Studies on the Constituents of Typha L.—IV. A Preliminary Study of Chemosystematics of Typha L.

From pollen grains of Typha davidiana, T. latifolia, T. angustata the same eight flavonoids have been isolated. They are identified as naringenin I, isorhamnetin II, quercetin III, isorhamnetin-3-O-(2^G-α-L-rhamnopyranosyl)-rutioside IV, quercetin-3-O-(2^G-α-L-rhamnopyranosyl)-rutinosida, V, isorhamnetio-3-O-rutinoside VI, isorhamnetino-3-O-neohesperidoside VII, kampferol-3-O-neohesperidoside VIII. Flavonoids of pollen grains of five species of Typha, including the above three species, were analysed by TLC with the result showing that the constituents in the pollen grains of the five species are very similar. The chemical comparison among Typha and Sparganium and 16 possibly related families shows that Typha is different from Pandanaceae or Pandanales and is similar to Restionaceae, Flagellariaceae, Juncaceae and Cyperaceae in some respects. Typha and Sparganium are very similar in many respects, and they could be treated in the same family, Typhaceae, which merit the rank of order, Typhales.     

Effect of extracts from in vitro-grown shoots of <Emphasis Type="Italic">Quillaja saponaria</Emphasis> Mol. on <Emphasis Type="Italic">Botrytis cinerea</Emphasis> Pers.

The ethanolic and aqueous extracts from in vitro shoots of Quillaja saponaria Mol. (Quillay) were studied for their antifungal activity against the phytopathogenic fungus Botrytis cinerea Pers. These extracts reduced conidial germination and mycelial growth of B. cinerea, ethanolic extracts being more active than aqueous extracts. In addition, the damage areas produced by this fungus on tomato leaves and strawberry fruits pre-treated with quillay extracts were diminished. The fungitoxic effect of in vitro-grown quillay extract was similar to those obtained with commercial fungicides of both natural (BC-1000) and synthetic (iprodione–dicarboximide) origin. On the other hand, the antifungal action of quillay extracts obtained from adult trees naturally grown was only slightly superior to the fungitoxic activity of the extract from in vitro plants. HPLC analysis of the extract showed that it contained saponins and some phenolic compounds such as chlorogenic, caffeic, vanillic, and salicylic acids, and scopoletin, which have been identified as antifungal agents on phytopathogenic fungi. The results obtained in this work, suggests that extracts of in vitro-grown quillay have an important protective effect against B. cinerea and support the use of an in vitro culture system as a biotechnological alternative to obtain environmental safe antifungal quillay extracts to control B. cinerea, contributing to the preservation of this indigenous Chilean species.     

Phylogenenetic approach of the section Bulbocodii D.C. of Narcissus based on cpDNA. A case of taxonomic inflation?

In this paper, we analyzed the phylogeny of the section Bulbocodii (genus Narcissus; Amarillydaceae) using the matK and trnL-F fragments of cpDNA in order to review the validity of the recognized taxa. Our results indicate that Narcissus obesus should be considered a valid species, and that N. blancoi is a distinct taxon. In addition, seven previously recognized species, N. juressianus, N. subnivalis, N. graellsii, N. conspicuus, N. citrinus, N. nivalis, and N. quintanilhae, should be assigned to an infraspecific rank under N. bulbocodium, as they are not valid species. In addition, we analyzed the distribution of the three morphological characters widely used in the systematics of this section and found that their variation does not agree with the phylogenetic results, rendering these characters limited taxonomical utility. This result suggests that the section Bulbocodii shows high morphological lability, which can explain the proliferation of nominal species.     

The recovering of breeding achievements of <Emphasis Type="Italic">Populus × leningradensis</Emphasis> bogd. and <Emphasis Type="Italic">Populus × newensis</Emphasis> bogd. Based on microsatellite analysis

The genotyping of 75 trees from poplar plantations in St. Petersburg and Leningrad oblast was conducted with microsatellite markers to identify the elite clonal varieties developed by P.L. Bogdanov in the period of 1938–1965. The information about the varieties was lost. The authentic herbarium specimens of poplar clonal varieties preserved at the St. Petersburg State Forest Technical University were used as reference genotypes. According to the results of DNA fingerprinting, we identified the clonal plantations of Populus × newesis Bogd. and Populus × leningradensis Bogd. from the Kartashevskii forest district and the arboretum of the St. Petersburg State Forest Technical University. The identified elite poplar hybrids have a higher frost resistant and a higher growth rate. They are recommended for plantation cultivation in the northwest of Russia.     

A study on biosynthesis of “citral” in lemongrass (<Emphasis Type="Italic">C. flexuosus</Emphasis>) cv. Suvarna

Incorporation of [1-¹³C]-glucose and fosmidomycin was achieved in young and rapidly expanding (aged 15 days) leaves of lemongrass (C. flexuosus) cv. suvarna to elucidate biosynthetic origin of citral (3,7-dimethyl-2,6-octadienal). Analyses of the resultant ¹³C-labeling patterns of citral by quantitative ¹³C-NMR spectroscopy revealed significant %¹³C enrichment at carbons C-3, C-5, C-7 and C-9 in citral. This labeling pattern of the citral is in accordance with their biosynthesis via 2C-methyl-d-erythritol-4-phosphate (MEP) pathway. However, incorporation of [1-¹³C]-glucose achieved in the presence of fosmidomycin resulted in a ¹³C-labeling pattern of citral which did not match with labeling pattern characteristic of the MEP pathway. In addition, we studied the activity pattern of the DXR enzyme following fosmidomycin (25, 50, 75 and 100 μM concentrations) treatment of the young (aged 15 days) leaves for 48 h. The results revealed that fosmidomycin (100 μM) caused drastic inhibition (>50 %) of the DXR enzyme activity. The levels of the citral measured in the fosmidomycin treated leaves were also found to be reduced with decrease the activity of DXR enzyme. In conclusion, the results of the present work revealed the presence of the MEP pathway and its role in the biosynthesis of citral in lemongrass. In addition, the critical role of the DXR enzyme in the citral biosynthesis is highlighted. This is the first report on elucidation of the MEP pathway in lemongrass and may help in deeper understanding of the monoterpene biosynthesis and regulation in the genus Cymbopogon of high industrial significance.     

Development of microsatellite markers for <Emphasis Type="Italic">Myracrodruon urundeuva</Emphasis> (F.F. &amp; M.F. Allemão), a highly endangered species from tropical forest based on next-generation sequencing

Myracrodruon urundeuva is a tree species of high economic importance due the strength and durability of its wood. Threatened of extinction in Brazil, it is present only in a few forest remnants, mostly in conservation units. Currently, there is little information on the genetic diversity of natural populations in Brazil and even less information about the genome of this species. Here, new species-specific microsatellite loci were developed based on next-generation sequencing (Illumina). More than 100,000 loci were identified in the run, with di- to hexanucleotides motifs. Of these, 20 loci were selected for validation in 30 individuals, with 15 successfully polymorphic loci detected. The number of alleles ranged among loci from 3 to 16, with an average of 7.73, expected (H _e ) and observed (H _o ) heterozygosity ranged from 0.246 to 0.902 and from 0.103 to 0.867, respectively. These results point out that these new set of markers has a great potential for use in population genetic studies for genetic conservation of the species.     

Use of protoplasts in the improvement of filamentous microorganisms. I. Action of N-methyl-N′-nitro-N-nitrosoguanidine on protoplasts of Streptomycetes

Summary The effects of N-methyl-N–nitro-N-nitroso-guanidine (NTG) on protoplasts of Streptomycetes are markedly different from its action on spores, showing high mutagenic activity even at concentrations having no marked effect on protoplast survival. Strain improvement, eg in chlorotetracycline-producing strains of S. aureofaciens, was most effective when protoplasts were subjected to prolonged treatment (2 h) with low concentrations of NTG (50 /ug/ml).     

Method of fixing the heterotic effect—implementation on plants (on the hundredth anniversary of the birth of V.A. Strunnikov)

The article is devoted to the 100th anniversary of the outstanding world-renown Russian scientist Vladimir Alexandrovich Strunnikov, Academician, Professor, Head of Group of Developmental Cytology and Sex Regulation at Koltzov Institute of Developmental Biology and Head of genetic studies on silkworms in a number of sericulture institutes in CIS. Laureate of the State Prize of the USSR (1981), Hero of Socialist Labor (1990), awarded the I.I. Mechnikov Gold Medal, Academy of Sciences of the USSR (1981), founder of the theory explaining the origin of heterosis. One of his most significant achievements is the “Methods of Fixing the Heterosis Effect,” which makes it possible to abandon the production of hybrid seed and increase the yield of many crops by 20–50%. Fixing the gene complexes that determine the heterosis effect will become the “springboard” that will allow obtaining even more productive heterotic hybrids on the basis of new-generation varieties. The efficiency of this method in plant objects at the organismal and molecular levels was shown in the All-Russia Research Institute of Rice. A modification of this method reducing its laboriousness and increasing its efficiency was developed.     

Effect of desiccation on physiological and biochemical indicators associated with the germination and vigor of cryopreserved seeds of <Emphasis Type="Italic">Nicotiana tabacum</Emphasis> L. cv. Sancti Spíritus 96

Cryopreservation is a valuable technique for the long-term conservation of plant germplasm and complementary to traditional seed storage methods. However, critical factors such as seed moisture content should be optimized before using this technique as a safe strategy for storing seeds such as those of Nicotiana spp. This study aimed to determine the effect of desiccation on physiological and biochemical indicators associated with germination and vigor in cryopreserved seeds of Nicotiana tabacum cv. Sancti Spíritus 96 (SS-96). The germination and vigor of seeds with a range of moisture content were assessed using electrolyte leakage and accelerated aging tests. In addition, these physiological indicators were related to the oxidative state of the seeds, in terms of the rate of O₂ ^·? generation and the H₂O₂ content, and the activity of enzymatic antioxidants superoxide dismutase and catalase. The cryopreserved seeds of N. tabacum SS-96 with a moisture content of 2.1% exhibited higher vigor probably due to the retention of membrane integrity, reflected by lower levels of lipid peroxidation and electrolyte leakage associated with the absence of oxidative stress. The results suggest 2.1% as the optimal moisture content for the storage of seeds of this cultivar, both at cryogenic temperatures and at 5°C.     

Effect of Tween 80 on 9α-steroid hydroxylating activity and ultrastructural characteristics of <Emphasis Type="Italic">Rhodococcus</Emphasis> sp. cells

Studied is the effect of the non-ionic surfactant Tween 80 on the microbial transformation of 4-androstene-3,17-dione into its 9α-hydroxy-derivative by resting Rhodococcus sp. cells. The surfactant was applied in the cultivation medium as an additional source of carbon, in the transformation reaction medium as a mediator of the steroid substrate solubility or was used for permeabilization of the glucose grown Rhodococcus sp. cells. Special attention is paid to the fact that Tween 80 accelerates the 9α-steroid hydroxylation reaction carried out by glucose-grown cells. When the surfactant was applied as a supplementary source of carbon, the rate of the steroid hydroxylation reaction was significantly lower. In addition, the kinetics of the transformation process changed into a linear one thus indicating a very slow, if any, product degradation. The fatty acid profile, cell surface hydrophobicity as well as cell ultrastructure observed by scanning and transmission electron microscopy in the Tween 80- and glucose-grown Rhodococcus sp. cells are compared and related with their 9α-hydroxylating activity.     

Ecology of the pteridophytes on the southern slopes of Mt. Kilimanjaro – I. Altitudinal distribution

140 taxa of 61 genera in 24 families of pteridophytes were recorded on the southern slopes of Mt. Kilimanjaro. These represent about one third of the entire pteridophyte flora of Tanzania. The families richest in species are the Aspleniaceae, the Adiantaceae, the Dryopteridaceae, the Thelypteridaceae and the Hymenophyllaceae. Due to its luxuriant montane rain forest, which receives a precipitation of up to over 3000 mm, Mt. Kilimanjaro is distinctly richer in pteridophyte species than other volcanoes in East Africa. However, compared with the mountains of the Eastern Arc, the number of pteridophytes on Mt. Kilimanjaro is smaller. This can be explained by the widely destroyed submontane (intermediate) forest rather than by the higher age of the Eastern Arc Mts.The altitudinal distribution of all ferns was investigated in 24 transects. On the southern slopes of Mt. Kilimanjaro they were found in an altitudinal range of 3640 m. Cyclosorus quadrangularis, Azolla nilotica, Azolla africana andMarsilea minuta are restricted to the foothills, while Polystichum wilsonii, Cystopteris nivalis and Asplenium adiantum-nigrum are species found in the highest altitudes.Based on unidimensionally constrained clustering and on the analysis of the lowermost and uppermost occurrence of species, floristic discontinuities within the transects were determined. From these data and from an evaluation of the distribution of ecological groups and life forms, 11 altitudinal zones could be distinguished: a colline zone (–900 m asl), a submontane zone (900–1600 m asl) with lower and upper subzones, a montane zone (1600-2800 m asl) divided into 4 subzones, a subalpine zone (2800–3900 m asl) with lower, middle and upper subzones, and finally a (lower) alpine zone above 3900 m. The highest species numbers were observed in the lower montane forest belt between 1600 and 2000 m altitude. The zonation of ferns found at Mt. Kilimanjaro corresponds well with the vegetational zonation described by other authors using bryophytes as indicators in different parts of the humid tropics.     

Influence of some plant phenolics on the activity of δ-endotoxin of Bacillus thuringiensis var. galleriae on Heliothis armigera

Bioassays with Bacillus thuringiensis var. galleriae Berliner -endotoxin and plant phenolics on Heliothis armigera Hübner enhanced the activity of B.t. var. galleriae endotoxin. The presence of plant phenolics with B.t var. galleria endotoxin not only reduced feeding potential and weight gain by the larvae, but also enhanced the LC50 value of the toxin. Our study demonstrates the effect of phytochemicals from resistant crop plants on the biocidal activity of B. thuringiensis strains in laboratory conditions.