Priming of pioneer tree Guazuma ulmifolia (Malvaceae) seeds evaluated by an automated computer image analysis

Abstract

Direct seeding is one of the most promising methods in restoration ecology, but low field seedling emergence from pioneer tree seeds still reduces its large scale applicability. The aim of this research was to evaluate seed priming for the pioneer tree species Guazuma ulmifolia. Priming treatments were selected based on seed hydration curves in water and in PEG 8000 solution. Seeds were primed in water for 16 h and in Polyethylene glycol -PEG 8000 (-0.8 MPa for 56 and 88 h) at 20°C to reach approximately 30% water content. Half of the seed sample of each treatment was dried back to the initial moisture content (7.2%); both dried and non-dried primed seeds as well as the unprimed seeds (control) were tested for germination (percentage and rate) and vigor (electrical conductivity of seed leachates). Seedling emergence percentage and rate were evaluated under greenhouse conditions, while seedling length and uniformity of seedling development were estimated using the automated image analysis software SVIS®. Primed seeds showed the highest physiological potential, which was mainly demonstrated by image analysis. Fresh or dried primed seeds in water for 16 h and in PEG (-0.8 MPa) for 56 h, and fresh primed seeds in PEG for 88 h, improved G. ulmifolia germination performance. It is suggested that these treatments were promising to enhance efficiency of stand establishment of this species by direct seeding in restoration ecology programs. Key words: SVIS®, forest seeds, seed vigor, restoration ecology, direct seeding Condicionamento fisiológico de sementes da árvore pioneira Guazuma ulmifolia (Malvaceae) avaliado por análise computadorizada de imagens RESUMO: A semeadura direta é um dos métodos mais promissores para a restauração ecológica, mas a baixa emergência de plântulas em campo a partir de sementes de árvores pioneiras ainda limita sua aplicabilidade em larga escala. Avaliou-se a resposta de sementes da espécie florestal pioneira Guazuma ulmifolia ao condicionamento fisiológico. Os tratamentos foram selecionados com base em curvas de hidratação em água e em solução osmótica de Polietilenoglicol -PEG 8000. As sementes foram condicionadas em água por 16 h e em PEG 8000 (-0,8 MPa por 56 e 88 h) a 20°C, atingindo teor de água de, aproximadamente, 30%. Metade das amostras de cada tratamento foi secada até atingir teor de água próximo ao inicial (7,2%); em seguida, avaliou-se o desempenho das sementes condicionadas submetidas ao não à secagem, além de sementes não condicionadas (testemunha), quanto à germinação (porcentagem e velocidade) e o vigor (condutividade elétrica dos exudatos das sementes). A porcentagem e a velocidade de emergência de plântulas foram avaliadas em condições de casa de vegetação, enquanto que o comprimento de plântulas e a uniformidade de desenvolvimento das plântulas foram estimados usando o software de análise computadorizada de imagens de plântulas SVIS®. As sementes condicionadas fisiologicamente apresentaram potencial fisiológico superior, demonstrado principalmente pelos resulta...

Análise de imagens de plântulas para avaliação do potencial fisiológico de sementes de berinjela

“…The parameters obtained by the computerized seedling analysis with SVIS ® software (seedling length and vigor and growth index) are efficient to differ between lots of high and low vigor eggplant seeds as traditional vigor methods. 2009) e Guazuma ulmifolia (Brancalion et al, 2010 …”

Computerized imaging analysis of seedlings for assessment of physiological potential of wheat seeds

“…The use of software SVIS ® has contributed for the assessment of physiological potential of seeds of cucumber (Chiquito et al, 2012), rattle pods (Crotalaria spp.) (Silva et al, 2012), castor bean (Kobori et al, 2010), soybean (MarcosFilho et al, 2009) and corn (Otoni and McDonald, 2005) and for assessment of physiological conditioning of sweet corn seeds (Gomes Junior et al, 2009) and mutamba (Brancalion et al, 2010). Such system may be a supplementary tool for interpretation others tests as accelerated aging, germination in low temperature, germination speed and growth of seedling, or even in identifying effects of chemical treatments and physiological conditioning; besides other situations in which monitoring of germination and growth of seedlings, at regular intervals, is of interest (Marcos-Filho et al, 2009).…”

Effects of hydropriming treatments on the invigoration of aged Dodonaea viscosa seeds and water‐holding polymer on the improvement of seedling growth in a lava field

“…Only a few studies have been conducted in trees from other ecosystems, including Callitris spp. (Adams ), Wigandia urens (González‐Zertuche et al ), Cecropia schreberiana (Sánchez et al ), Mimosa bimucronata , Guazuma ulmifolia (Brancalion et al , , respectively), Parkia multijuga (Calvi et al ), Albizia julibrissin (Sedghi et al ), Quercus rugosa (Castro‐Colina et al ), Aegle marmelos (Venudevan & Srimathi ), and Gmelina arborea (Moruf et al ), among others.…”