MSc

The study entitled “Characterization of kasthuri turmeric (Curcuma aromatica Salisib.)” was conducted at the Department of Plantation Crops and Spices and Department of Plant Biotechnology, College of Agriculture, Vellayani during the period 2003-'04. The objective of the study was to characterize kasthuri turmeric in comparison with ordinary turmeric (C. longa L.) and zedoary (C. zedoaria Rosc.). Studies were carried out using eleven accessions of kasthuri turmeric and two accessions each of ordinary turmeric and zedoary. Characterization in terms of morphological, biochemical, physiological, anatomical and yield characters were carried out. Molecular characterization using RAPD technique was also used in this study.
Analysis of variance of the observations showed significant difference among the accessions for most of the characters. Growth characters like plant height, leaf area, rhizome spread, root spread and rhizome thickness showed that zedoary is more vigorous and superior in above growth characters compared to kasthuri turmeric and ordinary turmeric. Most of the kasthuri turmeric accessions performed in between the zedoary and ordinary turmeric accessions for most of the growth characters analysed.
Biochemical studies revealed that the three accessions of kasthuri turmeric, T3 (IISR accession), T8 (Pala wild) and T11 (Kozhikode accession) performed uniquely and was superior in terms of essential oil content, crude fibre, protein and chlorophyll content. But the curcumin content was less than one per cent in these accessions. The zedoary and ordinary turmeric accessions used for comparative study recorded a higher curcumin content, less essential oil and crude fibre contents. A clear difference was established between these three accessions of kasthuri turmeric, ordinary turmeric and the zedoary.
Analysis of yield characters revealed that zedoary accessions are superior in rhizome yield and kasthuri turmeric accessions yielded higher compared to ordinary turmeric accessions. Physiological characters like dry matter production, lead are index, leaf area duration and harvest index were found higher in the zedoary accessions differentiating them from kasthuri turmeric and ordinary turmeric accessions. The anatomical characters studied were found to be similar and did not show any significant variations among various accessions.
Variability study showed high genotypic coefficient of variance and phenotypic coefficient of variance for most of the characters, revealing great extent of variability for these characters, suggesting good scope for improvement through selection. Correlation studies showed that genotypic correlation is higher than the phenotypic correlation and the environmental correlation was less, revealing strong association at genotypic level between the characters.
For the molecular characterization of kasthuri turmeric, DNA was isolated from young leaves of various accessions using Murray and Thompson method. The yield of DNA ranged from 1.26 to 6.39 ng l-1. The purity of DNA estimated using the O.D. ratio (A260/A280) ranged from 1.52 to 1.92. PCR amplification was carried out using 40 decamer primers (Operon Inc., CA, USA) of Kit A and Kit B and a total of 59 RAPDs were generated. Of these, 56 bands were polymorphic.
Out of the 40 primers screened, three primers (OPA-04, OPB-17 and OPB-18) were selected for amplifying DNA from all the Curcuma accessions. The estimation of similarity coefficient and construction of dendrogram revealed the presence and extent of genetic similarity among the 15 Curcuma accessions examined. The similarity coefficient values ranged from 0.25 and 1.00.
At 63 per cent similarity, the 15 accessions got divided into four clusters. First cluster consisted of only one accession, T15 which is the black zedoary accession. The accessions T7 and T10 together formed the second cluster. The third cluster included the three accessions T3, T8 and T11. The fourth cluster consisted of nine accessions at 63 per cent similarity. At 69 per cent similarity this cluster again got divided into two sub clusters. One sub cluster consisted of four accessions i.e., T4, T6, T9 and T5. Second cluster consisted of five accessions, i.e., T14, T1, T2, T12 and T13 are coming under this cluster.
The various accessions of kasthuri turmeric are spread under different clusters. The accessions T3, T¬8 and T11 having cent per cent similarity formed a single cluster. These three accessions are found to have dense pubescence under the leaf surface and had exactly similar plant habit. By considering the high essential oil content, camphoraceous aroma of the rhizomes, low curcumin content and the cent per cent similarity obtained from the molecular characterization studies, these three accessions can be concluded as the true kasthuri turmeric.