An attempt was made in this work to develop a strain-level molecular marker for unambiguous authentication of two Azospirillum inoculants, viz. A. lipoferum (strain Az204) and A. brasilense (strain Sp7). The sequence-characterized amplified region (SCAR) markers obtained from DNA fingerprints were designed for discrete detection of the strains. The SCAR primers could successfully amplify the target strain without cross-reaction with other Azospirillum strains, native isolates and other inoculants. The detection limit of SCAR primer for Az204 was 8.00 pg of DNA (approximately 10(5) cells per mL), and for Sp7, it was 0.49 pg of DNA (equal to 10(4) cells per mL). A simplified Sephadex G100-based crude DNA extraction protocol developed in this study was found suitable for SCAR marker-based strain authentication. Further, SCAR primers were assessed for simultaneous authentication as well as quantification of commercially prepared Azospirillum inoculants by quantitative real-time PCR (RT-PCR) and most-probable-number PCR (MPN-PCR). The RT-PCR assay can be able to quantify the commercial formulations as equal to culturable MPN method, while MPN-PCR failed for Az204. The SCAR marker-based strain authentication and presumptive quantification developed in the present work can contribute to improving the quality standard of commercial inoculants.
Diversity in plant life histories is primarily that found in the rate and duration of photosynthetic (vegetative) and reproductive growth. However, direct evidence for an anticipated trade-off between photosynthesis and reproduction is lacking in any plant lineage. Ferns allocate leaf space and resources to both photosynthesis and reproduction, potentially leading to competition for leaf resources between stomatal pores and reproductive spores. We hypothesized that a trade-off between stomatal density (StD; a proxy for photosynthetic capacity) and sporangial density (SpD; a measure of fertility) has evolved in monomorphic ferns due to the common space, time and resource constraints imposed by a highly conserved and globally low leaf mass per unit area (LMA) in ferns, where any increase in LMA indicated greater construction cost and longer leaf lifespan. We measured LMA, StD and SpD in 40 fern species in India that represented both monomorphic and dimorphic conditions from both terrestrial and epiphytic habits. Both StD and SpD showed a 50-fold range in monomorphic species whereas LMA was more conserved (six-fold range). LMA of terrestrial ferns was significantly lower than that of epiphytic ferns. Linear regression between LMA and StD was significantly positive in dimorphic terrestrial ferns (showing the lowest LMA among all ferns) and significantly negative in monomorphic epiphytic ferns (showing the highest LMA among all ferns). Dimorphic terrestrial ferns were highly fecund on their fertile leaves and showed a significantly higher StD to LMA ratio on their sterile leaves compared to monomorphic terrestrial ferns. Dimorphic ferns seem to maximize both StD and SpD by physical separation of photosynthesis and reproduction, and their characteristically low LMA (shorter leaf lifespan = smaller time window) potentially selects for high StD and high fertility. The regression between StD and SpD in monomorphic ferns was significantly linear and positive, although comparisons among closely related species (within families) showed negative correlations when both StD and SpD were high, captured also by a significant quadratic regression between StD and SpD in monomorphic ferns. Monomorphic terrestrial species bearing more spores per stomata showed relatively low LMA whereas those producing fewer spores per stomata possessed leaves with relatively high LMA. Monomorphic epiphytes produced as many spores as terrestrial species but showed significantly low StD for their high LMA. We discuss the evolutionary reasons behind these trends and conclude that monomorphic terrestrial ferns with high LMA (long leaf lifespan) tend to prioritize photosynthesis over reproduction, while monomorphic epiphytes (always high LMA) are significantly more fertile for lower photosynthesis. The role of LMA in framing the rules of competition between stomata and sporangia in monomorphic ferns provides a template for how photosynthesis may directly or indirectly influence reproductive strategies (and vice versa) in all land plants.
A new species of Selaginella, S. camusii is described and illustrated.
The halberd fern genus Tectaria Cav., is terrestrial, medium to large size herb, growing along the cut edges of hills and hillocks or edges of river. It is characterized by the presence of erect, creeping or suberect rhizome with dimorphic, subdimorphic or monomorphic fronds and anastomosing to free veins. Generally, it occurs in different habitats of the tropical to subtropical region of the world. Different members are exploited for various purposes in traditional medicinal system by local tribes. However, the diversity, distribution, conservation status and state of the knowledge about Tectaria (Tectariaceae) is not uniform worldwide including India. Therefore, the present investigation aims to study the diversity, distribution and conservation status of this genus from Peninsula and Western Ghats of India. Out of 24 species reported from India, nearly nine species occur in Deccan Peninsula and Western Ghats. A detailed distribution and conservation status with the identification key to the species of Tectaria distributed in this region is provided herewith.
Aims: To enumerate the fern diversity in the disturbed landscapes of Rajamala part of Eravikulam National Park, Western Ghats Study Design: Purposive sampling method was adopted in the study area and habitats suitable for ferns were surveyed. Place and Duration of Study: The study area is Rajamala, a tourist impacted site inside Eravikulam National Park in Kerala, India. Intensive field explorations were carried out in this area during February 2018- April 2019, to document the ferns and fern-allies. Methodology: A preliminary study was conducted in February 2018 to identify the probable habitats of ferns for further detailed study. Purposive sampling was done in the study area considering the most suitable habitats in both shola ecosystems and grassland ecosystems of the area. Materials for herbaria were processed using standard methods. The collected plants were identified with the help of standard field guides and flora. The potential medicinally important ferns were also listed out. Results: 54 species of pteridophytes including fern and fern allies belonging to sixteen different families were found from the Rajamala region of Eravikulam National Park. Aspleniaceae was the most common family with 11 species followed by Polypodiaceae. The majority of the Pteridophytes found in the region are showing terrestrial habit. Eleven species found in the study site are medicinally important. Conclusion: Despite the high tourism pressure in the study area, pteridophyte species richness is higher in the Rajamala region of Western Ghats. The suitable habitat with ideal substrate conditions and year-long moisture availability in the substrates could be the reason for a higher number of pteridophyte species in this area.
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