425 Amer J of Potato Res (2001) 78:425-4:31

Liberator: A Round White Chip-processing Variety with Resistance to Scab

D. S. Douches'*, K. Jastrzebski', J. Coombs', R. W. Chase', R. HanUllersctunicl V, and W. W. Kirk"

'Dq,l. nf Crup and 5011 SciencE's, Michigan Slate University, E. uU1Sing, M1481)2'1

U~jll "i BOlan}' and Plant 1'ctthology, iVlidllgan State Un.iversity, E. LanSlJ1g, MI4&lZ'1.

*Curr(!~pondiJlg author' D~vld S, Oouche~, PhoJl'" :s 17~'\'i3-3145: PAX 517-353-5174, douchesd@msl! eclu

ABSTRACT Liberator is a round wllite ch..ip-processing selection

with medium-high specific gravity and resistance to scab

(Streptomyces scabies Tllaxter). The tubers will chip

process out 0 r the field and Fro m 10 C 15 torage. Th e tu ber

appearance is si.milal" to Norcltip. Pust-harvest tuber tests

indicate a tolerance to fusariuIIl dl")' rot. Liberator was

tested in the North. Ceutral Regional Trials and the

'\'ation.al. Snack Food Association Trials. Under irrigated

conditions the yield and specific gravity are ::;imilar to

Snowden and Atlantic. Liberator has a full-season "ine

mat'.lrity that is similar to Snowden and tuber donnancy

equal to AtIa ntic.

RESUMEN Liberator es una variedad de papa de tllbcrculos

redondos y blancos para procesamiento; neue de mediana

a alta gravedad especifica y es resistente a la sarna

(Streptomyces scabies Thaxh'r). Los tuberculos pueden

ser procesaUos para chips inmediat.arnente despues de ser

cosechados 0 despues de ser almacellados a 10 C. La

aparencia de los tuberculos es similar a la varied ad

Norchip. Los tuberculos recien cosechados SOIl resistentes

a la pudrici6n por fusariuH1. Liberator fue evaluado en

experimentos de la Region Central Norte de los Estados

Unidos Yporia Asociaci6n National de Snack Food. Esta

variedad posee un alto rcndimiento y una gravedad especi­

fica si milar a Snowden y Atlantic en cultivo irrigado.

Tiene tambien lIIaduracion media t::I.rdia, similar a Snow­

den, y domlancia eQllivalente a Atlantic.

,'\cceplt"d for pu ill;, '~'li(),: \llg\IS(~. ~U() 1. ADDITIONAL I(Et WOW);;: S()IU7IVHI t"h(;)tls/u!l., p0tato. SII'f'ploTfl!lcCS

sC(Jbir:s.

BACKGROUND Lit l( 'l"atDr is a new rowld white chip-proCf',-,,,,ing potato vari­

ety (So/.(I'n:um luberoswn L) developed at Michigan State Uni­

verSIty WiUI resistance to scab (SlreplomyclJs scabies Thaxter).

LIberator was evaluatt>o <1..<; s",edling number MSA09 L-1. It is a selection from a cross made in 1988 betwl'en the moderately

scab-resislant breeding tine MS702-80 and chip-processing \"rol­

ety Norchip (Johansen et aI. IH69) for the purvose of brel.,Jin,'!

s, 'db-resistant chip-pro('~ing v;uielies. TIle name Uhlr<ltor was

chosen to acknowledge the resistance to scab in this round

white chip-processing vcuiety.

Liberator IS a round white chip-processing variety with a

medium set of brighl.-skirmed t.Ul>(TS similar in appear,ull'e to

Norchip (Figun:' I). The tubers have a low level of internal

defects. ';1\e plimary strength of this variety is its suong resis­

lance to scab combined with chip-processing quality. Another

sl n 'I' gt II of Liberator is lhat Ille tubers have a 1<.'\ d r.oler;:Ulce to

fllsarimll dry rot simjlar to Sr Iflwdell. Libemtor was tested in thr

North ('Piltral Regional Trials and lhe National Snack food

Association Trials Under inigated conditiOIlS. tIll' yield ,md src>­

cilk gravity an? similar to SnO\\'{len and At.hntk wilJl virl<? matu­

rity similar to Snowden, The pedigree of Liher<ltor is descnh('cl

in fignre 2.

The seedling generation was grown in 1988, followed by

two yew:. of selecUon and sepd muWplication 0.1', Ill", Cl<JIkS\illf'

Horticultural E>..l)eriment Statioll, Cbl'ks\ille. !vir. Sillce HJD2,

seed incn:::lse was r('located to the Lake ('icY Experimellt Sta­

(.ion, Since 199;1, Liberator has been tested in rerlicat.ed <1.::,ro­

nomic trials <1t lJH> Mont(',tlm Research Farm, Enlrican. MI. and

ill the scab nursery at the Michigan State University Soils F:llm,

East LaJlSing. i'vI r. In 19m it was enl I'red into I',Ulll trials in Mwllj·

g.Ul, Wlct then in 1999 was placed i.nto cOlllmerci;u seed produc­

Uon.

VARIETAL DESCRIPTION Plant Vine and Foliage: GnJ1vlil habit: lVkdiw'l 10 lall

height, spreading vdlll a balance between stems .mel. fohage \lS­

426 AMERlCAN JOURNAL OF POTATO RESEARCH Vol. 78

Atlantic

MS702-80 {

Wischip

Liberator (MSA091-1)

ND4731-1

Norchip {

M5009-2

FIGURE 2. Pedign:c of Liberator.

FIGURE l.

Tuber sample of Liberator from field trial at Montcalm Potato Rellearch Farol.

ible. Slerits: Anthocyanin weak, wings

are weal<. Lea'1-'es: Yellow-green (Royal

Horticulture Society [RH.S.) Color Chart

valHl:' 147A) with medium dense, short

pubescence; dosed leaf silho\l~tte: peti­

ole anthocyanin coloration is weak; leaf

stipul€'s arE' medium sized, Terminal

leaflets: Narrowly ovate witJ' acuminate

tip and obtuse base, with slight leanet

margin w<lviness. Pri.mmy lea.,flcls: Four

pairs per leaf, n,lfrowly ovate, with

acuminate tip and obtuse base, Sec­

O'ruta'lY and tertiIJry [cojlets: six pairs.

\line m.aturity: full senson.

Inflorescence: TItre€' (,0 eight with

an average of six per plant: mEW' of 12

florets per i.nfIOI-escence Corolla: Semi­

stellatl" In shape with <t white' color

(RH.S. Color Chart value 155C). Calyx:

Anthocyanin coloration absent AnIJu»~~:

Narrow cone shape with a yellow-orange color (RH.S. Color

Chart value JSA), Stigma: Capito'lt€: and greell (R.H.S. Color

Chart value 137C) Fertility: Pollen shed IS abUTlrlant and female

fertility is high. Berry set in the field is heavy.

Tubers; Shape: ROlUld. The average tllber lengtll x width x

thic!<lless is 83 nw x 70 rom x 56 nun with an average weight of

203 g. Skin: Bright and smooth with a buff color (fUI.S. Color

Chart VQ.1ue 162C). Eyes: Intermediate eye depUl, evenly distrib­

uted with an average 10 eyes/tuber; eyebrows have a slJghl

prominence. Flesh: CreMIl (R.H.S. ColoI' Chart vaJue 110). D(J?'­

maUCIj: Comparable to Atlantic.

DISEASE RESISTANCE

In Michigan thefE' is a nef'd for chip-processing vurieties

that have resistance to scab. Liberator was bred t-O cOllibinr scab

resistancE' WiUl chip-processing characteristics. Replicated liE'ld

1rials were conducted at the MSlJ Soils Farm Scab Nursery /'0

assess resistance to common and pitted scab. This ulseas(' trial

2001 DOUCH~S, d al.: LlBERATOR 427

TABLE 1-Scab (Strept.omyces scabies) disease reacl.i.on

jimn the Scab N~j rsery at/he Michigan Siale

Univf!/~';it.Y Soils Fro·Tn. Ea~t /.(msing, MI

Entry l(j!)',' 1998' 1999' 20011'

Liberator I.B !J') 1.0 O.S Atlantic :3.:3 :u :30 3;}

Snowrlen :2.;; :3.S :\.0 JO

'S('1\1I Disease Rat.ing "Scab DiseMe R.c1.ting

1: Pract.icaHy Nu Infection 0: No lnfl?dl()n 2: Low Infection 1: Low infection <SIX, 3: Avg. SlISC(·ptibility 2: Moderate Susc,'ptilHhty .J: High Susceptibility :} Int,ermecliat,,· [): SC\'ere Susceptibility 4: lIigh Susceptibility

5: Spvere ~u~r(>]Jl.iOihty

is a seVE're test for scab SUscf"ptibili(y From 1997 to 1909. tlw

varietiE's were ranked on a he;. scale based upon a combined

score for scab coverage amI lesion seve.-ity. A rating of 1.0 indi­

cates zero to a trace amOlUlt ()f inkd10n. A moderate resistance

(1.2 - 1.8) correlates ,vith <l0% lllfect.ion anri surface scab.

These two categories ar~ .,"')od IL'\els of scab tolerance. Suscep­

tible Lines h,lve > 25% infectiOn Wllh pitted lesions. Scores of 4.0

or greater arc fotUld on hnes with >50'Y0 infection and severely

pi lied lesions. In 2000. tllP SCNIC was I., \odiflecl to a 0-5 scale with

oequal to no inJection; I is a low infection (<.5%); 3 is intemw­

dia(e susceptibility; and >4 IS highly susn:ptible. Table I com­

pares Liberator to SOnle check vwieties. Based UpOIl four years

of tlials. Liberator has resistance to s<:ah that is superior to two

chip-processing varieties, Atlantic and Snowden. Some c1w('l<

cultiv<lrs OI,lt sort into the resistant c<ltegory are RUSSE't Bur­

bank, Pike, OnawD.Y and Supeliol' (data not shown).

,% pmi of Ule post-harvest evaluation. resistancf' to f'tIS(J)'­

i1m2 sum.lmcimnn (fusarium dry rot) was assessed by inoculat-

TABtE 2-Reoclion oj']Jo/alo lubel-S /0 hlsarhtm (hy 'I'Ot

(F\ISarium sambuc:i)) llm).

AV~l'ag<: Depr.h ()Il11\)~

Emry was lornJ 2000

Liberator 4H 7.8 107 AtJunlic 17 'i IGG H~

SnOwclE'1l G.G -IS 9.8

~ I ·11 lOGLSO".o:,

*'Tubers were W()UndNI, Lh01 L I] "Kulal (-''.I With a ph \g of lllyu'l ilUll.

Afler;;\ w,'eks, Uw lession (jpplh \\."" Illeasured.

ing eight to 10 whole tubers post-harvest t'ronl each line. The

tubers were held at 20 C for approximately;] wk tllld then tlK'

width dlld dq)th of the dry rot leSIOns were Illeasured. These

data for Liberator, Snowden, ,Ulrl Allaniic' are sumrnmized in

Table 2. Liberator is simIlar to SnowdE'n in elry rot. tolerancc>,

while Atlantic is more s\ Isceptibl!:' and typical of otlwr v3..1ielies.

Tolerance to dry rot is based upon inf ction depth. Ba'3ed upon

pn'\ious tests. Russl'l Norkotah 3..lld Supelior also have toler­

ancE' to fusarium dry rot (dala not sho\'.·'I).

Libemtor wa.'> also <.>vaIuated for foliar susc(>ptihlliry to late

blight (Ph:lJlophthoro Hiles/a n.s de Bary) and the tubers for

ef\-\lnia soft rot (£,-/(,"inin carotovo) respons0. Although r!:'sis­

t<mce wa." not observed, Ule infection level was not wJlike other

v<uieties. Liberator does express ['LRV <u)d mosaic symptoms. but.

it has not bt'en fonnally tes1ed for its level OfSUSCE'pljbility. Obser­

vations during field seed increasE' or during ,lgronordc trials did

not. mcLicati? allY unusual susceptibility to PVX. PVY, and PLRV.

AGRONOMIC PRODUCTION

F'iE'ld expedments were conrlucled at the Montcalm

Research F,um in Entrican, l'vIl, to llIeasure total and markE't1ble

yields, to detennille t)10er size dist.ribution, specific gravity. and

blackspot bruising, and t.o evaluate tuber appearance and inci­

dence of ext.emal and intemaJ defects. Liberator and other lines

;:lIId check varieties were plallt.!:'d in a mndomized (:ol1lple(e

block design v.ith four replications. Thc' pIOL" were 7.0 I III in

length .and spacing between plants was 30.5 cm. Inl,er-)'llw Sp,l(:­

ing was 86.4 em. Tot.al nitrogen fertilimtion e1uling [he S(\tson

was 200 kgIHa. Supplemi?ntal irrigation wa" applied as needed.

Yield was graderl into four size c1asse:,. inodence of E'xtenm] and

intemal defects in >8.:3-cm-diameter pot1toes were recordeil,

and samples fol' specific gra\ity, chip-processing, c1onmUlcy. ilJs­

ease tes~, and bluising t.ests WE're taken from :..l.08 cm to 8.3 cm

diameter pOlal'.WS.

Liberator's agronomic performance ha<; been tested for

mOre than fOlu' years at the lvlonlcalm Research ram) under irri­

gated conditions, threp years in t.be NOlth Cent.ra.! R(·gional Tli­

als, and two years in til€' N,ltional Snack Food Association 'Iiials.

~"our years of full season agronomic <lat.a at the Micrug,Ul Sktte

liniversity Montcalm Research F;llnl for LiberalDr in compari­

son to Atlantic and Snowden is summarized in Table :3. Tuber

specific gravity of Libi?rnl.Or is slightly I(mel' than Atl<Ulhc Uqf.

cOll1p'l.rable to Snowden. Under our trial conditions, the over­

si:te<l tubers of Atlanlj(' have a tendency to f')(1)I'ess hollow heart.

:"'iberator is less susceptiblt' 10 this conditIon. In t.he fom' years of

428 A:'vIERICA..l\I ,JOI-RNAL OF POTATO RESEARCH VoL 78

TABLE 3---Agnnwmic perform.ance trials at IJw M'id~igan State University MonlwJm Research FmTf[, Enf'll:can, Michiyun.

Yield (mtlha) Percent of Total' Tuber Qualitj~Specll\(; Days

Year US#I Total US#I Bs As OV PO Gravit)' HH lBS lDl-lan'esl

L,be ....<l!.or

199, 200 259 77 21 75 2 2 1.083 0 0 127 days [998 32,2 :38,9 83 9 64 18 8 1,075 0 I) 1.3:3 days [999 22,1 :30,6 72 22 72 0 6 1080 0 I 140 days 2000 454 528 80 9 til! 17 5 1.081 0 '2 III; d<lYs

Mean 299 :37,0 80 1-5 70 H 5 1.080 0

Atlall1)('

1997 23,6 28,2 84 14 71 llJ :3 1080 :3 () l27 days 1!)!)8 45.J 497 91 8 77 l:) I 1 USI S 0 1:33 days 19()(l :363 ,111:1 87 11 76 II :.1 1090 :, I l-m days

2000 4liB 5J9 87 7 59 ,)~ ~, G 1.086 8 '2 140 days

Meall :380 ,1;3.4 87 10 n 15 :] 1.087 :)

Snowden

1997 158 24,8 64 :30 6:3 I 0 IOSJ (J 0 127 d<l.vs lflflS ;J7,') 4:l8 BG 14 80 6 I 1075 '2 Il 1:3:.J (lays

19"Q '27,7 :3,~,2 79 21 74 4 I 1.080 0 il 140 days 201J1J 4J,5 40,<:> s..q II 78 11 0 1.(0) 1 0 H6 days

Mean 30,6 :37,6 80 21 ~ .. \ ,... 6 1.081 0

'Size Distribution: B: <: 5.1 c:m, A: 5.1 - 83 cm, OV: > 83cm, PO: PiCkOU1S ·Tub0r ().,wity· HH Hollow He,U1. IBS: InkrnaJ Brown Spot 111 Imber of tubers Ivith HH or IBS in .j.() oversize (>8:1 em) tuben;

tliab low 1)1 :rcemages of cull tubers were observed (2'Yu-8"Io). The TABLE 4-Yield and specific gmv-Uy of Liberator/rom {he

majolity of these tubers were misshapen, In the 1098 North Cen­l .....orlh CenlTal Regional. Potalo 7hals,

tral Regional Trials with inigation, Uberator's perfonnance was Yield (Mlha) Percent Specific similar to Snowden and Atlamic, but In 1999 the market~ble

Entry llSiil Total 1lS#1 GWVlty Maturity' yield was lower (73%) (Table 4). In bOUl years, Lhe vi ftc' II ',at wity

between varieties was si.milar. in the 1999 Snack Food Associa­u:m8 -4 Locations tion Trials, LiberalOJ' had higher yield than Snowden ,md was

l.Jber~tor <112 452 88 1086 3<1 Atlantic 39,9 46,1 89 1,091 3,;:; comparable to AUanlic Cfable 5). Uberalor was i.nduded in on­

Snowdell .11 fl 466 s..q 1.089 3.4 fann mal" in lvfJchigan lnlm 1997 to 2000. Table 6 summarizes

1999, 9 Locc'llon.s the agronomic perfomwllce of four locations. II ,.;hou lei be not ('d

Liberator 28,7 :38.8 7-3 1.086 3,7 that agronomIC perfomlanCf~ of Liberator was only observed al 114 3 ')Atlantic 379 82 1.091 inigated sites with sandy loam soil types.

Snowden :)1,1 4:35 &1 1087 '10 Chip-processing quality of Liberator was assessed 011 lubers 2000 - ,5 Locations from the North CI'J11 [,t! RI'gional Trials. Table 7A compan's lib­

!'lberator '1:.',:3 46.2 91 1.089 3.4 enItor to AUanlic and Snowden. In 1998 the chip color of Uber­0').\: lantic '1'1.2 477 1091 :3.:3

alor was equivalent to Atlantic and Snowden i.ll out-of-the-field::;nowden 4:18 480 em 1088 34 and 10 C storage samples, bul clarker t1':Ul Snowdrn from 5,7 C

*Matunly Rallllg storage (basvd on Ule aWlage of fOUf locati, ,ns) [n 1999, si III iLt r Ratings: I - 5

results were found from samples over eighl locations. In the1: Early (villes completely dead) 5: Late (vigorous vme: some !lowering) Michlg."lJl StatE' Unin'fSlty Trials and the Snack Fuuel Assoda­

2001 DO I CHES, r-I 01.: UBERATOR 429

TABLE 5-Yield (1'f/(1 ,specific ,rpmrity ofLibemJ..crrjrom Ihe . Snack Food Associat-ion Tria},,>

Yield (mtJha) Percent Spe<::ific EntIy llS#1 TOlal US#I Gr(l~ity

WOO'

Libemtor ,1:3.4 502 S8 1081 AtJilllli(' 44.7 49,\) 90 1.085 Snowden 32,8 :384 8<1 l.OS2

200(l" ----, ­

Liberator 37.1 42,5 88 1.082 Atlantic: 398 44.2 91 1.0S6 Snowden 33.4 40.6 82 1.085

'Avt>rage or Si.:x Locations: CA. FL, Me. l'1-IL pt\ and WA

'Averag<- of SlX Locations: CA. FL, ME, Ml, ,\lIN, and WA

tion Trials, chip-processing Qualify was assl)ssed on 25-tllbpf

sampl",s, taking two longitudinal slices from ""dl lubl'r. Chips

were frit'd at 185 C, and t118 color was tl1(·;lSI.lf\'d W~I h various

coIOllllletC'I':'> (j,f' A~ ron. Hunter) 01' evaluated \-1$ua II" witll Ole

Snack food A.<;sociaUon 1-5 color chart, Tuber samples were

also stored at 6.7 and 10 C for ch.ip processing out of storage in

.January ami April. In the MS\." I ri'lls tll(: chip color of Liberator

was comparable to that oj' Atlantic aHd Snowden (both out of

the field ami out or storage) except that the chip color of Snow­

den samples stored at 5.7 C was lighter (data Hot shov,m), Tabl€'

7B show~, rhe 1q!19 Snack Foo(] Association <:h ip prO(Tssmg

TABLE 6-Fir/.d (md sper:1jk gravUy of Liberator from

on-j(It"ln pmcess'ing potato triaL'>.

YIeld (nllJh<l) Percent Specific Entry US#) TolaJ liS#! Gravity

I! (!17 - f) Locations

LJbera!oJ ·13,;; W,O 87 1,084 Atlantic 44.4 492 DO 1083 Snowd"n 44.7 ,19.', !11 1.0S5

1998· .\ I..()cation~

Liberator .32,) :17 4 84 1,077 At.lantk .1\.') 47,0 S8 l.079 Snowden ·10.0 4·1.8 R9 1.07D

I mg - 4 LoCa!Wll<;

LIberator ,),'j I '410 ~S 1.080 II.l1tUltiC ~) S 44.\1 93 1.085 :';nowden :3G.O 42.'1 82 l.OSI

TABLB 7A-Chip color mlucs .frorn North Cen/:ral Regional

Trial.,.

~J MOllths Storage

OTF' OTF 57°C JO°C EnlJ:y H\U1tel~ V~sual' Hunler Hunter

1998 - 4 Locations

Llherator 59 52 oj Atlantic 59 !)I .58 Snowden 131 59 62

1999" 8 Loc;lWons

Liberawr 6:J 1.5 52 GO AllanlJC (\1 1.8 51 59 Snowden 63 1.4 57 6-3

2000" \1 L,(",;)l.\ons

Llbf:ral,or 1.4 AllilllUC 1.7 Snowden II

'OTF, Out or IIw field. 'H\mter v(l1ues pro~ided by lfSD.<\-AR5- PA Potato Research Work;lu' at &1st Grand Fork:s, MN, 'VISUal Ralmg uslIlg 1.h" Snack Food ASSO"];1l.1C'" Scale (1-5),

ffSUJ(S from out.-01~U1€'-liddsanlples. Again chip coJor scores for

Liberator were comparable to tl1e checks. Figure 3 shows a sam­

ple of Liberator chips from long-t,t>nn 9 C storage compared (,0

Dakola Pearl from the 1999 SF1\. Trial in Michlg,nl.

To E'valuat.e blackspot bruise, two 25-tuber samples wen"

collected (<I composij(' of four replications) from each line and

VanE'/)' at the Montcalm Rpsearch Faun at the I irne of grading.

TABLE 7B---Relative compwison ojchip CO{o1' 'values' from

S1Wck Food Association Trials.

Vlca(jon

Entry Flonda Millne Permsyl'-<lIUa tlUchir:'lj\ Washington

1909

Liber;ltor 58 71 58 65 52 Mlilllt.ic 55 ()8 fiG ':>:3 Snowden 61 h7 GO 6-'1 ,12

2000

Liberator flO 71 62 til I"·)AtlOlll)C 6{) 68 59

Snowd~n 59 71 of) 62

'Samples were chipped C"it of tile field,

.- -I

NvIERICAN JOURNAL OF POTATO RESEARCH Vol. 78

-S.to/HD 4-8F

CJ,ipp." (,,/4-/001'1" SFA

FIGURE 3. 1999-2000 SFA Crop 'l'rial commercial storage samples of Liberator (MSA091-1) and Dakota. Pearl. Tuber samples were stored at 48°F (9°C). Chips with interllaJ or extemal defects (dish on the right) were separated from dcfeet-free chlps (dish on tIle left).

One sample was placed in 10 C storage overnight and then ttun­ per tuber and 25o/<>4D% bruise-free tubers are typical of an inter­

bled in a hexagon plywood dru\ll 10 times to smmlate bruise­ meltiate level of bruising in our procedure, Bruising levels of

conducive cOJlditions, The other 25-tuber check sample was greater than 1.5 bruises per tuber and less than 20% bruise free

held at room temperature. After holding the samples at amhient are classified as Olore sensitive to bruising dwing handling. Each

indoor temperatures for 3 wk, the tubers were peeled in an abra­ year a sample of ttlbers that are not ttUnbled as describE'd above

sive peeler and indi",dual tubers were assessed for the nurl1b~r (check sample) are also evaluated {or blackspot brllising. The

01' blackspot bruises on each potato. These data from 1998 and incidence of blackspot bruising in the check sanlple was very

:2000 are shol-\11 in Table b. The bnlisE' data are representE'd in low for Uberator (Table 8).

two ways: percentage of bnrise-free potatoes and average num­

ber of bruises p€r tuber. Liberator h<tS blackspot susceptibility ELECTROPHORETIC PATTERNS sinlilar to Atl3Jlt.iC and SlIowden. This range of 0.0-1.2 bnrises

Leaf tissue was sampled from Liberator to con­

struct an el~ctrophoretkfingerprint. The proceduresTAULE 8-B/cu:k-spol. bruise results oj '~<\. "-size tuber samplP...s.

and alleliC' designations used are according to Douches 1998 1999 2000 and Ludlam (1991). The transcript for 10 enzynle loci is

Avg. Spot %1\,hr/'S Avg. Spot 'i;, Tubers Avg. Spot %Tubers described below: F:ntry P~r T1.rber Bruise Free r",rT'uber Brwse F'ree Per Tuber Bruise F'n:f:

Mdh-12 ]2]2]"4, Mdh-22:i2#22. 6-Pgd)h31S1:J?[J2. Check Samples' ldh-JI J2 J2 J2, Pg'i_ J2 12j2 14, GOI_1 3 13 J4j4, GOI­

Ll1)'i'rfll.or 00 96 0.4 72 0.5 60 232325 f!J, P.qm_lljl 1112 , Pgm-~22222.'j, D'ia­

Al.ianUC:: 00 96 [,3 4l 0.7 52 }1]111]2. ~n(lwden 0,0 100 0,\ 88 0,:3 69

This electrophoretic data is maintained as part of a Simul~ BntI5€" database with over 200 lines and varieUes. The elec­

LIberator l.0 :37 1.4 22 1.2 36 trophoretic fmgerprint is tmiQue to Ubcmtor. A(\antic:: 12 48 2,0 20 l.l 41 Snnwckll 09 30 l.l ;):3 1.1 24

CHEMISTRY 'Tuber s;lITlples were coU"'!:ic-d at harvest. graded, and held until evaluation. Samples were abrasive-peeled and scored. Total tuber glycoalkaJoids (TGA) w~re llleasured Tuber samples WelX' collected:it. harves~, held al 10 C at least 12 hr. and placed UI a

on tubers coUecled at harvt:.'S(. from 1997 to 2000, Thesesix-sirled plY'..'oorl drum and Ntated len ames to prOQuce ~imula1.ed bruising, Samples were abra.slv(>-p€eled <lJld scored. samples wen' sent to either Dr. Ken Deahl at the

2001 DOUCHES, c/, aL: UBERATOli 4Jl

TABl.E 9-7'o/,((l glycoalkaIJYi<l~' (mg I lOOg PWj from Jall­lwr/Jestqr{ tubers.

Entry 1998- I!.I"': 2001, Avg,

Liberator 8,7 ;17 4.6 !l7 Atlantic 9.', ..9 114 7{j

'Solid ph~jlon pairing .'xtrac:tjoll (C 18) II rLClPDA oel-l'cl)oJl 'Perki.ns - Mairt(.' 'LTSDA-ARS - l)eaJ11

USDNARStPSI Vegl:'table Laboratory or to Bnan Perkins at tJ1E'

University of Maine Food SafelY Laboratory for analysis. For

Illese TGA analyses th'" extraction and rapId higJl-perfoml<wce

liquid chromatographic detennination method was used (',1[­

man ~~ al )<)%), Tahl" 9 summarizes tllP TGA data for Liberator

along with Atlantk for 1~88--2000, III each year lhe level of TGA

W:LS well within tlwa 'cept<lble range (below 20 mg TGNIOO g

f'l'sh W1).

SEED AVAILABILITY

Virus-free tIssue ('ulnlre pl~Ultlets of LIberator were sent to

Sklarc-,:yk Seed Farm (8714 M32 East. Johimnesuurg, M1497fil~

phone: !) I 7-73 1-5452) and Kn.le~('r Seed fanll (2797 W. I-Iawkl>s

Hwy., Hawk~, M14D74:3; phone: 517-7:34-73(6), Snw I: aJl\(Hmls of

seed fOf testing can be obtained from Dave Douches at Mic'hi­

gan StatE' University (517-:155--6887, dOllchC'sd@msu.E'dll). Plant

Variet}' Protection is being applied for Liberator.

ACKNOWLEDGMENTS

Thl' oevelopmcnt. aJid lesti ng of Liberator was sUPP0r1.ed in

part by the Michi,~aJl Agncultural J:;xperiment Statlon, Michi"aJl

Potato Inclu'"-I ry CommIssion and the USDA Special Grant for

POlato l:lreectingIVariery Development. Chns l.ong, L~'III' I \uzka•

J{jm Pel"her, 3ll<'l.Jarred Driscoll provided technical support.

LITERATURE CITED (',=,,,n AS 5S, Shia, C,M, Ware, OJ. Pnl.nt'J~ ,uld G P l(il'sdwnhPUlE'1'.

1986, Rapid High-pE'rfollnance liquid chromatograp)llr rjp((>nlli­

nation oftl1\' potato glycoalkaJoids «-solaninE' and «-chaconine .J ,\~\ Foo(l Own, :34:279-282,

O()urhe:;, D.S .. and K, Lurlkun, 19DI ElectToph()rdJ(' ('har:l('l'°riwlJon of

NOrUl AmerIcan potaTO variefje~, Am POLaI.0.J (>",767-780,

.Johansl:'n, R H" J,T, Schulz, and ,J,E, Huguelet. J!)(i~). Nor('hlp' .~ 110\\'

early mntllrmg c1uppll1g vanNy ,,~lh lugh 1< ,till solids AI11 J'Qwtu J 4G;2;Y1-~:*,.