Development and polymorphism of simple sequence repeat DNA markers for the evergreen shrub Ilex leucoclada M.

We have developed 13 microsatellite loci from an enrichment library of genomic DNA in the evergreen shrub Ilex leucoclada. One hundred and eighty‐nine out of 432 clones were found to contain microsatellite repeats. Primer pairs were designed for 92 of these clones according to their sequence data. Thirteen of these primer pairs revealed polymorphism among 36 individuals sampled from 12 populations. Three to 27 alleles per locus were detected, and the expected heterozygosity ranged from 0.133 to 0.971. Because these 13 microsatellite markers showed high degrees of genetic variation, they should be useful tools for studying population and ecological genetics of I. leucoclada.     

Molecular evidence for hybridization ofIlex x wandoensis (Aquifoliaceae) by RAPD analysis

Based on the presence of intermediate morphological characters, such as serrated leaf margins and flower structures,Ilex x wandoensis was initially described as a putative natural hybrid betweenI. cornuta andI. Integra, and was formally described as a new hybrid species,I. x wandoensis C. F. Mill., and M. Kim. However, using molecular markers generated via random amplified polymorphic DNA (RAPD), we have now discovered hybridization in populations of theI. x wandoensis complex collected from Wando and Jeju Islands, Korea. Marker bands of the putative parent taxa also were found in some populations ofI. x wandoensis, confirming its hybrid origin. Morphological variability within and among those populations was confirmed by model-based clustering methods, using multilocus genotype data. Phenograms generated from RAPD bands indicated that some accessions ofI. x wandoensis clustered with one of the parental species. This implied the occurrence of hybridization and recurring backcrosses of the hybrid to both parents, resulting in various hybrid derivatives because of the segregation and recombination of traits.Ilex x wandoensis was more closely related toI. cornuta than toI. integra suggesting that it backcrossed more with the former than with the latter.     

The induction of spinescence in European holly leaves by browsing ungulates

Evidence is presented which suggests that the spinescence of leaves of European holly, Ilex aquifolium, deters feeding by ungulates and is induced by browsing. Spinescence decreased as leaf size increased; hence, spinescence may be achieved by reducing adult leaf size. Holly shrubs with very spiny leaves were browsed less often than less spiny shrubs. In the absence of browsing ungulates during a one year period, the spinescence of leaves of holly shrubs significantly decreased. Browsed shrubs exhibited reduced annual shoot growth, increased branching, and produced smaller leaves with high spinescence. The regrowth on browsed branches of holly trees was characterized by increased leaf spinescence relative to unbrowsed branches. Hence, the induced response was localized, thereby reducing the ability of browsing ungulates to exert selective pressures on holly trees.     

冬青科黑叶冬青的分类学修订

通过对标本和文献的研究,指出《中国植物志》中黑叶冬青的果枝图版和检索表存在的问题,澄清了《中国植物志》和《Flora of China》中将黑叶冬青(Ilex melanophylla H.T.Chang)被描述为粗枝冬青(Ilex robusta C.J.Tseng)的错误,并对黑叶冬青进行了分类学修订,在仅有的新种原文和模式产地植物志2种文献的基础上,补充和完善雄花枝、果序、果实、分核、分布等内容,将1～2果聚伞果序订正为1～3果聚伞果序,并重新编制了包括黑叶冬青在内的8个近缘种的检索表。     

湖南冬青属一新种

描述了湖南冬青一新种,壶果冬青（Ilex urceolatus C.B.Shang,K.S.Tang et D.Q.Du,sp.nov.）该种与细刺冬青（I.hylonoma Hu et Tang）和华中刺冬青（I.centrochinensis S.Y.Hu）有些相似,但其具有独特的特征与后两种有明显的区别,主要是新种叶缘波状,两側具10~19对尖锐细刺,果较大,宽9~12 mm,长11~17 mm,呈壶形,不为球形或近球形。该种发现于湖南涟源市金石镇栗坪村,2009年11月8日由杜多青和唐开山采集。模式标本（Holotype 2009118,NF）保存在南京林业大学标本室。     

Tree growth-climate relationship in the Azorean holly in a temperate humid forest with low thermal amplitude

Dendroclimatic records in areas with high relative humidity and low thermal amplitude are manifestly scarcer and only a few studies are applied to species that are present in areas with weak seasonality. The Azores archipelago with temperate climate, with low thermal amplitude, has unique biodiversity, including the Azorean holly, Ilex azorica Gand., that is dominant in most extant natural forests. Hence, the importance of understanding its behavior and relation with climate. In this study, we try to understand tree-ring patterns of this species and examine the relationship between radial tree growth and main climatic drivers. For this purpose, we sampled four populations from São Miguel Island and two from Terceira Island. We found a diffuse-ring porous wood with a common layer of vessels associated to the ring boundary, which was critical to identify annual tree-rings. Generalized linear models were used to relate different variations of temperature and precipitation parameters, resulting into a diverse climate-growth relationships of different populations, while the composite population exhibited pronounced effect of temperature. We conclude that, I. azorica forms reliable annual tree-rings, which can be statistically related to climate, mostly temperature. However, there are differences among specific sites, thus the climate sensitivity depends on other site characteristics, such as soil and slope, but probable also to other ecological drivers, such as the competition, water drainage, among others.     

Anthocyanins of holly fruits

Anthocyanin distribution in the fruits of Ilex closely followed an accepted taxonomic classification. Within the evergreen subgenus Aquifolium, species belonging to section Lioprinus produced only cyanidin pigments while in section Aquifolium, pelargonidin was the major anthocyanin. Likewise, in the deciduous subgenus Prinos, species of section Prinoides contained cyanidin pigments and those of section Euprinus had pelargonidin compounds. Exceptions to this pattern and the bearing of pigment studies on breeding are discussed.     

Sex ratios, size distributions, and sexual dimorphism in the dioecious tree Ilex aquifolium (Aquifoliaceae)

Sex ratio and sexual dimorphism in physiology and growth were studied in the dioecious tree Ilex aquifolium at two localities in northern Spain. Genet sex ratio was significantly male biased in one locality but not in the other. However, ramet and flowering ramet sex ratios were male biased at both study sites. Males had significantly thicker main trunks than females in one locality and produced more ramets in the other. Growth rate, estimated from mean width of annual rings, did not differ between localities, but males produced wider rings than females at both sites. Mean annual growth rates over the last 10, 20, and 30 yr were significantly higher for males. Measurements of chlorophyll fluorescence indicated that the efficiency of photosynthesis of leaves on nonfruiting branches of females was higher than for leaves on branches of male plants under low-light conditions, though not under saturating-light conditions. Efficiency of photosynthesis was significantly lower on fruiting branches of female plants than on nonfruiting branches. We discuss whether the observed between-sex differences are attributable to the higher cost of reproduction in females and/or to pollen competition.