Review of forests, wood products and wood biotechnology of Iran and Germany - Part II

The germination of freshly collected Juniperus polycarpos (K. Koch) seeds is very low and attributed to the large proportion of nonviable seeds in the seed lots. Thus, the aim of this study was to improve seed lot quality by removing nonviable seeds using two flotation techniques: incubation-drying-separation (IDS) and modified specific gravity (MSG) separation. We examined different IDS conditions (the specific incubation time, subsequent drying time and sorting media) for effectively sorting out nonviable seeds; and tested the feasibility of modified SG separation, which involved soaking seeds in water for a certain period before sorting in different concentrations of sucrose solution. Viable seeds were expected to absorb and metabolically bind more water during soaking than dead seeds could, and hence be sorted effectively depending on the viscosity of the sucrose solution. The viability of the seeds that floated or sank was determined in a topographical tetrazolium chloride (TTC) test. For the IDS trial, 7 days incubation followed by 9 h of drying and sedimentation in pure water or 200 gÁL -1 sucrose solution identified, respectively, 75 and 82 % of the seeds as viable (sunken) seeds. For the MSG trail, 77 % viable seeds were recovered in the sunken fraction when seeds were soaked for 48 h then immediately sorted in 600 gÁL -1 sucrose solution. In both cases, the loss of viable seeds in the discarded floating fraction was only 4 %. The results demonstrate that both IDS and MSG separation techniques substantially improved seed lot viability, but MSG separation is simple and needs no modern seed handling facility, and its efficacy relies on seed mass (due to the initial soaking) and the specific density and viscosity of the flotation medium.

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Araniella cucurbitina : the first molecular evidence of a Palearctic species of genus Araniella inhabiting India

Rajpoot

Kumar

Bahuguna

et al. 2017

Mitochondrial DNA Part A

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The present study represents first genetic record of single spider species Araniella cucurbitina, genus Araniella from Uttarakhand, India. There are 12 identified species under Araniella genus and they are distributed in Palearctic region. Here, we used known N = 47 (2 from present study and 45 from GenBank) cytochrome oxidase 1 (CO1) sequences of A. cucurbitina representing seven different geographical groups, additionally 23 sequences of eight Araniella species were used for phylogenetic relationship. The CO1 (561 bp) sequences of A. cucurbitina consisted of n = 14 haplotypes, where haplotype 14 (Hap 14) represents Indian species, while all 13 haplotypes (Hap1-13) shared between six A. cucurbitina groups. The overall 'h' and 'π' diversities among seven groups of A. cucurbitina were 0.85291 and 0.00888, respectively, while overall evolutionary divergence was 0.04. The Indian Hap 14, showed minimum sequence divergence (0.02) from Italy and Czech Republic haplotypes (Hap 6), it means it is the closest group compared to others. Evolutionary divergence among eight species of Araniella ranges from 0.003 to 0.114. The maximum likelihood (ML) topology based on 14 haplotypes of A. cucurbitina was divided into two major clades and further two subclades. Furthermore, ML topology between eight species of Araniella was divided into three major clades, where A. cucurbitina and A. proxima clustered together in clade 'A', while six others were present together in clade 'B' and 'C'. This study helps to identify the Indian species from the rest of Araniella species and other cucurbitina population across the world. This study further needs to be on a large scale to know the exact status distribution and molecular phylogeography of this single species of genus Araniella from India.

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Review of forests, wood products and wood biotechnology of Iran and Germany - Part II

Abstract: Bibliographische Information der Deutschen Nationalbibliothek Die Deutsche Nationalbibliothek verzeichnet diese Publikation in der Deutschen Nationalbibliographie; detaillierte bibliographische Daten sind im Internet über abrufbar.

Cited by 6 publications

References 130 publications

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Flotation techniques to improve viability of Juniperus polycarpos seed lots

Araniella cucurbitina : the first molecular evidence of a Palearctic species of genus Araniella inhabiting India

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