Effect of arbuscular mycorrhiza on the growth and development of micropropagated Annona cherimola plants

Annona cherimola Mill., cherimoya, is a tropical plantation crop of interest in fruit culture. Micropropagation techniques have been developed due to the need to increase productivity through clonal selection. Because of the mycorrhizal dependence exhibited by this crop for optimal growth and the recognized role of mycorrhiza establishment for the survival and development of most of the plants produced in vitro, the effect of mycorrhiza inoculation on the development of micropropagated plants of Annona cherimola was investigated. Mycorrhizal inoculation was assayed at two different stages of the micropropagation process: (i) immediately after the in vitro phase, before starting the acclimatization period, and (ii) after the acclimatization phase, before starting the post-acclimatization period under greenhouse conditions. Plantlet survival was about 50 % after the acclimatization period. Plant growth and development profited remarkably from mycorrhiza establishment. Most of the arbuscular mycorrhizal fungi (AMF) assayed greatly increased shoot and root biomass and leaf area. Micropropagated Annona plants seem to be more dependent on mycorrhiza formation for optimal growth than plants derived from seeds. The greatest effects of AMF on plant growth were observed when they were introduced after the acclimatization period

Effect of arbuscular mycorrhiza on the growth and development of micropropagated Annona cherimola plants

vokArbuskelimykorritsasienten vaikutus mikrolisätyn annoonan (Annona cherimola) kasvuun ja kehityksee

Arbuskelimykorritsasienten vaikutus mikrolisätyn annoonan (Annona cherimola) kasvuun ja kehitykseen

Annona cherimola Mill., cherimoya, is a tropical plantation crop of interest in fruit culture. Micropropagation techniques have been developed due to the need to increase productivity through clonal selection. Because of the mycorrhizal dependence exhibited by this crop for optimal growth and the recognized role of mycorrhiza establishment for the survival and development of most of the plants produced in vitro, the effect of mycorrhiza inoculation on the development of micropropagated plants of Annona cherimola was investigated. Mycorrhizal inoculation was assayed at two different stages of the micropropagation process: (i) immediately after the in vitro phase, before starting the acclimatization period, and (ii) after the acclimatization phase, before starting the post-acclimatization period under greenhouse conditions. Plantlet survival was about 50 % after the acclimatization period. Plant growth and development profited remarkably from mycorrhiza establishment. Most of the arbuscular mycorrhizal fungi (AMF) assayed greatly increased shoot and root biomass and leaf area. Micropropagated Annona plants seem to be more dependent on mycorrhiza formation for optimal growth than plants derived from seeds. The greatest effects of AMF on plant growth were observed when they were introduced after the acclimatization period.Annona eli kirimoija (Annona cherimola Mill.) on kiinnostava trooppinen hedelmäkasvi. Espanjassa kehitettiin kasvin mikrolisäystä, että kasvin kloonivalintaa voitaisiin tehdä sadontuottokyvyn parantamiseksi. Annona tarvitsee mykorritsaa saavuttaakseen optimaalisen kasvun. Aikaisemmissa kokeissa on todettu mykorritsasiirrostuksen lisäävän annoonan pikkutaimien henkiinjäämistä ja kehitystä. Tämän tutkimuksen tavoitteena oli selvittää arbuskelimykorritsasienten siirrostuksen vaikutusta mikrolisätyn annoonan kasvuun ja kehitykseen. Kasvit siirrostettiin kahtena ajankohtana, joko välittömästi taimien in vitro -vaiheen jälkeen ennen sopeuttamista jatkoviljelyolosuhteisiin tai sopeuttamisjakson jälkeen. Sopeuttamisvaiheen jälkeen taimien eloonjäämisprosentti oli vain n. 50. Mykorritsa paransi taimien kasvua ja kehitystä. Useimmat käytetyt sienikannat lisäsivät huomattavasti versojen ja juurten biomassaa sekä lehtialaa. Mikrolisätyillä Annona-taimilla näyttää olevan suurempi riippuvuussuhde mykorritsan kanssa kuin siemenistä kasvatetuilla taimilla. Mykorritsasienten vaikutus oli vahvin silloin, kun siirrostus tehtiin sopeuttamisjakson jälkeen