Single-copy,species-transferable microsatellite markers developed from loblolly pine ESTs

Microsatellites, or simple sequence repeats (SSRs), are usually regarded as the markers of choice in population genetics research because they exhibit high variability. The development cost of these markers is usually high. In addition, microsatellite primers developed for one species often do not cross-amplify in related species, requiring separate development for each species. However, microsatellites found in expressed sequence tags (ESTs) might better cross-amplify as they reside in or near conserved coding DNA. In this study, we identified 14 Pinus taeda (loblolly pine) EST-SSRs from public EST databases and tested for their cross-species transferability to P. contorta ssp. latifolia, P. ponderosa, and P. sylvestris. As part of our development of a P. contorta microsatellite set, we also compared their transferability to that of 99 traditional microsatellite markers developed in P. taeda and tested on P. contorta ssp. latifolia. Compared to traditional microsatellites, EST-SSRs had higher transfer rates across pine species; however, the level of polymorphism of microsatellites derived from ESTs was lower. Sequence analyses revealed that the frequencies of insertions/deletions and base substitutions were lower in EST-SSRs than in other types of microsatellites, confirming that EST-SSRs are more conserved than traditional SSRs. Our results also provide a battery of 23 polymorphic, robust microsatellite primer pairs for lodgepole pine.Communicated by O. Savolainen     

Characterization of microsatellite loci in white pine weevil (Pissodes strobi)

Microsatellites are codominant and highly polymorphic genetic markers. They are widely used in studying parentage and reproductive success in many insect species. We developed six microsatellite markers in Pissodes storbi. The number of alleles per locus ranges from 5 to 16 alleles, with a mean number of 10. The high allelic diversity observed in this study showed that they could be useful in the study of parentage and reproductive success in P. strobi.     

Identification of COS markers in the Pinaceae

Conserved ortholog set (COS) markers are evolutionary conserved, single-copy genes, identified from large databases of express sequence tags (ESTs). They are of particular use for constructing syntenic genetic maps among species. In this study, we identified a set of 1,813 putative single-copy COS markers between spruce and loblolly pine, then designed primers for 931 of these markers and tested these primers with DNA from spruce, pine, and Douglas fir. Of these 931 primers, 56% (524) amplified a product in both spruce and pine, and 71% (373) of these were single-banded; 224 amplicons were single-banded in all three species. Even though these COS markers were selected from large EST databases, a substantial proportion (20–30%) of amplicons displayed multiple bands or smears, suggesting significant paralogy. Sequencing of three single-banded amplicons showed high nucleotide similarities among 29 conifer species, suggesting orthology of single-banded amplicons. Screening for COS marker polymorphism in two pedigrees of white spruce and two pedigrees of loblolly pine revealed an average informativeness of 36% for spruce and 24% for pine (e.g., at least one parent was heterozygous for a single-nucleotide polymorphism within the entire amplified product). This corresponds to an average nucleotide heterozygosity of 0.05% and 0.03%, respectively, which is considerably lower than that found in other studies of spruce and pine. Thus, the advantages of COS markers for constructing syntenic maps are offset by their lower polymorphism. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Rapid method for DNA isolation from a tough cell wall green alga <Emphasis Type="Italic">Tetraspora</Emphasis> sp. CU2551

Genetic studies are important to understand the complex biological system of various organisms. Some eukaryotic green organisms have tough cell wall which precludes the efficient extraction of the genetic materials. Here, we developed the method for simple and rapid isolation of high quality DNA from a green alga Tetraspora sp. CU2551. The cell homogenization procedures were combined with physical force plus heat treatment to disrupt the cell envelope of Tetraspora sp. CU2551. Without protease treatment, vortexing with glass bead for 30–105 s at 70 °C led to the isolation of a high purity DNA which was suitable for downstream process. The improved method was successfully developed and could be applied for the rapid isolation of DNA from other unicellular and filamentous green microalgal strains.     

Breeding without Breeding: Is a Complete Pedigree Necessary for Efficient Breeding?

Complete pedigree information is a prerequisite for modern breeding and the ranking of parents and offspring for selection and deployment decisions. DNA fingerprinting and pedigree reconstruction can substitute for artificial matings, by allowing parentage delineation of naturally produced offspring. Here, we report on the efficacy of a breeding concept called "Breeding without Breeding" (BwB) that circumvents artificial matings, focusing instead on a subset of randomly sampled, maternally known but paternally unknown offspring to delineate their paternal parentage. We then generate the information needed to rank those offspring and their paternal parents, using a combination of complete (full-sib: FS) and incomplete (half-sib: HS) analyses of the constructed pedigrees. Using a random sample of wind-pollinated offspring from 15 females (seed donors), growing in a 41-parent western larch population, BwB is evaluated and compared to two commonly used testing methods that rely on either incomplete (maternal half-sib, open-pollinated: OP) or complete (FS) pedigree designs. BwB produced results superior to those from the incomplete design and virtually identical to those from the complete pedigree methods. The combined use of complete and incomplete pedigree information permitted evaluating all parents, both maternal and paternal, as well as all offspring, a result that could not have been accomplished with either the OP or FS methods alone. We also discuss the optimum experimental setting, in terms of the proportion of fingerprinted offspring, the size of the assembled maternal and paternal half-sib families, the role of external gene flow, and selfing, as well as the number of parents that could be realistically tested with BwB.     

The Use of Asian Ficus Species for Restoring Tropical Forest Ecosystems

Fig (Ficus spp.) trees have been promoted as framework species for tropical forest restoration throughout Asia, because they are considered to be keystone species. This article presents optimal propagation and planting techniques for six Asian dioecious Ficus species, which will enable their inclusion in forest restoration plantings across the Asia‐Pacific region: Ficus auriculata, F. fulva, F. hispida, F. oligodon, F. semicordata, and F. variegata. Nursery experiments compared the growth performance of propagating planting stock from seed and from leafy cuttings, whereas field experiments assessed the cost‐effectiveness and the relative performance of (1) direct seeding, (2) planting stock from seed, and (3) planting stock from cuttings. The most efficient method of producing Ficus spp. was from seed. Propagation from cuttings was much less successful. Seedlings produced from seed had the highest rates of growth and survival both in the nursery and in field trials. In field trials, use of planting stock from seed was also more cost‐effective than direct seeding and vegetative propagation. Establishment costs calculated on the basis of “per plant established” were $1.14 for seed, $6.95 for cutting, and $25.88 for direct seeding.     

Response of green alga Tetraspora sp. CU2551 under potassium deprivation: a new promising strategy for hydrogen production

Journal of Applied Phycology - With increasing world energy consumption, renewable energy sources can fulfill the need and many have net zero carbon dioxide emissions. One of these is hydrogen,...