DNA and seed orchards

Witness reports about what was learnt of relevance to seed orchards in the foreseeable future from the meeting “Application of DNA based tools for genetic research, molecular breeding, management and monitoring of genetic resources” immediately preceding the seed orchard conference. All participants registered for both meetings were suggested to make statements, five volunteered, the statements are listed below.

Darius Danusevicius: Development of DNA markers for the DNA sequences associated with phenology traits would especially be desirable for reproduction genetics with the ultimate aim to test the hypothesis of "future pre-recorded in the past"- is there a pattern in environmental variation during gamethogenesis, fertilization and embryogenesis to affect the genetic and epigenetic variation of the future generations? We also may use epigentic technologies to manipulate trees: e.g. silencing by RNRi. Better understanding of genomic imprinting and paramutation in trees: reciprocal crossings among individuals with contrasting flowering traits with known specific-allele markers to identify presence of absence of a particular allele and phenotypic expression of the trait.

Yousry El-Kassaby: The precise estimation of clonal gametic contribution to seedlots has never been a challenge for the maternal component point of view; however, the paternal side is a daunting task. The problem is not only restricted to the “within” orchard paternal contribution but also is to when and how much the “outside” pollen migration takes place. Recently the combined use of DNA fingerprinting technology and pedigree reconstruction, not only made the parental contribution determination possible, but also it allowed us to estimate it to the individual clone level and by phonological classes. The more we work and develop the necessary tools, the better our gene resource management gets.

Maria Gaspar: DNA based tools, like SSR markers, are now being used in different aspects of seed orchard management. These tools can assist the resolution of some existent dysfunctions in the clonal seed orchard, through clone identification, evaluation of pollen contamination, selfing rates and percentage of pollen contribution. Moreover, they can be very useful to obtain better estimations of genetic parameters used in tree-breeding programs. In populations where plus trees are selected, pedigrees are usually unknown, and it is assumed that all plus trees are genetically unrelated. Deviations from this assumption may lead to greater inbreeding and loss of genetic gain. Thus, genetic markers can be used for pedigree reconstruction, evaluation of the coancestry coefficient, providing more accurate estimations, increasing the predictable improvement of economical important traits

Øystein Johnsen: To become more efficient, we should implement fingerprint technology in tree breeding along the guidelines presented as “Breeding without breeding”. Marker-based breeding can be brought to applications within the next five years, we heard. A new EU-project (NOVELTREE) will reveal if this is realistic for more tree species. We need to explain why phenotypes do respond differently to identical environmental cues. Is variation in gene regulation (leading to quantitative difference in gene products) causally more important than sequence difference in structure genes (giving qualitative difference within gene products)? Search for DNA variation in promoter regions, in genes coding for transcription factors, as well as in regions coding for microRNAs, will tell us if we can use DNA variation as a major predictive tool in future breeding.

Xiao-Ru Wang: Genomic research and investigations into the molecular mechanisms controlling important traits, such as growth cessation, bud set, flower initiation, and wood quality, are progressing fast in Populus. In conifers, the on-going large scale genome scan and candidate gene-based association studies will gradually provide valuable information on the genetic architecture underlying adaptive and productive traits. At current stage, the most relevant applications of molecular techniques in tree breeding are in the areas of evaluation of genetic resources and the function of breeding programs, seed lots classification, and forest and nursery healthy examinations. The use of high-resolution DNA markers for pedigree reconstruction in open pollinated progenies of seed orchard, as BWB suggested by El-Kassaby, is an example of how molecular techniques can facilitate an innovative breeding strategy for outcrossing conifers.

Is there some more who participated in both conferences who like to make a similar statement (less than 125 words)? Or make a comment to some of the statements above? Or some of those who already contributed who want to modify what they said? You are welcome to try!