The influence of arbuscular mycorrhizal fungi on in vivo root initiation and development of Mr.S. 2/5 microcuttings was investigated. Micropropagated shoots of the Prunus cerasifera L. rootstock, clone Mr.S. 2/5, were placed in a sterile rooting mixture or inoculated with arbuscular mycorrhizal (AM) fungi. A part of the uninoculated microcuttings received auxin treatment (IBA 200 mg 1-1) or were supplied with a non-sterile sievate of mycorrhizal inoculum. Rooting percentage, root system morphology and growth increments of in vivo rooted microcuttings were evaluated. In vivo rooting of Mr.S. 2/5 shoots was obtained successfully but mycorrhizal inoculation did not show a positive influence on rooting ability of microcuttings. First harvest of plantlets was carried out very early, when mycorrhizal and non-mycorrhizal plants showed no significant growth differences. By this time, AM fungi had greatly increased the proportion of the root system present as higher-order laterals and branching intensity of roots. No significant alterations in root system morphology were observed in plants grown in amended soil and in plants receiving IBA treatment. Moreover, mycorrhizal inoculation appeared very important for rapid acclimatization and growth of in vivo rooted microcuttings. Thus mycorrhizal symbiosis induced early resumption of shoot apical growth during the acclimatization phase of Mr.S. 2/5 plantlets. At final harvest, growth attributes of mycorrhizal plants were therefore notably higher than in all the other treatments, and were estimated comparable to those of in vitro rooted plantlets obtained according to the standard procedure. These results show that mycorrhizal symbiosis induced significant alterations in root system morphology in in vivo rooted microcuttings of Mr.S. 2/5 rootstock and that acclimatization and growth of in vivo rooted microcuttings was positively affected by AM fungal inoculation.
|Autori:||FORTUNA P; MORINI S; GIOVANNETTI M|
|Titolo:||Effects of arbuscular mycorrhizal fungi on in vivo root initiation and development of micropropagated plum shoots|
|Anno del prodotto:||1998|
|Appare nelle tipologie:||1.1 Articolo in rivista|