Evaluation of diversity in dragon fruit (Hylocereus spp.) genotypes grown in Kerala, India

Abstract: The present study was conducted to evaluate the variability among the dragon fruit (Hylocereus spp.) genotypes in Kerala. The study was conducted in ten dragon fruit orchards of four different districts namely, Trivandrum, Pathanamthitta, Ernakulam and Thrissur during the period 2019-2021. The plants were evaluated based on the UPOV guidelines to identify the different genotypes that were being cultivated in Kerala with respect to their morphology and flowering along with yield and quality attributes. The results revealed that the commercial cultivation of dragon fruit in Kerala was found to be dominated by the dark pink/purple fleshed dragon fruit (Hylocereus costaricensis). The variability within this species was analysed using statistical techniques like factor analysis and cluster analysis. Maximum variability (59.38%) in the stem and flower characters were contributed by the intensity of red colour of bract, stem waxiness, stem sturdiness, margin of rib, spine colour, bud shape, bud apex shape, number of stigma lobes, length of style and distance between areoles. Similarly, maximum variability (62.74%) in the quality attributes were contributed by the fruit weight, position of bract towards peel, fruit width, fruit weight without peel, fruit length, flesh colour, fruit shape, width of base of bract, length of apical bract, outer TSS, TSS-acid ratio and core TSS. Based on the qualitative traits alone, six clusters were formed indicating the variations in plants which in turn, revealed the presence of different genotypes within the dark pink/purple fleshed dragon fruit.