Root Growth & Function The Origin of All that is Green · ROOT GROWTH & FUNCTION--The Origin of All...
Transcript of Root Growth & Function The Origin of All that is Green · ROOT GROWTH & FUNCTION--The Origin of All...
ROOT GROWTH & FUNCTIONROOT GROWTH & FUNCTION----The Origin of All that is GreenThe Origin of All that is Green----
Carolyn ScagelCarolyn ScagelUSDAUSDA--ARSARS--Horticultural Crops Research LabHorticultural Crops Research Lab
NURSERY RESEARCH PRIORITIESNURSERY RESEARCH PRIORITIES
• Propagation– Cuttings– Tissue Culture– Labor– Turnover
• Nutrition– Uptake– Efficiency– Timing
• Rhizosphere Organisms
• Pathogen/Pests
• Media– Formulations– Amendments
• Containers– Size,Configuration– Labor
• Hardiness
• Weed Control
ROOT PHYSIOLOGY RESEARCHROOT PHYSIOLOGY RESEARCH
• Nutrition– Uptake– Efficiency– Timing
• Propagation– Cuttings– Tissue Culture
• RhizosphereOrganisms
Plant Nutrition&
Growth
MycorrhizalFungi
Root Growth&
Function
Physiological aspects of root development, & Physiological aspects of root development, & function influencing crop productivity and quality.function influencing crop productivity and quality.
CROP FOCUSCROP FOCUS• Woody Perennials
– Largest portion of PNW nursery crops.– Underlying mechanisms for understanding woody plant
metabolism requires long-term research.
• Ericaceae– Cross over between nursery and small fruit production.– Special nutritional requirements.
• Geophyte Floral Crops– Grown for cut flower and vegetative production in PNW.– Optimal requirements of production dependant on
patterns of nutrient and carbon partitioning.
RESEARCH GOAL #1RESEARCH GOAL #1
-Reduce inputs-Reduce nutrient runoff-Increase nutrient use efficiency-Increase water use efficiency
Help develop cost effective and environmentally sustainable production practices
Nutrient ManagementNutrient Management• Importance:
– Optimal rates, timing of application, and formulations used are not well established.
– Links between nutritional status and stock quality are poorly defined.
RESEARCH GOAL #2RESEARCH GOAL #2Improve production efficiency and end product quality
-Decrease labor-Reduce time to market-Improve quality
Regulation of Root GrowthRegulation of Root Growth• Importance:
– Root formation is the rate limiting step in production of cuttings and tissue culture plants
– Amount, type, and form of roots correlated with stock quality and plant survival after transplanting
Mycorrhizal FungiMycorrhizal Fungi• Importance:
– Optimal uses of fungi duringcommercial nursery production
– Commercialization withoutapplication criteria inhorticultural systems.
– Variable understandingof expected results.
NUTRIENT MANAGEMENTNUTRIENT MANAGEMENT• Program Scope:
– Environment/culture– Formulations– Application methods– Timing– Plant type– Mycorrhizal Fungi
• Assessments:– Plant, soil, and water
nutrient analyses– 15N-compounds– Plant growth– Storage reserves– Transplant quality
NUTRIENT MANAGMENTNUTRIENT MANAGMENT–– Timing of Fertilizer Applications Timing of Fertilizer Applications ––
Highest uptake efficiency occurs when fertilizer availability isHighest uptake efficiency occurs when fertilizer availability issynchronized with plant uptakesynchronized with plant uptake
(With Oregon State and Mississippi State University)(With Oregon State and Mississippi State University) Bi et al. 2006
Date05/31 06/14 06/28 07/12 07/26 08/09 08/23 09/06
N U
ptak
e R
ate
(mg
d-1)
-2
0
2
4
6
8
Rhododendron 'PJM H-1'Rhododendron 'Cannon's Double'
A. Total Plant N Uptake Rate
Date05/31 06/14 06/28 07/12 07/26 08/09 08/23 09/06
N U
ptak
e Ef
ficie
ncy
(% F
ertil
izer
App
lied)0
10
20
30
40
Rhododendron 'PJM H-1'Rhododendron 'Cannon's Double'
B. N Uptake Efficiency
NUTRIENT MANAGMENT NUTRIENT MANAGMENT –– Timing of Fertilizer Applications Timing of Fertilizer Applications ––
Uptake can occur in the autumn.Uptake can occur in the autumn.Root and leaf losses decrease uptake efficiencyRoot and leaf losses decrease uptake efficiency
(With Oregon State and Mississippi State University)(With Oregon State and Mississippi State University) Bi et al. 2006
Time (Month)May Jun Jul Aug Sep Oct Nov Dec Jan Feb
N U
ptak
e R
ate
(mg
d-1)
-2
0
2
4
6
8
10
Rhododendron 'P.J.M. Compact'Rhododendron 'English Roseum'Rhododendron 'Gibraltar'
A. Total Plant Uptake Rate
Time (Month)
Jun Jul Aug Sep Oct Nov Dec Jan Feb
N U
ptak
e Ef
ficie
ncy
from
Fer
tiliz
er (%
)
0
10
20
30
40
50
60
70
Rhododendron 'P.J.M. Compact'Rhododendron 'English Roseum'Rhododendron 'Gibraltar'
B. Uptake Efficiency from Fertilizer
NUTRIENT MANAGMENT NUTRIENT MANAGMENT –– Fertilizer Application Methods Fertilizer Application Methods ––
Foliar Urea improved growth and efficiency of fertilizer useFoliar Urea improved growth and efficiency of fertilizer use
(With Oregon State and Mississippi State University)(With Oregon State and Mississippi State University) Bi et al. 2006
Autumn Foliar TreatmentNo Urea 3% Urea
Tota
l Pla
nt N
itrog
en C
onte
nt (m
g)
0
100
200
300
400
500 Rhododendron 'P.J.M. H-1'Rhododendron 'Cannon's Double'
aa
b
b
Autumn Foliar TreatmentNo Urea 3% Urea
Tota
l Pla
nt B
iom
ass
(g)
0
20
40
60
80No Spring NSpring N
Winter 2004
a
b
cc
Spring 2005
NUTRIENT MANAGMENT NUTRIENT MANAGMENT –– Fertilizer Application Methods Fertilizer Application Methods ––
Foliar urea improved growth and flowering.Foliar urea improved growth and flowering.Foliar urea decreased dependence on N in spring. Foliar urea decreased dependence on N in spring.
(Mississippi State University)(Mississippi State University)
No Urea in Autumn Foliar Urea Autumn
Bi 2006
No Spring N No Spring N Spring NSpring N
Hydrangea
NUTRIENT MANAGMENT NUTRIENT MANAGMENT –– Integrated Nutrient Management Integrated Nutrient Management ––
Using foliar urea with defoliant improves performanceUsing foliar urea with defoliant improves performance
(With Oregon State and Mississippi State University)(With Oregon State and Mississippi State University)
Defoliant in Autumn Urea & Defoliant in Autumn
Bi et al. 2005
P K SN CA MG
Relative Aboveground Weight (Peat=100)
0 200 400 600 800 1000 1200
Rel
ativ
e N
utrie
nt C
once
ntra
tion
(Pea
t=10
0)
0
50
100
150
200
250
300
350
400
'Freckles''Olympic Fire''Pink Charm'
Kalmia latifolia
NUTRIENT MANAGMENT NUTRIENT MANAGMENT –– Media Composition Media Composition ––
Kalmia latifolia
Bark/PerlitePeat
Bark/PerliteCoir
Bark/PerlitePeat/Coir
Coir can be use to improve Coir can be use to improve growth and enhance uptake of N, growth and enhance uptake of N,
P, and KP, and K
Scagel 2003
I
II
III
Enhanced Uptake
Non-limiting
NUTRIENT MANAGEMENTNUTRIENT MANAGEMENT–– Mycorrhizal Fungi & Fertilizer Type Mycorrhizal Fungi & Fertilizer Type ––
Mycorrhizae decreased conductivity of Mycorrhizae decreased conductivity of leachateleachate
Time After Planting (days)10 20 30 40 50 60 70 80 90
Con
duct
ivity
(mS)
0
100
200
300
400
500
600None, Inorganic FertilizerMYC, Inorganic FertilizerNone, Organic FertilizerMYC, Organic Fertilizer
Scagel 2006
Vaccinium ovatum
REGULATION OF ROOT GROWTHREGULATION OF ROOT GROWTH• Program Scope:
– N & C metabolism• Storage reserves• Stock plant nutrition
– Hormones• IAA• Ethylene• Polyamines
– Mycorrhizal Fungi• AMF• Ericoid• Ecto• Arbutoid
• Assessments:– Hormone analysis– Nutrition & composition– Rooting/survival– Gene regulation
REGULATION OF ROOT GROWTH REGULATION OF ROOT GROWTH –– Plant Composition Plant Composition ––
Optimal levels of stem N for rootingOptimal levels of stem N for rootingScagel 2001
Stem Nitrogen (mg/g)
0 20 40 60 80 100 120 140
Roo
ting
(% o
f cut
tings
with
root
s)
0
20
40
60
80
100
120
Pink CharmOlympic FireFreckles
Kalmia latifolia
REGULATION OF ROOT GROWTH REGULATION OF ROOT GROWTH –– Plant Composition Plant Composition ––
Form of N (protein) may be equally important to rootingForm of N (protein) may be equally important to rootingScagel 2001
Stem Protein (μg/g)
0 100 200 300
Roo
ting
(% o
f cut
tings
with
root
s)
0
20
40
60
80
100
120
Pink CharmOlympic FireFreckles
Kalmia latifolia
10 20 30 40 50 60 70 80 90 100
REGULATION OF ROOT GROWTH REGULATION OF ROOT GROWTH –– Plant Composition Plant Composition ––
Optimal rooting as a function of N form and N levelOptimal rooting as a function of N form and N level
Kalmia latifolia
Nitrogen (m
g/g)Protein(ug/g)
Rooting (
%)
Scagel 2001
REGULATION OF ROOT GROWTHREGULATION OF ROOT GROWTH–– Media Composition Media Composition ––
Media composition effects on N content can alter rootingMedia composition effects on N content can alter rootingScagel 2002
Cultivar
Pink Charm Olympic Fire Freckles
Nitr
ogen
Con
cent
ratio
n (m
g g-1
)
0
20
40
60
80
100
120Peat Peat/Coir Coir
Kalmia latifolia
~80 ~95
~70
REGULATION OF ROOT GROWTHREGULATION OF ROOT GROWTH–– Media Composition Media Composition ––
Media composition effects on protein content can alter rootingMedia composition effects on protein content can alter rootingScagel 2002
Cultivar
Pink Charm Olympic Fire Freckles
Prot
ein
Con
cent
ratio
n ( μ
g g-1
)
0
100
200
300
400Peat Peat/Coir Coir
Kalmia latifolia
~230
~300
~150
REGULATION OF ROOT GROWTH REGULATION OF ROOT GROWTH –– Mycorrhizal Fungi in Propagation Mycorrhizal Fungi in Propagation ––
Increased adventitious roots on cutting using mycorrhizal fungiIncreased adventitious roots on cutting using mycorrhizal fungi
Non-Inoculated Inoculated
Arctostaphylos uva-ursi
Linderman & Call 1977
REGULATION OF ROOT GROWTHREGULATION OF ROOT GROWTH––Mycorrhizal Fungi in Propagation Mycorrhizal Fungi in Propagation ––
Adding fungi to the rooting medium can achieve a rooting responsAdding fungi to the rooting medium can achieve a rooting responseethat is equal to or better than the response obtained by using rthat is equal to or better than the response obtained by using rootingooting
hormones alone.hormones alone.Scagel 2004
Percent Rooting (% of cuttings)
20 40 60 80 100 120
Roo
t Len
gth
(cm
)
0
100
200
300
400
500
No Hormone, No Mycorrhizal FungiHormone (IBA)Oidiodendron griseum (OG)IBA+OGHymenosphyus ericae (HE)IBA+HE
Leucothoe 'Rainbow'
REGULATION OF ROOT GROWTHREGULATION OF ROOT GROWTH–– Mycorrhizal Fungi in Propagation Mycorrhizal Fungi in Propagation ––
AMF induced changes in rooting may involve differentAMF induced changes in rooting may involve differentregulatory mechanisms than those involved primarily with auxin regulatory mechanisms than those involved primarily with auxin
responseresponseScagel 2004
Time After Sticking (Days)
0 2 4 6 8 10 12 14 16
Stem
Pro
tein
( μg
g-1)
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
No IBA, No AMFHormone (IBA)Mycorrhizal Fungi (AMF)IBA+AMF
Miniature Rose 'Scarlet Cupido'
GC-MSHPLC
Hormonal signals during root induction by mycorrhizal fungiHormonal signals during root induction by mycorrhizal fungi(With University of Helsinki)(With University of Helsinki)
REGULATION OF ROOT GROWTHREGULATION OF ROOT GROWTH–– Mycorrhizal Fungi & Stock Quality Mycorrhizal Fungi & Stock Quality ––
From Scagel, 1999Improved root growth after transplantingImproved root growth after transplanting
Scagel 2001
Time After Planting
Spring Year 1 Autumn Year 1 Autumn Year 2
Roo
t Gro
wth
(g)
0
50
100
150
200
250
Control IBAMycorrhizal FungiHormone & Mycorrhizal Fungi
Pseudotsuga menzesii
REGULATION OF ROOT GROWTHREGULATION OF ROOT GROWTH–– Mycorrhizal Fungi & Stock Quality Mycorrhizal Fungi & Stock Quality ––
From Scagel, 1999Improved survival after transplantingImproved survival after transplanting
Scagel 2001
Time After Planting
Spring Year 1 Autumn Year 1 Autumn Year 2
Surv
ival
(%)
0
20
40
60
80
100
120
Control IBAMycorrhizal FungiHormone & Mycorrhizal Fungi
Pseudotsuga menzesii
MYCORRHIZAL FUNGIMYCORRHIZAL FUNGI• Program Scope:
– Fertilizer use– Hormones and rooting– N & C metabolism
• Assessments– Surveys & inoculation
trials– Plant & soil analyses– Growth/partitioning– Colonization– Bulb & Flower
Production
MYCORRHIZAL FUNGI MYCORRHIZAL FUNGI –– Responsiveness to Inoculation Responsiveness to Inoculation ––
Selection during breeding can decrease responsiveness to Selection during breeding can decrease responsiveness to mycorrhizaemycorrhizae
BC (>3gen) EB (>2gen) PA (>2gen) GG (>1gen)
Bio
mas
s (g
)
0
20
40
60
80
100
Non-Inoculated Inoculated
Scagel 2005
Vaccinium spp.
MYCORRHIZAL FUNGI MYCORRHIZAL FUNGI –– Who’s On Your Roots Who’s On Your Roots ––
Using a combination of techniques to Using a combination of techniques to identify and evaluate function of identify and evaluate function of
ericoid mycorrhizal fungi in different ericoid mycorrhizal fungi in different production systemsproduction systems
(With University of Melbourne and Wisconsin)(With University of Melbourne and Wisconsin)
MYCORRHIZAL FUNGIMYCORRHIZAL FUNGI–– AMF & Production Time AMF & Production Time ––
Inoculation decreases time of stem emergenceInoculation decreases time of stem emergence
No Soil Treatment Soil Pasteurization
Stem
Em
erge
nce
Afte
r Pla
ntin
g (d
ays)
0
20
40
60
80
Non-Inoculated Inoculated
Scagel 2004
MYCORRHIZAL FUNGI MYCORRHIZAL FUNGI –– AMF & Production Time AMF & Production Time ––
Inoculation decreases time of flower emergenceInoculation decreases time of flower emergence
No Soil Treatment Soil Pasteurization
Flow
er E
mer
genc
e Af
ter P
lant
ing
(day
s)
0
20
40
60
80
100
120
Non-Inoculated Inoculated
Scagel 2003
MYCORRHIZAL FUNGI MYCORRHIZAL FUNGI –– AMF & Quality AMF & Quality ––
Inoculation increases flower productionInoculation increases flower production
Date6/5 6/19 7/3 7/17 7/31 8/14 8/28
Num
ber o
f Flo
wer
s (#
)
0
5
10
15
20
25
30None, Non-sterile soilAMF, Non-sterile soilNone, Sterile soilAMF, Sterile soil
Scagel 2004
COOPERATORSCOOPERATORS• Oregon State
– Les Fuchigami– Rich Regan
• Agriculture Canada– Shufu Dong
• Mississippi State University– Guihong Bi
• Cornell University– Lailang Cheng
• Ohio State– Hannah Mathers
• University of Wisconsin– Kevin Kosola
• University of Helsinki– Karoliina Niemi
• University of Melbourne– Cas McLean
• Meadow Lake Nursery• Fisher Farms• Fall Creek Farm & Nursery• Monrovia• Briggs Nursery• Brush Prairie Bogs• Winsmuir Farm• ZCallas
Symptoms of poor root health occur above ground before you realize roots are in trouble
and mimic symptoms of other problems.