Net photosynthetic rate evaluated in Argentinian cotton accessions (Gossypium hirsutum L.)

DILEO, PABLO N.; MUCHUT, ROBERTINO; SCARPIN, GONZALO J; CEREIJO, ANTONELA E.; WINKLER HORACIO M.; ROESCHLIN, ROXANA A.; LORENZINI, FERNANDO; SARTOR, G. J.; RODRÍGUEZ, GUSTAVO RUBÉN; PAYTAS, MARCELO J.

Congreso; Reunión Argentina de Fisiología vegetal; 2021

Measuring and understanding physiological parameterson crops is important to find genotypes with high performance and target futuredirections for crop breeding. The aims of this study were to estimate the net photosyntheticrate (PN) in accessions from the INTA cotton germplasm bank (BGSP),and to compare the PN in leaves from different positions in theplant and phenological stages. Eight accessions were sown in pots in arandomized complete blocks design, with four replications, under greenhouseconditions. PN was measured at 56, 71 and 84 days after sowing (DAS)under light intensity ranged from 900 to 1500 μmol photons.m−2.s−1.Statistical analysis was performed using a linear mixed-effect model with theaccessions, DAS and leaf positions as fixed effect and blocks and individualsas random effect. The highestaverage PN was obtained at 56 DAS (26.5), whereas the lowestaverage PN were obtained at 71 and 84 DAS (20.7 and 14.9,respectively). PN showed similar decreasing patterns in allthe studied accessions. Also,the PN decreased from the top to the lower leaves in the three DASevaluated. Additionally, we found significant interaction between DASand accessions. BGSP‑00269 showed the highest PN at 56 DAS, but one of thelowest PN at84 DAS. In contrast, BGSP‑00159 obtained the lowest value at 56 DAS andthe highest value at 84 DAS. The differential behavior on PNamong the accessions and phenological stages evaluated could allow us toestablish physiological to genotypic associations as a tool for selection inbreeding programs.