RAPD analysis of long term micropropagated rootstock plants of Apple Malling 7

Area of Science:

• Horticulture
• Plant Biotechnology
• Genetics

Background:

• Apple cultivation is vital in Himachal Pradesh, with significant land and production dedicated to it.
• High-density apple plantations necessitate large-scale production of quality, disease-free planting material.
• Plant tissue culture offers a method for producing true-to-type, disease-free plantlets.

Purpose of the Study:

• To develop a commercially viable in vitro propagation method for the semi-dwarf clonal apple rootstock Malling 7 (M7).
• To assess the genetic fidelity of micropropagated M7 plants to ensure stability for large-scale, long-term propagation.

Main Methods:

• Developed an in vitro propagation protocol for M7 rootstock using axillary branching from shoot tip explants.
• Assessed genetic stability of micropropagated plants using Random Amplified Polymorphic DNA (RAPD) markers.
• Compared banding patterns of in vitro and field-transplanted M7 plants with the mother clone.

Main Results:

• A large number of M7 plants were successfully transferred to field conditions.
• Out of 20 RAPD primers screened, 12 yielded 44 scorable bands.
• All banding patterns were uniform and monomorphic across different stages and comparable to the mother clone, indicating no genetic variation.

Conclusions:

• The developed micropropagation protocol is suitable for the large-scale, long-term clonal propagation of apple rootstock M7.
• The method ensures genetic stability and true-to-type propagation, minimizing risks associated with genetic instability.