Abstract

Collecting and characterizing plant material has been basic for crop improvement, and diversity has long been seen as vital for rational management and use of crops. Thirty (30) morphological characters and thirty (30) simple sequence repeat (SSR) markers were used to assess the diversity among 112 sweet potato (Ipomoea batatas [L.] Lam) cultivars in Burkina Faso and to develop a core collection. Eight morphological characters were able to differentiate the 112 accessions and to identify 11 duplicates while 28 SSR markers were more informative in discriminating the accessions and to identify five duplicates. The diversity assessment using the two approaches revealed high diversity with a coefficient of 0.73 using the phenotypic data, while moderate diversity with a coefficient of 0.49 was obtained using the SSR markers. These results show no correlation between the two approaches (with dissimilarity index of 0.95). A core collection was constituted using the SSR based data while the eight discriminative phenotypic descriptors will be used in the identification of cultivars.

Key words: Accessions, genetic diversity, germplasm, molecular markers, morphological characters, simple sequence repeat, sweet potato.

Abbreviation

Abbreviations: SSR, Simple sequence repeat; PCR, polymerase chain reaction; PIC, polymorphic information content; PT, plant type; GC, ground cover; VID, vine internode diameter; VIL, vine internode length; PVC, predominant vine colour; SVC, secondary vine colour; VTP, vine tip pubescence; GOL, general outline of leaf;  LLN, leaf lobes number;  LLT, leaf lobes type; MLS, mature leaf size;  ALVP, abaxial leaf vein pigmentation; PL, petiole length; PP, petiole pigmentation; SCLL, shape of central leaf lobe; MLC, mature leaf colour ; ILC, immature leaf colour; FH, flowering habit; PSC, predominant skin colour; IPSC, intensity of predominant skin colour; SSC, secondary skin colour; PFC, predominant flesh colour; SFC, secondary flesh colour; DSFC, distribution of secondary flesh colour; SRF, storage root formation; SRS, storage root shape;  LPSR, latex production in storage roots; OSR, oxidation in storage roots; SRSD, storage root surface defects; SRCT, storage root cortex thickness; UPGMA, unweighted pair group method using arithmetic average.