Sumathi M, Bachpai V K W, Deeparaj B, Mayavel A, Dasgupta Modhumita Ghosh, Nagarajan B, Rajasugunasekar D, Sivakumar V, Yasodha R
Institute of Forest Genetics and Tree Breeding, Coimbatore 641 002, India.
J Genet. 2018 Mar;97(1):323-329.
Eucalyptus is an important industrial species with tolerance to drought and salt stress. Genetic improvement activities including quantitative trait loci (QTL) mapping for pulping and adventitious rooting traits are in progress, but no information is available on the genomic regions on adaptive traits such as stomatal characteristics. In this study, an interspecific cross between Eucalyptus tereticornis and E. grandis was generated for the development of genetic map and QTL identification for stomatal traits. Simple sequence repeats (SSRs), inter-simple sequence repeats (ISSRs) and sequence related amplified polymorphism (SRAP)markers were used for genotyping the F1 individuals. Parent-specific geneticmaps (female, 1023.56 cM;male, 1049.64cM) and consensus map (1049.4 cM) were developed. QTL analysis was carried out to identify the chromosomal regions affecting stomatal density, area and pore length in adaxial and abaxial leaf surface. Seven QTLs were identified with phenotypic variation of 11.36 to 27.30% for stomatal density, area and pore length. Correlation of stomatal traits when combined with growth and wood properties would have greater implications for generation of stress tolerant eucalypt hybrids with higher productivity and adaptability.
桉树是一种重要的工业树种，具有耐旱和耐盐胁迫的特性。包括针对制浆和不定根性状的数量性状位点（QTL）定位在内的遗传改良活动正在进行中，但关于气孔特征等适应性性状的基因组区域尚无信息。在本研究中，为了构建遗传图谱和鉴定气孔性状的QTL，培育了尾叶桉和巨桉之间的种间杂交后代。利用简单序列重复（SSR）、简单序列重复区间（ISSR）和序列相关扩增多态性（SRAP）标记对F1个体进行基因分型。构建了亲本特异性遗传图谱（母本，1023.56 cM；父本，1049.64 cM）和整合图谱（1049.4 cM）。进行QTL分析以确定影响叶片近轴面和远轴面气孔密度、面积和孔长的染色体区域。共鉴定出7个QTL，其对气孔密度、面积和孔长的表型变异贡献率为11.36%至27.30%。气孔性状与生长和木材性质相结合的相关性，对于培育具有更高生产力和适应性的耐胁迫桉树杂交种具有更大的意义。
