Agronomic and hormonal approaches for enhancing flowering intensity in white Guinea yam (Dioscorea rotundata Poir.)

Abstract

Developing novel white Guinea yam (Dioscorea rotundata) varieties is constrained by the sparse, erratic, and irregular flowering behavior of most genotypes. We tested the effectiveness of nine agronomic and hormonal treatments to enhance flowering on D. rotundata under field conditions. Genotypes responded differently to flower-inducing treatments (p<0.001). Of the test treatments, pruning and silver thiosulfate (STS) were effective in increasing the number of spikes per plant and the flowering intensity on both sparse flowering and monoecious cultivars. STS and tuber removal treatments promoted female flowers on the monoecious variety while pruning and most treatments involving pruning favored male flowers. None of the treatments induced flowering on Danacha, a non-flowering yam landrace. Flower-enhancing treatments had no significant effect on flower fertility translated by the fruit set, since most treatments recorded fruit sets above the species’ average crossability rate. Flower-enhancing techniques significantly influenced number of tubers per plant (p = 0.024) and tuber dry matter content (DMC, p = 0.0018) but did not significantly affect plant tuber yield. Nevertheless, treatments that could enhance substantially flowering intensity, such as pruning and STS, reduced tuber yield. DMC had negative associations with all flowering-related traits. This study provided insights into white yam flower induction and suggests promising treatments that can be optimized and used routinely to increase flowering in yam crop, without significantly affecting flower fertility and tuber yield.

Development of Methods for Improving Flowering and Seed Set of Diverse Germplasm in Cassava Breeding

“…Indeed, in the present investigation, the percentage of female flowers increased from about 6-23% in STS-only treatments to over 89% in treatments that included BA (Table 1). Furthermore, recent studies on Guinea yam showed that pruning and STS were effective in increasing the number of spikes per plant and the flowering intensity on both sparse flowering and monoecious cultivars [34]. Hence, for breeding programs where the goal is the production of large numbers of seed progeny from desired parents, there is considerable potential benefit from the enhancement of female flower production using the combination of treatments described here.…”

Farming practices, varietal preferences, and land suitability analyses for yam production in Eastern D.R. Congo: implications for breeding initiatives and food sovereignty

“…In such a holistic approach, breeding should be the backbone since low attractiveness of yam, as compared to other crops, is attributed to lack of varieties with farmer-preferred traits (Adejumobi et al, 2022b). Fortunately, more than 50% of yam cultivars grown in eastern DRC flowered, and thus, it opens an avenue for cross-breeding to generate variable offspring for selection (Mondo et al, 2023). Some of the traits lacking in yam in DRC are mainly yield-related traits, earliness, disease and pest resistance, and tuber quality attributes (long post-harvest shelf life, low tuber flesh oxidation, sweet taste, tuber softness, short cooking time, high tuber dry matter, ease of peeling, reduced bitterness, tuber size and shape) of local landraces (Adejumobi et al, 2022b(Adejumobi et al, , 2023.…”