See discussions, stats, and author profiles for this publication at: https://www.researchgate.

net/publication/225246046

Assessing Genetic Diversity in Mexican Husk Tomato Species

Article in Plant Molecular Biology Reporter · September 2011

DOI: 10.1007/s11105-010-0258-1

CITATIONS READS

55 493

4 authors, including:

Ofelia Vargas-Ponce Pilar Zamora

University of Guadalajara University of Guadalajara
87 PUBLICATIONS 1,192 CITATIONS 38 PUBLICATIONS 360 CITATIONS

SEE PROFILE SEE PROFILE

Aaron Rodriguez
University of Guadalajara
58 PUBLICATIONS 754 CITATIONS

SEE PROFILE

All content following this page was uploaded by Ofelia Vargas-Ponce on 26 May 2015.

The user has requested enhancement of the downloaded file.

Plant Mol Biol Rep
DOI 10.1007/s11105-010-0258-1

Assessing Genetic Diversity in Mexican Husk Tomato Species

Ofelia Vargas-Ponce & Luis F. Pérez-Álvarez &
Pilar Zamora-Tavares & Aaron Rodríguez

# Springer-Verlag 2010

Abstract Mexico is the center of diversity of the husk Introduction

tomato (Physalis L., Solanaceae), which includes a number
of commercially important edible and ornamental species. Like other Solanaceae genera, Physalis L. includes a
Taxonomic identification is presently based on morpholog- number of commercially important edible and ornamental
ical characteristics, but the presence of high inter- and species. With the exception of P. alkekengi L., most of the
intraspecific morphological variation makes this task 90 species in the genus are native to the Americas, and their
difficult. Six ISSR primers were used on eight Mexican distribution ranges from the USA through Mexico and into
species of Physalis to determine their utility for interspe- South America, including the Antilles. Many weedy and
cific taxonomic discrimination and to assess their potential cultivated species have also been introduced to Old World
for inferring interspecific relationships. The six ISSR tropical regions (Martínez 1998; Whitson and Manos
primers amplified 101 bands, with 100% polymorphism 2005). With 50 native species, Mexico is the center of
across samples. The number of bands per primer varied diversity (D’Arcy 1991; Waterfall 1967). In natural areas
from 10 to 21. All primers produced different fingerprint and traditional agroecosystems, the fruit of at least ten wild
profiles for each species, confirming the ISSR value in species are collected for consumption, but only Physalis
taxonomic discrimination. Discrimination values based on philadelphica Lam. has been domesticated and cultivated in
Simpson’s diversity index varied from 0.48 to 0.58. Genetic the region for centuries.
interspecific similarity values ranged from 0.20 to 0.57, and The high diversity of Physalis species observed in
intraspecific similarity values were highest for Physalis Mexico parallels the presence of high inter- and intra-
angulata (0.71), followed by Physalis philadelphica (0.63) specific morphological variation. This variation is observed
and Physalis lagascae (0.55). The UPGMA analysis mostly in widely distributed species or those that are
grouped accessions of the same species together and managed and cultivated, making taxonomic identification
clustered together Physalis species of similar morphological more challenging.
traits. Thus, ISSR markers are useful in estimating genetic Physalis species are currently identified by morpholog-
relationships in Physalis. ical characteristics. A number of studies have been done
using morphological data to characterize species, to study
Keywords Physalis . Husk tomato . Genetic diversity . the systematics of some sections (Martínez 1998, 1999a;
Genetic relations . ISSR markers Seithe and Sullivan 1990; Sullivan 1985; Vargas-Ponce et
al. 1999, 2001, 2003), to determine the infrageneric
taxonomy (Martínez 1999b), and to understand the phylo-
O. Vargas-Ponce (*) : L. F. Pérez-Álvarez : P. Zamora-Tavares : genetic relationships between Physalis and the genera
A. Rodríguez related to the physaloid group (Axelius 1996; Estrada and
Departamento de Botánica y Zoología, CUCBA, Martínez 1999). Sequence data from part of the nuclear
Universidad de Guadalajara,
Waxy gene, the internal transcribed spacer of the nrDNA
Km. 15.5 carretera Guadalajara-Nogales, Nextipac,
Zapopan, Jalisco A.P. 1100, Mexico (ITS) and chloroplast regions (Martínez 1998; Whitson and
e-mail: ovargas@cucba.udg.mx Manos 2005) have also been used to address the phylogeny
 Plant Mol Biol Rep

of Physalis, related genera, and the Solanaceae (Olmstead Waterfall were represented by a single population, while
et al. 2008). Physalis angulata L. and Physalis lagascae Roem. and
The PCR-based technique using inter-simple sequence Schult. were represented by two populations each. The
repeats (ISSR) is widely used because of its technical highly morphologically variable P. philadelphica Lam. was
simplicity and reproducibility and the high polymorphism represented by three populations (Table 1).
of the markers (Arif et al. 2009; Bornet and Branchard
2001; Reedy et al. 2002; Zietkiewicz et al. 1994). ISSRs DNA Extraction and PCR Amplification
provide extremely useful data for estimating genetic
diversity (Ge et al. 2005; Nan et al. 2003; Petros et al. DNA was extracted from 20 mg of leaf samples following
2007; Gomes et al. 2009; Vargas-Ponce et al. 2009), the CTAB method of Doyle and Doyle (1987). The
phylogenetic analyses (Matos et al. 2001; Mort et al. extracted DNA of five individual plants from the same
2003; Wolfe and Randle 2001) for studying the inter- and population was mixed to create a genetic pool representing
intraspecific relations among plants (Archibald et al. 2006; each population using the approach of Martínez et al.
Petros et al. 2008; Wolfe and Randle 2001). The objective (2008), and Gilbert et al. (1998). Eleven primers were used
of the present study was to determine whether ISSR in the initial screening; six were selected because they
markers provide sufficient resolution for interspecific showed the highest potential to distinguish between species
discrimination of Mexican species of Physalis and to assess (Table 2). PCR was carried out twice by each ISSR primer
their utility for inferring interspecific relationships. with all Physalis samples included in the study. Only those
bands that were present in both runs were scored and
included in the data set. Each 20-μl PCR reaction mixture
Materials and Methods contained 60-ng genomic DNA, 10 mM buffer, 2.5 mM
MgCl2, 0.3 mM dNTPs, 0.2 μM primer, 0.5 unit Taq
Plant Material polymerase, and HPLC water. The PCR reactions were
performed in a PTC-100 thermal cycler (MJ Research, Inc.)
Samples were taken from 12 wild Physalis populations, programmed for an initial step of 4 min at 95°C; followed
representing eight species and five taxonomic sections of by 40 cycles of 1 min at 95°C, 1 min annealing temperature
the genus. The plants were collected in the states of (see Table 2), 2 min extension at 72°C; and a final 15 min
Aguascalientes, Coahuila, Colima, and Jalisco, Mexico extension at 72°C.
(Table 1). Three species are perennial, and five are annual. Amplification products were separated in 6% 19:1 bis-
Leaf material was collected and dried in silica gel from 11 acrylamide gels containing 7 M urea and TBE buffer IX. A
to 20 individuals per population. Physalis virginiana Miller, 100-bp molecular marker standard was included in each gel
Physalis cordata Miller, Physalis cinerascens (Dunal) to estimate band sizes. Electrophoresis was run at 70 V in a
Hitch., Physalis lignescens Waterfall, and Physalis sulphurea dual adjustable slab gel unit (CBS Scientific) until the

Table 1 Eight Physalis species and 12 populations included in the study

Species Section Geographic locations: latitude, longitude Voucher specimen

Physalis virginiana a Lanceolatae Saltillo, Coahuila 25°25′37″,100°59′50″ JS 301

Physalis cordatab Epeteiorhiza Tomatlán, Jalisco 19°56′30″,105°14′52″ JS 70
Physalis sulphureab Angulatae Tizapan, Jalisco 20°09′43″,103°02′44″ JS 19
Physalis cinerascensa Stellatae Saltillo, Coahuila 25°25′37″,100°59′50″ JS 302
Physalis lignescensa Coztomatae V.Carranza, Jalisco 19°44′47″,103°46′90″ OVP 456
Physalis philadelphica-1b Angulatae Aguascalientes 21°52′55″,102°17′29″ JS 246
Physalis philadelphica-2b Angulatae Atemajac, Jalisco 20°08′19″,103°43′34″ JS sn
Physalis philadelphica-3b Angulatae Cuquío, Jalisco 20°25′05″,104°19′08″ JS 334
Physalis angulata-1b Angulatae Juchitlán, Jalisco 20°05′02″,104°06′03″ OVP 2022
Physalis angulata-2b Angulatae Techaluta, Jalisco 20°04′32″,103°33′12″ OVP 2017
Physalis lagascae-1b Angulatae Cuyutlán, Colima 18°55′46″,104°03′56″ OVP 445
Physalis lagascae-2b Angulatae Acatic, Jalisco 20°46′50″,102°54′34″ OVP 917

Each population was represented with pooling ADN from five individuals
a
Perennial herbaceous
b
Annual herbaceous
Plant Mol Biol Rep

Table 2 ISSR primers used in the analysis, number of polymorphic loci, and discriminatory resolution of each primer (Simpson’s Index)

Primer sequence Annealing temperature (°C) Fragment size (bp) Number of loci analyzed Polymorphic loci (%) Simpson’s index

(GA)8 YG 56.5 280–1500 21 100 0.487

(CA)6 RY 50 280–1500 17 100 0.526
(CA)6 RG 47 200–1400 19 100 0.489
RY (GACA)3 47 200–1000 17 100 0.483
(CT)8 RG 47 350–800 10 100 0.500
(CT)8 RC 47 350–1600 17 100 0.579

R=A, G; Y=G, T

bromophenol blue indicator dye had traveled 20 cm. The utility of ISSR data for inferring fine relations among taxa
products were visualized with the silver staining technique showing close genetic relations.
of Sanguinetti et al. (1994).

Data Analysis Results and Discussion

A digital imaging system (Kodak Gel Logic 100) was used The six ISSR primers amplified 101 scorable bands
to record gel images as TIFF files. ISSR banding patterns (Table 2). The number of bands per primer varied from
were analyzed with Phoretix 1D image analysis software 10 to 21, with an average of 16.8 fragments per primer. The
(TotalLab). Bands were automatically assigned, then man- amplified product ranged from 200 to 1,600 bp, while the
ually adjusted based on the resulting images. Each unique number of products amplified per primer varied from 10
fragment size, considered as a locus for each primer, was [(CT)8RG] to 21 [(GA)8YG]. All primers produced 100%
scored as present (1) or absent (0) for each sample. The polymorphic bands, a very high interspecific percentage
polymorphic loci percentage (Pl) by primer across samples that has also been reported for Polygala (Polygalaceae),
was calculated using the POPGENE v.1.31 program (Yeh Guizotia (Asteraceae), Morus (Moraceae), and Agave
and Boyle 1999). Each primer’s discrimination potential (Agavaceae) (Lüdtke et al. 2009; Petros et al. 2007, 2008;
was expressed
P Pin terms of the Simpson’s diversity index Prasanta et al. 2008; Vargas-Ponce et al. 2009).
hj ¼ ð1  pi 2 Þ=n , where pi is the frequency of the
ith allele, and n corresponds to the number of loci detected ISSR—Taxonomic Discrimination Among Physalis Species
by each primer (Hunter and Gaston 1988; Lüdtke et al.
2009). A value of 1.0 indicates that the primer is able to All six primers produced different fingerprinting profiles
discriminate between all samples, and a value of 0.0 for each species (Fig. 1). In addition, four of the primers
indicates that all samples are identical. From the 101 generated species-specific bands. Primer (CA)6RG gener-
polymorphic bands, only 74 were chosen for the genetic ated a unique band for P. philadelphica (580 bp), and
relation analysis because of their clarity and constant primer (CA)6RY produced a specific band for P. cordata
amplification in all samples. These bands were generated (1,100 bp). Likewise, primer RY(GACA)3 yielded a band
with the primers (GA)8YG, (CA)6RY, (CA)6RG, and RY for P. cinerascens (590 bp) and another for P. sulphurea
(GACA)3. Genetic similarity among all samples was (700 bp). Last, the primer (CT)8RC resulted in a unique
calculated using the Nei and Li coefficient (Nei and Li band for P. cinerascens (700 bp), P. philadelphica
1979), which excludes absent bands from the analyses. (1,350 bp), and P. sulphurea (1,400 bp). Thus, ISSR
Genetic similarity values were used to estimate genetic markers can be useful in generating ISSR genetic finger-
relations, and then represented with a dendrogram generated prints specific to each Physalis species. Indeed, ISSRs have
by the unweighted pair-group mean analysis method using the been useful in the genomic fingerprinting of diverse plant
Freetree (Pavlicek et al. 1999). Relative support for the groups Reedy et al. (2002).
relations was assessed with bootstrap analyses (1,000 Banding patterns showed clear interspecific differentia-
replicates; Felsenstein 1985) using the Freetree (Pavlicek et tion and intraspecific similarity, demonstrating the value of
al. 1999) and Tree View (Page 1996) programs. Another ISSRs in taxonomic discrimination of Physalis species
genetic relation analysis was applied to a small subset of (Fig. 1). Simpson’s index values varied from 0.483 (primer
Physalis samples of Physalis section Angulatae (four RY(GACA)3) to 0.579 (primer (CT)8RC; Table 2) showing
species/eight populations, see Table 1) to assess the potential moderate to high potential to discriminate between samples.
 Plant Mol Biol Rep

However, Simpson’s index has been successfully used to

discriminate among microorganisms (Dillon et al. 1993;
Harth-Chu et al. 2009) and plants (Agostini et al. 2008;
Lüdtke et al. 2009), with values slightly greater than those
obtained here for Physalis.

Genetic Similarity and Relations

Genetic similarities, as shown by ISSRs, did not parallel

the morphological variation and ecological preferences
observed for the Physalis species included in this study.
Genetic interspecific similarity values, as calculated with
the Nei and Li coefficient, ranged from 0.20 to 0.57. The
highest values were observed for the P. lignescens/P.
sulphurea comparison (0.57) and the lowest for the P.
cinerascens/P. virginiana comparison (0.20). The genetic
similarity between P. lignescens and P. sulphurea contrasts
with their growing habits and habitat preferences. Physalis
Fig. 1 Inter-simple sequence repeat (ISSR) banding pattern obtained lignescens is a perennial herb growing in coniferous forests,
on acrylamide gels for 12 populations representing eight Physalis whereas P. sulphurea is an annual herb found in flood
species with the primer. (GA)8 YGM=DNA Molecular size marker plains (Vargas-Ponce et al. 2003). On the contrary, P.
(100 bp ladder) in the last lane. Lane/s: 1, P. virginiana; 2, P. cordata;
cinerascens and P. virginiana, although morphologically
3, P.sp; 4, P. cinerascens; 5, P. lignescens; 6, P. sulphurea; 7–9, P.
philadelphica; 10–11, P. angulata; 12–13, P.lagascae different, had a very low genetic similarity value, maybe
reflecting that both species are perennial herbs growing in a
Because Simpson’s diversity index is sensitive to the tropical, dry forest. In future studies, sampling must be
number of groups or samples and size of the group, the widened to better represent the genus Physalis, all of its
variation may be attributed to the unequal number of taxonomical sections, and the diversity in biological form
individuals per sample in the study (Dillon et al. 1993). and gradients in its ecological and geographical habitats.

Fig. 2 Genetic similarity relationship among eight Physalis species (a) and among Physalis species of Section Angulatae (b). The bootstrap
values are shown on the branches (1,000 permutations)
Plant Mol Biol Rep

The genetic similarity values between species pairs in Acknowledgments We thank to Laura Guzman-Dávalos by
comments on early manuscript draft and two anonymous revisers.
Physalis section Angulatae ranged from 0.24 to 0.59: P.
The Secretaría de Educación Pública-PROMEP and Secretaria de
philadelphica/P. angulata (0.32–0.59), P. philadelphica/P. Agricultura, Ganadería y Recursos Pesqueros-SINAREFI (P-007),
lagascae (0.24–0.39), P. philadelphica/P. sulphurea (0.25), both from México, granted financial support for this study to O.V.P.
and P. lagascae/P. angulata (0.36–0.45). Intraspecific
similarity values were highest for the three species of
References
the Physalis section Angulatae: P. angulata (0.71), P.
philadelphica (0.63), and P. lagascae (0.55). Similar
values have been reported for Polygala (Polygalaceae), Agostini G, Echeverrigaray S, Souza-Chies TT (2008) Genetic
relationships among South American species of Cunila D.
Cunila (Lamiaceacea), Guizotia (Asteraceae), and other Royenex L. based on ISSR. Plant Syst Evol 274:135–141
genera (Reedy et al. 2002; Agostini et al. 2008; Petros et Archibald JK, Crawford DJ, Santos-Guerra A, Mort ME (2006) The
al. 2008; Lüdtke et al. 2009). utility of automated analysis of Inter-Simple Sequence Repeat
The genetic relations phenogram (Fig. 2) that included (ISSR) loci for resolving relationships in the Canary Island
species of Tolpis (Asteraceae). Am J Bot 93:1154–1162
all samples showed two principal clusters diverging at the
Arif M, Zaidi NW, Singh YP, Rizwanul-Haq QM, Singh US (2009) A
0.31 phenon level. Cluster one (I) included P. cinerascens comparative analysis of ISSR and RAPDS markers for study of
(Physalis sect. Stellatae), P. sulphurea (Physalis sect. genetic diversity in Shisham (Dalbergia sissoo). Plant Mol Biol
Angulatae), P. lignescens (Physalis sect. Coztomatae), and Report 27:488–495
Axelius B (1996) The phylogenetic relationships of the physaloid
P. cordata (Physalis sect. Epeteiorhiza). Cluster two (II)
genera (Solanaceae) based on morphological data. Am J Bot
included P. angulata, P. lagascae, and P. philadelphica 83:118–124
of Physalis sect. Angulatae, and one population of P. Bornet B, Branchard M (2001) Nonanchored Inter Simple Sequence
virginiana (Physalis sect. Lanceolatae). Neither cluster Repeat (ISSR) marker: reproducible and specific tools for
genome fingerprinting. Plant Mol Biol Report 19:209–215
corresponds to the presently accepted intrageneric taxo- D’Arcy WG (1991) The Solanaceae since 1976, with a Review of its
nomic classification (Martínez 1999b). As mentioned Biogeography. In: Hawkes JG, Lester RN, Nee M, Estrada N
already, cluster II encompasses P. angulata, P. lagascae, (eds) Solanaceae III: taxonomy, chemistry and evolution. Royal
and P. philadelphica, but excluded P. sulphurea, which Botanic Gardens, Kew, pp 75–137
Dillon JR, Rahman M, Yeung K (1993) Discriminatory power of
belongs to the same section (Fig. 2a).
typing schemes based on Simpson’s index of diversity for
The analysis of distantly related lineages (e.g., P. Neisseria gonorrhoeae. J Clin Microbiol 31:2831–2833
cinerascens, P. lignescens, and P. virginiana) might Doyle J, Doyle J (1987) A rapid DNA isolation procedure for small
generate incongruence between genetic similarity values quantities of fresh leaf tissue. Phytochem Bull 19:11–15
Estrada E, Martínez M (1999) Physalis (Solanoideae: Solaneae) and
and taxonomic section affiliation. As a result, high boot-
allied genera: I. A morphology-based cladistic analysis. In: Nee
strap values support the intraspecific nodes but not the M, Lester RN, Jessop JP (eds) Solanaceae IV: advances in
interspecific ones. The cluster analysis of Physalis sect. biology and utilization. The Royal Botanic Gardens, Kew, pp
Angulatae had better resolution and higher boostrap values 139–160
Felsenstein J (1985) Confidence limits on phylogenies: an approach
(Fig. 2b), suggesting an advantage to including closely
using the bootstrap. Evolution 39:783–791
related species in the analyses. Two important aspects of Ge XJ, Zhang LB, Yuan YM, Hao G, Chiang TY (2005) Strong genetic
the genetic similarity analyses were found in the pheno- differentiation of the East-Himalayan Megacodon stylophorus
grams. First, samples corresponding to the same species (Gentianaceae) detected by Inter-Simple Sequence Repeats (ISSR).
Biodivers Conserv 14:849–861
grouped together. Second, the genetic differentiation
Gilbert JE, Lewis RV, Wilkinson MJ, Caligari PDS (1998) Developing
among Physalis species corresponded to the observed an appropriate strategy to assess genetic variability in plant
morphological variation between them, indicating that germplasm collections. Theor Appl Genet 98:1125–1131
distinctive morphological traits can be used to differentiate Gomes S, Martins-Lopes P, Lopes J, Guedes-Pinto H (2009)
Assessing genetic diversity in Olea europaea L. using ISSR and
the species. For example, the small corolla and the small
SSR markers. Plant Mol Biol Report 27:365–373
yellow anthers of P. angulata separate it from P. philadelphica Harth-Chu E, Espejo RT, Christen R, Guzmán CA, Höfle MG (2009)
(Vargas-Ponce et al. 2003). Multiple-locus variable-number tandem-repeat analysis for clonal
The results demonstrate that ISSR markers are useful in identification of Vibrio parahaemolyticus isolates by using
capillary electrophoresis. Appl Environ Microbiol 75:4079–4088
estimating genetic relations in Physalis. The markers are
Hunter PR, Gaston MA (1988) Numerical index of the discriminatory
also an effective tool for documenting interspecific varia- ability of typing systems: an application of Simpson’s index of
bility, discriminating species, and assessing intraspecific diversity. J Clin Microbiol 26:2465–2466
similarity and differentiation. Moreover, the development Lüdtke R, Agostini G, Sfoggia Miotto ST, Souza-Chies TT (2009)
Characterizing Polygala L. (Polygalaceae) species in Southern
of this highly versatile marker for Physalis opens the way
Brazil using ISSR. Plant Mol Biol Report 28:317–323
for implementing a wide range of studies needed to Martínez M (1998) Revisión de Physalis sección Epeteiorhiza
understand, use, and conserve species of husk tomato. (Solanaceae). Ann Ins Biol Bot 69:71–117
 Plant Mol Biol Rep

Martínez M (1999a) Physalis hunzikeriana (Solanaceae: Solanoideae), Reedy MP, Sarla N, Sidiq EA (2002) Inter Simple Sequence Repeat
una nueva especie del norte de México. Kurtziana 27:383–385 (ISSR) polymorphism and its aplicattion in plant breeding.
Martínez M (1999b) Infrageneric taxonomy of Physalis. In: Nee M, Euphytica 128:9–17
Lester RN, Jessop JP (eds) Solanaceae IV: Advances in biology Sanguinetti C, Diaz Nieto F, Simpson AJ (1994) Rapid silver staining
and utilization. Royal Botanic Gardens, Kew, pp 275–284 and recovery of PCR products separated on acrylamide gels.
Martínez J, Colunga-GarcíaMarín P, Zizumbo-Villarreal D (2008) Biotechniques 17:915–918
Genetic erosion and in situ conservation of Lima bean (Phaseolus Seithe A, Sullivan J (1990) Hair morphology and systematic of
lunatus L.) landraces in its Mesoamerican diversity center. Genet Physalis. Plant Syst Evol 170:193–204
Resour Crop Evol. doi:10.1007/s10722-008-9314-1 Sullivan JR (1985) Systematics of the Physalis viscosa complex. Syst
Matos M, Pinto-Carnide O, Benito C (2001) Phylogenetic relation- Bot 10:426–444
ships among Portuguese rye based on isozyme, RAPD and ISSR Vargas-Ponce O, Martínez M, Dávila P (1999) Physalis waterfallii
markers. Hereditas 134:229–236 (Solanaceae), una especie nueva de los estados de Jalisco y
Mort ME, Crawfordl DJ, Santos-Guerra A, Francisco-Ortega J, Michoacán. Acta Bot Mex 48:21–26
Esselman EJ, Wolfe AD (2003) Relationships among the Vargas-Ponce O, Martínez M, Dávila P (2001) Two new species of
Macaronesian members of Tolpis (Asteraceae: Lactuceae) based Physalis (Solanaceae) endemic to Jalisco, México. Brittonia
upon analyses of Inter Simple Sequence Repeat (ISSR) markers. 53:505–510
Taxon 52:511–518 Vargas-Ponce O, Martínez M, Dávila P (2003) La familia Solanaceae
Nan P, Shi S, Peng S, Tiang C, Zhong Y (2003) Genetic diversity in en Jalisco: el género Physalis. Colección Flora de Jalisco16.
Primula obconica (Primulaceae) from central and South-West Universidad de Guadalajara, Guadalajara, pp 1–127 pp
China as revelead by ISSR Markers. Ann Bot (Lond) 91:329–333 Vargas-Ponce O, Zizumbo-Villarreal D, Martínez-Castillo J, Coello-
Nei M, Li WH (1979) Mathematical model for studying genetic Coello J, Colunga-GarcíaMarín P (2009) Diversity and structure
variation in terms of restrictions endonucleases. Proc Natl Acad of landraces of agave grown for spirits under traditional
Sci USA 76:5269–5273 agriculture: a comparison with wild populations of A. angustifolia
Olmstead EG, Bohs L, Migid HA, Santiago-Valentin E, García VF, (Agavaceae) and commercial plantations of A. tequilana. Am J Bot
Collier SM (2008) A molecular phylogeny of the Solanaceae. 96:448–457
Taxon 57:1159–1181 Waterfall UT, Waterfall UT (1967) Physalis in Mexico, Central
Page RDM (1996) TREEVIEW: an application to display phyloge- America, and the West Indies. Rhodora 69:82–120, pp. 203–
netic trees on personal computers. Comput Appl Biosci 12:357– 239; 319–329
358 Whitson M, Manos PS (2005) Untangling Physalis (Solanaceae) from
Pavlicek A, Hrda S, Flegr J (1999) FreeTree—Freeware program for the physaloids: a two-genes phylogeny of the Physalinaeae. Syst
construction of phylogenetic trees. Folia Biol (Praha) 45:97–99 Bot 30:216–230
Petros Y, Merker A, Zeleke H (2007) Analysis of genetic diversity of Wolfe AD, Randle CP (2001) Relationships within and among species
Guizotia abyssinica from Ethiopia using inter simple sequence of the holoparasitic genus Hyobanche (Orobanchaceae) inferred
repeat markers. Hereditas 144:18–24 from ISSR banding patterns and nucleotide sequences. Syst Bot
Petros Y, Merker A, Zeleke H (2008) Analysis of genetic diversity and 26:120–130
relationships of wild Guizotia species from Ethiopia using ISSR Yeh FC, Boyle TJB (1999) Popgene v. 1.31. Microsoft Windows-
markers. Genet Resour Crop Evol 55:451–458 based freeware for population analysis. University of Alberta and
Prasanta KK, Srivastava PP, Awasthi AK, Raje US (2008) Genetic Centre for International Forestry Research, Edmonton
variability and association of ISSR markers with some biochem- Zietkiewicz E, Rafalski A, Labuda D (1994) Genome fingerprinting
ical traits in mulberry (Morus spp.) genetic resources available in by simple sequence repeat (SSR)-anchored polymerase chain
India. Tree Genet Genomes 4:75–83 reaction amplification. Genomics 20:176–183

View publication stats