Occurrence of thraustochytrids: the fungoid protists vis-a-vis marine macroalgae (seaweeds) along the coast of Goa, India

Thraustochytrids are fungoid protists ubiquitous in the marine environment and found to be associated with decaying macroalgae. Not much is known about their association with living macroalgae. Hence in the present study, different macroalgal samples were collected from various beaches of Goa to examine the presence of thraustochytrids during a four-year-long study. Brown, red and green algae were found to be substrata of thraustochytrids. Thraustochytrids were isolated on pine pollen baiting from 17 to 58% of the specimens. Thraustochytrids isolated from various macroalgae belonged to the genera Oblongichytrium, Schizochytrium, Ulkenia, and Thraustochytrium. Labyrinthula sp. was also found once on the green alga Bryopsis hypnoides. These were generally found during dry seasons rather than in monsoons. The seasonal occurrence of thraustochytrids was found to be associated with temporal variation in macroalgal diversity. The statistical analysis supported individual or interactive effects of both factors viz, seasons and macroalgal diversity, on the occurrence of thraustochytrids. Thraustochytrids were also isolated from seawater adjoining macroalgae and from estuarine water at all times of the year. Oblongichytrium sp. was isolated from the green alga Ulva compressa and Anjuna seawater samples at the same time, thus indicating that thraustochytrids from seawater could inhabit the macroalgae.

A Preliminary Assessment of Amblyseius andersoni (Chant) as a Potential Biocontrol Agent against Phytophagous Mites Occurring on Coniferous Plants

Development, survival and reproduction of Ambyseius andersoni (Chant), a predatory mite widely distributed in Europe, were assessed on different food items. These included two key pests of ornamental coniferous plants, i.e., Oligonychus ununguis (Jacobi) and Pentamerismus taxi (Haller) and pollen of Pinus sylvestris L. The rationale behind these experiments was to provide a preliminary assessment of the potential of A. andersoni as a biocontrol agent of the above phytophagous arthropods and evaluate pine pollen as an alternative food source for the predator. Under laboratory conditions (23 ± 0.5 °C, 70 ± 10% RH and 16L:8D) A. andersoni was able to feed, develop and reproduce on all tested diets. The shortest development time (egg to female) was obtained when the predator fed on P. taxi (mean = 5.12 d) and the longest was on pine pollen (mean = 6.55 d). The rm value was significantly higher on both tested prey (0.166 on P. taxi and 0.160 on O. ununguis) than on pollen (0.139). Thus, we do not recommend pine pollen for mass rearing of A. andersoni; however, we conclude that pollen may provide sufficient sustenance for the predator population under field conditions when prey are absent. The potential of A. andersoni as a biocontrol agent of O. ununguis and P. taxi is discussed.

RESOURCE STUDIES OF SCOTS PINE POLLEN GROWING IN THE MOUNTAIN ZONE OF NORTH OSSETIA-ALANIA

This research work is devoted to resource-based research on the harvesting of Scots pine pollen, as it is known that pine pollen is recognized worldwide as a unique "complete nutrition complex". It is also known that no plant resources can compare with pollen in terms of balance and activity of its constituent elements and BAS (biologically active substances), so its use in official medicine may be promising. In order to identify the possibility of using Scots pine pollen growing in the mountain zone of RSO-Alania on an industrial scale and using raw materials for obtaining broad-spectrum medicines, resource studies of Scots pine growth were conducted and areas forming a forest area that are promising for harvesting were identified, in particular, between the villages of Zintsar and Injinta in the mountain zone of the Alagir gorge of the Republic. A plot of about 3 hectares was taken for research. The operational stock of pine pollen was 117 kg, the volume of possible annual harvesting of pine pollen should not exceed 39 kg. The identified reserves of scots pine pollen growing in the mountain zone of the Alagirsky district of the Republic of North Ossetia-Alania allow us to recommend harvesting as a medicinal raw material in reasonable volumes. Of course, for reliable data on the recommended volumes of pollen harvesting, it is necessary to study all the places of growth of scots pine not only in the Alagirsky district of the republic, but also in other areas. Moreover, the research should be carried out both in the mountainous and in the flat part of the territory of the republic. Research in this direction continues.

Living Particulate Fluxes in Throughfall and Stemflow During a Pollen Event

Pollen shedding can produce rapid, abundant exchanges of nutrient-rich biomass 9 from plant canopies to the surface. When pollen deposits onto understory plants, it can be 10 washed off during storms via throughfall (a drip flux) and stemflow (a flux down plant stems). 11 Pollen deposition may also alter the organismal community on plant surfaces, changing other 12 biological particulates transported by throughfall and stemflow. We report concentrations and 13 fluxes of pollen and other biological particulates (flagellate cells, nematodes, rotifers, mites and 14 hexapodans) in throughfall and stemflow from an understory forb, Eupatorium capillifolium 15 (Lam. dogfennel), during a Pinus palustris (Mill. longleaf pine) pollen shedding event, then 16 compare these results to observations collected when pollen was absent. Pollen flux was 95.6 x 17 106 grains ha-1 season-1 from dogfennel canopies (63% and 37% transported by throughfall and 18 stemflow, respectively), representing 0.1-3.2 g ha-1. Median concentrations in flagellates, 19 nematodes and rotifers for throughfall and stemflow were higher during pollen shedding; 20 however, mites and hexapodan concentrations were similar regardless of pollen presence. This 21 is the first report of flagellate and hexapodan concentrations in canopy drainage waters. 22 Flagellate concentrations were higher than for other organisms—being similar to those 23 reported for streams, 105-107 cells L-1—and hexapodan fluxes were ~50 individuals m-2 per 1 cm 24 of rainfall. These results indicate that throughfall and stemflow can (i) transport ecologically 25 relevant amounts of pollen and organisms from the phyllosphere to the surface, and (ii) that 26 the composition and flux of biological particulates can change markedly during pollen shedding.

Common pine (Pinus sylvestris L.) pollen quality in JSC «Karabashmed» emission zone

The study results of Common pine mature pollen state in the smoke emissions from the plant JSC «Karabashmed» in connection with the level of technogenic impact are presented. It is shown that the state of the vegetation cover is in accordance with the level of technogenic pollution, determined by the accumulation degree of air pollutants in the snow cover. It was established that the soil and vegetation were degraded in the flare zone of the plant. There are no pine stands at a distance of less than 3.5 km from the source of smoke emissions. Symptoms of chronic and acute damage to the assimilation apparatus and disturbance of the generative sphere of pine at a distance of 8 km to the southeast were revealed. A significant similarity in the vital state of pine stands at a distance of 13 km (zone of low aerosol pollution) and 19 km (background conditions) from the source was established. At the same time, the frequency of small and degenerated pollen was many times higher in the pool of mature pine pollen in the stand under conditions of a low level of pollution than under background conditions. A high frequency of pollen grains with anomalies of air pockets was detected in the stand under background conditions. The results of the study indicate a high susceptability of the male generative system to technogenic pollution (accumulated soil, aerosol, gas) and the possibility of its bioindication in the absence of symptoms of damage to the assimilation apparatus. It was shown that disturbances in the development of male gametophyte in the zones of technogenic pollution are already realized at the early stages of microspore development and are revealed by the high frequency of small underdeveloped pollen. It was found that most of the pine trees growing on the soil of fine-stone-sandy composition correspond to the categories of weakened and dying ones, which makes it possible to recognize the conditions of the man-made land as extremely unfavorable for the growth and development of pine. The mature pine pollen of these stands is characterized by the peculiar features that distinguish it from the pollen of other stands. The conclusion is made about the negative effect of smoke emissions from the JSC «Karabashmed» plant on the condition of pine plantations and the male generative system of pine, even at a considerable distance from the source of emissions.