Epsilon Archive for Student Projects

Abstract

Morphological characterisation of germplasm helps in the identification of duplicate accessions, unique traits and the development of core collection. Cryopreservation serves as a complementary conservation method to field and in-vitro methods. This study aimed at evaluating the diversity of Ipomoea batatas landrace collection maintained in tissue culture at the National Plant Genetic Resources Centre (NPGRC) of South Africa. The response of the selected sweet potato accessions to cryopreservation as the complementary conservation method was also tested. Vegetative and storage root characters of the 51 sweet potato accessions were characterized using International Potato Centre descriptors for sweet potato and analyzed with Numerical Taxonomy System-pc software. Encapsulation-vitrification and encapsulation-dehydration protocols were tested for cryopreservation on selected accessions. The unweighted pair-group method using an arithmetic average (UPGMA) defined 22 clusters at a distance coefficient of approximately one. Four Principal Components cumulatively explained 46 percent of the variation, whereas four Principal Coordinate axes, explained 50 percent. Preliminary results presented here show that the NPGRC of South Africa conserves high morphological diversity of sweet potato landraces in the field and tissue culture. But, the results need to be verified with replicates.