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Reduced Lignin AlfalfaDr. Dave Combs

University of Wisconsin

Reduced Lignin AlfalfaHiGestTM Alforex

HarvXtraTM Forage Genetics International

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Yield and Quality Curve of Alfalfa

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Days of Regrowth

YieldForage Quality Optimal yield and

quality

Yield and Quality Curve of Alfalfa

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Conventional Alfalfa Quality

Low-Lignin Alfalfa Quality

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Value of Reduced Lignin Alfalfa Varieties

• Wider harvest window?

• Later harvest

– Greater tonnage per cutting

– Make use of full growing season

– Reduce number of cuttings

• a 15 to 18% lignin reduction means we could harvest 8 to 10 days later

• Improved forage quality

Primary CW

Secondary CW

Vegetative Alfalfa Cell Mature Alfalfa Cell

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NDF Lignin TTNDFD DOM% of DM % of DM % of NDF % of DM

Immature 33 5.4 54 71

Vegetative 37 6.2 50 67

Mid-maturity 43 7.3 47 63

Mature 50 8.4 46 60

Composition and Digestibility of Alfalfa Changes with Maturity

Lignin

Is a polymer of aromatic alcohols

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Hemicellulose

• Is a polymer of several sugars

• Has a random, amorphous structure

with little strength.

• Is hydrolyzed by microbial

hemicellulase enzymes.

• Lignin cross-links with hemicellulose

Primary Cell Wall

Relatively thin-flexible

membrane making up the

outer layer of plant cell

Secondary Cell Wall

Thickens as plant

matures

Primary and Secondary Cell Wall

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Importance of Lignin to the Alfalfa Plant

Provides strength to plants

Allows the plant vascular system to transport water in the plant without leakage.

Sequesters atmospheric carbon into vegetation

Is one of the most slowly decomposing components of dead vegetation, contributing a major fraction of soil organic matter.

Reduced lignin alfalfa varieties

Variety Lignin Reduction

Unit reduction (assuming 7% lignin)

HiGestTM

(Alforex)7 to 10% 0.49 to 0.7

HarvXtraTM

(Forage Genetics International)

10 to 15% 0.7 to 1.05

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Fiber Digestibility of Alforex Hi-GestTM 360 Alfalfa

28 Day Cut System (5 cuts)*

Alfalfa Variety pdNDF Dyn Kd TTNDFD

Hi-Gest 360 73.3 7.2 55.1

Conventional Check* 68.2 6.6 48.2

% Difference: 7% 10% 14%

35 day Cut System (3 cuts)* Alfalfa Variety pdNDF Dyn Kd TTNDFD

Hi-Gest 360 59.1 5.9 39.3

Conventional Check 54.8 5.4 35.6

% Difference: 8% 8% 10%

Conventional check = High yield Commercial Alfalfa variety not selected for High Quality

Variety NDF NDFD RFQHarvExtra 27.3c 56.2a 284aHiGest 360 28.3bc 52.5a 265abWL355RR 29.1b 51.5a 254bc54R02 30.7a 50.7b 237c

How do HiGest and HarvExtra Compare?

Sulc et al 2016

Forage Quality measurements averaged over 6

sampling dates during each of two cuttings in

California and Pennsylvania in the 2015 seeding

year

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Nobel Foundation gene knockouts -low lignin alfalfa

G-Lignin(guaiacyl)

S-Lignin(syringal)

H-Lignin(p-hydroxyphenyl)

Alfalfa lignin is composed primarily

of G-Lignin

HarvExtra Results

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Effect of harvest delay on yield, average of 4 cuttings (HarvExtra)

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7

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28 32 35

Yiel

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/a D

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Growth cycle Days

RR

RR/RL

Undersander, 2015

No Yield Drag with HarvExtra

Effect of harvest delay on NDFD, average of 4 cuttings (HarvExtra)

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28 32 35

ND

FD, %

of

ND

F

Growth cycle Days

RR

RR/RL

Undersander, 2015

7 day delay in quality decline

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Effect of Reduced Lignin Stacked Trait on Alfalfa Composition

ItemHarvest interval

Roundup Ready

Roundup Ready + Low Lignin

P Value Forage

Harvest interval

Lignin 28d 5.1 4.5 0.01 0.01

33d 5.8 5.2

35d 5.9 5.4

Li, Li, Undersander and Combs, 2015, ADSA abstract

Effect of Reduced Lignin Stacked Trait on Alfalfa Composition

ItemHarvest Interval

Roundup Ready

Roundup Ready + Low Lignin P Value

Forage

P Value Harvest interval

CP 28d 27.3 27.6 NS 0.01

33d 24.3 25.0

35d 22.8 23.4

NDF 28d 32.1 31.4 0.05 0.01

33d 32.8 32.1

35d 34.7 32.8

Li, Li, Undersander and Combs, 2015, ADSA abstract

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Effect of Reduced Lignin Stacked Trait on Alfalfa NDF Digestion

ItemHarvest interval

Roundup Ready

Roundup Ready + Low Lignin

P Value Forage

Harvest interval

TTNDFD 28d 52.1 56.3 0.05 0.01

33d 46.3 51.9

35d 46.8 51.1

Li, Li, Undersander and Combs, 2015, ADSA abstract

Low lignin alfalfa: Wide Area Field Test Results* Proceedings 2016 California Alfalfa and Forage

Symposium, Reno NV Nov 29-Dec1, 2016

• R. Mark Sulc and Angela Parker (The Ohio State University)

• Kenneth Albrecht and Dan Undersander (University of

Wisconsin-Madison)

• Kim Cassada (Michigan State University)

• Marvin Hall (Penn State University)

• Doo-Hong Min and Xuan Xu (Kansas State University)

• Steve Orloff (UCCE Farm Advisor, Siskiyuou County, Yreka, CA)

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Low Lignin Alfalfa Study(Sulc et al., 2016)

• Six States (KS, MI, OH, PA, CA, WI)• Three RR alfalfa Varieties

– HarvExtra-008 (Transgenic Reduced Lignin Alf + Transgenic RR)

– WL 355 RR (High Quality traditional selection plus Transgenic RR)

– Pioneer 54R02 (High yield traditional selection plus Transgenic RR)

• Two Trials– Trial one: Compare quality and composition over 6 regrowth

intervals and 2 growth cycles in the establishment year (2015)– Trial two: Evaluate harvest schedule effects on yield and nutritive

value of the three varieties in establishment year (2015)

Yield and Quality Curve of Alfalfa

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20

40

60

80

100

120

5 10 15 20 25 30 35 40 44

Perc

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t o

f M

axim

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Yie

ldo

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Days of Regrowth

Yield

Conventional Alfalfa Quality

Low-Lignin Alfalfa Quality

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Sulc et al, 2016

HarvXtra yield less within cutting but greater yield for HarvExtra at 38 d than for Wl355R or 54R02 at 28 d

Sulc et al, 2016

4-5 unit difference in fiber digestibility at each stage of regrowth

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Sulc et al, 2016

10 day delay in NDF accumulation with HarvExtra

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Sulc et al, 2016

Sulc et al, 2016

10 day difference in NDF digestibility

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Sulc et al, 2016

Digestibility of low lignin alfalfa types and

controls fed to lambs

100% alfalfa hay diet fed ad

libitum

aNDF% DM

ADL% DM

NDFD% NDF

DMD% DM

COMT Inactive 38.2 5.3 57.5* 67.5*

COMT Active (Control) 39.0 5.8 49.1 64.5

CCOMT Inactive 39.4 5.2 50.1 65.3

CCOMT Active (Control) 39.4 5.9 46.4 63.7

*Significant, P < 0.05

SOURCE: Mertens et al. 2008. J. Dairy Sci. Supple. 1

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Lactating cow responses to alfalfa hays with

down- regulated lignin biosynthesis

Alfalfa hay type1 CP% DM

NDF% DM

NDFD%NDF

Milklb/day

COMT Inactive 18.1 31.1 53.5** 84.7*

COMT Active (Control) 18.4 29.3 42.5 82.1

CCOMT Inactive 18.1 42.5 48.6** 84.5

CCOMT Active (Control) 18.3 31.1 44.5 86.7

1TMR diets - 50 % alfalfa hay, 10 % corn silage, 40 % concentrate

*Significant, P < 0.10; ** significant P <0.01

(different from control)

SOURCE: Weakley et al. 2008. J. Dairy Sci. Supple. 1

Value of Reduced Lignin Alfalfa Varieties

• Improved forage quality?– HarvXtra: 7-10 day delay in NDF and NDF digestibility relative to WL366RR or

54R02 in establishment year (Sulc et al, 2016)– Alforex ??

• Wider harvest window– HarvXtra 35 day cutting interval HarvExtra had similar NDF and NDFD as 28 day

cutting interval as WL366RR or 54R02

• Later harvest– Greater tonnage per cutting with 35 day cutting interval vs 28 day cutting

interval – yield drag with HarvExtra? Within cutting yes, but 38 d cutting interval with

HarvExtra was higher than 28 day cutting interval WL355RR or 54R02

• Other considerations– $300 tech fee/bag for RR/HarvXtra vs $150 tech fee for RR only– Alforex: not RR, no tech fee