Mapping and In og ession o QTL In ol ed in F ui
Shape T ansg essi e Seg ega ion in o ‘Piel de Sapo’
Melon (
Cucucumis melo
L.)
Au o a Dı
´az
1
*, Belkacem Za ou i
2
, Mohamed Fe gany
3¤
, Iban Edua do
3
, Jose
´M. A
´l a ez
4
, Bele
´n Pico
´
5
,
An onio J. Mon o e
1
*
1Ins i u o de Biologı
´a Molecula y Celula de Plan as (IBMCP). Uni e sidad Poli e
´cnica de Valencia (UPV)-Consejo Supe io de In es igaciones Cien ı
´ icas (CSIC), Valencia,
Spain, 2Labo a o io de Biologı
´a Molecula . Dp o. In es igacio
´n Ag oalimen a ia. Ins i u o Mad ilen
˜o de In es igacio
´n y Desa ollo Ru al, Ag a io y Alimen a io (IMIDRA),
Alcala
´de Hena es, Mad id, Spain, 3Cen e de Rece ca en Ag igeno
`mica (CRAG), IRTA-CSIC-UAB, Bella e a, Ce danyola del Valle
`s, Ba celona, Spain, 4Cen o de
In es igacio
´n y Tecnologı
´a Ag oalimen a ia de A ago
´n (CITA), Za agoza, Spain, 5COMAV-UPV, Ins i u e o he Conse a ion and B eeding o Ag icul u al Biodi e si y,
Uni e si ad Poli e
´cnica de Valencia, Valencia, Spain
Abs ac
A mapping F
2
popula ion om he c oss ‘Piel de Sapo’ 6PI124112 was selec i ely geno yped o s udy he gene ic con ol o
mo phological ui ai s by QTL (Quan i a i e T ai Loci) analysis. Ten QTL we e iden i ied, i e o FL (F ui Leng h), wo o
FD (F ui Diame e ) and h ee o FS (F ui Shape). A leas one obus QTL pe cha ac e was ound, lqs8.1 (LOD = 16.85,
R
2
= 34%), dqs12.1 (LOD = 3.47, R
2
= 11%) and sqs8.1 (LOD = 14.85, R
2
= 41%). lqs2.1 and sqs2.1 coseg ega e wi h gene a
(and omonoecious), esponsible o lowe sex de e mina ion and wi h pleio opic e ec s on FS. They display a posi i e
addi i e e ec (a) alue, so he PI124112 allele causes an inc ease in FL and FS, p oducing mo e elonga ed ui s. Con e sely,
he nega i e a alue o lqs8.1 and sqs8.1 indica es a dec ease in FL and FS, wha esul s in ounde ui s, e en i PI124112
p oduces e y elonga ed melons. This is explained by a signi ican epis a ic in e ac ion be ween sqs2.1 and sqs8.1, whe e
he e ec s o he alleles a locus aa e a enua ed by he addi i e PI124112 allele a sqs8.1. Roundes ui s a e p oduced by
homozygous o PI124112 a sqs8.1 ha do no ca y any dominan A allele a locus a(PiPiaa). A signi ican in e ac ion
be ween sqs8.1 and sqs12.1 was also de ec ed, wi h he alleles a sqs12.1 p oducing mo e elonga ed ui s. sqs8.1 seems
o be allelic o QTL disco e ed in o he popula ions whe e he exo ic alleles p oduce elonga ed ui s. This model has been
alida ed in assays wi h backc oss lines along 3 yea s and ul ima ely ob aining a sqs8.1-NIL (Nea Isogenic Line) in ‘Piel de
Sapo’ backg ound which yields ound melons.
Ci a ion: Dı
´az A, Za ou i B, Fe gany M, Edua do I, A
´l a ez JM, e al. (2014) Mapping and In og ession o QTL In ol ed in F ui Shape T ansg essi e Seg ega ion
in o ‘Piel de Sapo’ Melon (Cucucumis melo L.). PLoS ONE 9(8): e104188. doi:10.1371/jou nal.pone.0104188
Edi o : Rongling Wu, Pennsyl ania S a e Uni e si y, Uni ed S a es o Ame ica
Recei ed Feb ua y 4, 2014; Accep ed July 10, 2014; Published Augus 15, 2014
Copy igh : ß2014 Dı
´az e al. This is an open-access a icle dis ibu ed unde he e ms o he C ea i e Commons A ibu ion License, which pe mi s un es ic ed
use, dis ibu ion, and ep oduc ion in any medium, p o ided he o iginal au ho and sou ce a e c edi ed.
Funding: This wo k was suppo ed by g an s AGL2009-12698-C02-02 and AGL2012-40130-C02-02 om he Spanish Minis y o Economy and Compe i i eness o
AJM. AD was suppo ed by a JAE-Doc con ac om CSIC, MF by a Pos doc o al con ac om GRAG, IE by a ellowship om he o me Spanish Minis y o
Educa ion and BZ by a ellowship om Ins i u o Ag ono
´mico Medi e a
´neo de Za agoza (IAMZ), Spain. The unde s had no ole in s udy design, da a collec ion
and analysis, decision o publish, o p epa a ion o he manusc ip .
Compe ing In e es s: The au ho s ha e decla ed ha no compe ing in e es s exis .
* Email: [email p o ec ed]s (AD); amon o [email p o ec ed] (AJM)
¤ Cu en add ess: Ag onomy Depa men . Facul y o Ag icul u e Ain Shams Uni e si y, Cai o, Egyp
In oduc ion
Melon (Cucumis melo L., 2n = 2x = 24) is one o he mos
impo an ho icul u al c ops, anking in he nin h posi ion o he
wo ld p oduc ion o ege ables, wi h mo e han 27 million ons in
2012 [1]. In he las wo decades, melon p oduc ion has
expe ienced a 29% ise, wha has been accompanied by an
inc ease o 8% in he a ea ha es ed. I does no seem easible o
achie e he same gain in p oduc ion in he nex decades by
inc easing he land dedica ed o i s cul i a ion, so he e o s o
plan b eede s should be di ec ed o imp o e ai s ha ing a g ea
po en ial o inc ease yield and ui quali y. In his sense, ui
mo phology can be conside ed a quali y ai as i is one o he i s
ea u es o be pe cei ed. Al hough consume s associa e pa icula
sizes and o ms o ce ain ma ke classes (i.e. medium size and
ound can aloupes o la ge and o al inodo us), a whole wo ld o
possibili ies is being opened up be o e us wi h he de elopmen o
p oduc s wi h o iginal appea ance, ei he by adi ional b eeding,
like he ZESPRI GOLD kiwi ui cul i a [2], o by gene ic
enginee ing, like he pu ple oma o [3]. Mode n ma ke ends
demand smalle melons, as he amily size is p og essi ely alling;
and wi h ounde shapes, wha minimizes cos s and mechanical
damages du ing s o age and anspo .
Melon ge mplasm shows an imp essi e a ay o ui sizes and
mo phologies [4–6], anging om a ew ens o g ams up o 10 Kg
and om sligh ly la o ex emely elonga ed shapes. Mos o his
di e si y is ound in adi ional Cen al Asian land aces and wild
melons [7–8]. This gene pool is conside ed ‘‘exo ic’’ when
compa ed o he popula Occiden al a ie ies (i. e. Galias,
honeydews, wes e n shippe s, can aloups, and inodo us like ‘Piel
de Sapo’, om he e on e e ed o as ‘PS’) al hough i ep esen s a
aluable sou ce o a iabili y wi h a huge po en ial in b eeding
p og ams. In his sense, he accession PI124112 (C. melo ssp.
PLOS ONE | www.plosone.o g 1 Augus 2014 | Volume 9 | Issue 8 | e104188
ag es is a . momo dica) collec ed in 1937 in India is gene ically
e y dis an om comme cial cul i a s, as e ealed by s udies
ca ied ou wi h SSR (Simple Sequence Repea ) [5], [9], and
AFPL (Ampli ied F agmen Leng h Polymo phism) and SNP
(Single Nucleo ide Polymo phism) [10] ma ke s, and shows
esis ance o se e al ungal and i al diseases ( e iewed in [7]).
A ew majo genes wi h pleio opic e ec s on melon ui shape
(FS) a e cu en ly known, like and omonoecious (a), ha has been
ecen ly cloned [11] and is esponsible o sex de e mina ion
oge he wi h gynoecious (g), and like pen ame ous (p), ha con ols
ca pel numbe . Howe e , mos o he pheno ypic a ia ion
obse ed in FS seems o be caused by o he Quan i a i e T ai
Loci (QTL), as demons a ed by a numbe o QTL mapping
s udies ha ha e been unde aken o gene ically dissec i s
molecula basis [12–18].
Geno yping echnologies ha e expe ienced an au hen ic e o-
lu ion in he las ew yea s [19–20], wha has led o a enewed
in e es in QTL mapping. The a ailabili y o a o dable high-
h oughpu geno yping pla o ms will enable esea che s o
anno a e mo e p ecisely he genomic egions o in e es and speed
up d as ically he o me ly ime-consuming p ocess o ob aining
aluable plan ma e ial. All his will make possible o alida e QTL
and s udy pu a i e in e ac ions among hem, a he same ime ha
a o able alleles a e ans e ed in o eli e a ie ies wi h a minimal
d ag o non- a ge ed agmen s wi h po en ial de imen al e ec s.
Consequen ly, i is expec ed ha in a nea u u e, new QTL will
be added o hose al eady cloned in impo an c ops, like he QTL
o ui suga con en B ix9-2-5 [21], o ui size w2.2 [22], and
hose o ui shape o a e [23], ascia ed [24] and sun [25] in
oma o; a QTL o g ain sha e ing sh4 [26] and hose o
lowe ing da e Hd1 [27], Hd6 [28], Hd3a [29], and Ehd1 [30] in
ice; and he QTL o plan a chi ec u e Tb1 [31] and lowe ing
ime Dwa 8 [32] and Vg 1 [33] in maize, among o he s ( e iewed
in [34–35]). In mos cases, he s a egy ollowed was he posi ional
cloning, o wha he a ailabili y o Nea -Isogenic Lines (NILs) was
essen ial, highligh ing he impo ance o gene a ing he app op i-
a e gene ic ma e ial o be success ul. In his sense, he de elopmen
o a collec ion o NILs in melon be ween he Ko ean cul i a
‘Songwhan Cha mi’ and ‘PS’ [36] has allowed o dissec in single
Mendelian ac o s economically impo an ai s as ui mo phol-
ogy [14], [17], climac e ic ipening [37] and i us esis ance [38].
In he p esen wo k, we iden i y and localize se e al QTL
associa ed wi h melon ui mo phological ai s in a c oss be ween
he Spanish cul i a ‘PS’ and he Indian accession PI124112 and
s udy he in e ac ion be ween hose wi h he s onges and mos
obus e ec s. Fu he mo e, we ha e alida ed he QTL o FS
Figu e 1. F ui Shape (FS) polymo phism a each s age o he c ossing p og am o ob ain he
sqs8.1
-NIL. F ui s o (A) ‘PS’; (B) PI124112;
(C) 2M158-3 (F
1
); (D) di e en F
2
plan s o show he ansg essi e seg ega ion o FS; (E) 3M70-47 (F
2
); (F) 5M113-1 6‘PS’ (BC1); (G) 6M59-13 6‘PS’
(BC2); (H) 7M36-1 6‘PS’ (BC3); (I) 8M42-24 6‘PS’ (BC4); (J) 9M7-15 : (BC4S1); (K) 10M2-30 6‘PS’ (BC5); (L) 11M27 : (BC5S1), (L.1) 11M27-20:
he e ozygous a sqs8.1 and (L.2) 11M27-11: homozygous a sqs8.1; (M) he sqs8.1-NIL 12M57-3 OP (BC5S2).
doi:10.1371/jou nal.pone.0104188.g001
Mapping and In og ession o Melon F ui Shape QTL
PLOS ONE | www.plosone.o g 2 Augus 2014 | Volume 9 | Issue 8 | e104188
sqs8.1 in a QTL-NIL de eloped in he gene ic backg ound o he
cul i a ‘PS’, wha p oduces o ally ound melons ins ead o he
ypical o al ones.
Ma e ials and Me hods
All expe imen s we e conduc ed in compliance wi h he cu en
Spanish laws. No speci ic pe missions we e equi ed o he
expe imen s ca ied ou in hese wo loca ions, Cab ils and
Za agoza, as hey a e esea ch ins i u es, Ins i u de Rece ca i
Tecnologia Ag oalimen a ia (IRTA) and Cen o de In es igacio´n
y Tecnologı
´a Ag oalimen a ia de A ago´n (CITA), espec i ely.
Mo eo e , au ho s IE and JMA belong o IRTA and CITA,
espec i ely.
Plan ma e ial and pheno ypic e alua ion
The F
2
plan s o he mapping popula ion we e de i ed om a
single c oss be ween he monoecious Indian land ace accession
PI124112 (momo dica g oup) and he and omonoecious Spanish
cul i a ‘PS’ (inodo us g oup) (Figu e 1). PI124112 ypically
p oduces medium size, elonga ed and non-swee ui s, whe eas
ui s coming om ‘PS’ a e big, o al-shaped and e y swee [4–5].
A mul i-loca ion assay was conduc ed in summe o 2003 wi h a
o al o app oxima ely 400 F
2
plan s. On one hand, 200 o hem
we e andomly dis ibu ed in a g eenhouse a IRTA in Cab ils
(Ba celona, Spain), g own in d ip-i iga ed pea bags and sel -
pollina ed by hand. The emaining 200 plan s we e andomized in
an open ield wi hou i iga ion a CITA, loca ed in Za agoza
(Spain) and allowed o open-pollina e. The e iliza ion me hod
became i ele an as all he ui excep he seed con en is de i ed
om he ma e nal geni o . Ten plan s o e e y geni o plus he F
1
we e included in bo h ials.
F ui leng h (FL) and maximum ui diame e (FD) we e
measu ed on longi udinal sec ions o collec ed ui s and hen, FS
was calcula ed as he a io o FL o e FD.
The absence o s a is ically signi ican geno ype-by-en i onmen
(G6E) in e ac ions was es ed by calcula ing he leas squa e
means o FS in a wo-way ANOVA wi h he da a coming om six
o nine eplica es o F1, PI124112 and ‘PS’ in Cab ils and
Za agoza as a necessa y condi ion o me ge he da a coming om
he wo loca ions.
Pai -wise Pea son’s co ela ion coe icien was calcula ed
be ween he h ee ai s wi h he da a coming om he whole F
2
popula ion and also wi h hose ob ained in he wo loca ion assays
(Cab ils and Za agoza) independen ly.
Pe cen mid-pa en al he e osis (MPH) was calcula ed using he
da a de i ed om a o al o 15 eplica es o each o he geno ypes,
F
1
and he bo h pa en s, as:
MPH~2F1{P1{P2

=P1zP2

|100
whe e F1,P1and P2a e he mean alues o he F
1
, ‘PS’ and
PI124112, espec i ely, o he ai unde s udy.
One-way ANOVA and -S uden mean compa ison es s we e
ca ied ou wi h he da a coming om he whole F
2
popula ion
and also wi h hose ob ained in he wo loca ion assays
independen ly.
All s a is ical analyses we e pe o med using JMP 5.1.2
so wa e o Windows (SAS Ins i u e Inc., Ca y, NC).
DNA ma ke analysis in he mapping popula ion
A selec i e geno yping s a egy [39], which exploi s maximum
pheno ypic di e ences wi h a minimal labo and ime in es men ,
was app oached o s udy he FS ai . The plan s selec ed o be
geno yped we e hose wi h alues mo e ex eme han he mean o
he F
2
popula ion 61SD om each loca ion, esul ing in 84
indi iduals om bo h loca ions (File S1).
DNA was isola ed om young lea es acco ding o [40], wi h
sligh modi ica ions and geno yped wi h a o al o 133 ma ke s (66
SSRs, 65 SNPs and 2 Clea ed Ampli ied Polymo phic Si es,
CAPS) chosen o co e all he genome among hose a ailable in
he li e a u e (File S2). SSR ma ke s we e ampli ied ollowing he
p o ocol wi h M13- ailed o wa d p ime s plus dye labeled M13
p ime s desc ibed by [41] and subsequen ly analyzed on a 3130
Gene ic Analyze (Applied Biosys ems). Geno yping wi h SNP
ma ke s was ca ied ou using he Sequenom MassA ay iPLEX
sys em (Illumina), ollowed by MALDI-TOF mass spec ome y a
Se icio de In es igaciones Biome´dicas, Unidad Cen al de
In es igacio´n (Uni e si y o Valencia, Valencia, Spain). Ampli i-
ca ions o he CAPS ma ke s, AluICAPS [11] and PSI_25-H03
[42], we e pe o med in 25-ml olume solu ions con aining 20 ng
o genomic DNA, 7.5 mM T is HCl (pH 9.0), 5 mM KCl, 2 mM
(NH
4
)
2
SO
4
, 2.5 mM MgCl
2
, 0.2 mM o each dNTP, 0.2 mMo
e e se and o wa d p ime s and 2.5 U o DNA polyme ase
(Bio ools, Mad id, Spain). PCRs we e ca ied ou on a TC-512
he mocycle (Techne, UK) p og ammed wi h an ini ial dena u -
a ion s ep a 94uC o 5 min, ollowed by 35 cycles o 94uC o
30 s, 62uC o 45 s and 72uC o 1 min, plus a inal elonga ion
s ep a 72uC o 5 min. A 10-ml olume o he AluICAPS and
PSI_25-H03 PCR p oduc s we e diges ed wi h he es ic ion
enzymes AluI and Bsh1236I (Fe men as, Fishe Scien i ic, Mad id,
Spain), espec i ely, ollowing he supplie ’s ecommenda ions and
sepa a ed by aga ose gel-elec opho esis.
Linkage map cons uc ion and QTL analysis
The linkage map was cons uc ed using MAPMAKER 3.0 [43]
and he dis ances we e calcula ed wi h he Kosambi unc ion [44].
Ma ke s we e associa ed wi h he g oup command wi h LOD.
3.0. When possible, hey we e pu in o de wi hin each g oup
using he o de command wi h LOD.3.0, ollowed by a
e i ica ion wi h he ipple command and he building o he
amewo k map. I necessa y, emaining ma ke s in he g oup
we e included wi h he place command. I he p e ious app oach
did no ende any map, he compa e unc ion was used o
de e mine he bes possible o de o i e s a ing ma ke s, adding
he emaining ones wi h he y command. In he case o g oups
wi h a low numbe o ma ke s, he o de and dis ances we e
es ima ed using he g oup command, ollowed by compa e, wha
gene a ed he amewo k map. Finally, maps we e d awn wi h
MapCha e sion 2.2 [45].
QTL analysis was pe o med o each loca ion independen ly
and o da a om bo h loca ions me ged oge he using Windows
QTL Ca og aphe 2.5 [46] wi h he composi e in e al mapping
(CIM, [47]) p ocedu e. The LOD sco e h eshold o a signi ican
le el p,0.05 was calcula ed by a pe mu a ion es wi h 1000
esamplings, gi ing a alue o LOD.2.5 o he whole popula ion
o all ai s and la ge numbe s in he indi idual popula ions.
Addi ionally, he h eshold LOD.2.5 was also es ablished o he
single loca ion analyses. Ma ke s associa ed o he mos obus
QTL (6 ou o he 10 QTL as se e al o hem sha e he same
ma ke as he s onges linked one, i.e. lqs8.1 and sqs8.1) we e
geno yped in all F
2
plan s in o de o ob ain unbiased es ima es o
he gene ac ion (d/[a]). The QTL we e named acco ding o he
nomencla u e sys em adop ed by [48], whe e he i s le e s
Mapping and In og ession o Melon F ui Shape QTL
PLOS ONE | www.plosone.o g 3 Augus 2014 | Volume 9 | Issue 8 | e104188
designa e he ai abb e ia ion, ollowed by a ‘‘Q’’ ha s ands o
QTL, hen a le e e e ed o he mapping expe imen (‘‘s’’, in his
case), ollowed by a digi ep esen ing he linkage g oup (LG) o
which he QTL maps, and hen ollowed by a do and a inal digi
ha dis inguishes di e en QTL om he same expe imen on he
same LG. In hose cases in which wo o e lapping QTL we e
iden i ied in a limi ed egion and o he same ai , hey we e
e ec i ely conside ed as only one QTL.
S udy o QTL in e ac ions
Epis a ic in e ac ions be ween he FS QTL de ec ed we e
in es iga ed by wo-way ANOVA wi h he JMP 5.1.2 so wa e o
Windows and using he geno ypic da a om he linked ma ke s in
all F
2
plan s (no only he subse employed o he selec i e
geno yping). These ma ke s we e AluICAPS in he case o sqs2.1,
CMAT141 o sqs8.1, and ECM 67 o sqs12.1. In e ac ions
we e conside ed o be s a is ically signi ican when p#0.05. Sum o
squa es alues we e used o calcula e he pe cen age o he
pheno ypic a ia ion explained by he in e ac ion be ween wo
QTL (R
2
).
QTL alida ion by de eloping a QTL-NIL
The s a egy ollowed o alida e one o he FS QTL de ec ed
and o in og ess i in o he ‘PS’ eli e cul i a consis ed in selec ing
a single F
2
plan om he ial loca ed in Cab ils, ha ca ied he
PI124112 alleles a he QTL egion and also showed ound ui ,
and backc oss i o he pa en al ‘PS’ (Figu e S1). Fi e ounds o
backc ossing guided by a doubled selec ion, pheno ypic ( a o ing
ound-shaped ui s) and assis ed by ma ke s linked o he a ge
QTL ( o moni o he in og essions ha bo ing PI124112 alleles),
we e ca ied ou . Simul aneously, backg ound ma ke s co e ing
all he genome we e also employed o g adually inc ease he
pe cen age o he ecu en pa en genome by selec ing agains he
dono (PI124112) genome. An ad anced backc oss selec ion,
10M2-30, was geno yped wi h 548 SNPs using he Golden-Ga e
assay (Illumina, San Diego, CA) desc ibed in [10] in o de o e i y
in og ession size and in eg i y, and he composi ion o he
genomic backg ound. A e wo cycles o sel - e iliza ion, he
de ini i e in og ession line in he BC5S2 gene a ion was ob ained
(Figu e 1M).
Pheno ypical e alua ions o he ui s we e conduc ed in he
g eenhouse a se e al s ages o he backc oss scheme. In 2008, 42
ui s collec ed om 37 plan s belonging o h ee ull-siblings BC4
amilies (8M42-37, 41 and 42) ca ying he PI124112 allele o he
FS QTL in LG VIII (homozygous and he e ozygous o wo linked
ma ke s placed 23.3 cM apa in he gene ic map) we e e alua ed
in Cab ils. In 2009, BC4S1 plan s (Figu e S1) we e geno yped wi h
he ma ke s linked o he QTL and 30 o hei ui s we e
pheno yped in a g eenhouse a Poly echnic Uni e si y o Valencia.
The coseg ega ion o ma ke s and FS pheno ypes was assessed by
ANOVA. Finally, in 2012, melon ui s om he BC5S2 amily
12M57 and he pa en al cul i a ‘PS’ we e analyzed in Paipo a
(Valencia). 12M57, de i ed om a homozygous plan o he
closes ma ke s o he FS QTL sqs8.1 (11M27-11, Figu e S1),
con ained he in og ession o he PI124112 allele a hose same
ma ke s linked o he QTL. Means o he ui s p oduced by 10
12M57 plan s we e compa ed wi h means o he ui s collec ed
om 15 ‘PS’ plan s by a - es .
Resul s
Pheno ypic a ia ion in mo phological ai s
Cul i a ‘PS’ p oduces o al-shaped ui s (FS = 1.460.1;
Table 1 and Figu e 1A), while PI124112 displays elonga ed ui s
(FS = 1.760.2; Table 1 and Figu e 1B). The F
1
exhibi ed highe
FS alues (FS = 2.060.2, Table 1 and Figu e 1C), in acco dance
wi h bes -pa en he e osis o his cha ac e p e iously obse ed in
melon [16], pa icula ly in hyb ids be ween exo ic accessions and
‘PS’ (inodo us g oup), caused mainly by an inc ease in FL [5]. No
signi ican G6E in e ac ion was obse ed o FS, he e o e he
pa en al mean alues we e calcula ed wi h he da a coming om
bo h loca ions. In Cab ils, he MPH alues we e 77%, 10% and
60% o FL, FD and FS, espec i ely; in he assay loca ed in
Za agoza, 120%, 34% and 68%, espec i ely; and o he whole
se o da a, 100%, 24% and 64%, espec i ely. In all cases,
he e osis was con i med and, hough he e a e sligh di e ences in
he MPH alues o each cha ac e among assays, he anking
emains unal e ed.
A con inuous dis ibu ion o alues was obse ed in he F
2
(Figu e 2), as expec ed in a quan i a i e ai like FS, wi h alues
anging om 0.86 (obla e ui s) o 3.23 (ex emely elonga ed
ui s), making clea a ansg essi e seg ega ion o his cha ac e
in his popula ion (Figu e 1D and Figu e 2C). T ansg essi e
seg ega ion was also obse ed o FL. In bo h cases, i was
obse ed in bo h di ec ions in he whole F
2
popula ion (Table 1
and Figu e 2), al hough he pheno ypes whe e mo e ex eme o
he highe alues, ha means ui s wi h a mo e elonga ed shape.
In all cases, indi iduals wi h ui s exceeding he mid-pa en alue
63.84SD we e ound. The ai showing a b oade ange o alues
was FL ( om 7.1 o 38 cm), displaying ex eme alues co e-
sponding o 26.56 and +13.52 imes he SD o he mid-pa en al
FL. Con e sely, FD showed he lowes a ia ion ( om 7.30 o
17.70 cm), wha ep esen s he mid-pa en FD alue 23.84SD
and +5.55SD, espec i ely. In be ween hese wo cases, he FS
alues anged om 24.31SD and +11.23SD he mid-pa en
alues, espec i ely.
FL and FS showed a highly signi ican (p,0.001) and s ong
co ela ion wi h alues o he Pea son’s co ela ion coe icien o
0.84 o he whole popula ion, and 0.86 and 0.83 o he
subpopula ions o Cab ils and Za agoza, espec i ely. In con as ,
FD and FS we e no signi ican ly co ela ed in any case.
Linkage map cons uc ion
One hund ed and wen y- wo ou o he 133 o al ma ke s (63
SNPs, 57 SSRs and 2 CAPS) used o geno ype he F
2
mapping
popula ion could be inco po a ed o a gene ic map consis ing in 18
LGs ha span 1437.3 cM (Figu e 3), wha ende s a densi y o 1
ma ke e e y 11.8 cM. By compa ing wi h he melon consensus
map [48], each LG could be iden i ied, inding ha i e o hem
we e pa ial LGs o he in eg a ed map. The map shows an
a e age ma ke gap o 13.8 cM.
QTL associa ed wi h ui mo phology ai s
Gi en ha no G6E in e ac ion was ound among loca ions,
da a om bo h loca ions we e me ged o subsequen QTL
analysis. A o al o en QTL o ui mo phology- ela ed ai s
we e posi ioned along he melon gene ic map (Table 2 and
Figu e 3) wi h he selec i e geno yping s a egy, i e unde lying FL
(in LGs II, IIIb, VIa, VIII and Xb), wo esponsible o FD (in LGs
IIIa and XII), and h ee con olling FS (in LGs II, VIII and XII).
LOD sco e alues anged om 2.80 o 16.85, in he case o
dqs3a.1 and lqs8.1, espec i ely. The QTL wi h he highes
e ec o each o he h ee cha ac e s s udied we e lqs8.1
(LOD = 16.85, R
2
= 34%), dqs12.1 (LOD = 3.47, R
2
= 11%) and
sqs8.1 (LOD = 14.85, R
2
= 41%). The emaining QTL accoun ed
o 4 o 17% o he pheno ypic a ia ion. LOD peaks o he wo
majo QTL loca ed in LG II, lqs2.1 and sqs2.1, and in LG VIII,
lqs8.1 and sqs8.1, o e lapped comple ely (Figu e S2).
Mapping and In og ession o Melon F ui Shape QTL
PLOS ONE | www.plosone.o g 4 Augus 2014 | Volume 9 | Issue 8 | e104188
The in e al de ined by he ma ke s lanking he QTL anged
om 12.9 ( lqs3b.1) o 69.1 ( lqs6a.1) cM, being less han 26 cM
o i e ou o he en QTL (Table 2).
The QTL on LG VIII ( lqs8.1 and sqs8.1) we e consis en ly
de ec ed in he h ee analyses ( ha is, wi h he me ged da a and
wi h hose coming om indi idual loca ions, File S3). The QTL
sqs2.1 was also de ec ed in he h ee analyses wi h a
LOD = 2.5.The es s o he QTL we e iden i ied in wo o he
analyses, excep o lqs10b.1. In all cases, he addi i e e ec s sign
emained in a iable ac oss he di e en en i onmen s.
Since sqs2.1, sqs8.1 and sqs12.1 we e he QTL mos
consis en ly de ec ed among analyses, all plan s we e geno yped
wi h ma ke s AluICAPS, CMAT141, and ECM67, loca ed in he
espec i e QTL egion, in o de o ob ain unbiased es ima es o
hei e ec s (Table 2). Same di ec ion e ec s o he exo ic allele
(PI124112) o FL and FS QTL wi h he same ch omosomal
loca ion we e obse ed. In his sense, lqs2.1 and sqs2.1 displayed
a posi i e alue o he addi i e e ec (a), 3.06 and 0.27,
espec i ely, wha means ha he PI124112 allele causes an
inc ease in FL and FS, p oducing mo e elonga ed ui s.
Con e sely, he nega i e alue o a o lqs8.1 and sqs8.1
(24.95 and 20.50, espec i ely) is indica i e o a dec ease in bo h
cha ac e s, FL and FS, wha esul s in ounde ui s, e en i
PI124112 i sel p oduces e y elonga ed melons. In all he
emaining QTL, excep o dqs12.1, de ec ed wi h he da a
coming om Cab ils and wi h he whole se (a=21.03 and a=
21.10, espec i ely), he PI124112 allele con ibu ed o inc ease
he alue o he pa icula mo phological ai (Table 2 and File
S3). So, he PI124122 allele a dqs12.1 will ende elonga ed ui s
by dec easing hei diame e s, whe eas in he case o lqs2.1 and
sqs2.1, a simila pheno ype will be ob ained by inc easing he
leng h o he ui .
Gene ac ion alues anged om 20.35 and 20.32 ( lqs8.1 and
sqs8.1, espec i ely) o 0.75 ( lqs2.1 and sqs2.1; Table 2). In mos
cases, he alleles a he QTL loci showed an addi i e e ec , excep
o lqs2.1 and sqs2.1, whe e he inhe i ance mode is nea
comple e dominance. In gene al, he gene ac ion alues ob ained
o he same QTL using he subse s o da a coming om bo h
loca ions (File S3) ag ee wi h he ones calcula ed when all he da a
we e pooled oge he , wi h sligh di e ences ha can be a ibu ed
o he smalle sample size o he i s analysis.
The addi i e e ec a sqs8.1 is suppo ed by he pheno ypic
da a, as he he e ozygous NIL- sqs8.1 displays a FS alue (i.e.
1.24) in e media e be ween he wo homozygo es, he homozygous
line o he PI124112 allele (i.e. 1.06) and he ‘PS’ pa en (a e age
FS = 1.40).
QTL 6QTL in e ac ion
In o de o de ec he pu a i e e ec s o o he genomic egions
on each o he FS QTL, all he possible digenic in e ac ions
be ween hem we e s udied al hough only hose ha we e
s a is ically signi ican when p#0.05 a e shown (Table 3 and
Figu e 4).
Table 1. Mean and S anda d De ia ion (SD) alues o he ai s o he pa en s, he F
1
and he whole F
2
.
FL FD FS
Mean SD Mean SD Mean SD
‘PS’ 19.5 1.3 14.0 1.1 1.4 0.1
PI124112 14.8 1.8 9.2 1.1 1.6 0.2
F
1
25.1 3.5 12.7 1.8 2.0 0.2
F
2
19.5 5.7 11.7 2.0 1.7 0.5
FL: F ui Leng h; FD: F ui Diame e ; FS: F ui Shape.
doi:10.1371/jou nal.pone.0104188. 001
Figu e 2. F equency dis ibu ion o he ai s ac oss he F
2
popula ion de i ed om he c oss ‘PS’ 6PI124112. (A) FL (F ui Leng h), (B)
FD (F ui Diame e ) and (C) FS (F ui Shape). Bo h pa en s and F
1
alues a e ma ked. In he uppe box, 25
h
,50
h
and 75
h
qua iles a e displayed; he
sample mean and he 95% con idence in e al a e ep esen ed by a diamond, and he ou lie alues as do s. The b acke along he edge o he box
s ands o he pa o he g aph in which 50% o he obse a ions a e ga he ed oge he . Mean and s anda d de ia ion es ima es o a no mal
dis ibu ion a e also shown.
doi:10.1371/jou nal.pone.0104188.g002
Mapping and In og ession o Melon F ui Shape QTL
PLOS ONE | www.plosone.o g 5 Augus 2014 | Volume 9 | Issue 8 | e104188

sqs2.1 6 sqs8.1
A signi ican in e ac ion was iden i ied be ween sqs2.1 and
sqs8.1 (p = 0.013, Figu e 4A, Table 3), ha explains a 4% o he
gene ic a iance o FS.
lqs2.1 has been p e iously iden i ied as gene a[12], [49] and
he ma ke linked o i (AluICAPS) is ac ually he causal mu a ion
o and omonoecy [11]. Fo ha eason and om now on, he
alleles a his locus will be e e ed o as A and a.
I is well known ha he dominan allele A causes elonga ed
shapes in some gene ic backg ounds [12], as becomes clea in he
cases o homozygous o PS allele a locus sqs8.1 (PsPs). Fo each
o he h ee possible geno ypes a locus a (AA, Aa, aa), he lowes
Figu e 3. Loca ion o 10 QTL esponsible o mo phological ui ai s mapped in a F
2
popula ion de i ed om he c oss ‘PS’ 6
PI124112. FL: F ui leng h, open ba s; FD: F ui Diame e , ha ched ba s; and FS: F ui Shape, solid ba s. Leng h o QTL ba s co esponds o he wo-
LOD suppo in e als ( om peak ma ke ) based on he esul s ob ained by CIM using Windows QTL Ca og aphe 2.5. Numbe s on he le side
co espond o he dis ance in cM (acco ding o [44]) om he op o each ch omosome.
doi:10.1371/jou nal.pone.0104188.g003
Mapping and In og ession o Melon F ui Shape QTL
PLOS ONE | www.plosone.o g 6 Augus 2014 | Volume 9 | Issue 8 | e104188
Table 2. QTL de ec ed o FL, FD and FS using he me ged da a om wo loca ions o he F
2
popula ion om he c oss ‘PS’ 6PI124112.
T ai LG QTL name
a
Flanking ma ke s In e al size (cM) LOD sco e
a
b
d
b
d/[a]
b
R
2c
Homologue QTL ID
a
Homologue published QTL
d
Re e ence
e
FL II lqs2.1 CMPSNP431-ECM61 38.4 8.44 3.06 2.29 0.75 0.16 lqn2.1 l2.1 [54]
FL IIIb lqs3b.1 ECM205-CMPSNP998 12.9 2.92 +0.05 lqc3.5 3.5 [14]
FL VIa lqs6a.1 ECM52-CMTCN41 69.1 9.56 +0.11 lqc6.4 6.4 [14]
FL VIII lqs8.1 GCM241-PSI_25-H03 23.3 16.85 24.95 21.71 20.35 0.34 lqc8.3 8.3 [14]
lqn8.1 l8.1 [54]
FL Xb lqs10b.1 CMPSNP671-CMPSNP665 31.6 3.02 – 0.04 – – –
FD IIIa dqs3a.1 CMBR100-AI_18-E05 25.6 2.80 – 0.11 – – –
FD XII dqs12.1 ECM67-CMTCN14 52 3.47 21.03 20.17 20.17 0.11 dqi12.1 w6.10 [65]
FS II sqs2.1 CMPSNP431-AluICAPS 16.9 6.74 0.27 0.20 0.75 0.17 sqj2.1 s2.3 [15]
sqq2.1 s2.2 [12]
sqn2.1 sh2.1 [54]
FS VIII sqs8.1 GCM241-PSI_25-H03 23.3 14.85 20.50 20.16 20.32 0.41 sqc8.3 8.1 in [14]
sqn8.1 sh8.1 [54]
FS XII sqs12.1 AI_35-A08-CMPSNP361 53.1 3.61 0.15 0.03 0.21 0.03 sqa12.1 s11.1 [13]
sqp12.1 s12.1 [12]
sqc12.1 12.1 [14]
FL: F ui Leng h; FD: F ui Diame e ; FS: F ui Shape.
a
Nomencla u e acco ding o [48].
b
Only calcula ed o QTL in which he whole popula ion was geno yped wi h he s onges linked ma ke (s); o he es , only he sign is shown.
c
When possible, calcula ed using he da a coming he whole popula ion geno yped wi h he s onges linked ma ke (s); o he es , he alue ob ained by he QTL analysis using he selec i e geno yping subse o samples is
shown.
d
Nomencla u e acco ding o he au ho s ha o iginally iden i ied he QTL.
e
Re iewed in [48] and, he FS QTL, in [53].
doi:10.1371/jou nal.pone.0104188. 002
Mapping and In og ession o Melon F ui Shape QTL
PLOS ONE | www.plosone.o g 7 Augus 2014 | Volume 9 | Issue 8 | e104188
alues o FS index ( ounde ui s) we e always obse ed in he
homozygous o he PI124112 allele a locus sqs8.1 (PiPi)
(Figu e 4A). So, when he PI124112 allele is p esen a sqs8.1
and he dominan A allele is absen a locus a(PsPiaa and PiPiaa),
he e is a conside able dec ease o FS.
In he homozygous PiPi, he di e ences among he h ee
di e en geno ypes a locus aa e he sligh es . I seems ha
homozygous PiPi a sqs8.1 diminish o , in some way, a enua es
he e ec s o he dominan A allele o gene aon ui elonga ion.
In he case o he e ozygous geno ypes a sqs8.1 (PsPi), some
di e ences can be obse ed depending on he alleles p esen a
locus a(A_ a e expec ed o p oduce mode a ely elonga ed ui s
while aa will ende ed mo e ounded ones). So, we can only see
ma ked di e ences in he h ee possible geno ypes a gene awhen
he PI124112 allele is no p esen a QTL sqs8.1 (no masking
e ec ) o i is in he e ozygosis, PsPs o PsPi (mode a e a enua ion
o he pheno ype caused by A), wi h FS showing nea ly pa allel
inc emen s when hese wo scena ios a e compa ed. In bo h cases,
he elonga ed pheno ype caused by he a o emen ioned dominan
A allele becomes clea , as homozygous AA p oduce he mos
elonga ed ui s, ollowed by he he e ozygous (Aa).
sqs8.1 6 sqs12.1
A signi ican in e ac ion was iden i ied be ween sqs8.1 and
sqs12.1 (p = 0.014, Figu e 4B, able 3), explaining 7% o he
gene ic a iance o FS.
Simila ly o wha can be obse ed in he in e ac ion sqs2.1 6
sqs8.1, he lowes alues o FS ( ounde ui s) a e ob ained when
he PI124112 allele is in homozygosis a sqs8.1 QTL (PiPi)
(Figu e 4B). In such a case, he pheno ypic a ia ions due o he
di e en allelic composi ion a sqs12.1 locus a e p ac ically
impe cep ible. Those di e ences in he FS alue become mo e
e iden wi h he p esence o he PS allele a sqs8.1, speci ically
when i is in homozygosis (PsPs). In e es ingly, he highes alue o
FS ( he mos elonga ed ui s) a e eached o he PS homozygous
a sqs8.1 locus ha a e homozygous o he PI124112 a sqs12.1
(PsPsPiPi), wha is o ally in line wi h he posi i e addi i e alue o
sqs12.1 QTL ( he Pi allele causes an inc ease in he FS index).
He e, unlike wha happens in he p e ious in e ac ion, wi hin
he same geno ype o QTL sqs8.1, he inc ease in FS due o he
PI124112 allele a sqs12.1 becomes clea when he PI124112
allele is absen a locus sqs8.1.
QTL alida ion in he sqs8.1-NIL
The iden i ica ion and mapping o he sqs8.1 QTL in he F
2
popula ion has allowed us o use ma ke -assis ed selec ion o
p ecisely in og ess he PI124112 allele esponsible o he ound
shape in o he eli e cul i a ‘PS’ as he esul o a backc oss
p og am (Figu e S1). To ensu e he in eg i y and main enance o
he QTL e ec s, wo ounds o QTL e i ica ion we e ca ied ou
in in e media e gene a ions.
Figu e 4. Digenic in e ac ions s udied by wo-way ANOVA be ween he FS QTL using he ma ke s signi ican ly linked o hem. (A)
sqs8.1 and sqs2.1 ( sqs2.1 6 sqs8.1); (B) sqs12.1 ( sqs8.1 6 sqs12.1). Alleles a locus lqs2.1 a e named A and a since his QTL has been p e iously
iden i ied as gene a[12], [49]. PsPs: homozygous o he allele PS (solid line); PsPi: he e ozygous (dashed line); PiPi: homozygous o he allele
PI124112 (do ed line).
doi:10.1371/jou nal.pone.0104188.g004
Table 3. Signi ican digenic in e ac ions be ween all he FS QTL.
QTL pai Sou ce DF Sum o Squa es F Ra io P ob
.
F
sqs2.1- sqs8.1 sqs2.1 (AluICAPS) 2 7.83 35.72 ,0.0001
sqs8.1 (CMAT141) 2 26.79 122.21 ,0.0001
sqs2.1 (AluICAPS) 6 sqs8.1 (CMAT141) 4 1.42 3.24 0.0132
*
sqs8.1- sqs12.1 sqs8.1 (CMAT141) 2 23.02 82.76 ,0.0001
sqs12.1 (ECM67) 2 1.59 5.71 0.0038
sqs8.1 (CMAT141) 6 sqs12.1 (ECM67) 4 1.78 3.19 0.0142
*
The in e ac ions we e explo ed by wo-way ANOVA using he geno ypes o he closes ma ke s in he whole F
2
popula ion de i ed om he c oss ‘PS’ 6PI124112.
*
: In e ac ions we e conside ed o be s a is ically signi ican when p#0.05.
doi:10.1371/jou nal.pone.0104188. 003
Mapping and In og ession o Melon F ui Shape QTL
PLOS ONE | www.plosone.o g 8 Augus 2014 | Volume 9 | Issue 8 | e104188
In 2008, he e ec o he sqs8.1 was moni o ed wi h ma ke s
CMAT141 and PSI_25-H03 in BC4 plan s (Table 4, 8M-codes in
Figu e S1). Plan s ca ying he PI124112 allele in he e ozygosis a
sqs8.1 p oduced signi ican ly ounde melons han plan s ca ying
he PS allele in homozygosis (F = 21.10 and F = 25.94 o
CMAT141 and PS_25-H03, espec i ely, p,0.001).
In 2009, he h ee geno ypes a sqs8.1 (moni o ed wi h ma ke
CMAT141 and PSI_25-H03) seg ega ed in a BC4S1 popula ion
(9M7, Figu e S1), e-con i ming he coseg ega ion o PI124112
alleles a sqs8.1 wi h he ound ui pheno ype (Table 4;
F = 13.75 and p,0.001 o CMAT141; F = 5.71 and p,0.01 o
PSI_25-H03).
A he nex s age, whole-genome geno yping was pe o med in a
selec ed BC5 plan (10M2-30) in o de o check he in eg i y o he
in og essed egion and he composi ion o he gene ic back-
g ound. The a ge in og ession ha bo ed 8.5 Mb in he LG VIII,
and he e we e only se en addi ional in og essions anging om
250 kb o 86.8 Mb.
Finally, he de ini i e in og ession line was ixed in a BC5S2
amily (12M57, Figu e S1). The amily 12M57 showed highly
signi ican sho e and ounde ui s, ha is, lowe alues o FL
and FS, espec i ely (Table 4; F = 10.27 and F = 105.71, o FL
and FS, espec i ely, and p,0.001). Addi ionally, signi ican
e ec s on FD we e also obse ed (F = 10.90, p,0.001, Table 4).
Discussion
The F
2
popula ion be ween ‘PS’ and PI124112 showed an
imp essi e a iabili y o ui mo phology. T ansg essi e seg e-
ga ion in bo h di ec ions was ound o FL and FS, indica ing ha
a leas one o he pa en s con ibu ed alleles wi h opposi e e ec s
and making possible o ob ain geno ypes ha could ende ound
ui s. In ac , he exis ence o an allele inducing ound-shaped
melons was iden i ied in he geni o PI124112 and e i ied wi h an
in og ession line in he ‘PS’ backg ound. The e ec s o his allele
seem o be masked by epis a ic in e ac ions wi h o he gene(s) in
he PI124112 backg ound, and hose e ec s we e un eiled in he
‘PS’ backg ound. A simila disco e y has been epo ed ecen ly
wi h he ob aining o a climac e ic line de i ed om he c oss
be ween wo non-clima e ic melon accessions, ‘PS’ and ‘Shong-
wan Cha mi’ [37]. This is a u he indica ion o he ichness o
he melon gene pool ha emains s ill la gely unexplo ed.
The seg ega ing popula ion coming om pa en s gene ically
dis an and wi h mo phological di e ences used in his wo k has
e ealed i sel as sui able o he gene ic dissec ion o mo pholog-
ical ai s and mapping QTL. Fu he mo e, he mos obus FS
(and he highly co ela ed FL) QTL de ec ed ( lqs2.1, sqs2.1,
lqs8.1 and sqs8.1) we e consis en ac oss he loca ions es ed, in
ag eemen wi h o he esul s published [16], in which QTL
a ec ing FS displayed a high he i abili y, wha explained hei
ep oducibili y in assays ca ied ou in di e en loca ions and
along se e al yea s.
The a ailabili y o a melon consensus map including he
posi ion o QTL con olling a panoply o impo an ai s [48]
made easie he compa ison o he QTL iden i ied he e wi h hose
p e iously desc ibed. In his sense, mos QTL con olling he same
cha ac e s s udied in his wo k ha e been de ec ed p e iously and
mapped o simila genomic posi ions (Table 2). In ac , homolo-
gous QTL ob ained in di e en popula ions can be assigned o all
he QTL desc ibed he e, excep in he case o lqs10b.1 (only
de ec ed wi h he ull se o da a) and dqs3a.1 (no ound in
Cab ils). Only a QTL associa ed o FL was ecen ly epo ed in
he LG II o he ela ed cucu bi Zucchini (Cucu bi a pepo L.) in a
egion syn enic o he LG III o melon a which dqs3a.1 maps
[50]. Howe e , his QTL could no be con i med in u he
backc oss gene a ions.
The QTL in LG II ( lqs2.1 and/o sqs2.1) was p e iously
iden i ied as a pleio opic e ec o he gene a[12], [49], whose
alleles a e esponsible o sex de e mina ion in melon lowe s [51]
as i has been epo ed in o he plan species like Vi is ssp. [52].
The dominan inhe i ance mode obse ed o he alleles a lqs2.1
and sqs2.1 loci also suppo s i . The cloning o he gene has
un eiled ha he causal mu a ion o he and omonoecious melon
ypes is in he ac i e si e o 1-aminocyclop opane-1-ca boxylic acid
syn hase [11].
The map posi ion o sqs8.1 (and lqs8.1, as hey o e lap)
happened o be simila o hose epo ed o o he FS QTL
(Table 2; e iewed in [48], [53]), sqc8.3 (8.1 in [14]) and sqn8.1
( sh8.1 in [54]). Those QTL we e de ec ed in a NIL popula ion
de i ed om he c oss ‘PS’ (C. melo a . inodu us)6PI161375
‘Shongwan Cha mi’ (C. melo a . chinensis), and a Recombinan
Inb ed Line (RIL) popula ion coming om he c oss PI414723 (C.
melo a . momo dica)6‘Dulce’ (C. melo a . e icula us),
espec i ely. So, sqs8.1 seems o be allelic o hose majo QTL
unde lying ui mo phology in a b oad a ay o melon
ge mplasm. The PI161375 and PI414723 alleles p oduced
elonga ed ui s. On he con a y, PI124112 allele (in a ce ain
allelic combina ion in ans wi h gene a a ian s) induced ound
ui s, wha may be showing he exis ence o an allelic se ies a his
QTL when di e en ge mplasm sou ces a e in es iga ed. Th ee
mo e QTL ha e been epo ed in he su ounding egion ( sqa8.1,
sqn8.1 and sqc8.1, compiled in [48]) and wo addi ional ones
u he away in he same ch omosome ( sqc8.1 and sqp8.2,
e iewed in [48]). These esul s sugges ha an impo an pa o
he loci con olling FS in melon could be concen a ed in he LG
VIII. I is also possible ha some o hem a e he same QTL ha
he one desc ibed he e (ha bo ing common and/o new alleles).
To disce n be ween hese wo cases, highe esolu ion in he
mapping and QTL s udies is equi ed. Simila QTL clus e s ha e
Table 4. F- alues ob ained om ANOVA o alida e he e ec s o QTL sqs8.1 on FS.
2008 2009 2012
CMAT141 PSI_25-H03 CMAT141 PSI_25-H03 CMAT141
FL 5.58
*
8.76
**
10.10
***
4.82
*
10.27
***
FD 3.46
ns
2.49
ns
0.53
ns
0.38
ns
10.90
**
FS 21.10
***
25.94
***
13.75
***
5.71
**
105.71
***
Da a coming om he assays ca ied ou along 3 yea s we e used. Plan s we e geno yped wi h linked ma ke s (CMAT141 and/o PSI_25-H03).
FL: F ui Leng h; FD: F ui Diame e ; FS: F ui Shape.
***
P,0.001;
**
P,0.01;
*
P,0.05;
ns
P.0.05.
doi:10.1371/jou nal.pone.0104188. 004
Mapping and In og ession o Melon F ui Shape QTL
PLOS ONE | www.plosone.o g 9 Augus 2014 | Volume 9 | Issue 8 | e104188