Morphogenesis in cultured thin layers and pith explants of tobacco. 1: Effect of putrescine on cell size, xylogenesis and meristemoid organization

6-benziladenina 6-benzyladenine auxinas auxine auxins ba benzyladenin callogenese cells cellule hipertrofia hormonas hormone hormones hypertrophie hypertrophy in vitro medula meristemas meristems moelle morphogenese morphogenesis nicotiana tabacum phytohormon pith plant growth substances poliaminas polyamine polyamines sustancias de crecimiento vegetal