Читать книгу Biotechnology of Fruit and Nut Crops - Группа авторов - Страница 38

The success of micrografting depends on the method of grafting, size of the scion and age of the rootstock. Micropropagation of cashew results in formation of extremely brittle roots which break and adversely affect the survival of plantlets when transferred to soil. Micrografting overcomes the limitations of rooting and hardening problems of cashew microshoots. Mantell et al. (1998), Mneney and Mantell (2001), Thimmappaiah et al. (2002) and Ramanayake and Kovoor (1999) reported the use of in vitro grown seedlings as rootstocks. Keshavachandran and Riji (2007) utilized in vitro grown 8–9-day-old seedlings as rootstocks. Scions of micropropagated shoots were grafted onto in vitro seedlings and cultured in liquid MS medium, supplemented with 23.25 μM kinetin, 5.37 μM NAA, 2.08 μM brassinolide and 3% sucrose for 15 days. When side and cleft grafting were used, 100% establishment of the graft union was observed after 2 weeks. The scions showed increased length within 4 weeks, and the plantlets were transferred to the field.

Exogenous application of auxins such as NAA and IAA is consistent in all the in vitro fusion grafts and development reports. Activated charcoal (Keshavachandran and Riji, 2007), citric acid solution (Ramanayake and Kovoor, 1999) and a pretreatment soak in sterile distilled water or diethyldithiocarbamic acid (DIECA) reduced wound-induced phenolic exudation and browning.