Genetic divergence in anthurium andreanum linden

Abstract

Genetic divergence studies were conducted on 100 different genotypes of Anthurium andreanum Linden, comprising of 20 varieties and 80 F I hybrids generated from a previous hybridization programme in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani. As the parental varieties themselves had a long history of hybridization in their background, the entire material was highly heterozygous. Significant genotypic differences were observed among the hundred genotypes for all the ten characters namely plant height, spathe length, spathe width, number of suckers per plant, length of leaf blade, width of leaf blade, candle length, inclination of candle with the spathe, number of spadices per plant per year and leaf area. Except for number of spadices/plantlyear, all the characters were highly influenced by genotypic variation. High heritability with a good genetic advance was found for all the characters studied, except for number of spadices/plantl year which exhibited medium heritability and low genetic advance. These results indicate that selection of plants which are phenotypically superior with respect to nine of the characters studied will certainly result in a significant improvement in the next generation. Environmental correlation was absent for all the characters except for number of spadices/plantl year indicating the influence of environment on this character suggesting

3 Based on the gca and sea effects, the parent 'Honeymoon Red' was found to be the best general combiner for several traits like plant height, width of leaf blade, length of spathe, number of spadices/plant/year, duration of female phase, days of interphase, life of spadix and carotene content. For the characters, length and width of leaf blade, leaf area, time taken for first flowering, inclination of candle, days to intiation of female phase, duration of male phase, duration of female phase, total anthocyanin content and total carotenoids, the best general combiner was 'Kalympong Red'. For the characters, plant height, length and width of leaf blade, suckering ability, the best general combiner was 'Pink'. The parent 'Chilli Red' was the best general combiner for characters viz., days from emergence to maturity of leaves, length and width of leaf blade, leaf area, candle length, inclination of candle, number of flowers/candle, total anthocyanin content and days of interphase. The parent 'Liver Red' was the best general combiner for characters namely candle length, inclination of candle, internode length, length and width of leaf blade, leaf area, suckering ability, number of flowers/candle, pollen fertility, total anthocyanin content and total carotenoids. The heterosis of F l's over parent 'Liver Red', which is the most acceptable semi-commercial variety under the study, was worked out. Most of the F 1 hybrids registered negative heterosis, for characters such as plant height, length and width of leaf blade, days from emergence to maturity of leaves, leaf area, time taken for first flowering and inclination of candle. This is highly desirable in the case of Anthurium, because, the best commercial varieties of Anthurium should have medium plant height with medium sized leaves for accommodation of more plants within

4 a unit green house area, earliness to maturity of leaves and shorter time taken for first flowering for enhancing the number of leaves and flowers/ plant/year and a reduced inclination of candle for accommodating more flowers at the time of packing for transportation. Based on the anthocyanin contents, the probable spathe colour genotypes of fi ve selected parents and their lO F I hybrids of the present study have been worked out for the first time in Anthurium by correlating the total average anthocyanin content of the spathe of each variety to the incremental effect of the two anthocyanin producing genes, M and o. To sum up, this pioneering study, the first of its kind in Anthurium, indicates that hybridisation is the easiest and sure method for achieving genetic improvement in this export oriented cutflower crop. Reductions in plant height, leaf size, leaf area, days to maturity of leaves, days to first flowering and inclination of candle observed in the hybrids when compared with the parents are highly desirable attributes of commercial hybrids. The fact that the character number of spadices/plant/year is controlled by the environment indicates that flower productivity can be enhanced by judicial manipulations of environmental conditions. Spathe colour genotypes of five parents and their ten hybrids have been determined for the first time based on the anthocyanin pigment assay of their spathes. The study highlights the feasibility of producing commercially viable indigenous anthurium hybrids for commercial cultivation in Kerala.