Kasturi Bai, K.V.Naresh Kumar, S.Rajagopal, V.Vijayakumar, K.2015-02-032015-02-032008-12Indian J. Hort. 65(4), December 2008: 471-476http://hdl.handle.net/123456789/6174Study was conducted in coconut for understanding the importance of chlorophyll fluorescence (Chl. fluorescence) transients in seedling selection for drought tolerance. The observations on Chl. Fluorescence transients along with leaf water potential (leaf) were carried out in selected hybrid combinations of Dwarf x Tall during irrigated and water with-held conditions. The data from the whole experiment as well as transformed values were subjected to principal component analysis (PCA). The results clearly indicated significant differences between seedling combinations and between the two periods. The interaction between the combinations and treatment also was found to be significant. The ranking of the combinations based on Chl. fluorescence transients indicated the combinations with LCT as the pollen parent showed better adaptation to water stress conditions followed by Fiji Tall combinations. The PCA considering the Chl. fluorescence transients as well as leaf indicated relative dispersion of the genotypes which imply a high level of genetic diversity for water-stress tolerance in the combinations examined. Further, the observations clearly revealed that performance of seedlings, under stress cannot be predicted from performance in non-stress condition. Based on principal component loadings it can be suggested that Chl. fluorescence transients viz., F0 and t½ and leaf are important traits which can be used to differentiate and screen the coconut seedlings that can adapt to water stress condition.enCoconutchlorophyll fluorescenceprincipal component analysisleaf water potentialwater stressArticle