Cardinales temperatures phenotyping

Cardinales temperatures

phenotyping

A. Audebert

2

_{Global Rice Phenotyping Network Worshop}

Interest

Related with climat change

• High / Low temperature adaptation • Phyllochron / Plastochron knowledge • Growth and development model

Principle

• Leaf elongation measurement on L6 – Leaf growth curve

• Logistic Fonction

– LER determination

• Slope at inflexion point

• Cardinal temperature determination – LER = f(température)

• Beta fonction (Topt, Tbase, Tmax)

Temperature (°C) 0 10 20 30 40 Leaf Elonga tion Rat e (cm /h) 0,0 0,2 0,4 0,6 0,8 1,0                          T Topt T Topt T Topt T T Topt T T T R Y max min min min max max max Top Tmax Tb 0 10 20 30 40 50 60 0 100 200 300 400 500 Temps (heures) E lo n g a ti o n ( c m )

Série4 Série5 Série6 Série7 Actives Prédictions Modèle

ATP 341 : IRAT 112 à 23°C Y1 = 53.753 / (1 + Exp ( 2.193 -2.613E-02*X1))

REP 4 REP 3 REP 2 REP 1

Modélisation T0 estimé                          T Topt T Topt T Topt T T Topt T T T R LER max min min min max max max

Experiment

• Years 2010 and 2011 • Orytage funds

• Japonica panels (200 varieties)

• 2 replications in time (2010 and 2011) • 1 growth chamber and 1 phytotron

– Photoperiod 12/12; Humidity 70%

• 6 temperatures tested (16, 20, 23, 26, 30 et 35°C) • Traits

Methode

T (°C) LERma x (r el .) β-function => To, Tb Topt (°C) 26 28 30 32 34 36 F re q u e n c y ( % ) 0 5 10 15 20 25 30 SD = 1.53 To = 27…36 °C

Cardinal temperatures

of rice under

controlled conditions

(japonica panel, 200 acc.)

Tbase (°C) 8 10 12 14 16 F re q u e n c y ( % ) 0 5 10 15 20 25 30 SD = 1.309 Tb = 8.5…16 °C Linear function => Tb

Mean [Tbase; Topt] (°C) 18 19 20 21 22 23 24 25 26 Freq u e n cy (%) 0 5 10 15 20 25 30 SD = 0.73 Topt - Tbase (°C) 12 14 16 18 20 22 24 26 F re q u e n c y ( % ) 0 5 10 15 20 25 30 SD = 1.92

Different temperature windows of japonica

rice varieties

•Some varieties are specific for a narrow range of temperatures (low, or high)

•Some varieties are capable to grow in a large range of temperatures (better plasticity ?) Narrow range Wide range Low

Conclusions

• The method is well adapted to determine the cardinal temperatures

– But

• Tedious and fastidious

– To improve it

• Need more points at extreme temperatures (but difficult) • More facilities (growth chambers) and observers

• Good diversity observed for the three cardinal temperatures among

japonica rice varieties

• Association study will be done further with SNPs

• indicas and temperate japonicas phenotyping