ABSTRACT
The analysis of the pollen grain fertility of Riccinus communis (castor-oil plant) is of great importance for breeding programs, allowing for suitable handling and use of collections and the creation of cultivars of interest for biodiesel production. In this work, a predictive process was chosen based on the cytological method of pollen-grain staining and in-vitro pollen germination after low-temperature treatments for preservation to verify the pollen viability, which is important in seed fertilization and formation. The conventional cytological staining technique with 2% acetic carmine was used for pollen grain viability analysis for the cultivars IAC-80, Cafelista, AL-Preta and AL-Guarany 2002, while the method of in-vitro germination after treatment at -196° C, -80° C and -18° C, from 15 to 30 days, was used for the cultivar IAC-80. The IAC-80 and Cafelista cultivars showed pollen viability values above 95%, while AL-Preta and AL-Guarany 2002 showed 88.48 and 86.46%, respectively. The pollen grains of castor-oil cultivars also presented a high percentage of pollen viability at anthesis. Therefore, it is possible to use the pollen grains of all the analyzed cultivars for fertilization induction in breeding programs. The results indicate that the average percentage of the pollen-grain viability in-vivo was not influenced by the storage period. It was also observed that there were differences among the low-temperature treatments, although the percentage of viability was low, suggesting the need for the application of a suitable evaluation technique.
KEY WORDS
Ricinuscommunis L.; castor-oil; pollen grain; plant breeding; cryopreservation
Thumbnail
Thumbnail
