The analysis of reciprocal transfer experiments to estimate the durations of the photoperiod-sensitive and photoperiod-insensitive phases of plant development: An example in soya bean

Abstract

Plants of the quantitative short-day crop soya bean [Glycine max (L) Merrill] cv Davis were grown in a plastic house in a diumally alternating temperature regime (30/20 °C) and transferred from a long- (16-18 h d-1) to a short-day regime (12 h d_1) and vice versa at various times after sowing Photopenod influenced the period from sowing to flowering, for example, a delay of about 50 d between the long- and short-day controls A model was developed so as to enable the complete data set to be analysed simultaneously in order to estimate the durations of the photopenod-msensitive pre-inductive phase (a,), the photopenod-sensitive inductive phase in the short- (/s) and long- day (/J regimes, and the photopenod-msensitive post-inductive phase (a,) of plant development The model was fitted using the ITNONLINEAR directive of GENSTAT V and it described the observations well (adjusted R1 = 0-913), the fitted values were al = 17 7 d (s e 0-57), /8 = 6 5 d (s e 0-99), /L = 55 4 d (s e 2 81), and u3 = 19 5 d (s e 0-93) The analytical procedure developed is applicable to reciprocal transfer experiments in other flowering plant species The estimate of a, for cv Davis is substantially greater than a previously published estimate for this cultivar, and leads us to question the widespread assumption that all soya bean cultivars respond to photopenod soon after emergence. © 1992 Annals of Botany Company.