Induction of Embryogenic Callus in Cashew (Anacardium occidentale L.) by Cotyledon, Nucellus and Testa with Antioxidants Effect

Abstract

Aims: This work aims to evaluate the influence of different growth regulators combined with antioxidants on the induction of callus with different explants in cashew.
 Materials and Methods: Nucellar tissues, cotyledons and testa from elite tree nuts are cultured on media that differ in their concentration of 6-Benzylaminopurine (BAP: 0 mg/l; 0.25 mg/l; 0.5 mg/l) and Acid 2,4 dichlorophenoxyacetic (2,4-D: 0 mg/l; 0.8 mg/l). Therefore, for the control of the browning of the explants, the effect of activated charcoal and polyvinylpyrrolidone was tested. The amount of callus formed is evaluated after 28 days and after 90 days by simple observation according to a given scale. 
 Results: Analysis of variance of callus formation 28 days after the culture of explants shows that the interaction between growth regulators and antioxidants significantly influences (p < 0.05) the induction of callus. The combination BAP 0.25mg/l and 2,4-D 0.8mg/l produces on average more callus (0.47 ± 0.00). There is a very significant difference (P < 0.05 to p<0.001) in the effect of growth regulators and antioxidants on obtaining callus after 90 days of cultivation. The 0.25 mg/l combination of BAP and 0.8 mg/l of 2,4-D still appears to be the best combination of growth regulators for callus with 58% of callus formed. Cotyledons in the presence of PVP respond better than activated charcoal. The nucellus are the explants that respond better in the presence of activated charcoal. The test for Least Significant Difference reveals that PVP significantly promotes (p <0.05) the production of a large number of calli (77%) unlike activated charcoal (9%) after 90 days of culture.
 Conclusion: Summary, for obtaining viable and embryogenic callus in cashew, the combination of BAP at 0.25 mg/L and 0.8 mg/L of 2,4-D is the best and this in the presence of PVP with cotyledons.