02548nas a2200145   4500008004100000245011600041210006900157260001400226300001600240490000700256520197400263100001902237700001502256856013102271       2000                        eng d00aExploring the genetic basis and proximate causes of female fertility advantage in gynodioecious Thymus vulgaris0 aExploring the genetic basis and proximate causes of female ferti  c2000/10//  a1510 - 15200 v543 aIn many gynodioecous species, females produce more viable seeds than hermaphrodites. Knowledge of the relative contribution of inbreeding depression in hermaphrodites and maternal sex effects to the female fertility advantage and the genetic basis of variation in female fertility advantage is central to our understanding of the evolution of gender specialization. In this study we examine the relative contribution of inbreeding and maternal sex to the female fertility advantage in gynodioecious Thymus vulgaris and quantify whether there is genetically based variation in female fertility advantage for plants from four populations. Following controlled self and outcross (sib, within population, and between-population) pollination, females had a more than twofold fertility advantage (based on the number of germinating seeds per fruit), regardless of the population of origin and the type of pollination. Inbreeding depression on viable seed production by hermaphrodites occurred in two populations, where inbreeding had been previously detected. Biparental inbreeding depression on viable seed production occurred in three of four populations for females, but in only one population for hermaphrodites. Whereas the maternal sex effect may consistently enhance female fertility advantage, inbreeding effects may be limited to particular population contexts where inbreeding may occur. A significant family X maternal sex interaction effect on viable seed production was observed, illustrating that the extent of female fertility advantage varies significantly among families. This result is due to greater variation in hermaphrodite (relative to female) seed fertility between families. Despite this genetic variation in female fertility advantage and the highly female biased sex ratios in populations of T. vulgaris, gynodioecy is a stable polymorphism, suggesting that strong genetic and/or ecological constraints influence the stability of this polymorphism.1 aThompson, J, D1 aTarayre, M  uhttps://thymus.myspecies.info/ref/exploring-genetic-basis-and-proximate-causes-female-fertility-advantage-gynodioecious-thymus02707nas a2200157   4500008004100000020001400041245010300055210006900158260008000227300001400307490000700321520192700328100001502255700001902270856026002289       1997                        eng d  a1010-061X00aPopulation genetic structure of the gynodioecious Thymus vulgaris L. (Labiatae) in southern France0 aPopulation genetic structure of the gynodioecious Thymus vulgari  bthe journal rests with European Society for Evolutionary Biologyc1997/03//  a157 - 1740 v103 aIn a self-compatible gynodioecious species, the abundance of female plants (which are obligate outcrossers) relative to hermaphrodites (which may self and outcross) may be a critical factor influencing genetic diversity and population structure. In the gynodioecious Thymus vulgaris L., female frequency varies from 5 to 95%, providing a suitable model to examine this issue. In this study, we use allozyme markers to (1) evaluate the relationship between female frequency, genetic diversity and population structure, (2) determine whether females and hermaphrodites vary in heterozygote deficiency and (3) examine whether other factors such as plant density are related to heterozygote deficiency. Twenty three natural populations, with female frequencies ranging from 11 to 92%, were sampled in and around the St-Martin-de-Londres basin in southern France. Based on four polymorphic allozyme loci, we found no significant correlation between female frequency and heterozygote deficiency. A significant (P < 0.05) F sub(IS) value over loci and over populations of 0.11 was detected. The F sub(IS) value per population showed a significant heterozygote deficiency in 11 of the 23 populations. However, no significant difference between female and hermaphrodite F sub(IS) values was found. A significant heterozygote deficiency only occurred in populations of intermediate density. There was little differentiation among populations (F sub(ST)= 0.038) nor among subpopulations within each population. The significant F sub(IS) values are thus mostly due to inbreeding effects. The lack of a correlation between F sub(IS) values and female frequency may be due to outcrossing in hermaphrodites and/or restoration of male fertility which may occur to a greater extent at low female frequency. The similarity of female and hermaphrodite F sub(IS) values indicates that females may occasion high levels of biparental inbreeding1 aTarayre, M1 aThompson, J, D  uhttp://muse.lib.auth.gr:9797/com/csa/?MuseHost=www-mi2.csa.com&MuseFirst=1&id=2&recnum=4&SID=f6761d6ffa2f8c20dd10ff73e34434f8&MusePath=%2Fids70%2Fview_record.phphttp://muse.lib.auth.gr:9797/com/blackwell-synergy/?MuseHost=www.blackwell-synergy.com&MuseFir03502nas a2200157   4500008004100000245006000041210005800101260001200159300001400171490000700185520293900192100001503131700001903146700001703165856016203182       1998                        eng d00aThirty-Five Years of Thyme: A Tale of Two Polymorphisms0 aThirtyFive Years of Thyme A Tale of Two Polymorphisms  c1998///  a805 - 8150 v483 aThe aromatic or wild thyme (Thymus vulgaris) is a small, woody shrub of the Labiatae family that inhabits open areas in the western Mediterranean basin. Two types of polymorphic variation exhibited by thyme have provided for the study of the evolutionary dynamics of genetic polymorphisms. First, wild thyme plants bear either female or hermaphrodite flowers but not both, which makes them gynodioecious. In southern France, populations exhibit female frequencies ranging from 5% to more than 90%, which is much higher than other gynodioecious species. Second, six different genetically determined monoterpene compositions of thyme's oil can be found in southern France. The authors John D. Thompson, Domenica Manicacci, and Michele Tarayre have synthesized 35 years of past research on the gynodioecy and oil compound variation of thyme in reference to the high frequency of females and number of oil compounds. The average female frequency of the thyme populations is approximately 60%, which indicates cytoplasmic inheritance. Although nuclear genes are also involved in the determination of sexual phenotype, cytoplasmic sterility genes may block male function. Field investigations have determined that female frequency is correlated with population age, with young populations bearing a high number of females. The male function of nuclear genes is suspected of being restored from the sterility influence of cytoplasmic genes by appropriate alleles of restorer genes in the nuclear genome. The possibility that restorer alleles are lacking in patches of colonizing populations is suggested by the low levels of mitochondrial DNA and chloroplast DNA diversity in the populations. Studies have also shown that male-fertility restoration is more frequent when the females are pollinated by males of the original populations than for females cross-pollinated by distant populations. Other fitness considerations include a possible inbreeding depression among hermaphrodites, reduced seed production resulting from resource allocation toward pollen, and a variable sexual resource investment in hermaphrodites. Eleven species of the genus Thymus ranging from southeastern Spain to south-central France were studied by T. Adzet and others who found a pattern of geographic variation in their occurrence, with the three chemotypes of cineol, borneol, and camphene found in southeastern Spain; the phenolics of carvacrol and thymol abundant in northern Spain and southern France; and nonphenolics increasing in frequency toward the northern latitudes. The geographical distribution indicates an adaptive strategy whereby phenolic compounds are produced in response to hot, dry climates and nonphenolic compounds are produced in cool, moist habitats. The geographical distribution also occurs at a microhabitat scale according to microclimates and is thought to be in response to drought stress, interspecific competition, and herbivory1 aTarayre, M1 aThompson, J, D1 aManicacci, D  uhttp://muse.lib.auth.gr:9797/com/csa/?MuseHost=www-mi2.csa.com&MuseFirst=1&id=2&recnum=2&SID=686e18bda0daa536a33eb2d7c501c5dc&MusePath=/ids70/view_record.php02512nas a2200229   4500008004100000245007500041210006900116260001400185300001200199490000700211520165300218100002101871700000501892700000501897700003701902700001901939700001501958700001601973700001501989700001802004856026002022       2004                        eng d00aMultiple genetic contributions to plant performance in Thymus vulgaris0 aMultiple genetic contributions to plant performance in Thymus vu  c2004/02//  a45 - 560 v923 a1 Diverse genetic factors can affect plant performance. Here we evaluate how maternal and paternal origin, maternal and offspring sexual phenotype and degree of outcrossing jointly influence performance of gynodioecious Thymus vulgaris. 2 In uniform conditions we quantified size and survival of second-generation (G(2)) offspring produced by selfing and outcrossing on the open-pollinated offspring (G(1)) of G(0) females from four populations that differ in sex ratio, selfing rate and chemical type. We controlled for environmental variation, maternal effects and plant age. 3 Offspring with maternal parents from populations dominated by plants that synthesize phenolic monoterpenes had greater survival and size than those from populations with non-phenolic chemotypes. In addition, outcrossing among populations with pollen donors from non-phenolic populations significantly reduced progeny performance. These results suggest chemotype-mediated local adaptation. 4 The progeny of hermaphrodites showed significant inbreeding depression, which despite the pollination treatment x family and pollination treatment x population interactions, showed no consistent variation in relation to population inbreeding levels. 5 For a given level of outcrossing, the progeny of hermaphrodites showed greater among-family and among-population variation in plant size than those of females. Variation in nuclear restorer gene composition across cytoplasmic backgrounds may cause this variation. 6 T. vulgaris, diverse genetic factors jointly affect performance, a result with general implications for understanding fitness variation in natural populations.1 a.Thompson, JohnD1 a1 a1 a.Linhart, IsabelleLitricoandYanB1 aThompson, J, D1 aTarayre, M1 aGauthier, P1 aLitrico, I1 aLinhart, Y, B  uhttp://muse.lib.auth.gr:9797/com/blackwell-synergy/?MuseHost=www.blackwell-synergy.com&MuseFirst=1&prevSearch=allfield:(thymus+AND+(labiatae+OR+lamiaceae))&StartMuseCookie=I2KBRCK=1;+path=/;+SERVER=10.0.20.25:8080;+path=/;+JSESSIONID=gbdwEZ34tGZWt4uGDaLvr02851nas a2200181   4500008004100000020001400041245011800055210006900173260009400242300001400336490000800350520199200358100001502350700001802365700001502383700001702398856025402415       1995                        eng d  a0029-854900aIntra-specific variation in the inhibitory effects of Thymus vulgaris (Labiatae) monoterpenes on seed germination0 aIntraspecific variation in the inhibitory effects of Thymus vulg  aAffiliation: CNRS,Ctr Ecol.Fonct.& Evolut., Rt Mende,34033 Montpellier, Francec1995/01//  a110 - 1180 v1013 aThe ecological role of plant secondary compounds has received a great deal of attention yet little is known regarding variation in the ecological significance of different compounds produced by a single species. This is particularly pertinent to species where variation in compound presence is under genetic control. In this study we have quantified variation in the inhibitory effects of the six dominant monoterpene oils produced by different genotypes (or chemotypes) of Thymus vulgaris on achene germination of an associated species (Brachy-podium phoenicoides), and seeds of T. vulgaris itself, in controlled experimental conditions. The experiments involved the germination of seeds of the two species with crushed leaves or pure essences of the six chemotypes, i.e. four experimental trials. A significant inhibitory effect against B. phoenicoides was found for both crushed leaves and the range of concentrations of purr oils used in the trial. The two phenolic compounds had a greater effect than the non-phenolic leaves and pure oils. The significant differences between non-phenols and the controls declined faster over time for crushed leaves and low concentrations of the pure essences than did that between the phenolics and the controls. There was a significant inhibitory effect against the germination of T. vulgaris seeds for the crushed leaves and the pure oils, although the contrast between the non-phenols and the phenols was not significant. The effect of the different oils varied depending on the seed source of the thyme seeds used in the trial. This is suggested to be due to differences in the rates of outcrossing among the sampled populations. The effects of the oils on the associated species, B. phoenicoides, were not found to be greater than their effects on the germination of thyme seeds. The results are discussed in the context of a potential role for such inhibitory effects in relation to the onset of rainfall and suitable germination conditions.1 aEscarre, J1 aLinhart, Y, B1 aTarayre, M1 aThompson, JD  uhttp://www.scopus.com/scopus/inward/record.url?eid=2-s2.0-0028977472&partnerID=40&rel=R6.5.0http://muse.lib.auth.gr:9797/com/csa/?MuseHost=www-mi2.csa.com&MuseFirst=1&id=2&recnum=5&SID=f6761d6ffa2f8c20dd10ff73e34434f8&MusePath=/ids70/view_record.php02413nas a2200193   4500008004100000020001400041245018400055210006900239260001400308300001600322490000700338520162600345100001401971700001401985700001901999700001502018700002402033856016202057       1997                        eng d  a0002-912200aThe spatial genetic structure of cytoplasmic (cpDNA) and nuclear (allozyme) markers within and among populations of the gynodioecious Thymus vulgaris (Labiatae) in southern France0 aspatial genetic structure of cytoplasmic cpDNA and nuclear alloz  c1997/12//  a1675 - 16840 v843 aRecent advances in molecular biology have allowed the development of techniques to contrast spatial differentiation in nuclear and cytoplasmic genes and thus provide important data on relative levels of gene flow by pollen and seed in higher plants. In this paper, we compare the spatial structure of nuclear (allozymes) and cytoplasmic (cpDNA) genes among populations of the gynodioecious Thymus vulgaris in southern France. Based on a combination of three restriction enzymes (CfoI, EcoRV, and PstI), eight chlorotypes (combination of three restriction enzyme patterns revealed by Southern hybridization of Beta vulgaris cpDNA) were identified in the 13 studied populations. One chlorotype was particularly abundant and was detected in nearly all populations. Only one chlorotype was specific to a single population. Up to four different chlorotypes were observed in some populations. An F sub(ST) of 0.238 (P < 0.002) for cpDNA haplotypes indicates spatial structure of cytoplasmic genes among the studied populations. Similar patterns were found within a single young population (CAB) structured in patches and surrounded by a continuous cover of T. vulgaris where the F sub(ST) is 0.546 (P < 0.002). No significant correlation between sex and chlorotype nor between cpDNA diversity and female frequency was detected. Allozyme markers showed markedly less spatial structure (F sub(ST) = 0.021 among populations and 0.019 in the CAB population, P < 0.001). This difference between cpDNA and nuclear allozyme markers suggests that pollen dispersal is more important than seed dispersal both among and within populations1 aCuguen, J1 aCouvet, D1 aThompson, J, D1 aTarayre, M1 aSaumitou-Laprade, P  uhttp://muse.lib.auth.gr:9797/com/csa/?MuseHost=www-mi2.csa.com&MuseFirst=1&id=2&recnum=1&SID=720ce478dc2df80d779b696384a1418e&MusePath=/ids70/view_record.php02411nas a2200193   4500008004100000020001400041245018400055210006900239260001200308300001600320490000700336520162600343100001401969700001401983700001901997700001502016700002402031856016202055       1997                        eng d  a0002-912200aThe spatial genetic structure of cytoplasmic (cpDNA) and nuclear (allozyme) markers within and among populations of the gynodioecious Thymus vulgaris (Labiatae) in southern France0 aspatial genetic structure of cytoplasmic cpDNA and nuclear alloz  c1997///  a1675 - 16840 v843 aRecent advances in molecular biology have allowed the development of techniques to contrast spatial differentiation in nuclear and cytoplasmic genes and thus provide important data on relative levels of gene flow by pollen and seed in higher plants. In this paper, we compare the spatial structure of nuclear (allozymes) and cytoplasmic (cpDNA) genes among populations of the gynodioecious Thymus vulgaris in southern France. Based on a combination of three restriction enzymes (CfoI, EcoRV, and PstI), eight chlorotypes (combination of three restriction enzyme patterns revealed by Southern hybridization of Beta vulgaris cpDNA) were identified in the 13 studied populations. One chlorotype was particularly abundant and was detected in nearly all populations. Only one chlorotype was specific to a single population. Up to four different chlorotypes were observed in some populations. An F sub(ST) of 0.238 (P < 0.002) for cpDNA haplotypes indicates spatial structure of cytoplasmic genes among the studied populations. Similar patterns were found within a single young population (CAB) structured in patches and surrounded by a continuous cover of T. vulgaris where the F sub(ST) is 0.546 (P < 0.002). No significant correlation between sex and chlorotype nor between cpDNA diversity and female frequency was detected. Allozyme markers showed markedly less spatial structure (F sub(ST) = 0.021 among populations and 0.019 in the CAB population, P < 0.001). This difference between cpDNA and nuclear allozyme markers suggests that pollen dispersal is more important than seed dispersal both among and within populations1 aCuguen, J1 aCouvet, D1 aThompson, J, D1 aTarayre, M1 aSaumitou-Laprade, P  uhttp://muse.lib.auth.gr:9797/com/csa/?MuseHost=www-mi2.csa.com&MuseFirst=1&id=2&recnum=1&SID=720ce478dc2df80d779b696384a1418e&MusePath=/ids70/view_record.php