Crataegus Spp.) from Central and Southern Mexico

Genet Resour Crop Evol (2008) 55:1159–1165 DOI 10.1007/s10722-008-9316-z

RESEARCH ARTICLE

Variability of three regional sources of germplasm of Tejocote (Crataegus spp.) from central and southern Mexico

Carlos A. Nuń˜ez-Colıń Æ Rau´l Nieto-A´ ngel Æ Alejandro F. Barrientos-Priego Æ Jaime Sahaguń-Castellanos Æ Sergio Segura Æ Fernando Gonza´lez-Andre´s

Received: 1 October 2007 / Accepted: 3 March 2008 / Published online: 11 April 2008 Ó Springer Science+Business Media B.V. 2008

Abstract Tejocote (Crataegus spp.) is a genus of Multivariate statistical methods were used to eluci- fruit-bearing trees distributed widely throughout date patterns of variation in each of these regional Mexico; 13 species are reported for the north and sources. The sources displayed very low intra-source central zones and two or more species may be present variability. The source from Chiapas showed signif- in southern Mexico. Accessions of this genus are icant statistical differences in all morphological safeguarded in the Germplasm Bank of Tejocote at variables evaluated, as a result, this genetic pool is the Autonomous University of Chapingo, mainly considered as different from the other two sources. from three regional sources, i.e. the states of Puebla, The sources from the states of Puebla and Mexico Mexico, and Chiapas, including five different species only differed by 22.79% (with P B 0.05), and thus that belong to series Mexicanae and series Crus-galli. they could be considered as components of a single They can be morphologically characterized by leaves genetic pool. The most highly discriminant variables from different shoot types, flowers and fruits. were from the leaf, such as basal angle, petiole length/major axis length ratio, minor axis length/ major axis length ratio, and number of veins. Electronic supplementary material The online version of this article (doi:10.1007/s10722-008-9316-z) contains Keywords Central and southern Mexico supplementary material, which is available to authorized users. Genetic resources Germplasm Bank C. A. Nuń˜ez-Colıń(&) R. Nieto-A´ ngel Mexican hawthorns Morphological variability A. F. Barrientos-Priego J. Sahaguń-Castellanos Rosaceae subfamily Maloideae Instituto de Horticultura, Departamento de Fitotecnia, Universidad Autońoma Chapingo, Km. 38.5 Carretera Mexico-Texcoco, Chapingo, Estado de Mexico 56230, Mexico Introduction e-mail: [email protected] Several species of genus Crataegus are widely used S. Segura around the world; for example, some Chinese species Centro Regional Universitario Centro Occidente, Universidad Autońoma Chapingo, Morelia, of Crataegus fruits are used for fresh consumption Michoacan 58000, Mexico and processing and as ingredient in Chinese medi- cines. In China, they are regarded as ‘‘fruit for good F. Gonza´lez-Andre´s health’’ (Guo and Jiao 1995). Departamento de Ingenierıá Agraria, E. S. T. Ingenierıá Agraria, Universidad de Leoń, Leon, In Southern USA a mayhaw exists (Crataegus Castilla y Leon 24071, Spain series Aestivales (Sarg. ex Schneider) Rehder) until 123 1160 Genet Resour Crop Evol (2008) 55:1159–1165 recently the fruit of these species has only been used locally in marmalades, butters, preserves, jellies, condiments, syrups, wines, desserts and as food for wildlife (Payne and Krewer 1990). Crataegus mexicana Moc. et Sesse´ is cultivated in Mexico, Guatemala, Honduras, Costa Rica, the Andes of Peru and Ecuador, South of California, Arizona and South Africa. The fruits of this specie, rich in vitamin C, are consumed fresh or processed to marmalade, jam, jelly and syrup. Because of the storability of the fruits and different ripening times in different altitudes, fresh fruits are available for a Fig. 1 Mexican sites sampled for this study; map was created longer time (Bu¨ttner 2001). Also this fruit tree is by using DIVA-GIS software (Hijmans et al. 2002) reported as a good rootstock by drought conditions for apple, pear, quince and several Crataegus species one can observe significant morphological variation (Nieto-A´ ngel and Borys 1999). among accessions, but initial taxonomic determina- The common name in Mexico for species of the tions by Borys and Vega-Cuen (1984) reported that genus Crataegus is ‘‘Tejocote,’’ derived from the the accessions located in the Germplasm Bank were Nahuatl word ‘‘Texocotl,’’ which literally means C. pubescens (Kunth) Steud. (Actually a synonym of stone-fruit (Cabrera 1992). Since, the pre-Hispanic C. gracilior Phipps), with the possibility that some time in Mexico, tejocote fruits were collected for accessions from Chiapas were C. nelsoni Eggl. consumption and sowed in gardens of American However, based on a review of the literature, the Indian villages. More recently, the genus has been most probable species are C. mexicana Moc. et Sesse´ cultivated in commercial orchards (Nieto-A´ ngel and and C. gracilior Phipps for accessions from Puebla Borys 1993). Species of Crataegus form an important and Mexico, and C. nelsoni Eggl. and Eggleston’s C. part of traditional Mexican culture, and are used in stipulosa (Kunth) Steud. for accessions from Chiapas. the All Saints and Christmas holidays, mainly in the All species belong to series Mexicanae (Loud.) production of fruit-based beverages and as treats Rehder except C. gracilior that belongs to series inside pinãtas (Borys and Leszczyn˜ska-Borys 1994). Crus-galli (Loud.) Rehder (Phipps et al. 1990). Phipps (1997) reported 13 species of Crataegus The objective of our study was to evaluate patterns native to Northern and Central Mexico, of which nine of morphological variability within and among are endemic, three are shared with the United States regional sources of tejocote germplasm and identify of America and one with Peru and Ecuador, but the most important variables for describing and Phipps (1997) did not focus on southern Mexico, discriminating among accessions. where Eggleston’s (1909) classification is the only known to cover this area. Eggleston (1909) noted two species that were not taken into account by Phipps Materials and methods (1997), which may be additional species or synonyms (Nuń˜ez-Colıń et al. 2004). The present study was carried out with accessions Accessions of the genus Crataegus have been from the Germplasm Bank of Tejocote (Crataegus conserved in the Germplasm Bank of Tejocote in spp.) located in the ‘‘San Juan’’ Experimental Field of vivo and ex situ in the Autonomous University of the Autonomous University of Chapingo (BGT- Chapingo (UACh), Mexico, since 1981 (Nieto-A´ ngel UACh) (19°290 North Latitude, 98°530 West Longi- and Borys 1992). The accessions are from the tude, altitude of 2,240 m). highlands of Chiapas, near San Cristo´bal de las Casas; from the eastern part of the state of Mexico, Plant material near and around Texcoco; and from the west-central part of Puebla, near Calpan and Huejotzingo (Borys Ninety-one accessions of the BGT-UACh collection and Vega-Cuen 1984) (Fig. 1). In these collections, were evaluated; 50 from Chiapas, 18 from the state of 123 Genet Resour Crop Evol (2008) 55:1159–1165 1161

Mexico, and 23 from Puebla (Fig. 1 and see Supple- petiole length, petal area, petal Feret diameter, style mental Data, Appendix 1). Accessions represent length/ﬂower length ratio, stamen major axis length individual clones, collected as bud wood between and stamen Feret diameter. 1982 and 1989, and then grafted onto seedling The third principal component showed 10.70% of rootstocks of tejocote. the total morphological variation, and it was strongly associated with three characteristics: teeth number of Evaluated data leaf margins from reproductive shoots, roundness index of leaves from large vegetative shoots, and Fifty-one morphological variables were evaluated, 24 endocarp weight/fruit weight ratio. from leaves of three different shoot types (reproduc- The fourth principal component showed 9.51% of tive shoots, short and long vegetative shoots), 17 the total morphological variation, and it was associ- from ﬂowers and 10 from fruits (See Supplemental ated with two variables: roundness index of leaves Data, Appendix 2); all of them are important from a from reproductive shoots and the Feret diameter of taxonomic point of view (Phipps 1997; Phipps et al. leaves from large vegetative shoots (see Supplemen- 2003). tal Data, Appendix 3).

Statistical methods Patterns of variation among accessions

We conducted canonical discriminant analysis (CDA) Figure 2 displays the pattern of dispersion of acces- with a Mahalanobis distance and resubstitution test sions across the first three principal components, and and multivariate analysis of the variance (MANOVA) the internal variability ± standard error is shown in with a Tukey test to quantify differences among Fig. 3. sources and to identify those variables best to Internal variability ± standard error (Fig. 3) is not discriminate among accessions. We also employed so high, although the highest intra-variability is in the the internal variability formula developed by Nuń˜ez- Puebla source, followed by Chiapas, and the most Colıń and Barrientos-Priego (2006) to quantify intra- homogeneous source being the State of Mexico. source variation. All analyses were carried out by means of the procedures PRINCOMP, DISCRIM, and GLM in SAS Version 8 (SAS 1999).

Results

Morphological characteristics

The principal component analysis was obtained from the correlation matrix of the evaluated variables, where the first principal component showed 23.79% of the total morphological variation, and it was most strongly associated with six characteristics: minor axis length/ major axis length ratio of leaves from reproductive and large vegetative shoots, petiole length/major axis length ratio of leaves from reproductive shoots, number of leaf veins from reproductive and short vegetative shoots, and flower receptacle length. The second principal components presented 13.71% of the total morphological variation, and it Fig. 2 Three-dimensional representation of 91 Crataegus accessions representing three regional sources based on the was most strongly associated with seven character- first three principal components from the Germplasm Bank of istics: apex angle of leaves from reproductive shoots, Tejocote of the Autonomous University of Chapingo 123 1162 Genet Resour Crop Evol (2008) 55:1159–1165

large vegetative shoots, and HUE angle coloration from fruits. The second CR showed the remaining variation, and it was most strongly associated with the variables: area of leaves from short vegetative shoots and Feret diameter of leaves from short vegetative shoots (see Supplemental Data, Appendix 4). Figure 4 displays the pattern of dispersion of accessions in a graph formed by the two CRs. Clearly, the Puebla source included accession 48, which was clustered with accessions originated from the State of Mexico (Table 2). A test of Mahalanobis distances (Table 3) showed that the three regional sources were significantly Fig. 3 Internal variability ± standard error (Nuń˜ez-Colıń and different, with accessions from the states of Puebla Barrientos-Priego 2006)of91Crataegus accessions representing three regional sources from the Germplasm Bank of and Mexico being the most similar. A second Tejocote of the Autonomous University of Chapingo comparison among regional sources was carried out on the basis of Multivariate Analysis of Variance (MANOVA). The first value of the MANOVA is the The accessions from Chiapas are expected to have Exact Wilks Lambda of 0.0307, supporting, at the the lowest probability of including atypical individ- P \ 0.0001 level, the Mahalanobis finding of signif- uals (because it shows the lowest internal variability; icant statistical differences among regional sources. Nuń˜ez-Colin and Barrientos-Priego 2006) relative to The two canonical roots, CR1 and CR2, revealed the other two sources that can be considered homo- significant differences among sources (Table 4); geneous because the intra-source variability was not however, accessions from the states of Puebla and high. Mexico did not show significant statistical differences for CR1-associated variables (P B 0.05), but both Inter-source variation sources were statistically different from the Chiapas source. For CR2, all sources showed significant Our inter-source analysis was based on a CDA, statistical differences (P B 0.05) (Table 5). carried out with regional source as a classification variable; for this reason, the variability is partitioned only in two canonical roots (CR) (Table 1). Discussion The first CR accumulated 77.51% of the total morphological variation, and it was strongly associ- Morphological characteristics ated with ten characteristics: minor axis length/major axis length ratio of leaves from the three different Based on our PCA and CDA results, leaf character- shoot types, petiole length/ major axis length ratio of istics were the most useful in defining and comparing leaves from reproductive and large vegetative shoots, Crataegus germplasm sources. All accessions are the number of leaf veins from reproductive and short established in the Germplasm Bank, for this reason vegetative shoots, basal laminar angle from short and the environmental variation is minimal and a good

Table 1 Eigenvalues from canonical discriminant analysis of 51 morphological variables measured from 91 Crataegus accessions representing three regional sources from the Germplasm Bank of Tejocote at the Autonomous University of Chapingo Canonical root Eigenvalue Proportion of variance Cumulative variance Likelihood ratio Approximate F value P [ F

1 8.4332 0.7751 0.7751 0.03073043 3.51 \0.0001 2 2.4482 0.2249 1.0000 0.29000956 1.91 0.0191

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Table 4 Multivariate analysis of variance for dependent variables CR1 and CR2 of CDA conducted on three regional sources of 91 Crataegus accessions from the Germplasm Bank of Tejocote at the Autonomous University of Chapingo Dependent variable Mean square F value R2

CR1 371.2373586* 371.24 0.894037 CR2 107.7191369* 107.72 0.709990 ** Signiﬁcant with P B 0.01

Table 5 Comparison among three different regional sources of 91 Crataegus accessions from the Germplasm Bank of Te- jocote at the Autonomous University of Chapingo for CR1 and Fig. 4 Graph of 91 Crataegus accessions representing three CR2 using the Tukey’s test regional sources using two canonical roots from the Germ- Comparison between Differences Differences plasm Bank of Tejocote of the Autonomous University of regional sources between means between means Chapingo for CR1 for CR2

Table 2 Resubstitution test to a posteriori probability of Puebla–Me´xico 0.1253 1.9825* membership in each origin (reclassification data presented in Puebla–Chiapas 5.7954* 4.6186* bold) from canonical discriminant analysis of 51 morphologi- Me´xico–Chiapas 5.6700* 2.6361* cal variables measured from 91 Crataegus accessions representing three regional sources from the Germplasm Bank * Significant with P B 0.05 of Tejocote at the Autonomous University of Chapingo Origin Chiapas Me´xico Puebla Total variation in leaf variables among germplasm sources Chiapas Number 50 0 0 50 can be explained by differences among species, mainly % 100 0 0 100 leaf differences (Eggleston 1909; Phipps 1997). Me´xico Number 0 18 0 18 Chiapas source represented mainly by C. nelsoni and % 0 100 0 100 C. stipulosa and the other sources represented mainly Puebla Number 0 1 22 23 by C. mexicana and C. gracilior (see Appendix 1); % 0 4.35 95.65 100 however Mexico and Puebla sources show differences Total Number 50 19 22 91 mainly in leaf variables. In a study using endocarp % 54.94 20.88 24.18 100 variation of tejocote accessions significant differences were found among the same origins used in our study (Nieto-A´ ngel et al. 1997), however their taxonomic Table 3 Mahalanobis distances among three different regio- determinations were confused. nal sources and corresponding P values for 91 accessions of Crataegus from the Germplasm Bank of Tejocote at the Autonomous University of Chapingo Patterns of variation within sources Source Chiapas Me´xico Puebla The three sources have different patterns of variation; Chiapas 39.09833 37.51652 taxonomic determinations with Phipps (1997) and Me´xico \0.0001 21.34683 Eggleston (1909) keys can explain these results, Puebla \0.0001 0.0276 because Mexico source presents two species (C. mexicana and C. gracilior), Puebla source presents three species (C. mexicana, C. gracilior and two comparison can be carried out. Although most accessions non identified), and Chiapas source presents accessions from central and southern Mexico belong four species (C. nelsoni, C. stipulosa, C. gracilior and to series Mexicanae, except C. gracilior (series four accessions non identified). However, the results, Crus-galli) (Phipps et al. 1990; Phipps 1997), the which were obtained by the use of Nuń˜ez-Colıń and 123 1164 Genet Resour Crop Evol (2008) 55:1159–1165

Barrientos-Priego (2006) formula, explain the varia- two studied sources. Phipps (1997) reported the tion of Puebla and Mexico sources for outlier opposite, for this reason it is necessary to study and to accessions existence, and Chiapas source for the make a reclassification for the Southern Mexican variability in the all accessions within this source. Crataegus. Some specimens have been sent to Dr. Phipps for taxonomic corroboration. Inter-source variation The State of Mexico and Puebla sources cannot be established as different sources because they only The dispersion of accessions in the graph formed differ in the CR2 (it represents only 22.49% of the from the two CR designed to reveal inter-source total variability) and it is a minimal part of the total variation (Fig. 4), suggests the existence of important variability, and they should be considered as the same differences between accessions from Chiapas and genetic source (genetic pool), and most of the those accessions from the other two regional sources variation is of intra-specific type variability, this on the CR1 axis, and among all three sources on the regional source have the same species and the CR2 axis. Accessions from Chiapas displayed the variation would be in great part by domestication most circular leaves, with the fewest leaf veins, and eco-types (Borys 1996; Nieto-A´ ngel et al. 1997; fruits tending towards a reddish coloration, in com- Phipps 1997). parison with the other two sources which displayed leaves that were longer than wide, a higher number of Acknowledgements The study was supported in part by leaf veins, and more yellowish fruits. This indicates scholarship 169581 of the Mexican National Council for Science and Technology (CONACYT) and by the National that the Chiapas source had different species in Service for Seed Inspection and Certification (SNICS) of the comparison with the other two sources, although all Mexican Ministry of Agriculture (SAGARPA) through Project accessions from Chiapas belong to series Mexicanae 53 of the National System for Plant Genetic Resources— (Phipps et al. 1990, 2003), these variations corre- Network for Fruit Crops. The authors thank Juan Lo´pez- ´ Santiago for field assistance and help in collecting flower and sponds with those reported by Nieto-Angel and Borys leaf data and thank the Plant Science Department of the (1993), Borys (1996), Nieto-A´ ngel et al. (1997), and Universidad Autońoma Chapingo for permission to work in its Nuń˜ez-Colıń et al. (2004). experimental field and other facilities. The sources from Puebla and State of Mexico differed mainly in CR2. The accessions from Puebla showed larger leaves, resulting in greater photosyn- References thetic area, which might result into greater fruit Borys MW (1996) Valores del tejocote (Crataegus spp.) production (Borys 1996) or even bigger fruits, traits diversificacioń de caracteres. Revista Chapingo Serie that are important for commercial production as a Horticultura 2:51–84 fruit crop (Faust 1989). Borys MW, Leszczyn˜ska-Borys H (1994) Tejocote (Crataegus The accession 48 of Puebla source may be spp.)—planta para solares, macetas e interiores. Revista Chapingo Serie Horticultura 1:95–107 wrongly located, this should belong to State of Borys MW, Vega-Cuen A (1984) Seleccioń de tipos de tejo- Mexico source (Table 4), and the accession origin cote Crataegus pubescens H. B. K. en los Estados de must be corroborated, to determine if there is an Chiapas, Puebla y Me´xico. Revista Chapingo 44–45: existence of a documentation error during the arrival 193–199 Bu¨ttner R (2001) Rosaceae. In: Hanelt P, Institute of Plant to the Germplasm Bank or perhaps a farmer took it Genetics and Crop Plant Research (eds) Mansfeld’s many years ago from Mexico to Puebla. encyclopedia of agricultural and horticultural crops: The MANOVA results, as an instrument to except ornamentals. Springer, Berlin, pp 417–532 compare regional sources, gave clues to state that Cabrera LG (1992) Diccionario de Aztequismos. Ediciones Colofoń, DF, Me´xico, 166 pp the Chiapas source is statistically different Eggleston WW (1909) The Crataegi of Mexico and Central (P = 0.05) relative to the other two sources, and America. Bull Torrey Bot Club 36:501–514 should be considered as a different genetic source Faust M (1989) Physiology of temperate zone fruit trees. (genetic pool), although it can share some species, Wiley, New York, 338 pp Guo T, Jiao P (1995) Hawthorn (Crataegus) resources in different species may be found in relation to those China. Hortscience 30:1132–1134 found in central Mexico, and this source showed the Hijmans RJ, Guarino L, Bussink C, Barrantes I, Rojas E (2002) largest inter-specific variability relative to the other DIVA-GIS Versioń 2. Sistema de informacioń geogra´fica 123 Genet Resour Crop Evol (2008) 55:1159–1165 1165

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