Method for evaluating embryonic embryonic lethal gene using megagametophyte of conifer seeds: Method for applicable to outcross or open pollinate seeds

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K05744
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40010:Forest science-related
• Research Institution: Gifu University
• Principal Investigator: Mukai Yuzuru 岐阜大学, 応用生物科学部, 教授 (80283349)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 胚致死遺伝子 / 連鎖地図 / 2親性近交弱勢 / 胚乳 / 分離比

Outline of Final Research Achievements

Linkage maps for the parent trees used for out-cross and selfing were constructed using the SSRs and the SNPs obtained by MIG-seq analysis and identified the respective linkage group (LG) of consensus map Cryptomeria japonica. Using the megagametophytes of the seed, the segregation ratio were scanned along at the loci located on the linkage maps for parent trees.
Although the loci mapped on the LG11 showed significant distorted segregation in the out-cross seeds, significant segregation did not find in the selfing seeds of the both parents. Loci showing marginal significant distortion among the cross- and selfing seeds were found in the LG10, suggesting effect of biparental inbreeding depression.
Because of low genome coverage (60%) of the linkage maps and incomplete haplotype data in many loci, location and effect of embryonic lethal loci could not analyzed. In addition, because of the low seed soundness, effect of embryonic lethal loci in open pollinated seeds could not evaluated.

Free Research Field

森林遺伝学

Academic Significance and Societal Importance of the Research Achievements

他殖及びその両親の自殖種子の胚乳を用いて、両親の連鎖地図を作成し、連鎖地図上の位置が共通で偏った分離比を示す遺伝子座を探索した。有為ではないが、他殖および自殖家系に共通する偏った分離比を示す遺伝子座が見つかった。この結果から、２親性近交弱勢に起因する胚致死遺伝子座の存在が示唆された。残念ながら分離データの欠測値が多かったため、研究目標を完全に達成することができなかったが、理論上、胚乳を用いる分析は他殖や自然受粉種子にも応用できる有効な配置し遺伝子検出法であると思われる。研究目標の達成には、不完全な分離データの原因となる不完全な胚乳の単離やDNAの収量不足などを改良する必要がある。