Variability in morphological, physiological and biochemical characters in kalmegh (Andrographis paniculata Nees.)

Abstract

An experiment ID kalmegh (Andrographis panicu/ata Nees.) was conducted in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara during 1998-2000, with the objectives of understanding the morphological variability, growth pattern, optimum stage of harvest and the variation in different biochemical compounds among the accessions. The accessions were collected from Kerala and neighbouring states. Ten accessions were compared based on 50 morphological, 16 physiological and 3 biochemical characters. In general, accessions showed uniform root, inflorescence, flower and fruit characters. However a limited variation for habit, stem and leaf characters existed among most of the accessions. In general, accessions showed variability for characters namely total plant dry weight, stem dry weight, leaf dry weight and root dry weight when observed at 1, 2, 3 and 4 months after transplanting. Ranking of the accessions was not consistent on the various dates of harvest. Optimum stage of harvest is recommended as 3 months after transplanting. At this stage maximum herbage yield was recorded by accession Ac-4. Physiological parameters namely Leaf area and LAI showed steady increase up to three months after transplanting and thereafter it declined. LAR, RGR, CGR and NAR recorded higher values at earlier dates. Heritability (broad sense) of characters showed inconsistency at various dates of harvest. However leaf dry weight showed higher heritability on all dates. At 3 months after transplanting i.e. the optimum stage of harvest, heritability was high for all the characters relating to herbage yield and most of the physiological parameters.

Biochemical studies revealed that the total phenol content and andrographolide content varied considerably among the accessions. Phenol content in the plant increased with an increase in dry weight while Andrographolide content increased with a proportionate increase in moisture content.