Dergiler / Journal of Agricultural Sciences / 2014 / Cilt: 20 Sayı: 3
Morphological and Anatomical Investigations on Old Home x Farmingdale 333 / Pyrus elaeagrifolia in Vitro Micrografts
- Sayfa
- 269–279
- DOI
- —
Özet
In this study, the possibility of creation of a specific pear rootstock combination by micrografting was investigated. Two genotypes; ‘Old Home x Farmingdale 333’ (Pyrus communis L.) which is a clonal semi dwarf pear rootstock resistant to fireblight and pear decline, and Pyrus elaeagrifolia known as tolerant to Fe-chlorosis, salinity and drought stresses were used to obtain a clonal, semi dwarf and tolerant to the stresses pear rootstock combination. In vitro P. elaeagrifolia seedlings were used as rootstock, and in vitro shoots of ‘OH x F 333’ were used as semi dwarf interstock. Cleft grafting was applied in micrografts. Grafted seedlings were cultured on Murashige and Skoog basal medium with ½ strength of macronutrients for 8 weeks. Cultures were incubated under white fluorescent light, 16 h per day. However, complete darkness was applied for 1 or 2 weeks at the beginning of incubation for the darkness treatments. Graft take success in the control treatment was significantly higher (97.9%) than darkness treatments (90.5% and 82.5%, respectively). Ultrastructural observations with transmission electron microscope revealed that dividing cambial initials reached to 2-3 layers and new xylem and phloem elements distinctly differentiated in transversal sections of the graft union after 8 weeks of micrografts in the control and dark treatments. The results indicated that a successful graft union formation occurred. To the best of our knowledge, this is the first report of in vitro micrografting on Pyrus elaeagrifolia Pallas.
Abstract
In this study, possibility of creating a specific interstock / rootstock combination to obtain a clonal, semi dwarf, composite pear rootstock tolerant to various stresses by micrografting was investigated. In vitro shoots of ‘Old Home x Farmingdale 333’ (Pyrus communis L.) which is a clonal semi dwarf pear rootstock resistant to fireblight and pear decline was used as interstock, and in vitro Pyrus elaeagrifolia Pallas seedlings known as tolerant to Fe-chlorosis, salinity and drought stresses was used as rootstock. Cleft grafting was applied in micrografts. Grafted seedlings were cultured on Murashige and Skoog basal medium with ½ strength of macronutrients for 8 weeks under white fluorescent light for 16 h day. Cultures, except the control, received complete darkness either 1 or 2 weeks at the beginning of incubation. Graft take success in the control treatment was significantly higher (97.9%) than darkness treatments of 1 or 2 weeks (90.5% and 82.5%, respectively). Ultrastructural observations with transmission electron microscope revealed that dividing cambial initials reached to 2-3 layers, and new xylem and phloem elements distinctly differentiated in transverse sections of the graft union 8 weeks after micrografting in the control and darkness treatments. The results indicated a successful graft union formation.