Effect of Low pH and Aluminum Toxicity on the Photosynthetic Characteristics of Different Fast-Growing Eucalyptus Vegetatively Propagated Clones

Abstract

Knowing how acid soils and aluminum in soils may limit the growth of Eucalyptus trees in plantations is important because these plantations grow in many tropical and subtropical regions. Seedlings of four vegetatively propagated Eucalyptus clones, E. grandis × E. urophylla ‘GLGU9’(G9), E. grandis × E. urophylla ‘GLGU12’ (G12), E. urophylla × E. camaldulensis ‘GLUC3’ (G3) and E. urophylla ‘GLU4’(G4), were subjected to liquid culture with Hoagland nutrient solution for 40 days, then treated with four different treatments of acid and aluminum for 1 day. The four treatments used either pH 3.0 or 4.0 with or without added aluminum (4.4 mM) in all possible combinations; a control used no added aluminum at pH 4.8. Subsequently, the photosynthetic parameters and morphology of leaves from eucalypt seedlings were determined and observed. The results showed that the tested chlorophyll content, net photosynthetic rate, transpiration rate and water use efficiency were apparently inhibited by aluminum. Under uniform Al concentration (4.4 mM), the Al-induced limitation to photosynthetic parameters increased with pH, indicating acid stimulation to Al toxicity. Among all treatments, the most significant reduction was found in the combination of pH 3.0 and 4.4 mM Al. The photosynthetic and transpiration rates showed similar trends with G9 > G12 > G3 > G4, suggesting that G9 and G12 had higher Al-tolerance than other two clones. Microscopic observation revealed changes in leaf morphology when exposed to Al stress; for example, a reduced thickness of leaf epidermis and palisade tissue, the descendant palisade tissue/spongy tissue ratio and leaf tissue looseness. Overall, the acid and aluminum stress exerted negative effects on the photosynthetic activity of eucalypt seedlings, but the differences in tolerance to Al toxicity between the clones were favorable, offering potential to improve Eucalyptus plantation productivity by selecting Al tolerant clones.

Nitrogen deposition and climate change effects on tree species composition and ecosystem services for a forest cohort

“…, Yang et al. ). Furthermore, this varying sensitivity of trees to increased N and acidified soil conditions can interact with co‐occurring stressor, such as pest damage, disease, fire, and tropospheric ozone, further negatively impacting the health of trees and altering forest composition (Strengbom et al.…”

PERTUMBUHAN JABON (Anthocephalus cadamba Miq.) PADA LAHAN MARGINAL BERJENIS TANAH ULTISOL DI RIAU

“…Sementara itu, kandungan Al tanah yang berlebih merupakan racun dan menjadi salah satu faktor utama yang menghambat pertumbuhan dan bahkan menyebabkan kematian tanaman (Brunner & Sperisen, 2013;Hodson, 2012). Hal ini dikarenakan Al yang berlebih dapat menghambat penyerapan unsur hara makro, pembentukan rambut akar, pembentukan klorofil, pemanjangan akar dan pertumbuhan pucuk (Moosavi & Ronaghi, 2011;Rehmus, Bigalke, Valarezo, & Mora, 2015;Yang et al, 2015;Yu, Liu, Wang, Chen, & Xu, 2011).…”

“…Upaya lainnya adalah dengan melakukan program pemuliaan pohon untuk memperoleh bibit/klon yang mempunyai toleransi tinggi di tanah masam, miskin hara dan beraluminium tinggi. Yang et al (2015) telah memperlihatkan beberapa klon Eucalyptus spp. dengan kemampuan toleransi yang tinggi terhadap pengaruh negatif Al.…”

Emergence and physiological behavior of provenances of pinhão manso in function of level of aluminum

“…During plant growth, aluminum is accumulated in the root system, thereby affecting its emergency, growth, and development, the diameter of roots is increased and the number of lateral roots is increased (MACEDO et al, 2011;GORDIN, et al, 2013). This effect could be secondary to aluminum accumulation resulting from the decreased photosynthetic activity and stomatal conductance and altered photochemical and biochemical reactions of CO 2 fixation (SOUSA et al, 2012;YANG et al, 2015).…”