caa a22 4500 39752109X CHVBK 20180308164633.0 cr unu---uuuuu 161202e199506 xx s 000 0 eng 10.1093/jxb/46.6.711 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.6.711 Fluctuating temperatures have different effects on embryonic sensitivity to ABA in Sorghum varieties with contrasting pre-harvest sprouting susceptibility [Elektronische Daten] [R.L. Benech-Arnold, Graciela Kristof, HaydÈe S. Steinbach, R.A. Sanchez] The effect of fluctuating temperatures on the germination of immature caryopses of two Sorghum varieties presenting contrasting susceptibility to pre-harvest sprouting was investigated. Fluctuating temperatures were able to stimulate germination of immature caryopses of both varieties from early stages of development (i.e. 15 d after pollination). Isolated embryos from both varieties germinated well in water irrespective of the thermal regime of incubation. However, the ability of ABA to block germination in Redland B2 (sproutingsusceptible) isolated embryos was significantly reduced when embryos were incubated under fluctuating temperatures from 23 DAP onwards. No such effect was found in IS 9530 (sprouting-resistant) embryos. No differences in the pattern with which embryonic ABA content decreased during whole grain incubation were found in 25 and 35 DAP grains from both varieties incubated under constant or fluctuating temperatures. Therefore, these results indicate that alternating temperatures can promote germination through different mechanisms. One of them is the decrease in embryo sensitivity to ABA inhibition which appears to be acting in Redland B2 caryopses from 23 DAP onwards; the other one seems to be independent of ABA level and sensitivity and is active at very early stages of development in one variety (Redland B2) and throughout seed development in the other (IS 9530). © Oxford University Press Research Papers nationallicence Germination nationallicence dormancy nationallicence fluctuating temperatures nationallicence abscisic acid nationallicence seed development nationallicence Sorghum bicolor nationallicence Benech-Arnold R.L. Cátedra de Cerealicultura, Facultad de Agronomia, Universidad de Buenos Aires Avenida San Martin 4453, 1417 Buenos Aires, Argentina aut Kristof Graciela Cátedra de Cerealicultura, Facultad de Agronomia, Universidad de Buenos Aires Avenida San Martin 4453, 1417 Buenos Aires, Argentina aut S. Steinbach HaydÈe Cátedra de Cerealicultura, Facultad de Agronomia, Universidad de Buenos Aires Avenida San Martin 4453, 1417 Buenos Aires, Argentina aut Sanchez R.A. Cátedra de Fisiologla Vegetal, Facultad de Agronomia, Universidad de Buenos Aires Avenida San Martin 4453, 1417 Buenos Aires, Argentina aut Journal of Experimental Botany Oxford University Press 46/6(1995-06), 711-717 0022-0957 46:6<711 1995 46 exbotj https://doi.org/10.1093/jxb/46.6.711 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.6.711 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Benech-Arnold R.L. Cátedra de Cerealicultura, Facultad de Agronomia, Universidad de Buenos Aires Avenida San Martin 4453, 1417 Buenos Aires, Argentina aut NATIONALLICENCE 700 1- Kristof Graciela Cátedra de Cerealicultura, Facultad de Agronomia, Universidad de Buenos Aires Avenida San Martin 4453, 1417 Buenos Aires, Argentina aut NATIONALLICENCE 700 1- S. Steinbach HaydÈe Cátedra de Cerealicultura, Facultad de Agronomia, Universidad de Buenos Aires Avenida San Martin 4453, 1417 Buenos Aires, Argentina aut NATIONALLICENCE 700 1- Sanchez R.A. Cátedra de Fisiologla Vegetal, Facultad de Agronomia, Universidad de Buenos Aires Avenida San Martin 4453, 1417 Buenos Aires, Argentina aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/6(1995-06), 711-717 0022-0957 46:6<711 1995 46 exbotj Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford