09 corelli
TRANSCRIPT
Leaf physiological traits and plant based indices for
detecting water stress tolerance in apple
L. Manfrini, B. Morandi, E. Pierpaoli, M. Zibordi and L. Corelli Grappadelli
P. Losciale
Good water management in orchards: Fruit-tree water status and irrigation Montpellier, June 15-16, 2015
P.E. Lauri, J.L. Regnard, E. Costes
Good water management in orchards: Fruit-tree water status and irrigationMontpellier, June 15-16, 2015
Pn & gs: direct measures but time consuming (~3 min/leaf)
Which is the best parameter to measure?
Ψ: Ψleaf, quick but not always reliable; Ψstem, reliable but time consuming
Tleaf: easy and quick to measure but not always reliable
Chl fluorescence: easy and quick to measure but not always reliable
MAA
July, 16-20, 2012, Geisenheim, Germany
Identification of a cluster of physiological parameters, potential candidates for phenotyping
Aims
Setting a water stress (WS) protocol easy to perform and to be replicated elsewhere
Good water management in orchards: Fruit-tree water status and irrigationMontpellier, June 15-16, 2015
Discrimination of WS Tolerant genotypes
The “ideal” tool should be reliable, easy and quick (less than 30 sec) to measure
17 apple genotypes, 2 of which are parentals (Granny Smith & Stark Delicious), grafted on Pajam rootstock
July, 16-20, 2012, Geisenheim, Germany Materials & Methods
Plants were moved into the greenhouse (Tmax = 28 °C and RH ~ 60%)
The experiment was started after the shoots had grown in the greenhouse for a length exceeding 80-100 cm.
Multi-year multi-site experiment
July, 16-20, 2012, Geisenheim, Germany
One plant for each genotype was irrigated at field capacity (t0) and weighed (W) at t0 and on each subsequent day (tn), during which it was allowed to loose water via evapotranspiration, till visibly detectable stress symptoms (shoot apex curling, leaf wilting, etc.) appearance (ts).
FAW= Fraction of Available Water (Wt0-Wts)/Wt0 = 10%Wt0
The Fraction of Remaining Water (FRW) on the last day before visible symptoms appeared (tr) was considered as the threshold at which the pots should be maintained to be sure that they were under stress conditions (WS), although not visible yet.
FRW= 1- (Wt0-Wtr)/(Wt0-Wts) = 37% WA
1. Setting a water stress (WS) protocol
Materials & Methods
July, 16-20, 2012, Geisenheim, Germany
1. Setting a water stress (WS) protocol
Timet0 t1 t2 … tn … tr ts
Pot +
pla
nt W
eigh
t
Wt0 Wtr Wts
Materials & Methods
After 2 weeks under water stress
1.Leaf net photosynthesis (Pn)2.Leaf stomatal conductance (gs)3.Tleaf-Tair (DT)4.JPSII
5.Ψs6.Ψl
2. Identification of a cluster of physiological parameters, candidate for phenotyping protocol
Materials & Methods
Results & DiscussionPn
(µm
ol m
-2s-1
)1. Setting a water stress (WS) protocol
2011
7 23 26 35 37 38 40 41 48 54 57 70 96 97 106111117121125 gs stk
02468
10121416
ws
7 23 26 35 37 38 40 41 48 54 57 70 96 106
111
117
121
125
GS
STK
0
2
4
6
8
10
12
14
ws
Results & DiscussionPn
(µm
ol m
-2s-1
)1. Setting a water stress (WS) protocol
2012
Good water management in orchards: Fruit-tree water status and irrigationMontpellier, June 15-16, 2015
6 variables
Results & DiscussionMVA
(PCA on ratio WS/WW)
2. Physiological parameters for phenotyping
Background on the IPL index
Pn = f
• -e exiting from PSII• CO2 concentration at the
carboxylative sites
• Carboxylative activity of RuBisCo
Good water management in orchards: Fruit-tree water status and irrigationMontpellier, June 15-16, 2015
Background on the IPL index• -e exiting from PSII
• CO2 concentration at the carboxylative sites
• Carboxylative activity of RuBisCo
JPSII (Chl F)• gs
• gm
ΔT
• KO
• KC
Tl
Good water management in orchards: Fruit-tree water status and irrigationMontpellier, June 15-16, 2015
Multiple regression analysis…
Good water management in orchards: Fruit-tree water status and irrigationMontpellier, June 15-16, 2015
Results & Discussion2. Physiological parameters for phenotyping
Good water management in orchards: Fruit-tree water status and irrigationMontpellier, June 15-16, 2015
6 variables (~3 min per leaf)
Results & DiscussionMVA
(PCA on ratio WS/WW)
2. Physiological parameters for phenotyping
3 variables (~30 s per leaf)
K-means Clustering using F1,F2 or IPL
Good water management in orchards: Fruit-tree water status and irrigation
Results & Discussion
WS tolerance GenotypeSusceptible 7, 23
Intermediate 26, 37, 70, 125Tolerant 41, 54, STK
2011-2012 BO-MTP
53% genotype in the same category
Good water management in orchards: Fruit-tree water status and irrigationMontpellier, June 15-16, 2015
Conclusions• IPL seems to be an useful tool for
detecting plant performance and water status
• Problems relating to the replicability of WS protocol occurred when
different years/ “type” of plant were compared
However …
Good water management in orchards: Fruit-tree water status and irrigationMontpellier, June 15-16, 2015
Conclusions• Reliable and quick to measure variables
can help us at improving the WS protocolLooking at the pattern instead of a single point
Thanks for your attention
Good water management in orchards: Fruit-tree water status and irrigationMontpellier, June 15-16, 2015
Good water management in orchards: Fruit-tree water status and irrigationMontpellier, June 15-16, 2015
Results & Discussion2. Physiological parameters for phenotyping
VIII International Symposium on Irrigation of Horticultural cropsLleida, 8-11 June 2015
Results & DiscussionAbbé Fétel Pear