In this paper we investigated how succession has altered soil properties in relation to plant biomass and litter characteristics in mid Himalayan region of India. The natural forest with four succession phases were identified. The early stages are (1) pure Pinus roxburghii forest of coniferous shade intolerant species (2) middle stage is a Pinus roxburghii + Quercus leucotricophora (60: 40) forest with combination of coniferous and deciduous species (3) later stage is a Quercus leucotricophora + Pinus roxburghii (60: 40) and (4) climax stage is a Pure Quercus leucotricophora forest of shade tolerant deciduous broadleaf species. The soil samples were collected from surface (0–15 cm) and subsurface (15–30 cm and 30–45 cm) levels. The soil properties showed gradual improvement with progress in succession phases. Our study shows that, there was a substantial increase in level of soil organic carbon and nitrogen from early to climax phase. Soil pH was significantly lower in early succession phase. The highest available nitrogen was under climax (pure oak) and least in early phase (pure pine) (402 and 347 Kg ha–1 in surface soil, respectively). The concentration of very labile carbon (fraction 1) was highest in climax and least in early stage. The highest biomass accumulation was in climax (pure oak, 420.6 Mgha–1), followed by oak + pine (348.7 Mgha–1) and least in pine + oak (299.3 Mgha–1). Out of 4 stages, shrub biomass was maximum in early (pure pine) (20.5 M Mgha–1), being 6.57% of total biomass and least in climax (pure oak) (10.7 Mgha–1), being 2.54% of total biomass. Further, the labile carbon pools showed a strong positive correlation with total biomass at different succession stages. The recalcitrant carbon pool had significant negative correlation with biomass. Hence, the study suggests that, this increase in soil organic carbon, nitrogen and soil fertility parameters are in accordance to changes in biomass and litter fall characteristics with progress in forest succession.
D.R. Bhardwaj, Sharmistha Pal and Pankaj Panwar
Tao Deng, Richard J. Abbott, Wenqing Li, Hang Sun and Sergei Volis
Historical processes during the Quaternary are likely to have left a signature on the geographical distribution of intraspecific genetic variation. In particular, high genetic uniqueness could be expected within glacial refugia for multiple species. We aimed to test this for plants in China and whether multi-species hotspots of genetic diversity are good indicators of glacial refugia in this region. From chloroplast DNA haplotype data for 116 species we calculated two local genetic diversity metrics for each species: haplotype genetic richness and genetic uniqueness. From these two, only uniqueness could reliably identify refugia, whereas richness may indicate either glacial refugia or areas recolonized by genetic lineages from different refugia in the postglacial period. Our results suggest the occurrence of numerous cryptic refugia and their likely importance in the maintenance and evolution of the Chinese flora, and indicate that an approach that locates geographic hotspots of genetic diversity data can reliably identify refugia.
Jitendriya Panigrahi, Saikat Gantait and Illa C. Patel
The present study formulates a method for comprehensive production of vasicinone, a quinazoline alkaloid, from multiple plant parts of in vitro and in-field-grown Justicia beddomei. HPTLC analysis of plant parts was executed with methanolic extract using toluene: butanol: butyl acetate (9:0.5:0.5; v/v/v) as the solvent system. Validation of methodology was accomplished using TLC plates (silica gel 60 F254-pre-coated aluminium sheet) following the ICH manual to maintain accuracy, precision and repeatability with a linearity ranging 2–6 μg/spot. Validation data offers precision to the methodology adapted in the present study (LOD 1 μg/spot and LOQ 3 μg/spot). It was evident that in vitro samples produced relatively higher levels of vasicinone than that of their in-field counterparts. The highest vasicinone (2.07±0.025% of dry weight) production was quantified from in vitro stem, signifying a new resource for the production of vasicinone from identified parts of in vitro and in-field propagated J. beddomei plants.
Yiftach Vaknin and Irina Mogilevski
Adaptive variation of plant species is best evaluated under environmental gradients. Silybum marianum is a native to the Mediterranean basin, distributed continuously along an aridity gradient from northern Israel to the edge of the Negev desert. To elucidate the adaptive significance of traits associated with proximity to the desert and with increasing levels of aridity, we compared northern populations from the mesic Mediterranean end of the aridity gradient with southern, adjacent to the Negev desert populations, from the arid end. The F1 self-progeny of all populations were evaluated under open field conditions. Plants originated from southern populations grew taller and narrower, completed their life cycle earlier, and produced more abundant, smaller achenes, with a higher content of polyphenols, which grew into smaller seedlings. Correlative analysis revealed a latitudinal cline towards the desert, of a longer life cycle, and fewer, heavier, better germinating achenes, which grew into larger seedlings. We concluded that the proximity to the desert was reflected in the appearance of genotypes with improved chances of survival under arid conditions and with higher contents of polyphenols.
Noga Sikron-Persi, Gila Granot, Gideon Grafi and Aaron Fait
The biochemical composition of Zygophyllum dumosum Boiss (Zygophyllaceae) was analyzed in petioles collected in the summer and winter from plants growing in a natural ecosystem on a southeast-facing slope of the Negev desert. UPLC-QTOF MS based analysis identified season specific sulfur containing phenylpropanoids unreported in plants. Sulfuric-caffeic and -ferulic acid derivatives and isorhamnetin 3-O-(4-sulfate-rutinoside) were measured to accumulate specifically in the summer. The reported identification and accumulation of sulfate containing metabolites during the hot and dry summer can be related to the putative protective role reported for these compounds.
Oz Barazani and Jotham Ziffer-Berger
Sofia Shevtsov, Omer Murik, Hagit Zer, Ofir Weinstein, Nir Keren, Ori Fragman-Sapir and Oren Ostersetzer-Biran
The sparsely distributed Limodorum abortivum is a European-Mediterranean orchid species, which grows on decomposing plant material. Although some chlorophyll-pigmentation is observed in the degenerated scales-shaped leaf and stems regions of the plant, its photosynthetic capacity is assumed to be insufficient to support the full energy requirements of an adult plant. In Israel, L. abortivum shows a patchy distribution patterns in the Galilee, Golan, Carmel and Judean regions. To gain more insights into the physiology and photosynthetic activity of L. abortivum, we analyzed the organellar morphologies, photosynthetic activities the chloroplast-DNA sequence by Illumina-HTS. Microscopic analyses indicated to the presence of mature chloroplasts with well-organized grana-thylakoids in the leaves and stems of L. abortivum. However, the numbers of chloroplasts per cell and the grana ultrastructure density within the organelles were notably lower than those of model plant species and fully photosynthetically-active orchids. The cpDNA of L. abortivum (154,954 bp) encodes 60 proteins, 34 tRNAs and 4 rRNAs. The coding-regions of 24 genes are interrupted by 26 group-II intron-sequences. While many genes related to photosynthesis (RuBisCo, PSI, PSII and cytochrome b 6 /f subunits) have remained intact in the cpDNA, the majority of the NADH-dehydrogenase (ndh) subunits were either lost or became nonfunctional (i.e. pseudogenized). In agreement with previous reports, the photosynthetic-rates of adult Limodorum plants were found to be very low, further indicating that carbon-assimilation activity is insufficient to support the energy requirements of an adult plant, and may suggest that L. abortivum have adopted nutritional strategies similar to that of mycoheterotrophic orchid species.
Several types of defensive Batesian mimicry seem to be much more common in plants than was historically and is currently considered. It is based either on visual aspects (shape, coloration, and even movement), on odors, and on combinations of both these sensing modalities. Various characters that seem to function as defensive Batesian mimicry, may also simultaneously take part in pollination, physiological functions, or in other defensive mechanisms. The defended models for the visual Batesian mimics in plants belong to several categories: (1) spiny, thorny and prickly plant species, (2) mechanically or chemically defended parts of the same individual plant, or other members of the same species (auto mimicry), (3) colorful and chemically defended plants, (4) dangerous animals (aggressive, toxic), (5) fungal attacks, (6) animal action and animal damage cues, and (7) oozing defensive white latex. Olfactory defended models include: (1) toxic plants, (2) animal alarm pheromones, and (3) animal carrion and feces odors. Many more descriptive, genetic, phylogenetic and experimental studies have to be done in order to better understand the role of defensive Batesian mimicry in plant biology.
Gidi Ne’eman, Avi Shmida and Avi Perevolotsky
Sivan Golan, Yoni Waitz, Jotham Ziffer-Berger, Michal Barzilai, Nir Hanin, Zalmen Henkin and Oz Barazani
Germination behavior of the widespread southeastern Mediterranean shrub Sarcopoterium spinosum was conducted to assess its respond to post-fire cues. Germination experiments were conducted on 10 populations along a rainfall gradient – from productive, fuel-rich and fire-prone mesic Mediterranean populations, as well as from those in arid and fuel-poor environments. Our results indicate that post-fire cues induced germination of S. spinosum only among populations that originated from sites that are prone to wild fires. As wild-fires in this region occur mainly during the long dry season, but rarely ignited by natural factors, the adaptation to human made fires in natural populations of the southeastern Mediterranean environments is discussed.