Fluted pumpkin [Telfaria occidentalis (Hook F.)]: genetic diversity and landrace identification using phenotypic traits and RAPD markers

Abstract

Fluted pumpkin [Telfaria occidentalis (Hook F.)] is a nutritious tropical vegetable crop. Genetic diversity was evaluated in a collected set of Telfairia occidentalis Hook F. landraces. Various phenotypic traits were examined in a total of 23 landraces and a subset of 12 landraces. Data analysis revealed that considerable variation observed in the 23 fluted pumpkin landraces was in the fruit weight. The 12 landraces had moderate variation in total chlorophyll and carotene contents whereas low variation was observed in leaf length and width. Twelve subset fluted pumpkin landraces were genotyped using 10 selected Random Amplified DNA polymorphism (RAPD) markers. The number of alleles detected per marker ranged from 3 to 5, with a total of 40 alleles. The mean percentage polymorphic loci observed was 56.8. All primers had low resolving power (Rp) with a mean of 0.85. Genetic similarity values ranged from 0.63 and 0.88 with a mean of 0.76. The Dice coefficient genetic similarity using unweighted pair group method using arithmetic averages (UPGMA) grouped the 12 landraces in 2 (groups I and II) according to extent of genetic relationship among the analysed fluted pumpkin landraces. Similar groupings were projected in the principal component analysis (PCA). The lines PUE05 and PUI09 are closely related and they also exhibited farthest genetic distance from the other landraces in both the UPGMA and PCA. These results show that more effort should be geared towards genetic conservation of Telfairia occidentalis Hook F.

Keywords: Telfaria occidentalis (Hook F.)], Genetic diversity, Landraces identification, Phenotypic traits, RAPD markers