Plant biometric characterization and leaf micromorphometry of Talinum triangulare (Jacq.) Willd cultivated under shade

• Published in: Revista Ceres 2018-02, Vol.65 (1), p.44-55
• Main Authors: Alexandre, Ellen Carla Francisca, Pereira, Leandro Spíndola, Andrade, Jose Weselli de Sá, Vasconcelos Filho, Sebastião Carvalho, Jakelaitis, Adriano
• Format: Article
• Language: English
• Subjects: AGRICULTURE, MULTIDISCIPLINARY; anatomy; growth; luminosity; plasticity
• ISSN: 0034-737X; 2177-3491; 2177-3491
• DOI: 10.1590/0034-737x201865010007

ABSTRACT Talinum triangulare (Jacq.) Willd, known as Ceylon spinach, Surinam purslane, or waterleaf, is cultivated for medicinal and food purposes. Among environmental factors, light is an important regulator of primary production, contributing to plant growth. However, the success of each plant species depends on its morphoanatomical responses to light. The aim of this study was to determine whether T. triangulare leaf micromorphometry is affected when grown in full sun and under shade, and if so, which plant biometric variables are affected. T. triangulare cultivation was tested in beds arranged in blocks under shade levels of 0, 18, 30, and 50%. Each bed was considered a basic experimental unit, totaling four replications per treatment. Plant height, stem diameter, leaf area, leaf fresh weight, stem fresh weight, specific leaf area, leaf area ratio, abaxial epidermis, and mesophyll thickness were higher as shade levels increased. However, there was a decrease in the number of leaves, root to shoot ratio, stomatal density on abaxial and adaxial surfaces, and palisade parenchyma thickness. Nevertheless, root length, leaf and stem dry weights, leaf weight ratio, adaxial stomatal index, adaxial epidermis, and spongy parenchyma thickness remained constant. Plants responded differently to shade, with morphological and anatomical changes, suggesting a phenotypic plasticity and raising the possibility of being grown both in shaded environments and in full sunlight. RESUMO Talinum triangulare (Jacq.) Willd, conhecida como espinafre do Ceilão, beldroega graúda e folha d’agua é cultivada com fins medicinais e alimentares. Entre os fatores ambientais, a luz é um importante regulador da produção primária, contribuindo para o crescimento das plantas. No entanto, o sucesso de cada espécie de planta depende das respostas morfoanatômicas à luz. O objetivo deste estudo foi determinar se a micromorfometria da folha de T. triangulare e qual das variáveis biométricas da planta são afetadas quando cultivada em pleno sol e sob sombreamento. O cultivo de T. triangulare foi testado em canteiros dispostos em blocos com níveis de sombreamento de 0, 18, 30 e 50%. Cada canteiro foi considerado uma unidade experimental básica, totalizando quatro repetições por tratamento. A altura da planta, o diâmetro do caule, a área foliar, a massa fresca da folha, a massa fresca do caule, a área foliar específica, a razão de área foliar, a espessura da epiderme abaxial e do mesofilo foram maiore