Suitability of seed esterases for establishing distinctness, uniformity and stability of pearl millet genotypes

摘要

Plant morphological characters have been the universally undisputed descriptors applied for testing distinctness, uniformity and stability (DUS) of crop varieties. However, these descriptors, other than being limited in number, make the process time-consuming and also less reliable owing to its interaction with the environment in which the variety is grown and subjectivity in decision-making. The potential of biochemical descriptors such as seed esterases has been well established for diversity analysis and varietal identification. However, their suitability as DUS test characters merits investigation. In the present study, seed esterases were used to examine distinctness of 45 pearl millet genotypes comprising 14 hybrids and their parental lines. Among 45 genotypes studied, 36 could be differentiated from each other and 11 were grouped into four categories at 2.29 X 10(-3) probability of identical match by chance. The utility of this marker to study uniformity and stability was analysed using two genotypes, 841B and D23. Analysis of single-earhead seeds from 100 individual plants, which are morphologically similar, revealed no variations within a variety in 841B and one variant in D-23, which is attributed to the residual heterozygosity. The possibility of esterase markers for testing the DUS of new pearl millet genotypes to give protection under the Protection of Plant Varieties and Farmers' Rights Act, 2001 has been discussed.