Effect of photoperiod and temperature on leaf initiation rates in wheat (Triticum spp.)
1989; Elsevier BV; Volume: 21; Issue: 2 Linguagem: Inglês
10.1016/0378-4290(89)90048-8
ISSN1872-6852
Autores Tópico(s)Genetics and Plant Breeding
ResumoData of some experiments in the literature are compared and statistically analysed to confirm the assumption of independence of wheat leaf initiation from daylength, and to evaluate the mean effect of temperature. Independence is demonstrated by the strict proportionality between the total number of initiated leaf primordia and the time to double ridges for any daylength treatment. The mean temperature response of leaf initiation rate is evaluated as the slope of a regression line between the same two variables fitted for different thermal treatments. On such a basis a linear model is constructed where daily leaf primordium initiation rates are calculated as a function of temperature. Data from a specific field experiment are then used to test the model. In the experiment, two varieties (Maris Huntsman and Creso) and two sowing dates (late November and early February) are compared. Predicted and observed dates of double-ridge appearance and the predicted number of initiated primordia match rather accurately for both sowing dates and varieties, confirming the previous hypothesis. It is concluded that most of the genotypic variability in wheat ontogenesis is accounted for by the effect of photoperiod on earliness of floral induction and, therefore, on the final main stem leaf number.
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