Physiological Assessment of Temperature Stress Tolerance in Selectively Fertilzed Coconut Hybrids

In vitro pollen germination study is one of the important technologies for understanding the functions of pollens as well as in many areas of pollen biotechnology particularly in pollen selection. Ability to separate germinated and non-germinated pollen offers selective treatments and can be used for identifying stress tolerant and sensitive alleles carried by their pollen grains. The present study was carried out in Kerasree and Keraganga selectively fertilized (S.F) coconut hybrids produced through pollen selection. Pollens were subjected to germination in specific media maintained at different levels of water stress induced by PEG 6000 and the critical water potential for pollen germination was identified. The water stress tolerant pollen grains at critical level were selected and used for fertilization. Evaluation of temperature stress tolerance of these two selectively fertilized hybrids along with their normal hybrids and west coast tall (WCT) was carried out by assessing their critical temperature stress for pollen germination. Both Kerasree selectively fertilized and Keraganga selectively fertilized hybrids recorded highest critical temperature of 420C for pollen germination with germination percentage of 20.17 and 22.77 respectively compared to their normal hybrids (380C) and WCT (400C).