Interrelation of Ecophysiological and Morpho-Agronomic Parameters in Low Altitude Evaluation of Selected Ecotypes of Sweet Potato (Ipomoea batatas [L.] Lam.)

Esteban Burbano-Erazo,Laura Espitia,Jazmín Pérez,Alfredo Morales,Iván Pastrana,Carina Cordero,Amparo Rosero,Evelin Gomez,Leonardo López

doi:10.3390/horticulturae6040099

Esteban Burbano-Erazo, Laura Espitia + Show 7 more

Open Access

https://doi.org/10.3390/horticulturae6040099

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Abstract

Sweet potato is a crop with a wide capacity to adapt to adverse conditions. To study the tolerance of the sweet potato to a low-altitude environment, 34 genotypes comprising three groups from different altitude conditions ranging from 18–599, 924–1298, 1401–2555 meters above sea level were evaluated. These genotypes were evaluated through ecophysiological parameters: net photosintetic rate (Pn), stomatal conductance (GS), transpiration (E), leaf internal CO2 (ICO2), vapor pressure deficit (VPD) and leaf internal temperate (LT). sSubsequently, water use efficiency (WUE) and carboxylation efficiency index (CEI) were estimated. Simultaneously, morpho-agronomic characterization of the genotypes was conducted including descriptors and morpho-colorimetric parameters. A wide ecophysiological variability was found among genotypes from high, intermediate and low altitudes, when those were evaluated under low altitude conditions. The genotypes that presented major soil coverage efficiency and leaf size showed greater Pn, WUE and CEI, and Low VPD and E, aspects that benefited the ability to form roots the under low-altitude environment. The altitudinal origin of the genotypes influenced the ecophysiological response under low altitude conditions. The capacity of certain sweet potato genotypes to tolerate low altitude conditions were due to to different mechanisms, such as certain morphoagronomic traits that allowed them to adjust their physiological processes, especially those related to photosynthesis.

Highlights

Sweet potato (Ipomoea batatas (L.) Lam.) is a crop that generates edible energy in the form of storage roots with high nutritional content, mainly from carbohydrates [1]
Sweet potato ecotypes collected from several altitude conditions showed a wide response in the tolerance to low altitude conditions
Characteristics of high photosynthetic rate (Pn), carboxylation efficiency index (CEI) and low vapor pressure deficit (VPD) were decisive in the tolerance of ecotypes to low altitude conditions

Summary

Introduction

Sweet potato (Ipomoea batatas (L.) Lam.) is a crop that generates edible energy in the form of storage roots with high nutritional content, mainly from carbohydrates [1]. Unlike other crops, where the development of the aerial part is important for productivity, in sweet potato, the determining morpho-physiological processes are mainly in the formation and development of storage roots that depend directly the carbohydrates translocation from the leaves to the roots [2,3,4], in some countries the aerial part is consumed [5]. As a C3 plant, has the advantage of responding positively to an increase of CO2 concentration in the environment, mainly due to its direct effect on photosynthesis and stomata physiology, generating in response a higher yield of storage roots [10]; this behavior is modulated by the availability of water.

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