Introgressive hybridization in two southern California species of Rhus (Anacardiaceae)

Five populations ofRhus integrifolia andR. ovata were studied and, based upon morphological characteristics and pollen viability, a number of putative hybrids were found in those areas where the two species are sympatric. Diagnostic characteristics most useful for distinguishing the species and their hybrids are leaf morphology, sepal pubescence, petiole length, and petal size. Introgression was evident in at least three populations, which suggested that hybridization between the two species is an ancient phenomenon. Evolutionarily, hybridization between the two taxa has probably been of little consequence.     

Laccase in Anacardiaceae

The presence of a typical laccase is demonstrated in the cavities of the secretory ducts of a number of species of the Anacardiaceae, including Mangifera indica and Schinus molle. In addition mango fruit contains catechol oxidase. The presence of laccase may be of chemotaxonomic value.     

Micropropagation of Anacardiaceae species of economic importance: advances and future prospects

The Anacardiaceae family comprises tropical and subtropical deciduous trees with growing economic potential namely, Pistacia vera L. (pistachio), Mangifera indica L. (mango), Anacardium occidentale L. (cashew), and Sclerocarya birrea (A. Rich.) Hochst. subsp. caffra (Sond.) Kokwaro (marula). The rich gene pool offered by their respective wide genetic diversity as well as the greater adaptation to semi-arid environments makes these species ideal candidates for the development of future commercial cultivars. Some notable achievements have been recorded in the micropropagation of these Anacardiaceae species in the order M. indica > P. vera > A. occidentale > S. birrea subsp. caffra. This review highlights advances, challenges, and future prospects in micropropagation research of these Anacardiaceae family members for the past three decades. In addition, the review discusses the potential of liquid cultures and synthetic seed encapsulation technologies in the development of future research strategies.     

Embryology and fruit development in four species of Pistacia L. (Anacardiaceae)

Pistacia atlantica, P. palaestina, P. lentiscus and P. saportae , were found to have great similarity in their embryology and fruit development. The anatropous, pendulous and crassinucellate ovule was initially unitegmic; later, the integument split close to the micropyle, forming a partial second integument. After anthesis there was a development of a hypostase and an obturator. The development of the Polygonum-type embryo sac followed division of a megaspore mother cell, giving a tetrad or triad of megaspores. The functional megaspore was the chalazal one. The ovary developed into a mature pericarp after anthesis, even when pollination was prevented, and before the zygote divided. Therefore, the fruit can be parthenocarpic. The ovule started to grow after initiation of embryo development until it filled the cavity within the pericarp. The zygotes were dormant for 4–18 weeks after pollination. In P. saportae reproduction became arrested during the development of the embryo sac; only very few abnormal embryos were found. No fixed pattern of embryo development could be discerned. The endosperm was initially nuclear, becoming cellular when the embryo started to develop. The seed coat was derived from the integument and the remnants of the nucellus.     

Karyotype differentiation among Spondias species and the putative hybrid Umbu-cajá (Anacardiaceae)

Spondias L. comprises at least nine Neotropical species, including the widely cultivated S. monbim and S. tuberosa. Umbu‐cajá, a putative hybrid between these two species, is also grown. In this paper, the karyotypes of five Spondias species and Umbu‐cajá were analysed for evidence of this hybridization. Chromosome banding with chromomycin A₃ and the distribution of 5S and 45S rDNA sites were used to characterize the plants, also genomic in situ hybridization using nuclear DNA from both putative parents and the hybrid as probes. All material presented the same chromosome number (2n = 32) and morphology, but differed in the number and distribution of bands. Spondias monbim and S. tuberosa, the supposed relatives of Umbu‐cajá, displayed similar banding patterns, with five to six chromosome pairs having terminal bands, whereas Umbu‐cajá exhibited bands on both members of nine chromosome pairs. The three other species, S. venulosa, S. cytherea and S. purpurea, showed less closely related karyotypes, with bands in 12–18 chromosome pairs. In situ hybridization with 5S and 45S rDNA probes revealed one site of each probe per haploid chromosome complement in all material. However, in S. tuberosa, the location of 5S rDNA was different from the other species and found no counterpart in Umbu‐cajá. Several tests with total DNA from S. mombin and S. tuberosa against metaphase chromosomes of Umbu‐cajá failed to differentiate the individual genomes in the hybrid. From the chromosome banding and the distribution of rDNA sites, as well as from the genomic in situ hybridization, it seems clear that Umbu‐cajá is related closely to S. monbim and S. tuberosa, but it is karyotypically homozygous and distinct from theses other species. Karyotypically, the three other investigated species were related less closely to Umbu‐cajá. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155 , 541–547.     

Allocation to reproduction and relative reproductive costs in two species of dioecious Anacardiaceae with contrasting phenology

Background and Aims

The cost of reproduction in dioecious plants is often female-biased. However, several studies have reported no difference in costs of reproduction between the sexes. In this study, the relative reproductive allocation and costs at the shoot and whole-plant levels were examined in woody dioecious Rhus javanica and R. trichocarpa, in order to examine differences between types of phenophase (i.e. physiological stage of development).

Methods

Male and female Rhus javanica and R. trichocarpa were sampled and the reproductive and vegetative allocation of the shoot were estimated by harvesting reproductive current-year shoots during flowering and fruiting. Measurements were made of the number of reproductive and total current-year shoots per whole plant, and of the basal area increment (BAI). The numbers of reproductive and total current-year shoots per 1-year-old shoot were counted in order to examine the costs in the following year at the shoot level.

Key Results

A female-biased annual reproductive allocation was found; however, the ratio of reproductive current-year shoots per tree and the BAI did not differ between sexes in Rhus javanica and R. trichocarpa. The percentage of 1-year-old shoots with at least one reproductive current-year shoot was significantly male-biased in R. trichocarpa, but not in R. javanica, indicating that there was a relative cost at the shoot level only in R. trichocarpa. The female-biased leaf mass per shoot, an indicator of compensation for costs, was only found in R. javanica.

Conclusions

Relative reproductive costs at the shoot level were detected in Rhus trichocarpa, which has simultaneous leafing and flowering, but not in R. javanica, which has leafing followed by flowering. However, the costs for the whole-plant level were diminished in both species. The results suggest that the phenophase type may produce the different costs for R. javanica and R. trichocarpa through the development of a compensation mechanism.Key words: Modularity, phenology, reproductive allocation, reproductive cost, Rhus javanica, Rhus trichocarpa     

Application of IUCN criteria and Red List categories to species of five Anacardiaceae genera in Madagascar

The conservation status of five genera of Anacardiaceae in Madagascarwas determined by applying IUCN risk assessment criteria to recent taxonomicrevisions and available specimen data. A major problem in establishing protocolsfor efficiently protecting and conserving Madagascar's biodiversity is the lackof essential biological information. In light of this, primary occurrence dataappears to be an invaluable tool for assessing both current and historic speciesdistributions. GIS technology was used to create species distribution maps forhistoric vs. recent occurrence data to analyze the change in conservationstatus, extent of occurrence, and area of occupancy for each of the targetspecies. A GAP analysis reveals that 14 (100%) of the target species for whichdata were available are considered threatened by IUCN standards. Furthermore, 11(79%) species showed a decrease both in the number of subpopulations and theirextent of occurrence when compared to historic distributions. This studyhighlights the importance of two factors necessary to address modernconservation questions. Sound conclusions regarding the conservation status ofindividual species requires a strong taxonomic framework and good collectiondata for a species distribution. However, because specimen data are very oftenincomplete and biased both geographically and taxonomically, reaching soundconclusions requires field knowledge of individual species to compensate forthese limitations.     

A new species of Tapirira (Anacardiaceae) from the Isthmus of Tehuantepec,Mexico

Tapirira chimalapana is a new species of tree common in the rain forests and lower montane forests of the Isthmus of Tehuantepec in the Mexican states of Veracruz and Oaxaca. It is most similar to the AndeanT. guianensis Aubl. subsp.subandina Barfod &; Holm-Niels. but differs from this and all other congeners by having larger petals on pistillate flowers than on staminate flowers and by pubescence features. Details of field characteristics, distribution, ecology, phenology, germination, and local names and uses are included.     

Production of phenylacetylcarbinol in various yeast species

Summary Production of phenylacetylcarbinol (PAC) was measured in various yeast species. The yeast strains tested were cultivated under submerged conditions in a medium containing corn steep and sucrose as the main components; sucrose, acetaldehyde and benzaldehyde were added to the grown cultures. In a first series of experiments the initial rate of PAC production, i.e. the PAC production determined 30 min after the addition of benzaldehyde was determined in 38 yeast strains, mostly of the generaSaccharomyces andCandida. The amount of PAC produced varied from zero (12 strains) to 1.24 mg ml^–1. In a second series of experiments, 15 strains, which in the first series had shown a higher PAC production, were further tested. Sucrose, acetaldehyde and benzaldehyde were added to the cultures until the PAC production ceased. The highest PAC production (6.3 mg ml^–1) was reached in the strainSaccharomyces carlsbergensis Budvar; the production was slightly lower in 4 strains of the generaSaccharomyces, Candida andHansenula.     

Regeneration processes in various species of planarians

Blastema growth and functional maturation of the pharynx during regeneration in various planarian species were compared. The intensity of blastema growth was highest in Polycelis tenuis; the lowest, in Schmidtea mediterranea. In the sexual and asexual races of Girardia tigrina blastema growth differed inconsiderably. The function of the pharynx during the regeneration of caudal fragments lacking pharynx was manifested in G. tigrina in the usual amount of time, while in the regeneration of head fragments lacking pharynx, this function occured earlier. In other planarian species of the other two typed, the times of pharynx regeneration had no regular character and took longer compared to the same process in G. tigrina.     

漆树科植物漆酚的多样性及演化关系研究

漆酚是漆树科植物独有的化学成分,具有良好的抗氧化、抗肿瘤、抗病毒等生物活性,极具药物和工业生产开发价值。该研究通过对国内外有关漆树科各类群有关漆酚数据的搜集和整理,开展漆树科漆酚的多样性与分布情况的综合统计;同时在利用核基因ETS和叶绿体基因rps16和trnL-F重建漆树科系统发育树的基础上,探讨漆酚在漆树科及各属间的起源和演化关系。结果表明:(1)漆树科漆酚具有较高的多样性,在其苯环和-R链上都有很大的变异。(2)发现漆酚仅存在于Anacardioideae亚科中,是该亚科的一个重要界定特征。(3)基于漆酚苯环结构和-R链特征的祖先性状重建分析表明,漆树科的漆酚是由邻苯二酚向间苯二酚演化,而漆酚-R链的十五烃(烯)基则是向十七烃(烯)基平行演化。     

Floral structure and evolution in the Anacardiaceae

WANNAN, B. S. & QUINN, C. J, 1991. Floral structure and evolution in the Anacardiaceae. Carpel morphology and anatomy is investigated in 17 genera and carpellode morphology in 12 genera. There is an evolutionary sequence in the family from poorly differentiated, nearly apocarpous gynoecia towards syncarpous gynoecia with clearly defined stigmata, styles and ovaries. There has also been marked reduction culminating in pseudomonomery. The carpellodes of the male flowers appear more conservative, and provide evidence of affinities between genera with quite different fertile gynoecia. The characters have been polarized using Burseraceae as a sister group. Data from these sources, as well as from pericarp anatomy, wood anatomy and biflavonoid content indicate that the long standing intrafamilial classification into five tribes is artificial, and that the two small satellite families, Blepharocaryaceae and Julianiaceae should be included in the family. A large monophyletic group is recognized comprised of essentially four of the existing tribes (Anacardiëae, Dobineëae, Semecarpeae, Rhoëae), as well as the two satellite families. This group incorporates two subgroups of more closely allied genera. The remaining genera (mostly Spondiadeae) are very diverse, and for the present are placed in an artificial group characterised by a set of plesiomorphs. Relationships within this group must be resolved before a satisfactory taxonomy of the family can be achieved.     

Toxic oxygen species and protective systems of the chloroplast

Salin, M. L. 1988. Toxic oxygen species and protective systems of the chloroplast. -Physiol. Plant. 72: 681–689.
As a consequence of living in an environment enriched in oxygen, which they themselves at least partially generate, photosynthetic organisms are exposed to large fluxes of oxyradicals and reactive oxygen species. Among these are superoxide, hydrogen peroxide, hydroxyl radical and singlet oxygen. These highly reactive intermediates pose the threat of toxicity unless neutralized by scavenger substrates or enzymes. The production of oxyradicals and intermediates by chloroplasts as well as the means of protection are discussed in this review.