Germination response of diverse wild and landrace chile peppers (Capsicum spp.) under drought stress simulated with polyethylene glycol

Abstract

Responses to drought within a single species may vary based on plant developmental stage, drought severity, and the avoidance or tolerance mechanisms employed. Early drought stress can restrict emergence and seedling growth. Thus, in areas where water availability is limited, rapid germination leading to early plant establishment may be beneficial. Alternatively, germination without sufficient water to support the seedling may lead to early senescence, so reduced germination under low moisture conditions may be adaptive at the level of the population. We studied the germination response to osmotic stress of diverse chile pepper germplasm collected in southern Mexico from varied ecozones, cultivation systems, and of named landraces. Drought stress was simulated using polyethylene glycol solutions. Overall, survival time analysis revealed delayed germination at the 20% concentration of PEG across all ecozones. The effect was most pronounced in the genotypes from hotter, drier ecozones. Additionally, accessions from wetter and cooler ecozones had the fastest rate of germination. Moreover, accessions of the landraces Costeño Rojo and Tusta germinated more slowly and incompletely if sourced from a drier ecozone than a wetter one, indicating that slower, reduced germination under drought stress may be an adaptive avoidance mechanism. Significant differences were also observed between named landraces, with more domesticated types from intensive cultivation systems nearly always germinating faster than small-fruited backyard- or wild-types, perhaps due to the fact that the smaller-fruited accessions may have undergone less selection. Thus, we conclude that there is evidence of local adaptation to both ecozone of origin and source cultivation system in germination characteristics of diverse chile peppers.

Penentuan Konsentrasi Peg Untuk Seleksi Toleransi Kekeringan Pada Fase Benih Menggunakan 3 Varietas Cabai Lokal Sumatera Barat

“…Perlakuan stress kekeringan dengan pemberian PEG 20% pada padi Lokal Lampung tidak memberikan pengaruh terhadap perkecambahan (Chrisnawati et al, 2020). Namun pemberian konsentrasi PEG 20% pada plasmanutfah cabai lokal Meksiko menyebabkan terhambatnya perkecambahan benih cabai (Bernau et al, 2020). (Millah et al, 2021)melakukan skiring 22 genotipe cabai koleksi IPB menggunakan konsentrasi PEG 15%.…”

Screening of Red Rice (Oryza sativa L.) Landraces for Drought Tolerance at Early Stages Using PEG 6000

“…Drought stresses simulated by PEG at 20% were reported to delay germination in all tested pepper (Capsicum spp.) genotypes (Bernau et al 2020). Drought stress simulated by PEG 6000 at germination stages significantly changed soluble protein content, peroxidase activity, and malondialdehyde in Larix olgensis A. Henry.…”

Environment of origin and domestication affect morphological, physiological, and agronomic response to water deficit in chile pepper (Capsicum sp.)

“…In wild and landrace chile pepper, local adaptation may also be possible, where individuals (referred to as accessions) originating from low precipitation environments may possess elevated tolerance to soil water deficit. For example, a recent germination study identified adaptive responses in chile pepper associated with precipitation [ 15 ]. Landraces from hotter, drier ecozones had significantly delayed germination, suggesting a possible adaptive response related to drought avoidance.…”