In Pakistan, Peach (Prunus persica) is second most important stone fruit, after plum. The economic life of peach orchards is 7 to 10 years and the most important factors responsible for this decline have been identified as the use of inappropriate rootstock and calcium induced iron chlorosis. A major problem with wild peach rootstock is its genetic variability.
Introduction
In Pakistan, Peach (Prunus persica) is second most important stone fruit, after plum. The economic life of peach orchards is 7 to 10 years and the most important factors responsible for this decline have been identified as the use of inappropriate rootstock and calcium induced iron chlorosis. A major problem with wild peach rootstock is its genetic variability.
Technology Development and Demonstration
Different types of rootstock have been used for peach in the world. GF 677 is a potential rootstock under Pakistani soil conditions resulting to extend the economic life of peach orchards beyond 15 years. It is considered to be a rootstock for calcareous and high pH soil conditions because it is resistant to calcium induced iron chlorosis and to avoid replant disease syndrome. It is resistant to peach rust, crown gall, root knot,
and is more vigorous in growth than peach seedling rootstocks. Fruit yield, average fruit weight and fruit quality is higher in trees on GF 677. However, GF 677 cannot be propagated through seed, being a hybrid (Peach x Almond). Demand of peach plants grafted on GF 677 may not be met by conventional multiplication of this rootstock; therefore in vitro propagation has become an inevitable alternative to the conventional methods. However, no report exists about its multiplication through tissue culture in Pakistan. Hence, at NARC, Islamabad protocols for in vitro shoot proliferation, rooting, and acclimatization have been standardized.
The Technology
For shoot proliferation study, MS (a high salt medium) and AND (a low salt medium) media were compared with different BAP concentrations (0.3, 0.6, 0.9 mg l-1). For rooting, half strength MS medium was used with different IBA concentrations (0.3, 0.4,
0.5, 1.0, 2.0, 3.0, 4.0, mg l-1). It was concluded that, MS was the best for multiplication of peach rootstock GF 677 and 0.6 mg l-1 BAP was the most affective concentration of cytokinin. Of the different concentrations of IBA tested, 0.4 mg l-1 was suitable auxin for rooting without any callus interphase. Well rooted plantlets were transferred to greenhouse and grown successfully with 80% survival. Field nursery of the greenhouse acclimatized plants has also been developed.
Key References
Ahmed, T., H. U. Rahman, and M. H. Laghari. (2004). Effect of different Auxins on in vitro rooting of peach rootstock GF 677. Sarhad Journal of Agriculture 20(3): 373-375.
Ahmed, T., H. U. Rahman, and M. H. Laghari. (2003). Effect of culture media and growth regulators on micropropagation of peach rootstock GF 677. Pakistan Journal of Botony, 35 (3): 331-338.
Reference : parc.gov.pk
