The momi fir (Abies firma) has been targeted as a species for genetic resource conservation because of the recent decline in its natural populations. Additional molecular marker resources are needed to examine gene flow to understand the genetic dynamics of each population. We developed 15 genomic microsatellite (SSR) markers for A. firma and applied them to separate biparentage assignments of dispersed seeds in a natural population by assaying embryos and megagametophytes. The 15 markers were polymorphic, with the expected heterozygosity averaging greater than 0.74. Separate biparentage analysis, using the seven selected effective markers, was successful to assign paternal and maternal trees separately and thus estimate the paternal and maternal immigrant gene flow from nearby populations. The newly developed genomic SSR markers in the present study, by constructing a marker set together with previously developed markers, will provide higher discriminatory power for parentage analysis and should be useful for estimating gene flow for ongoing conservation genetics studies of A. firma.

In the twentieth century, a substantial decline in Pinus thunbergii populations in Japan occurred due to the outbreak of pine wood nematode (PWN), Burshaphelencus xylophilus. A PWN-P. thunbergii resistant trees-breeding project was developed in the 1980s to provide reforestation materials to minimalize the pest damage within the population. Since climate change can also contribute to PWN outbreaks, an intensive reforestation plan instated without much consideration can impact on the genetic diversity of P. thunbergii populations. The usage and deployment of PWN-P. thunbergii resistant trees to a given site without genetic management can lead to a genetic disturbance. The Iki-no-Matsubara population was used as a model to design an approach for the deployment management. This research aimed to preserve local genetic diversity, genetic structure, and relatedness by developing a method for deploying Kyushu PWN-P. thunbergii resistant trees as reforestation-material plants into Iki-no-Matsubara. The local genotypes of the Iki-no-Matsubara population and the Kyushu PWN-P. thunbergii resistant trees were analyzed using six microsatellite markers. Genotype origins, relatedness, diversity, and structure of both were investigated and compared with the genetic results previously obtained for old populations of P. thunbergii throughout Japan. A sufficient number of Kyushu PWN-P. thunbergii resistant trees, as mother trees, within seed orchards and sufficient status number of the seedlings to deploy are needed when deploying the Kyushu PWN-P. thunbergii resistant trees as reforestation material planting into Iki-no-Matsubara population. This approach not only be used to preserve Iki-no-Matsubara population (genetic diversity, genetic structure, relatedness, and resilience of the forests) but can also be applied to minimize PWN damage. These results provide a baseline for further seed sourcing as well as develop genetic management strategies within P. thunbergii populations, including Kyushu PWN-P. thunbergii resistant trees.

Major conifer species with a widespread geographic distribution are growing under diverse climatic conditions. For such species, populations in regions with low resource availability, where producing additional cones is costly, presumably have more individuals that produce larger, highly viable cones with a higher resource-use efficiency. Geographic variations in cone characteristics (cone and seed size, seed production and productivity per cone) were examined for 28 Pinus densiflora natural populations (628 trees) across the species’ distribution in Japan. The degree of phenotypic differentiation across populations (P_ST) varied among the ten characteristics investigated. The average P_ST value (0.139) was higher than the previously reported neutral genetic variation of the species (F_ST = 0.013). The more northeastern populations produced cones of larger size (in length, width and mass), had higher seed production (number of filled seeds, seed mass per cone) and had higher seed productivity (indicators for seed production per cone development cost). A generalized linear mixed model showed that geographic variation in cone size and seed productivity per cone of populations was correlated negatively with annual solar radiation and mean temperature. The larger cone size and higher seed productivity per cone observed in northeastern populations support the hypothesis of higher resource-use efficiency, and could result from a genetic or plastic response under lower temperature and less radiation.

四国の固有樹種シコクシラベの集団レベルでの遺伝子保存（生息域外保存）について検討するため，石鎚山の成木集団の2豊作年（2011年，2014年）において母樹別に採種した種子プールの遺伝的多様性を，核マイクロサテライト（SSR）マーカー6座に基づき評価した。採種母樹間での種子プールの遺伝的多様性の違いについて把握するとともに，2014年種子のデータについて，母樹の無作為抽出プログラミングにより採種母樹数の増加に伴う種子プールの遺伝的多様性の推移を解析し，成木集団との比較を行った。その結果，胸高直径の小さい採種母樹ほど種子プールの遺伝的多様性が高い傾向が，2豊作年で一貫して認められた。希薄化曲線に基づく採種母樹数と得られる種子プールの遺伝的多様性の関係は統計量によって違いが見られた。しかし，対立遺伝子の有効数とヘテロ接合体率の期待値においては，おおむね30母樹前後で，成木集団と遜色なくかつ集団内の種子プールをほぼ補完するような遺伝的多様性が確保された。本研究の知見は，稀少樹種も含めた樹木集団の遺伝子保存のための種子の収集戦略（採種戦略）の策定に大きな示唆を与えるものである。

We developed 32 microsatellite markers from an enriched genomic DNA library of hinoki (Chamaecyparis obtusa), one of the most important Japanese forestry conifer species. From a total of 1,056 cloned plasmids, 96 sequence-specific primer pairs were designed from 110 candidate clones. We selected 32 primers that showed successful amplification and marked polymorphism and evaluated their characteristics using DNA from 38 C. obtusa elite trees planted in the Forest Tree Breeding Center. The markers were highly polymorphic, with the number of alleles ranging from 8 to 32 (mean: 20.09), and expected heterozygosity ranging from 0.811 to 0.958 (mean: 0.901). Progress in breeding projects and studies of the ecological genetics of this species can be expected through the use of this enlarged marker pool.