Methodology development to obtain cashwe tree haploids (Anacardium occidentale L.) through rising of anthers

Abstract

Culture media and environments were investigated aiming to develop methodologies to obtain haploids of cashew tree (Anacardium occidentale L.) through anthers culture. Floral buttons explants were taken from early dwarf clones CCP 76. Incidence of oxidation and contamination, as well as degree of development, was observed. As to the index of development, it was observed that anthers presented better development when kept initially at dark and then transferred to the previous medium, but with different concentrations or proportions, or when transferred to a medium known to favor anthers growth after initial induction. Overall, activated coil added to the nutrient medium inhibited oxidation in detriment of anthers managed under light, whose places were switched every four days within the same Petri dish, which presented higher incidence of oxidation. The best degree of development was reached in MS and MS/4 media and, also, when Thidiazuron was added in the concentration of 0,005 µM. The results showed that the studied anthers developed callus, without, however, the presence of embryogenic cells, suggesting the need of further studies, such as switching medium after initial dark shock.