media. The induction of embryogenic tissue was stimulated by Gresshoff and Doy (GD) medium with nitrogen compounds reduced to one half and with 0.5 mg/l BA and 2.0 mg/l 2.4-D. Still, the most important factor in this process was the development stage of embryos in the ovule. An induction frequency of 10% was obtained on the ovules in which embryos were in the pre-cotyledonary stage. When the dominant embryo in the ovule was in the cotyledonary stage, the induction frequency was lower or absent. Proliferation of embryogenic tissue was achieved on the media with reduced concentration of growth regulators, and the initial stages of embryo maturation were obtained on the media with ABA and 5% sucrose.Izolovane ovule Pinus heldreichii (Christ.) gajene su in vitro na hranljivim podlogama radi ispitivanja mogućnosti indukcije somatske embriogeneze. Hranljiva podloga Gresshoff and Doy (GD) sa azotnim jedinjenjima, smanjenim na polovinu i BA 0.5 mg/L i 2.4-D 2.0 mg/L, stimulisala je indukciju embriogenog tkiva. Ipak, najvažniji faktor u ovom procesu bio je stadijum razvića embriona u ovuli. Frekvencija indukcije od 10% dobijena je na ovulama u kojima su embrioni bili u prekotiledonarnom stadijumu razvića. Kada je dominantni embrion u ovuli bio u kotiledonarnom stadijumu razvića, frekvencija indukcije bila je manja ili je nije ni bilo. Proliferacija embriogenog tkiva dobijena je na podlogama sa smanjenom koncentracijom regulatora rastenja, a početni stadijumi sazrevanja embriona na podlogama sa ABA i 5% saharoze.Projekat ministarstva br. 143026