RESUMEN
Grafting typically offers a shortcut to breed tree orchards throughout a multidimensional space of traits. Despite an overwhelming spectrum of rootstock-mediated effects on scion traits observed across several species, the exact nature and mechanisms underlying the rootstock-mediated effects on scion traits in cacao (Theobroma cacao L.) plants often remain overlooked. Therefore, we aimed to explicitly quantify rootstock-mediated genetic contributions in recombinant juvenile cacao plants across target traits, specifically cadmium (Cd) uptake, and its correlation with growth and physiological traits. Content of chloroplast pigments, fluorescence of chlorophyll a, leaf gas exchange, nutrient uptake, and plant biomass were examined across ungrafted saplings and target rootstock × scion combinations in soils with contrasting levels of Cd. This panel considered a total of 320 progenies from open-pollinated half-sib families and reciprocal full-sib progenies (derived from controlled crosses between the reference genotypes IMC67 and PA121). Both family types were used as rootstocks in grafts with two commercial clones (ICS95 and CCN51) commonly grown in Colombia. A pedigree-based best linear unbiased prediction (A-BLUP) mixed model was implemented to quantify rootstock-mediated narrow-sense heritability (h 2) for target traits. A Cd effect measured on rootstocks before grafting was observed in plant biomass, nutrient uptake, and content of chloroplast pigments. After grafting, damage to the Photosystem II (PSII) was also evident in some rootstock × scion combinations. Differences in the specific combining ability for Cd uptake were mostly detected in ungrafted rootstocks, or 2 months after grafting with the clonal CCN51 scion. Moderate rootstock effects (h 2> 0.1) were detected before grafting for five growth traits, four nutrient uptake properties, and chlorophylls and carotenoids content (h 2 = 0.19, 95% CI 0.05-0.61, r = 0.7). Such rootstock effects faded (h 2< 0.1) when rootstock genotypes were examined in soils without Cd, or 4 months after grafting. These results suggest a pervasive genetic conflict between the rootstock and the scion genotypes, involving the triple rootstock × scion × soil interaction when it refers to Cd and nutrient uptake, early growth, and photosynthetic process in juvenile cacao plants. Overall, deepening on these findings will harness early breeding schemes of cacao rootstock genotypes compatible with commercial clonal scions and adapted to soils enriched with toxic levels of Cd.
RESUMEN
BACKGROUND: The burden of treatment can overwhelm people living with type 2 diabetes and lead to poor treatment fidelity and outcomes. Chronic care programs must consider and mitigate the burden of treatment while supporting patients in achieving their goals. OBJECTIVE: To explore what patients with type 2 diabetes and their health providers consider are the workload and the resources they must mobilize, i.e., their capacity, to shoulder it. METHODS: We conducted focus groups comprised of 30 patients and 32 clinicians from three community health centers in Chile implementing the Chronic Care Model to reduce cardiovascular risk in patients with type 2 diabetes. Transcripts were analyzed using thematic content analysis techniques illuminated by the Minimally Disruptive Medicine framework. FINDINGS: Gaining access to and working with their clinicians, implementing complex medication regimens, and changing lifestyles burdened patients. To deal with the distress of the diagnosis, difficulties achieving disease control, and fear of complications, patients drew capacity from their family (mostly men), social environment (mostly women), lay expertise, and spirituality. Clinicians found that administrative tasks, limited formulary, and protocol rigidity hindered their ability to modify care plans to reduce patient workload and support their capacity. CONCLUSIONS: Chronic primary care programs burden patients living with type 2 diabetes while hindering clinicians' ability to reduce treatment workloads or support patient capacity. A collaborative approach toward Minimally Disruptive Medicine may result in treatments that fit the lives and loves of patients and improve outcomes.