Effect of Glomus intraradices spore abundance of the inoculum on percent mycorrhizal colonization and growth of Vigna mungo (L.) Hepper

Arbuscular mycorrhizal (AM) fungi are well known symbiotic microorganism found to improve the growth of host plant by mobilizing immobile nutrients, mainly phosphorus, from the soil. However, the effect of AM fungi on host plant growth depends on the percentage mycorrhizal colonization, whereas it is not clear that the percent mycorrhization impacts by AM fungal spore abundance of the inoculum. Therefore, the current investigation was conducted to know the effect of percent mycorrhization of Glomus intraradices on the growth of blackgram inoculated with varied numbers of AM fungal spores via seed biotization (1 to 10 AM fungal spores per seed). Percent mycorrhizal colonization and plant growth characteristics of blackgram were recorded after 10, 20 and 30 days of sowing (DOS). Our results are revealed that the percentage of mycorrhizal colonization significantly influenced based on the availability of AM fungal spore richness of the biotized seeds, which leads to altered crop growth. Percent mycorrhizal colonization in the roots of blackgram increased with increasing AM fungal spore abundance per seed and it ranges from 10 to 70 %. Moreover, mycorrhizal colonized plants recorded higher shoot and root length, leaf area, leaf area index, shoot and root biomass production as well as chlorophyll content over control, conversely it was increased further with increasing percent mycorrhizal colonization, which is directly proportional to the richness of the AM fungal spores per seed. Therefore, AM fungal spore abundance is one of the governing factors that influence percent mycorrhizal colonization in roots of plants besides AM fungal and plant species and soil condition

Unravelling the carbon pools and carbon stocks under different land uses of Conoor region in Western Ghats of India

Land uses are pivotal in global carbon cycles. The native forest lands possess a greater potential to sequester higher carbon, which can directly address soil quality and climate change problems. Unfortunately, the rapid conversion of forests to other land use over the past few decades has significantly declined the concentration of carbon in the soils.  Therefore, in order to estimate the impact of land-use change (LUC)  on soil carbon status, this present study was attempted under major ecosystems (Forest (FOR), cropland (CRP), tea plantation (TEA)) of Conoor. Results from findings revealed that total organic carbon (TOC) concentration and carbon pools were significantly  (p<0.05) higher in FOR than in CRP and TEA.  TOC (0-45 cm) recorded in FOR, CRP and TEA was 32.88, 11.87 and 18.84 g kg-1 and it decreased along the depth increment. Carbon stock (t ha-1) in FOR, CRP and TEA (0-45cm) was 68.10, 26.04, 42.42. Microbial biomass carbon (MBC) was higher in FOR (283.08 mg kg-1) followed by TEA (94.64 mg kg-1) and CRP (76.22 mg kg-1). The microbial biomass nitrogen (MBN) followed; FOR > TEA > CRP. These results clearly indicate that the LUC has inflicted a greater impact on soil carbon status and its extent was quantified using the land degradation index (LDI). The LDI (0-45 cm) recorded in CRP (-38.65) and TEA (-61.75) signals the need for immediate implementation of carbon management strategies in the CRP and TEA ecosystem to keep the soils of Conoor alive and prevent land degradation

Carbon management Index under different land uses of Conoor region of Western ghats in Tamil Nadu

The increased land-use change (LUC) from native lands to other land use at the Conoor region of western ghats in Tamil Nadu has severely declined soil carbon concentration.  Therefore to quantify this decline, Carbon Management Index (CMI) was worked out under major land uses {(Forest (FOR), cropland (CRP), tea plantation (TEA)} using total organic carbon (TOC) and carbon pools under varying degrees of lability {a) NLC (non-labile carbon) b) VLC (very labile carbon) c) LC (labile carbon) d) LLC (less labile carbon)}. Results portray that the carbon pools were significantly (p < 0.05) higher in FOR than in TEA and CRP. The contribution of active pools {(very labile carbon (VLC) and labile carbon (LC)} towards TOC was higher in TEA and CRP, whereas in FOR, the passive pool {(less labile carbon (LLC) and non-labile carbon (NLC)} was higher. TOC (0-45 cm) was concentrated on the surface soils of FOR (32.88 g kg-1), CRP (11.87 g kg-1) and TEA (18.84 g kg-1) and it gradually declined with the increase in depth. The decline in TOC was maximum between 0 – 15 and 15 – 30 cm depth in CRP (30.62%) and FOR (22.17%), whereas it was maximum (37.16%) between 15 -30 and 30 -45 cm depth in TEA. Therefore, LUC spotlights the degradation of carbon pools and its extent was quantified using the carbon management index (CMI). The CMI (0 – 45 cm) recorded at CRP (12.93) and TEA (32.62) signals the need for an implementation of carbon management strategies at Conoor to keep the soils alive and protect biodiversity

Enzymatic Activity and Efficacy of Plant Growth Promoting Bacillus amyloliquefaciens on Feeding Behaviour of Spodoptera frugiperda on Maize

Maize is a third important cereal crop which has been heavily infested with the invasive pest Spodoptera frugiperda. An alternate biological mode of control is necessary instead of seeking inorganic chemical control. Plant endophytes could be of great option for controlling plant pathogens and pest. In this context, the present study aimed to evaluate the potential of Bacillus amyloliquefaciens isolated from maize (COH6) leaf apoplastic fluid. This bacterium was found to have plant growth promoting traits like indole acetic acid, siderophore, ammonia and hydrogen cyanide production. In addition, it was found to produce hydrolytic enzymes such as protease, pectinase, chitinase, and lipase which imply its bioprotective potential. Further foliar spray of B. amyloliquefaciens with cell concentration of 108 CFU ml-1 on 4 days old maize seed germination @ 5 ml per plant showed greater colonization percentage (8.30×108 CFU g-1 fresh leaf) over other doses (1, 2, 3 & 4 ml plant-1). The highest feeding deterrence was observed when Spodoptera frugiperda fed on leaves inoculated with 5 ml of B. amyloliquefaciens

Maize Apoplastic Fluid Bacteria Alter Feeding Characteristics of Herbivore (<i>Spodoptera frugiperda</i>) in Maize

Maize is an important cereal crop which is severely affected by Spodoptera frugiperda. The study aims to identify endophytic bacteria of maize root and leaf apoplastic fluid with bioprotective traits against S. frugiperda and plant growth promoting properties. Among 15 bacterial endophytic isolates, two strains—namely, RAF5 and LAF5—were selected and identified as Alcaligenes sp. MZ895490 and Bacillus amyloliquefaciens MZ895491, respectively. The bioprotective potential of B. amyloliquefaciens was evaluated through bioassays. In a no-choice bioassay, second instar larvae of S. frugiperda fed on B. amyloliquefaciens treated leaves (B+) recorded comparatively lesser growth (1.10 ± 0.19 mg mg−1 day−1) and consumptive (7.16 ± 3.48 mg mg−1 day−1) rates. In larval dip and choice bioassay, the same trend was observed. In detached leaf experiment, leaf feeding deterrence of S. frugiperda was found to be greater due to inoculation with B. amyloliquefaciens than Alcaligenes sp. The phenolics content of B. amyloliquefaciens inoculated plant was also found to be greater (3.06 ± 0.09 mg gallic acid g−1). However, plant biomass production was more in Alcaligenes sp inoculated treatment. The study thus demonstrates the potential utility of Alcaligenes sp. and B. amyloliquefaciens for improving growth and biotic (S. frugiperda) stress tolerance in maize

Growth and metabolic characteristics of oleaginous microalgal isolates from Nilgiri biosphere Reserve of India

Abstract Background Renewable energy for sustainable development is a subject of a worldwide debate since continuous utilization of non-renewable energy sources has a drastic impact on the environment and economy; a search for alternative energy resources is indispensable. Microalgae are promising and potential alternate energy resources for biodiesel production. Thus, our efforts were focused on surveying the natural diversity of microalgae for the production of biodiesel. The present study aimed at identification, isolation, and characterization of oleaginous microalgae from shola forests of Nilgiri Biosphere Reserve (NBR), the biodiversity hot spot of India, where the microalgal diversity has not yet been systematically investigated. Results Overall the higher biomass yield, higher lipid accumulation and thermotolerance observed in the isolated microalgal strains have been found to be the desirable traits for the efficient biodiesel production. Species composition and diversity analysis yielded ten potential microalgal isolates belonging to Chlorophyceae and Cyanophyceae classes. The chlorophytes exhibited higher growth rate, maximum biomass yield, and higher lipid accumulation than Cyanophyceae. Among the chlorophytes, the best performing strains were identified and represented by Acutodesmus dissociatus (TGA1), Chlorella sp. (TGA2), Chlamydomonadales sp. (TGA3) and Hindakia tetrachotoma (PGA1). The Chlamydomonadales sp. recorded with the highest growth rate, lipid accumulation and biomass yield of 0.28 ± 0.03 day−1 (μexp), 29.7 ± 0.69% and 134.17 ± 16.87 mg L−1 day−1, respectively. It was also found to grow well at various temperatures, viz., 25 °C, 35 °C, and 45 °C, indicating its suitability for open pond cultivation. The fatty acid methyl ester (FAME) analysis of stationary phase cultures of selected four algal strains by tandem mass spectrograph showed C16:0, C18:1 and C18:3 as dominant fatty acids suitable for biodiesel production. All the three strains except for Hindakia tetrachotoma (PGA1) recorded higher carbohydrate content and were considered as potential feed stocks for biodiesel production through hydrothermal liquefaction technology (HTL). Conclusions In conclusion, the present investigation is a first systematic study on the microalgal diversity of soil and water samples from selected sites of NBR. The study resulted in isolation and characterization of ten potent oleaginous microalgae and found four cultures as promising feed stocks for biodiesel production. Of the four microalgae, Chlamydomonadales sp. (TGA3) was found to be significantly thermo-tolerant and can be considered as promising feedstock for biodiesel production

Additional file 2: of Growth and metabolic characteristics of oleaginous microalgal isolates from Nilgiri biosphere Reserve of India

xml file of phylogenetic data. (XML 50 kb