Photosynthetic characteristics of upland cotton (Gossypium hirsutum) recessive genic male sterile line YA-1 with virescent trait

N. YANG, X.X. LIU, X.P. ZHANG, H.Q. DENG, X.L. SHEN, C.M. TANG

Photosynthetica 2025, 63(3):234-245 | DOI: 10.32615/ps.2025.018  

The upland cotton strain YA-1 can be used for hybrid seed production and recurrent selection. However, the effect of YA-1 virescent phenotype on photosynthetic traits remains unclear. This study demonstrated that the chlorophyll and carotenoid contents, light-saturation point, light-compensation point, and PSⅡ reaction center activities are lower than those of green leaves of wide type. In contrast, light-energy utilization efficiencies, net photosynthetic rate, transpiration rate, stomatal conductance, concentrations of Rubisco and phosphoenolpyruvate carboxylase, photosynthetic performance indices, and energy distribution parameters of the...

Leaf gas exchange and photosynthetic light-response curves of cassava genotypes under drought stress during the early growth stage and after recovery

K. VONGCHAROEN, S. SANTANOO, P. ITTIPONG, P. BANTERNG, N. VORASOOT, S. JOGLOY, P. THEERAKULPISUT

Photosynthetica 2025, 63(3):246-261 | DOI: 10.32615/ps.2025.021  

This study aimed to gain insights into the photosynthesis capacity and genotypic differences in response to drought imposed at an early growth stage of cassava. Leaf water potential (LWP), leaf gas exchange, and photosynthetic light-response curves were investigated in six field-grown cassava genotypes under full irrigation and drought imposed for 60 d during 3-5 months after planting. During the drought period, mean LWP at predawn (LWP_pre) was significantly lower than that in the control plants, while the mean midday LWP (LWP_mid) was similar. During the drought period, the mean stomatal conductance was reduced from 0.36 to...

Variations in the photoprotective responses of trees and seedlings of the endangered Pitavia punctata (Ruiz & Pav.) Molina

S. ESPINOZA, D. MUÑOZ-CONCHA

Photosynthetica 2025, 63(3):262-266 | DOI: 10.32615/ps.2025.023  

Pitavia punctata (Ruiz & Pav.) Molina ('Pitao') is an endangered species that regenerates under the shade. We monitored the photochemical efficiency of photosystem II in four localities spanning the geographical distribution of the species in Central Chile. Technical fluorescence parameters and JIP-test-derived parameters were measured in trees (up to 15 m) and seedlings (< 50 cm). We observed significant effects of the type of plant and locality on the performance index (PI_ABS) and maximum fluorescence (F_M). PI_ABS was higher in trees from the Los Barros locality (PI_ABS = 41), whereas seedlings located...

In honor of Reto Jörg Strasser: A pioneer of chlorophyll a fluorescence research

A. STIRBET, G. GOVINDJEE, A. SRIVASTAVA

Photosynthetica 2025, 63(3):267-281 | DOI: 10.32615/ps.2025.024  

Chlorophyll (Chl) a fluorescence measurements are widely used in the study of photosynthesis, and Reto Strasser is a well-known pioneer in this domain. In 2019, the current authors, together with Vineet Soni, and Neera Bhalla Sarin, celebrated his 75^th birthday. Here, we pay tribute to him on his 82^nd birthday through a brief description of the key results we had obtained with him, over the years, on the understanding and exploitation of the OJIP Chl a fluorescence transient. The topics of these studies have been quite diverse, from the oxygen clock, the bicarbonate effect in Photosystem II, the adaptability of...

A thank you note for Julian Eaton-Rye, the wonderful staff at Photosynthetica, and all the scientists who participated in the 2018 special issue

G. GOVINDJEE

Photosynthetica 2025, 63(3):282-287 | DOI: 10.32615/ps.2025.025  

Cadmium and high light stress interactions highlight limits of PSII in Arabidopsis thaliana

R. SINGH

Photosynthetica 2025, 63(3):288-290 | DOI: 10.32615/ps.2025.027  

Role of nitrogen utilization in facilitating photosynthetic compensation of soybean under vertically heterogeneous light

X.R. MA, X.M. SONG, E.Z. ZHANG, J.B. DU, X. SUN

Photosynthetica 2025, 63(3):291-295 | DOI: 10.32615/ps.2025.026  

Photosynthetic compensation enables high-density planted crops to use the available light efficiently. However, the underlying mechanism remains unclear. Herein, soybeans (Glycine max L. Merr.) were treated with vertically heterogeneous light (HL) to simulate the light conditions in high-density planting. The net photosynthetic rate (P_N) increased in upper unshaded leaves (UL) while it decreased in lower shaded leaves (LL) under HL. This evident photosynthetic compensation was accompanied by a preferential distribution of N to UL. Correspondingly, the amounts of chlorophyll (Chl) and Rubisco increased in UL. At the...

Avoiding leakage when classifying drought stress from OJIP fluorescence - comment on Xia et al. (2025)

E.P. PASTORE

Photosynthetica 2025, 63(3):296 | DOI: 10.32615/ps.2025.031  

Evaluating physiological traits of Coffea canephora clones intercropped with Hevea brasiliensis

I.D.P. PEREIRA, S. DOUSSEAU-ARANTES, J.A. MACHADO FILHO, L.O. ARANTES, M.M. MENDES, V.F. SANTOS, G.A.R. DE SOUZA, B. CERRI NETO, D. CASSOL, A.R. FALQUETO

Photosynthetica 2025, 63(3):297-308 | DOI: 10.32615/ps.2025.028  

In this study, we evaluated the physiological response of the photosynthetic apparatus [using chlorophyll a fluorescence (ChlaF) measurements], changes in leaf nutrient contents, and productivity of 16 Coffea canephora clones grown alone (NC, full sunlight) or intercropped with Hevea brasiliensis (IC, shaded). Shade from H. brasiliensis trees influenced the physiological performance of coffee plants. Some of these coffee clones achieved clear responses to shading by rubber trees, indicating that the responses of coffee plants to intercropping are genotype-specific. The PSII complex of the NC plants was more susceptible...