Drought tolerance responses of rampai (Solanum pimpinellifolium) accessions from Lampung, Indonesia under different water availability levels

Drought is a major constraint to tomato production under climate change. Identifying accessions that can maintain growth, yield stability, and fruit quality under limited water is therefore essential. Solanum pimpinellifolium (rampai) has potential adaptive traits to abiotic stress, but its response to drought is still poorly understood. This study evaluated drought tolerance of local S. pimpinellifolium accessions from Lampung using agronomic traits and drought tolerance indices. This experiment used a factorial randomized complete block design with 12 accessions (one commercial and eleven local) and two levels of water availability (well-watered and drought). Drought conditions significantly decreased plant height, leaf number, fruit cluster number, fruit number, and fruit weight. In contrast, the leaf greenness index and total soluble solids increased under drought stress. Growth and yield responses varied among accessions. Accessions DT11, DM20, DM28, and DR19 showed performance comparable to the commercial accession, with above-average Drought Resistance Index values and a Yield Index greater than 1. Accessions DM20, DM28, and DR19 adapted to drought by increasing net assimilation rate, while DT11 and DR19 showed adaptation through a higher root-to-shoot ratio. These findings confirm that combining agronomic performance with drought tolerance indices is effective for identifying S. pimpinellifolium accessions suitable for drought-prone environments.