Fortification of sweet potato progenies for enhanced root dry matter and micro-nutrient density through genetic recombination

Experiment was conducted in the rainforest agro-eco-zone of Southeastern Nigeria under rain fed condition at the sweet potato breeding ground of National Root Crops Research Institute, Umudike, Nigeria to generate 10,000 botanical seeds for further evaluation for high root yield, dry matter and micro-nutrient content, to identify high flowering parent(s) and to select compatible parent(s) for further genetic recombination. The treatment which consisted of 14 parents of bi-parental crossing was laid out in a randomized complete block design with seven parents, each per plot per block and replicated three times while the other seven parents were maintained in different plots as pollen donors. Data collected were on: total number of emerged flowers visually counted, total number of flowers covered, total number of flowers pollinated, total number of capsules formed, total number of flowers aborted, total number of seeds obtained from crosses, number of good seeds, number of unfilled seeds, percentage of good seeds. Data collected were statistically analyzed using Statistical Package for Social Sciences (SPSS, version 15.0). Differences between means were tested using analysis of variance (ANOVA) while means separation was done using standard error of difference means at 5% probability. The results obtained showed that despite the seemingly high total number of flowers produced from the controlled crosses (14520), only 17.4% of this figure yielded good seeds. The objective of realizing 10,000 botanical seeds through the hand pollination was not achieved as a result of high flower abortion arising probably from moisture stress which was severe during seed filling. The variety Tio-joe gave the highest flower production of 2334. The relatively high number of capsules of 347obtained from the cross between UMUSPO 3 and NRSP/2 indicated high compatibility between the two parents which suggested that the two parents could be used for further recombination for micro-nutrient enhancement.