yucca

Summary

Summary: A genus (and common name) in the Asparagaceae family. It is known for SAPONINS in the root that are used in SOAPS.

Top Publications

  1. Kim S, Park S, Kang S, Kang H, Oh H, Bae C, et al. Hypocholesterolemic property of Yucca schidigera and Quillaja saponaria extracts in human body. Arch Pharm Res. 2003;26:1042-6 pubmed
    This study was undertaken to observe the effects of the blend of partially purified Yucca schidigera and Quillaja saponaria extracts on cholesterol levels in the human's blood and gastrointestinal functions, and to determine if a new ..
  2. Drummond C, Xue H, Yoder J, Pellmyr O. Host-associated divergence and incipient speciation in the yucca moth Prodoxus coloradensis (Lepidoptera: Prodoxidae) on three species of host plants. Heredity (Edinb). 2010;105:183-96 pubmed publisher
    A wide range of evolutionary processes have been implicated in the diversification of yuccas and yucca moths, which exhibit ecological relationships that extend from obligate plant-pollinator mutualisms to commensalist herbivory...
  3. Segraves K, Pellmyr O. Testing the out-of-Florida hypothesis on the origin of cheating in the yucca-yucca moth mutualism. Evolution. 2004;58:2266-79 pubmed
    ..We used the obligate pollination mutualism between yuccas and yucca moths to examine the origins of a nonpollinating cheater moth, Tegeticula intermedia, and its pollinating sister ..
  4. Holtshausen L, Chaves A, Beauchemin K, McGinn S, McAllister T, Odongo N, et al. Feeding saponin-containing Yucca schidigera and Quillaja saponaria to decrease enteric methane production in dairy cows. J Dairy Sci. 2009;92:2809-21 pubmed publisher
    An experiment was conducted in vitro to determine whether the addition of saponin-containing Yucca schidigera or Quillaja saponaria reduces methane production without impairing ruminal fermentation or fiber digestion...
  5. Smith C, Godsoe W, Tank S, Yoder J, Pellmyr O. Distinguishing coevolution from covicariance in an obligate pollination mutualism: asynchronous divergence in Joshua tree and its pollinators. Evolution. 2008;62:2676-87 pubmed publisher
    ..history of a putative case of codivergence in the obligate pollination mutualism between Joshua trees (Yucca brevifolia) and two sister species of pollinating yucca moths (Tegeticula spp...
  6. Olas B, Wachowicz B, Tomczak A, Erler J, Stochmal A, Oleszek W. Comparative anti-platelet and antioxidant properties of polyphenol-rich extracts from: berries of Aronia melanocarpa, seeds of grape and bark of Yucca schidigera in vitro. Platelets. 2008;19:70-7 pubmed publisher
    ..study was to investigate and compare the anti-platelet action of extracts from three different plants: bark of Yucca schidigera, seeds of grape and berries of Aronia melanocarpa (chokeberry)...
  7. Smith C, Pellmyr O, Althoff D, Balcázar Lara M, Leebens Mack J, Segraves K. Pattern and timing of diversification in Yucca (Agavaceae): specialized pollination does not escalate rates of diversification. Proc Biol Sci. 2008;275:249-58 pubmed
    The yucca-yucca moth interaction is one of the most well-known and remarkable obligate pollination mutualisms, and is an important study system for understanding coevolution...
  8. Favel A, Kemertelidze E, Benidze M, Fallague K, Regli P. Antifungal activity of steroidal glycosides from Yucca gloriosa L. Phytother Res. 2005;19:158-61 pubmed
    The antifungal activity of a crude steroidal glycoside extract from Yucca gloriosa flowers, named alexin, was investigated in vitro against a panel of human pathogenic fungi, yeasts as well as dermatophytes and filamentous species...
  9. Marzocco S, Piacente S, Pizza C, Oleszek W, Stochmal A, Pinto A, et al. Inhibition of inducible nitric oxide synthase expression by yuccaol C from Yucca schidigera roezl. Life Sci. 2004;75:1491-501 pubmed
    b>Yucca schidigera extract finds wide commercial application in foods, cosmetics and pharmaceuticals...

More Information

Publications62

  1. Smith C, Drummond C, Godsoe W, Yoder J, Pellmyr O. Host specificity and reproductive success of yucca moths (Tegeticula spp. Lepidoptera: Prodoxidae) mirror patterns of gene flow between host plant varieties of the Joshua tree (Yucca brevifolia: Agavaceae). Mol Ecol. 2009;18:5218-29 pubmed publisher
    ..using a natural experiment that examines the role of natural selection on phenotype matching between yuccas and yucca moths (Tegeticula spp...
  2. Fidan A, Dundar Y. The effects of Yucca schidigera and Quillaja saponaria on DNA damage, protein oxidation, lipid peroxidation, and some biochemical parameters in streptozotocin-induced diabetic rats. J Diabetes Complications. 2008;22:348-56 pubmed publisher
    The aim of this study was to examine the effects of Yucca schidigera, Quillaja saponaria, and a mixture of both plants on streptozotocin-induced diabetic rats. Animals were allocated into five groups with 10 rats each...
  3. Diab Y, Ioannou E, Emam A, Vagias C, Roussis V. Desmettianosides A and B, bisdesmosidic furostanol saponins with molluscicidal activity from Yucca desmettiana. Steroids. 2012;77:686-90 pubmed publisher
    Bioactivity-guided separation of the aqueous methanolic extract of Yucca desmettiana leaves, which in a preliminary screening exhibited significant molluscicidal activity, led to the isolation and structure elucidation of two new ..
  4. Althoff D, Segraves K, Smith C, Leebens Mack J, Pellmyr O. Geographic isolation trumps coevolution as a driver of yucca and yucca moth diversification. Mol Phylogenet Evol. 2012;62:898-906 pubmed publisher
    ..important in diversification of obligate mutualistic interactions such as the one between yuccas and pollinating yucca moths...
  5. Althoff D. A test of host-associated differentiation across the 'parasite continuum' in the tri-trophic interaction among yuccas, bogus yucca moths, and parasitoids. Mol Ecol. 2008;17:3917-27 pubmed publisher
    ..Here, I examined the importance of host-associated differentiation in a parasitoid wasp that develops on yucca moths in the genus Prodoxus...
  6. Soltanian M, Sun A, Dai Z. Reactive transport in the complex heterogeneous alluvial aquifer of Fortymile Wash, Nevada. Chemosphere. 2017;179:379-386 pubmed publisher
    b>Yucca Mountain, Nevada, had been extensively investigated as a potential deep geologic repository for storing high-level nuclear wastes...
  7. Wappler T, Labandeira C, Engel M, Zetter R, Grímsson F. Specialized and Generalized Pollen-Collection Strategies in an Ancient Bee Lineage. Curr Biol. 2015;25:3092-8 pubmed publisher
    ..pollination have emphasized narrowly specialized pollinator mutualisms such as figs and fig wasps and yuccas and yucca moths...
  8. Gordon M, Edwards M, Sweeney C, Jerina M. Effects of added chelated trace minerals, organic selenium, yeast culture, direct-fed microbials, and Yucca schidigera extract in horses: II. Nutrient excretion and potential environmental impact. J Anim Sci. 2013;91:3909-16 pubmed publisher
    ..diet formulated with chelated trace minerals, organic selenium, yeast culture, direct-fed microbials (DFM) and Yucca schidigera extract would decrease excretion of nutrients that have potential for environmental impact...
  9. Xu D, Miao J, Yumoto E, Yokota T, Asahina M, Watahiki M. YUCCA9-Mediated Auxin Biosynthesis and Polar Auxin Transport Synergistically Regulate Regeneration of Root Systems Following Root Cutting. Plant Cell Physiol. 2017;58:1710-1723 pubmed publisher
    ..PAT-related genes were induced after root pruning, and the YUCCA inhibitor yucasin suppressed root regeneration in PAT-related mutants...
  10. Wenzig E, Oleszek W, Stochmal A, Kunert O, Bauer R. Influence of phenolic constituents from Yucca schidigera bark on arachidonate metabolism in vitro. J Agric Food Chem. 2008;56:8885-90 pubmed publisher
    b>Yucca schidigera Roezl. (Agavaceae) has been traditionally used to treat a variety of diseases including arthritis and rheumatism...
  11. Cha J, Kim W, Kang S, Kim J, Baek D, Jung I, et al. A novel thiol-reductase activity of Arabidopsis YUC6 confers drought tolerance independently of auxin biosynthesis. Nat Commun. 2015;6:8041 pubmed publisher
    b>YUCCA (YUC) proteins constitute a family of flavin monooxygenases (FMOs), with an important role in auxin (IAA) biosynthesis...
  12. Xie Y, Straub D, Eguen T, Brandt R, Stahl M, Martínez García J, et al. Meta-Analysis of Arabidopsis KANADI1 Direct Target Genes Identifies a Basic Growth-Promoting Module Acting Upstream of Hormonal Signaling Pathways. Plant Physiol. 2015;169:1240-53 pubmed publisher
    ..When exposed to shade, we found three YUCCA genes, YUC2, YUC5, and YUC8, to be transcriptionally up-regulated, which correlates with an increase in the levels ..
  13. Olas B, Wachowicz B, Stochmal A, Oleszek W. Anti-platelet effects of different phenolic compounds from Yucca schidigera Roezl. bark. Platelets. 2002;13:167-73 pubmed
    ..including trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene and yuccaols A and C were isolated from the bark of Yucca schidigera...
  14. Lledias F, Hernandez F, Rivas V, García Mendoza A, Cassab G, Nieto Sotelo J. A Rapid and Reliable Method for Total Protein Extraction from Succulent Plants for Proteomic Analysis. Protein J. 2017;36:308-321 pubmed publisher
    ..well-resolved SDS/PAGE protein patterns in extracts from different members of the subfamilies Agavoideae (Agave, Yucca, Manfreda, and Furcraea), Nolinoideae (Dasylirion and Beucarnea), and the Cactaceae family...
  15. Goyal A, Karayekov E, Galvão V, Ren H, Casal J, Fankhauser C. Shade Promotes Phototropism through Phytochrome B-Controlled Auxin Production. Curr Biol. 2016;26:3280-3287 pubmed publisher
    ..Promotion of phototropism depends on PIF-mediated induction of several members of the YUCCA gene family, leading to auxin production in the cotyledons...
  16. Althoff D, Svensson G, Pellmyr O. The influence of interaction type and feeding location on the phylogeographic structure of the yucca moth community associated with Hesperoyucca whipplei. Mol Phylogenet Evol. 2007;43:398-406 pubmed
    ..We used a community of four yucca moth species, monophagous on the host plant Hesperoyucca whipplei (Agavaceae), to examine how the type of ..
  17. Balestrieri C, Felice F, Piacente S, Pizza C, Montoro P, Oleszek W, et al. Relative effects of phenolic constituents from Yucca schidigera Roezl. bark on Kaposi's sarcoma cell proliferation, migration, and PAF synthesis. Biochem Pharmacol. 2006;71:1479-87 pubmed
    Yuccaols (A, B, C) are phenolic constituents isolated from Yucca schidigera bark characterized by unusual spirostructures made up of a C15 unit and a stilbenic portion closely related to resveratrol...
  18. Althoff D. Shift in egg-laying strategy to avoid plant defense leads to reproductive isolation in mutualistic and cheating yucca moths. Evolution. 2014;68:301-7 pubmed publisher
  19. Smith C, Tank S, Godsoe W, Levenick J, Strand E, Esque T, et al. Comparative phylogeography of a coevolved community: concerted population expansions in Joshua trees and four yucca moths. PLoS ONE. 2011;6:e25628 pubmed publisher
    ..we examined demographic and phylogeographic patterns in a highly specialized, coevolved community--Joshua trees (Yucca brevifolia) and their associated yucca moths...
  20. Zhu X, Lei G, Wang Z, Shi Y, Braam J, Li G, et al. Coordination between apoplastic and symplastic detoxification confers plant aluminum resistance. Plant Physiol. 2013;162:1947-55 pubmed publisher
    ..Here, we found that three auxin overproducing mutants, yucca, the recessive mutant superroot2, and superroot1 had increased aluminum sensitivity, while a transfer DNA ..
  21. Borchert M, Defalco L. Yucca brevifolia fruit production, predispersal seed predation, and fruit removal by rodents during two years of contrasting reproduction. Am J Bot. 2016;103:830-6 pubmed publisher
    The distribution of Yucca brevifolia, a keystone species of the Mojave Desert, may contract with climate change, yet reproduction and dispersal are poorly understood...
  22. Zinkgraf M, Gerttula S, Groover A. Transcript profiling of a novel plant meristem, the monocot cambium. J Integr Plant Biol. 2017;59:436-449 pubmed publisher
    ..Here we report high-quality transcriptomes for monocot cambium and early derivative tissues in two monocot genera, Yucca and Cordyline...
  23. Chen L, Tong J, Xiao L, Ruan Y, Liu J, Zeng M, et al. YUCCA-mediated auxin biogenesis is required for cell fate transition occurring during de novo root organogenesis in Arabidopsis. J Exp Bot. 2016;67:4273-84 pubmed publisher
    ..IAA) to provide direct evidence that auxin is produced after leaf explant detachment, a process that involves YUCCA (YUC)-mediated auxin biogenesis...
  24. Poulet A, Kriechbaumer V. Bioinformatics Analysis of Phylogeny and Transcription of TAA/YUC Auxin Biosynthetic Genes. Int J Mol Sci. 2017;18: pubmed publisher
    ..Auxin biosynthesis via the tryptophan aminotransferase of arabidopsis (TAA)/YUCCA (YUC) route involving tryptophan aminotransferases and YUC flavin-dependent monooxygenases that produce the auxin ..
  25. Rojas J, Uribe Y, Zuluaga A. Powder and compaction characteristics of pregelatinized starches. Pharmazie. 2012;67:513-7 pubmed
    ..The aim of this study was to evaluate the powder and tableting properties of pregelatinized starches obtained from yucca, corn and rice and compare those properties with those of Starch 1500...
  26. Pellmyr O, Krenn H. Origin of a complex key innovation in an obligate insect-plant mutualism. Proc Natl Acad Sci U S A. 2002;99:5498-502 pubmed
    ..The well known obligate pollination mutualism between yuccas and yucca moths is a major model system for studies of coevolution, and it relies on the key innovation in the moths of ..
  27. Leebens Mack J, Pellmyr O. Patterns of genetic structure among populations of an oligophagous pollinating yucca moth (Tegeticula yuccasella). J Hered. 2004;95:127-35 pubmed
    ..The pollination association between yuccas and yucca moths is a classic example of an obligate mutualism often suggested to have been affected by coevolution...
  28. Machado R, Robert C, Arce C, Ferrieri A, Xu S, Jiménez Alemán G, et al. Auxin Is Rapidly Induced by Herbivore Attack and Regulates a Subset of Systemic, Jasmonate-Dependent Defenses. Plant Physiol. 2016;172:521-32 pubmed publisher
    ..and fatty acid conjugate elicitors and is accompanied by a rapid transcriptional increase of auxin biosynthetic YUCCA-like genes...
  29. Tenon M, Feuillere N, Roller M, Birtić S. Rapid, cost-effective and accurate quantification of Yucca schidigera Roezl. steroidal saponins using HPLC-ELSD method. Food Chem. 2017;221:1245-1252 pubmed publisher
    b>Yucca GRAS-labelled saponins have been and are increasingly used in food/feed, pharmaceutical or cosmetic industries...
  30. García Martín J, Mosquera J, Lado C. Morphological and molecular characterization of a new succulenticolous Physarum (Myxomycetes, Amoebozoa) with unique polygonal spores linked in chains. Eur J Protistol. 2018;63:13-25 pubmed publisher
    ..This new species appeared on decayed leaves and remains of succulent plants (Agave, Opuntia, Yucca) growing in arid zones...
  31. Himler A, Machado C. Host specificity, phenotype matching and the evolution of reproductive isolation in a coevolved plant-pollinator mutualism. Mol Ecol. 2009;18:4988-90 pubmed publisher
    ..Smith et al.'s study represents an important step to fill the gap in our understanding of how reciprocal selection may lead to speciation in coevolved plant-pollinator mutualisms. ..
  32. Talmi Y, Wolf M, Migirov L, Kronenberg J. Ear trauma caused by a yucca plant leaf spine. Ear Nose Throat J. 2009;88:E11 pubmed
    Three uncommon cases of ear trauma caused by a yucca plant leaf spine are presented. One patient presented with tympanic perforation and the second with mixed hearing loss after spontaneous closure...
  33. Svensson G, Raguso R, Flatz R, Smith C. Floral scent of Joshua trees (Yucca brevifolia sensu lato): Divergence in scent profiles between species but breakdown of signal integrity in a narrow hybrid zone. Am J Bot. 2016;103:1793-1802 pubmed
    ..b>Yucca brevifolia and Yucca jaegeriana are pollinated by different moth species in allopatry, but in a narrow contact ..
  34. Wisløff H, Uhlig S, Scheie E, Loader J, Wilkins A, Flåøyen A. Toxicity testing of saponin-containing Yucca schidigera Roetzl. juice in relation to hepato- and nephrotoxicity of Narthecium ossifragum (L.) Huds. Toxicon. 2008;51:140-50 pubmed
    b>Yucca schidigera juice in doses of 1.5 g (63 mg sapogenin) and 3.0 g (126 mg sapogenin) per kg live weight was administered intraruminally to 30 lambs for 21 days to investigate whether the saponins in Y...
  35. FöldeÅ¡iová M, Baláži A, Chrastinová Ä, Pivko J, Kotwica J, Harrath A, et al. Yucca schidigera can promote rabbit growth, fecundity, affect the release of hormones in vivo and in vitro, induce pathological changes in liver, and reduce ovarian resistance to benzene. Anim Reprod Sci. 2017;183:66-76 pubmed publisher
    This study evaluated the effect of Yucca schidigera (YS) extract on the physiological, reproductive, and endocrine indexes of New Zealand White rabbit does...
  36. Park J, Hyun S, Kim A, Kim T, Char K. Observation of biological samples using a scanning microwave microscope. Ultramicroscopy. 2005;102:101-6 pubmed
    ..The concentration dependence of the signals shows that our scanning microwave microscope technique can be useful for investigating the local electric behavior of biological samples with a simple model of ionic conduction. ..
  37. Vlčková R, Sopková D, Andrejčáková Z, Valocký I, Kadasi A, Harrath A, et al. Dietary supplementation of yucca (Yucca schidigera) affects ovine ovarian functions. Theriogenology. 2017;88:158-165 pubmed publisher
    b>Yucca (Yucca schidigera) is a popular medicinal plant due to its many positive effects on animal and human physiology, including their reproductive systems...
  38. Golemanov K, Tcholakova S, Denkov N, Pelan E, Stoyanov S. Surface shear rheology of saponin adsorption layers. Langmuir. 2012;28:12071-84 pubmed publisher
    ..In addition, we study the surface shear rheological properties of Yucca saponins, which are of steroid type...
  39. Qu L, Wang J, Ruan J, Yao X, Huang P, Wang Y, et al. Spirostane-Type Saponins Obtained from Yucca schidigera. Molecules. 2018;23: pubmed publisher
    ..In our on-going program of screening these kinds of constituents from natural products, Yucca schidigera was found to be rich in them, and nine new spirostanol saponins, Yucca spirostanosides A₁ (1
  40. Ham Dueñas J, Chapa Vargas L, Stracey C, Huber Sannwald E. Haemosporidian prevalence and parasitaemia in the Black-throated sparrow (Amphispiza bilineata) in central-Mexican dryland habitats. Parasitol Res. 2017;116:2527-2537 pubmed publisher
    ..We compared haemosporidian prevalence and parasitaemia between habitat types, including Yucca-dominated scrublands (closed habitat) and creosotebush scrublands (open habitat), and between seasons, including ..
  41. Liu G, Gao S, Tian H, Wu W, Robert H, Ding Z. Local Transcriptional Control of YUCCA Regulates Auxin Promoted Root-Growth Inhibition in Response to Aluminium Stress in Arabidopsis. PLoS Genet. 2016;12:e1006360 pubmed publisher
    ..Here, we report that YUCCA (YUC), which encodes flavin monooxygenase-like proteins, regulates local auxin biosynthesis in the root apex ..
  42. Takato S, Kakei Y, Mitsui M, Ishida Y, Suzuki M, Yamazaki C, et al. Auxin signaling through SCFTIR1/AFBs mediates feedback regulation of IAA biosynthesis. Biosci Biotechnol Biochem. 2017;81:1320-1326 pubmed publisher
    ..Furthermore, YUCCA (YUC) gene expression was repressed in response to auxin treatment, and expression of YUC7 and YUC8 increased in ..
  43. Santacruz Reyes R, Chien Y. Yucca schidigera extract--a bioresource for the reduction of ammonia from mariculture. Bioresour Technol. 2010;101:5652-7 pubmed publisher
    ..Consequently, YUPE is identified as a natural, safe, and effective solution for ammonia reduction in seawater and mariculture. ..
  44. Olas B, Wachowicz B, Stochmal A, Oleszek W. Inhibition of blood platelet adhesion and secretion by different phenolics from Yucca schidigera Roezl. bark. Nutrition. 2005;21:199-206 pubmed
    b>Yucca schidigera is a plant that grows in Mexico, and it has a very high level of saponins and phenolic compounds with antioxidant action. The products of Y...
  45. Althoff D, Segraves K, Sparks J. Characterizing the interaction between the bogus yucca moth and yuccas: do bogus yucca moths impact yucca reproductive success?. Oecologia. 2004;140:321-7 pubmed
    b>Yucca moths are most well known for their obligate pollination mutualism with yuccas, where pollinator moths provide yuccas with pollen and, in exchange, the moth larvae feed on a subset of the developing yucca seeds...
  46. Morris W, Bronstein J, Wilson W. Three-way coexistence in obligate mutualist-exploiter interactions: the potential role of competition. Am Nat. 2003;161:860-75 pubmed
    ..Our results suggest that mutualist/exploiter coexistence may be more easily achieved than previously thought, thus highlighting the need for a better understanding of competition among and between mutualists and exploiters. ..
  47. Vartanyan M, Orimoto K, Dragovic A, Crock C, Dobson M, O Leary S. Garden terror - case series of twenty eight serious ear injuries caused by yucca plants. Clin Otolaryngol. 2017;: pubmed publisher
    The yucca plant (genus Yucca, family Asparagaceae, subfamily Agavoideae) is a ubiquitous plant whose long and sharp leaf spines (Fig 1) are accountable for an increasing number of ear injuries presenting to the Emergency Department of ..
  48. Starr T, Gadek K, Yoder J, Flatz R, Smith C. Asymmetric hybridization and gene flow between Joshua trees (Agavaceae: Yucca) reflect differences in pollinator host specificity. Mol Ecol. 2013;22:437-49 pubmed publisher
    ..Here, we examine evidence for hybridization and gene flow between two subspecies of Joshua tree (Yucca brevifolia brevifolia and Yucca brevifolia jaegeriana) pollinated by two sister species of yucca moth...
  49. Godsoe W, Yoder J, Smith C, Pellmyr O. Coevolution and divergence in the Joshua tree/yucca moth mutualism. Am Nat. 2008;171:816-23 pubmed publisher
    ..We test the hypothesis that differential selection by two sister species of pollinating yucca moths (Tegeticula spp...
  50. Li L, He Y, Wang Y, Zhao S, Chen X, Ye T, et al. Arabidopsis PLC2 is involved in auxin-modulated reproductive development. Plant J. 2015;84:504-15 pubmed publisher
    ..In addition, we found that expression of the auxin biosynthetic YUCCA genes was increased in plc2 plants...
  51. Cole W, James A, Smith C. First Recorded Observations of Pollination and Oviposition Behavior in Tegeticula antithetica (Lepidoptera: Prodoxidae) Suggest a Functional Basis for Coevolution With Joshua Tree (Yucca) Hosts. Ann Entomol Soc Am. 2017;110:390-397 pubmed publisher
    b>Yucca moths (Tegeticula spp.) are the exclusive pollinators of Joshua trees (Yucca brevifolia s. l.). The moths actively pollinate the Joshua tree flowers and lay their eggs in the style...
  52. Zhang J, Cong Q, Fan X, Wang R, Wang M, Grishin N. Mitogenomes of Giant-Skipper Butterflies reveal an ancient split between deep and shallow root feeders. F1000Res. 2017;6:222 pubmed publisher
    ..Grub-like at the later stages of development, caterpillars of these species feed and live inside yucca roots. Adults do not feed and are mostly local, not straying far from the patches of yucca plants...
  53. Flatz R, Yoder J, Lee Barnes E, Smith C. Characterization of microsatellite loci in Yucca brevifolia (Agavaceae) and cross-amplification in related species. Am J Bot. 2011;98:e67-9 pubmed publisher
    Microsatellite primers were characterized in Yucca brevifolia for use in population genetic studies and, particularly, analyses of gene flow between varieties...