Comparison of pepper accessions acting as rootstocks: A case with low P inputs

Abstract

[EN] Fertilization is essential for maintaining production in agriculture. Yet, in too high quantity it causes high impact in environment and in farmers economy. This is especially true in the case of phosphorus (P) fertilization. Finding genotypes adapted to low P conditions may help to reduce the problem. P efficiency depends to some extend on the ability of the roots to acquire this mineral, therefore using efficient rootstocks would provide a higher acquisition of P, maintaining the good characteristics of the scion varieties. In this study, twenty diverse pepper accessions ( Capsicum annuum L.) have been evaluated as possible rootstocks to increase P acquisition and yield in pepper under no P fertilization. Plant production, biomass, P content and physiological phosphorous use efficiency were evaluated for 'Lobo' variety grafted onto different rootstocks. In addition, root traits, measured manually (shovelomics) and semi-automatically (Winrhizo) were studied. The results showed a great diversity in the root traits for the studied accessions. These root traits changed significantly when the accessions act as rootstock, indicating great rootstock/scion interactions. In general, all the rootstocks adapted their root size and shape to that displayed by 'Lobo' root system. Some accessions seemed to have some incompatibility whereas some others enhanced the scion performance. It was possible to identify some genotypes suitable to act as rootstocks for pepper with good performance under low P conditions. Root length, root weight, branching, and root angle were identified as key root traits for plant growth and P acquisition under low P conditions.