Morphophysiological response of Indonesian red pepper varieties (Capsicum annuum) under drought stress

¹ Department of Biology, Institut Teknologi Sepuluh Nopember, 60111 Surabaya, East Java, Indonesia
² Department of Medical Laboratory Technology, Politeknik Kesehatan Kementerian Kesehatan, 80244 Denpasar, Bali, Indonesia
³ Department of Urology, Kumamoto University, 860-8555 Kumamoto, Japan

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Red chili (Capsicum annuum) is a globally important horticultural crop valued for bioactive compounds including capsaicin, flavonoids, and antioxidants. Drought stress is a major abiotic factor limiting chili productivity, yet the morphophysiological responses of different varieties under water deficit are not well understood. This study evaluated four chili varieties Ciko, Lembang 1, Tanjung 2, and Lingga exposed to 14 days of drought stress, while control plants were irrigated daily. Plant height and root length were measured to assess morphological responses, and relative water content, total chlorophyll, and carotenoid levels were determined using spectrophotometry to assess physiological responses. Drought stress significantly reduced plant height, relative water content, and total chlorophyll in all varieties, with Lingga showing the greatest reductions and Ciko the least. In contrast, root length slightly increased, reflecting an adaptive strategy for improved water acquisition. Carotenoid content remained relatively stable, indicating a protective role against oxidative stress. These findings reveal varietal differences in drought tolerance and highlight key morphophysiological traits that confer resilience. Understanding these responses provides a foundation for breeding and selecting drought-tolerant chili cultivars to sustain productivity under climate variability.