Intervarietal hybridization in Anthurium andreanum Linden

Abstract

The present study on evaluation of morphological characters and compatibility reactions among ten selected Anthurium andreanum varieties, was undertaken to analyse the scope for genetic improvement in this crop. The analysis of variance revealed significant variation among the ten varieties for the twelve quantitative characters studied. This reveals the high genetic potential for the improvement of this crop. Variability studies indicated that high phenotypic and genotypic coefficients of variation for the characters plant height, position of candle, days to initiation of female phase, number of days in female phase and spathe size. The characters with heritability coupled with high genetic advance values were plant height, spathe size, spathe-candle ratio, position of candle, number of flowers per candle and days to initiation of female phase, indicating additive gene action. Plant height was found to be positively correlated with number of leaves or spadices per year. Spathe size and candle length were positively correlated. Candle length had high positive genotypic correlation with position of candle and number of flowers per candle. Pollen fertility ranged from 42 per cent in Liver Red to 13.7 per cent in Mauritius Orange. Study of pollen emergence pattern revealed significant differences among the varieties. Pollen emergence was completely absent in Pompon Red, Nitta Orange and Midori Green during the period of study. Pollen production was high in the cooler months of October to December and

was suppressed during the hot months of March to June. Cross compatibility analysis based on the results of intervarietal hybridisation was done using the three parameters; i.e., percentage of candles bearing fruits, percentage fruit set and percentage seed •germination. The percentage of fruit bearing candles were highest for Nitta Orange (51.93 per cent) and lowest for Mauritius Orange (9.51 per cent). The only two selfings that produced fruiting candles were LR x LR and DT x DT. The number of fruits per candle ranged from five to 183. The variety Pompon Red had the highest average number of fruits per candle and it was lowest for Lady Jane. The percentage of fruit set was below 50 per cent for all the crosses except PR x LR. The crosses involving Pompon Red as female parent had the highest percentage of fruit set. The number of days taken for seed germination varied from three to twelve days. The seed germination was highest (87.5 per cent) for the cross DT x MW. Among the varieties it ranged from 69 per cent in Tropical Red to 2.3 per cent in Midori Green. Seedling survival at four to six month stage was highest for the crosses of Mauritius Orange and the lowest for those of Midori Green. The cross TR x MW showed 100 per cent seedling survival. Scoring of the compatibility reactions based on fruiting candles, fruit set and seed germination, on a scale ranging from O to 9, showed the highest compatibility' score of nine for PR x LR and CR x MW crosses. The best female parents were identified as Nitta Orange, Liver Red and Pompon Red

based on the overall performance. The analysis of the performance of varieties as pollen parents on the same basis showed that Ceylon Red, Merengue White and Liver Red are the best pollen parents. These observations showed that the performance of a variety as female parent was different from its performance as male parent. Only the variety Ceylon Red and Liver Red performed well both as female and male parent.