In vitro germination and viability of pollen grain of coconut accessions

Abstract

Storage as a means of maintaining the pollen viability is important for the preservation of the genetic variability, facilitates the exchange of germplasm and greatly contributes to the generation of variability obtained from artificial crosses, increasing the efficiency of breeding programs. The objective of this study was to select different culture media for the in vitro germination of pollen grain of dwarf and tall coconut accessions, as well as to determine the viability of pollen grain at room temperature conditions. For this purpose, Brazil Green Dwarf (BGD) and Brazilian Tall (BRA) pollen grains derived from the Coconut Active Germplasm Bank of Embrapa Coastal Tablelands Sergipe were used. To evaluate the effect of different culture media on the in vitro germination of pollen grains of anão verde do Brasil de Jiqui (AVeBrJ) and gigante do Brasil Praia do Forte (GBrPF)  accessions, they were inoculated on to Petri dishes containing 2 ml of culture media. The pollen viability was assessed by staining with 1% acetic carmine and in vitro germination at 0, 24, 48 and 72 hours. The culture medium of Lora is suitable to assess the in vitro germination of pollen grain of the AVeBrJ and GBrPF accessions. The pollen grain of the AVeBrJ accession showed intermediate viability (66.87%) at room temperature up to 23.14 hours by in vitro germination.  The pollen grain of the GBrPF accession showed high viability, above 70%, at room temperature up to 120 hours by in vitro germination.