Chen L.-Y.,Zhejiang University |
Cao Y.-N.,Zhejiang University |
Yuan N.,Zhejiang University |
Nakamura K.,Academia Sinica, Taiwan |
And 2 more authors.
Molecular Breeding | Year: 2015
Neolitsea sericea (Lauraceae), endemic to East Asian land-bridge islands, is an economically important tree species because of its characteristic aroma and timber uses. However, due to the lack of efficient molecular markers, the genetic diversity and historical demography of this endemic species is not clearly understood. In this study, we performed high-throughput transcriptome sequencing of N. sericea leaves using the Illumina HiSeq™ 2000 sequencing platform, and generated large transcript sequences for functional characterization and development of gene-associated SSR markers. A total of 68,624 unigenes (mean length 733 bp) were assembled from about 54.7 million reads, and 41,130 (59.94 %) unigenes of all the assembled unigenes showed similarity to public databases. From 68,624 unigenes, 13,213 expressed sequence tag–simple sequence repeats (EST-SSRs) were identified. Di-nucleotide SSRs were the most abundant motif (36.5 %), followed by mono- (32.3 %) and tri-nucleotide (26.5 %) repeats. From the 13,213 EST-SSRs, 1191 primer pairs were designed for marker mining. After selecting 131 of these pairs at random for further validation, 13 polymorphic pairs were identified as polymorphic SSR loci. These 13 EST-SSR markers showed intermediate levels of genetic diversity (e.g., NA = 7.15; mean HE = 0.51) when surveyed across six populations from East China (2), Taiwan (1), Korea (1), and the Ryukyus (1) and Honshu (1) of Japan. Both genetic distance and structure analyses identified two genetic clusters largely congruent with recent findings revealed by variations in chloroplast DNA sequences and genomic SSRs. The EST-SSR markers developed in our research will be an information resource for future studies on ecological, evolutionary, and conservation genomics in N. sericea. © 2015, Springer Science+Business Media Dordrecht.
Xu J.-K.,Dongsha Town People's Government |
Chen W.,Zhoushan Forestry Academy |
Wang J.,Zhoushan Forestry Academy |
Fei X.-H.,Zhoushan Forestry Academy
Chinese Journal of Ecology | Year: 2015
A field experiment was conducted in a nursery of Zhoushan Forestry Institute in 2013 to compare the effects of different fertilization strategies [ i.e. no fertilization (CK) , one-time fertilization (DF) , linear fertilization (LF) , average fertilization (AF) and exponential fertilization (EF)] on growth and nutritional characteristics of M. thunbergii seedlings. The results showed that the treatment effect on plant height, ground diameter and biomass followed the order of EF> AF>LF>DF>CK. The height and basal diameter in EF treatment were significantly higher than in DF and CK (P<0.05), the total biomass and the nutrient contents in EF treatment were higher than in the other four treatments, but there was no significant difference between AF, LF and DF. As compared to DF, LF and AF, fertilizer efficiency by EF increased by 0.89, 1.42 and 1.73 times, respectively. © 2015, editorial Board of Chinese Journal of Ecology. All rights reserved.