Evaluation of provenances for seedling attributes in rosewood (Dalbergia latifolia Roxb.)

Abstract

A randomised block design experiment involving the performance of selected provenances, i.e., Trivandrum, kollam, Wyanad, Idukki and Thrissur (local provenance) of Dalbergia latifolia Roxb. Initiated during June 1999 was used for the present investigation. This study was undertaken to examine the seed characteristics, germination characters, growth parameters and physiological characters. Seed characteristics like 100 seed weight and individual seed weight showed significant variation among the provenances. The seeds from Trivandrum provenance was found to be superior than the others. Idukki registered the lowest mean value for the individual seed weight and the others were on par. Germination behaviour of rosewood provenances in the laboratory conditions showed significant variation except in the case of days taken to complete germination. Wyanad provenance recorded the highest germination percentage and other germination characters like peak value, mean daily germination and germination value were superior for Idukki provenance and it was statistically comparable with the Kollam provenance. Except mean daily germination and germination value, significant variation was shown by the provenances with respect to the germination characters in the field conditions. Idukki provenance was superior with respect to germination percentage and was on par with Wyanad provenance. Inferior performance in the case of peak value was shown by Thrissur (local provenance) and the others were comparable. More time for completion of germination was taken by Kollam which was having a statistically inferior germination percentage. Biometric observations also showed significant variation among the provenances except leaf area. At 60 DAS Trivandrum and Kollam were superior over the others for shoot height. Wyanad and Idukki which registered the least values at 60 DAS were superior towards the later stages of growth. Statistically inferior performance was shown by local provenance at all stages of the experimental period. For root length and collar diameter also similar trend was followed. With respect to number of leaves per plant superior performance was registered by the Wyanad provenance, but for leaf area both Wyanad and Idukki performed better. Trivandrum, Wyanad and Kollam provenances were comparable for the number of lateral roots and physiologically active fresh lateral roots were superior for Trivandrum and Idukki provenances. Biomass production which plays an important role in the ultimate biological yield, showed significant variation among the provenances. Kollam, Wynad and Idukki provenances were statistically superior for various biomass characters such as stem, leaf, root and shoot dry weight. Physiological parameters like relative growth rate and net assimilation rate showed significant variation among the provenances. Idukki, Kollam and Trivandrum were superior with respect to relative growth rate and Kollam registered the highest mean for the net assimilation rate which was on par with Wyanad and Idukki provenances. Chlorophyll content, which decides the photosynthetic potential in plants did not show any significant difference among the provenances throughout the experimental period.