Abstract

Ailanthus triphysa, (Dennst.) Alston, the most suitable species for match industry needs productivity improvement, since the plantations are pest susceptiable and less productive. There is a very high demand for this species while supply is very muchlimited. Two of the options for productivity improvement were selection of suitable species of Ailanthus and genetic improvement of A. triphysa. Experiments were conducted to study the nature of genetic variability, heritability and correlation of economically important characters and also the breeding system prevailing in A. triphysa. Establishment of seed orchard also has been envisaged. The study conducted has revealed that A. triphysa has a high family heritability for height and moderately high heritability for basal girth. The single tree heritability was found to be moderately high for height while it was low for basal girth. The phenotypic and genotypic coefficient of variation were found to be low for both characters. Strong positive genetic correlation was noted between height and basal girth which makes the improvement programme easy. Growth characters with high heritability value also make productivity improvement faster in the sense that phenotypic selection without the recourse of progeny test will suffice to a certain extent. The results from species trial have shown that A. intergrifolia spp. calycina is better in growth performance in early years besides having a high level of pest resistence. But A. triphysa is preferred for the match industry since it has aromatic resin in its wood which avoids waxing of splints. As the basic step in any tree improvement programme, 70 plus trees of A. triphysa were selected from natural forests, house compounds and plantations in Kerala. A seedling seed orchard is established at Palappilly of Chalakudy Division in an area of half a hectare with 27 progenies which will be a source of improved seeds. The study conducted to understand the breeding system has revealed that A. triphysa is dioecious and strictly cross breeding. Since it is a widely outcrossing species, intrapopulation variation is expected to be very low