Shortening the generation cycle in faba bean (Vicia faba) by application of cytokinin and cold stress to assist speed breeding

Abstract

The aim of this study was to reduce the length of the breeding cycle for faba bean by accelerating seed setting. We examined the mode and time of exogenous 6-benzylaminopurine (BAP) (cytokinin) application, and cold treatments and their combinations in two faba bean genotypes. Acropetal node number of pod and seed set and pollen viability were recorded during the experiments. Application of BAP improved pollen germination. The application of 10-5 M BAP 4 days after flowering increased seed set at the lower nodes. Cold treatment (8/4°C day/night for 2 days) after the onset of flowering induced the formation of more pods and faster pod set compared to the non-cold treatment. The time to first seed was significantly reduced, and pollen viability was increased in plants exposed to cold treatment. Increased pollen viability also showed a significant positive correlation with seed setting. The combinations of 10-5 BAP and cold treatment together had similar and independent effects. These results will accelerate plant breeding in faba bean by providing additional tools for reducing generation time.

Historical review of faba bean improvement in western Canada

“…Both conventional and molecular breeding tools are needed to accelerate the development and release of improved drought-adapted faba bean cultivars with relatively high and stable yield. Recently, we have developed a speed breeding protocol for faba bean (Mobini et al, 2020) as a tool for developing diverse germplasm and improved varieties in a shorter time span.…”

Integrating speed breeding with artificial intelligence for developing climate-smart crops

“…Conversely, the speed breeding suit can also revamp the accuracy and efficiency of genome editing technology by rapidly accelerating the generation cycle after the successful transfer of Cas9 construct in plants [ 79 ]. Integration of speed breeding with classical breeding approaches has been tested and confirmed in various crop plants like chickpea, pea, lentils, faba bean, and pigeon pea [ 67 , 68 , 70 , 80 , 81 ]. These researchers, in their study, used a speed breeding facility to reduce the generation cycle of plants by growing them under extended (20–22 h) photoperiod and adequate temperature conditions.…”

Opportunities and challenges of speed breeding: A review

“…(2.3 μM), promoted in vitro flowering at 100% and seed set (90%) in faba bean (Mobini et al, 2015). Additionally, increased seed set was achieved by exogenous application of 6-benzylaminopurine (10 -5 M BAP) four days after flowering in faba bean (Mobini et al, 2020). (MS) culture medium supplemented with 0.175 mg/L indole-3-acetic acid (IAA) and 0 mg/L 6-benzylaminopurine (BAP) was found to be suitable for embryo culture of lentil (Bermejo et al, 2016).…”

“…For instance, combining auxin and cytokinin hormones, in the form of flurprimidol (0.3 μM), indole‐3‐acetic acid (5.7 μM) and zeatin (2.3 μM), promoted in vitro flowering at 100% and seed set (90%) in faba bean (Mobini et al., 2015). Additionally, increased seed set was achieved by exogenous application of 6‐benzylaminopurine (10 –5 M BAP) four days after flowering in faba bean (Mobini et al., 2020). Subsequently, Mobini and Warkentin (2016) used a combination of flurprimidol (0.9 μM) and 4‐chloroindole‐3‐acetic acid (0.05 μM), resulting in 90 and 80% flowering and seed set in lentils.…”