Morphological and anatomical characteristics of needles in seedlings and vegetative progeny of different ages from mutational witches’ brooms of Pinus sibirica Du Tour

The study was carried out using three objects: 1) clones of the mutational witches’ brooms and the normal crown grafted together on the same rootstock; 2) mutant seedlings of the witches’ brooms; 3) clones of the witches’ brooms mutant seedlings. It was shown that the morphological and anatomical needle characteristics are affected as by the presence and the expression of the mutation, as well as the age of the maternal tree and the presence of a rootstock. Each factor and the interaction of some factors makes a significant contribution to the differences between the groups in the main needle characteristics. The mutant seedlings and their clones formed the shortest needles; they also had smaller areas of the central cylinder, resin ducts, mesophyll and vascular cylinder. Morphological and anatomical needle traits varied between the families, the needle length was a rather conservative trait in the families. Some differences between the groups from different families of witches’ brooms were due to the natural diversity of the maternal witches’ brooms.

Molecular Identification and Karyological Analysis of a Rampant Aspen Populus tremula L. (Salicaceae) Clone

A rampant highly heterozygous aspen (Populus tremula L.) clone “Meshabash” has been revealed in course of population genetic diversity analysis in a native stand in the Republic of Tatarstan, Russia. Here we report the results of karyological analysis showing that this highly vigorous clone is diploid (2n=38) while typically triploid aspen demonstrates increased growth rate and resistance to aspen trunk rot caused by fungus Phellinus tremulae. By means of DNA identification of a series of model trees using 14 SSR loci we outlined the area occupied by this clone (at least 1.94 ha) and demonstrated that its ramets constitute 40 out of 48 genotyped trunks on the plot with the maximal distance between ramets 254 m. Since aspen is able to regenerate after cutting or die-off of maternal tree by root suckers at a distance up to 20–35 m this assumed that current stand appeared as a result of such spreading from an ortet tree during at least 5 generations. Trunk rot damage in the wood of model trees indicated low influence of this pathogen on viability and performance of the studied clone that can be associated with its extreme heterozygosity level (0.926) exceeding all the studied trees in this research plot and in three other control samples.

About natural regeneration of English oak growing under the canopy of maternal stand

Oak is practically not renewed naturally under the canopy of maternal tree stand under the Central forest steppe. Conversion of oak natural regeneration in knots (with its subsequent total loss) caused by the complex of reasons: From the very young age oak needs enough amount of light (70…80 %). Based on our own research and careful study of the literature on this issue, we conclude that eventually the inability of oak to renew and grow under maternal canopy, changing generations, its biological property. Thus, oak, having formed forest environment, provides the further evolution of forest ecosystems of forest steppe within it.

Using Simple Sequence Repeats (SSRs) to Measure Pollen Flow in a Flowering Dogwood Orchard

Dispersal of flowering dogwood pollen in an orchard was evaluated by performing parentage analyses on open pollinated seedlings collected from a single maternal tree. Pollen sources for 45 seedling trees were established using three polymorphic simple sequence repeat (SSR) loci. Previous data suggest that Cornus florida pollen is typically limited to travel between closely situated trees. If this is true, breeding may be simplified by crossing trees through open pollination rather than more laborious current methods involving pollination cages. However, the expected leptokurtic distribution, in which the likelihood that pollen transfer will occur between trees decreases quickly as distance increases, was not seen. Although the majority of paternal trees were located within the 12 m (39.4 ft) radius of the study area, the trees most likely to have donated pollen were some of those located the greatest distance from the mother tree. Unusual pollen movement may be explained, in part, by asynchronous flowering times of trees within the study or by genetic similarities exhibited between the mother tree and potential pollen donors in the area. Additionally, andrenid and halictid bees, which were the predominant pollinators observed at this site, may have moved pollen farther than expected.

Spontaneous Hybridization between Pinus sylvestris L. and P. mugo Turra in Slovakia

Molecular evidence for spontaneous hybridization between Pinus sylvestris L. and P. mugo Turra in the putative hybrid swarm populations of the species in Slovakia was provided based on PCR-RFLP analysis of the cpDNA trnV-trnH region. Species-specific restriction profiles generated by Hinf I digests of the cpDNA products reliably identified P. sylvestris and P. mugo haplotypes of the embryos from open pollination. Simultaneous analysis of the respective cpDNA region in megagametophytes and embryos of individual seeds along with needles of a given maternal tree has enabled to score either the P. sylvestris or P. mugo haplotypes in the embryos illustrating hybridization patterns between the two species. Data obtained in this way indicate a relatively extensive hybridization which takes place between P. sylvestris and P. mugo. The extent of hybridization varied among populations as evidenced by the 41.1-58.7% proportion of hybrid embryos registered on the locality Habovka, and by the 8.3% and 2.7% proportions of hybrid embryos on the localities Tisovnica and Sucha Hora, respectively. The approach itself is recommended as a convenient method for monitoring the hybridization patterns in sympatric zones of the studied pine species.

The development of habitat selection by subadult koalas

Dispersal by subadults is the principal source of gene flow between groups of koalas in Queensland, so understanding the behaviour of these immature animals is a priority for understanding the ecology of the species. Recent reports postulate that dispersing young koalas may inherit maternal tree selection, but avoid competing with adults. We compared the tree use and diet of adult female koalas with that of their offspring on St Bees Island, Queensland, using radio-tracking and faecal cuticle analysis, to examine this prediction. Koalas at St Bees Island used both fodder and non-fodder species during daytime, moving into fodder species at night. Koala diets were dominated by Eucalyptus tereticornis with E. platyphylla and Corymbia intermedia also represented. Utilisation of daytime tree species was diverse, but at night koalas were found almost exclusively in those species present in their diet. Use of trees during daytime by natal young and young adult koalas were similar to that of maternal adults, but tree use by intermediate stages (independent and dispersing young) during daytime varied from that of the mothers. This resource separation indicates that if tree utilisation for resting is learned from the mother, young animals are excluded from preferred trees while dispersing.

Genetic Studies in Peach: Inheritance of Sweet Kernel and Male Sterility

Inheritance of the sweet kernel trait was studied in F1 and F2 families generated by crossing `Summer Beaut' nectarine (sweet kernel) with `Ellerbe' and `Biscoe' peach. F1 plants showed bitter kernel. Segregation in the F2 fit a 3 bitter : 1 sweet phenotypic ratio, suggesting that sweet kernel is controlled by a single recessive gene, for which the symbol sk is proposed. Sweet kernel (sk) was linked to nectarine (g) at a map distance of 12 cM. Seed bitterness phenotype is controlled by the genotype of the maternal tree and not the genotype of the individual embryo. Inheritance of male sterility derived from plant introduction (PI) 240928 and allelism of male sterile genes found in `Chinese Cling' and `White Glory' were investigated. Analysis of F1, F1 open-pollinated, and BC1 families derived from crossing PI 240928 with six different wild-type cultivars showed that male sterility in PI 240928 is controlled by cytoplasmic factors. Allelism studies showed that the male-sterile gene found in `White Glory' is not allelic to ps found in `Chinese Cling', and hence is designated ps2.