Effective Metabolic Carbon Utilization and Shoot-to-Root Partitioning Modulate Distinctive Yield in High Yielding Cassava Variety

Abstract

Increasing cassava production could mitigate one of the global food insecurity challenges by providing a sustainable food source. To improve the yield potential, physiological strategies (i.e., the photosynthetic efficiency, source-to-sink carbon partitioning, and intracellular carbon metabolism) can be applied in breeding to screen for superior genotypes. However, the influences of source-to-sink carbon partitioning and carbon metabolism on the storage root development of cassava are relatively little understood. We hypothesized that carbon partitioning and utilization vary modulating the distinctive storage root yields of high and low-yielding cassava varieties, represented in this study by varieties Kasetsart 50 (KU50) and Hanatee (HN), respectively. Plant growth, photosynthesis measurements, soluble sugars, and starch contents of individual tissues were analyzed at different developmental stages. Also, the diurnal patterns of starch accumulation and degradation in leaves were investigated through iodine staining. Despite a comparable photosynthetic rate, KU50 grew better and yielded greater storage roots than HN. Interestingly, both varieties differed in their carbon partitioning strategies. KU50 had a high photosynthetic capacity and was better efficient in converting photoassimilates to carbon substrates and allocating them to sink organs for their growth. In contrast, HN utilized the photoassimilates at a high metabolic cost, in terms of respiration, and inefficiently allocated carbon to stems rather than storage roots. These results highlighted that carbon assimilation and allocation are genetic potential characteristics of individual varieties, which in effect determine plant growth and storage root yield of cassava. The knowledge gained from this study sheds light on potential strategies for developing new high-yielding genotypes in cassava breeding programs.

The link between changing in host carbon allocation and resistance to Magnaporthe oryzae : a possible tactic for mitigating the rice blast fungus

“… 73–75 Additionally, rice varieties that naturally display effective carbon allocation strategies linked to strong resistance against rice blasts can be identified and promoted through selective breeding programs. 75 The goal of this approach is to lessen the need for outside interventions by developing crops with better carbon allocation on innate resistance traits. Efficient management of carbon allocation can also be achieved through the application of precision agriculture techniques 76–78 that maximize carbon inputs according to disease risk assessments.…”

Cluster-based photography and modeling integrated method for an efficient measurement of cassava leaf area

“…Each plot was grown with separate species and age. The distance between the plants and the row was 0.8 m × 1 m. In the greenhouse, leaves of KU50 and HN were harvested at 2 MAP at Forschungszentrum Ju ¨lich, Germany [31]. In total, 1,899 fully-expanded leaves were collected from 15 plants grown in the field and greenhouse (Table 1).…”

Symplasmic phloem loading and subcellular transport in storage roots are key factors for carbon allocation in cassava

“…However, it is not clear how assimilates are partitioned between leaves, stems, and storage roots, and how this is partitioning is regulated throughout storage root development. However, this process is critical because ineffective carbon flux to storage roots negatively affects yield (Ruiz-Vera et al, 2020, Chiewchankaset et al, 2022). Similarly, the mechanism by which assimilates enter the phloem system in the first place remain unclear to date.…”