Efficacy of plant extracts and biocontrol agents against Pythium aphanidermatum inciting chilli damping-off

The fungitoxic effects of 66 medicinal plants belonging to different families were evaluated in vitro on Pythium aphanidermatum, the causal agent of chilli damping-off. Of these, Zimmu leaf extract (Allium sativum L. × Allium cepa L.) showed the highest inhibition of mycelial growth of P. aphanidermatum (13.7 mm). The antimicrobial compounds were isolated from Zimmu leaf extract and 22 compounds were identified through gas chromatography mass spectroscopy (GC–MS). Biocontrol agents Trichoderma viride and Pseudomonas fluorescens and Zimmu extract were also tested alone and together in vitro and in vivo experiments for control of P. aphanidermatum. The in vitro studies revealed that combination of T. viride + P. fluorescens + Zimmu leaf extract showed the highest mycelial growth inhibition over the control. Both antagonists were compatible with each other and with Zimmu leaf extract. The pot culture studies revealed that seed treatment with combined application of T. viride + P. fluorescens + Zimmu leaf extract was superior in reducing the pre and post-emergence damping-off incidence (8.3 and 17.0%, respectively), and increased the plant growth and yield (shoot length and root length of 13.7 and 6.3 cm, 146 g/plant, respectively) of chilli when compared to control.     

Isolation of a Pseudomonas fluorescens metabolite/exotoxin active against both larvae and pupae of vector mosquitoes

A formulation was developed from the metabolite(s) of a novel Pseudomonas fluorescens Migula strain (VCRC B426) and tested against 4th-instar larvae and pupae of three species of vector mosquitoes, Anopheles stephensi Liston, Culex quinquefasciatus Say and Aedes aegypti (L). The larvae and pupae of An. stephensi were the most susceptible to the formulation, followed by those of C. quinquefasciatus and Ae. aegypti, in that order, and the dosage requirement for pupal mortality was less than that required for larval mortality. The LC50 dosage requirements for larvae of these mosquito species were, respectively, 70.4, 511.5 and 757.3 microg protein ml(-1), whereas for pupae they were, respectively, 2.0, 9.4 and 19.2 microg protein ml(-1). The lethal fraction was purified from the culture broth and its molecular mass, as determined by high performance liquid chromatography, was 44kDa. This is the first report of a microbial formulation acting upon mosquito pupae, a non-feeding stage. Its mode of action and efficacy to control mosquitoes under field conditions need to be studied further.     

Developing the prerequisites for sustainable land use in Albania

Abstract. When Albania emerged from its seclusion in 1991, the scientific community had its first opportunity to interact with its international counterparts. Soil resource assessment was made with systems developed in the early 1950s, laboratory facilities to provide supporting data were poor, and it was recognized that a new assessment was urgently needed. The country faces a major challenge in reforestation and soil conservation against a background of overgrazing by sheep and goats and clearing of trees and scrubs for fuelwood. Even orchard and olive trees were used as fuelwood during the winters of 1990 and 1991. Since then, gully and rill erosion has accelerated on many of the sloping lands. In addition to reforestation and conservation measures to reduce the pressures on the sloping land, it is necessary to enhance productivity on the fertile valley bottom soils where most of the agriculture is confined. In the recent past, grain yields have declined due to reduced fertilizer use (low purchasing capacity), and poor management practices. More recently productivity has slowly improved, but land degradation, particularly erosion, has visibly increased. USDA Natural Resources Conservation Service in collaboration with the Land Resources Institute of Albania, initiated work on a new national soil map through collation of existing information and field studies. The land unit for land use planning, evaluation, and general management decisions, is the Major Land Resource Area (MLRA). Each MLRA encompasses geographically associated soils, the majority of which have broadly similar patterns ofclimate, water resources, and land uses. The MLRAs presented here are based on the soil map of Albania at 1 : 200 000 scale. The MLRA information provides an overview of the landscape and natural resources. It can be used to assess land suitability for various crops, opportunities to achieve self sufficiency in food production, selection of areas for both field crops and highvalue crops for export, and identification of appropriate farming system technologies. Each MLRA will have a set of degradation processes which can be flagged, therefore each of them becomes a unit for decision making with respect to investments in research and mitigating technologies. The task is far from complete. Appropriate databases are needed to support the decisions that are being made at national level. To complement the MLRA and related database, decision support systems are needed for the important task of developing policy options.     

Studies on enzymatically liberated lignin in some Indian hardwoods

Summary Total effect of action of the wood-destroying fungusPolyporus palustris, belonging to the brown rot group, has been studied on mango (Mangifera indica) and chorapine (Hardwickia pinnata) woods, for various periods of attack at definite intervals and the lignin liberated was extracted. It was observed that the production of lignin was found to increase; if the fungus was allowed to attack for considerable periods and approximately 50 to 60% lignin was produced within two years.     

Primary rat embryo cells transformed by one or two oncogenes show different metastatic potentials

Second-passage rat embryo cells were transfected with a neomycin resistance gene and the activated form of the c-Ha-ras I gene, or with these two genes plus the adenovirus type 2 E1a gene. Foci of morphologically transformed cells were observed in both cases; however, the frequency of transformation was at least ten times higher with two oncogenes than with the ras gene alone. All the transformed cell lines gave rise to rapidly growing tumors when injected subcutaneously into nude mice. All but one of the cell lines transformed by the ras oncogene alone formed metastatic nodules in the lungs of animals that had been injected subcutaneously with transformed cells. When transformed cells were injected intravenously, all the ras single-gene transformants gave rise to many metastatic lung nodules. In contrast, cell lines transformed with ras and E1a did not generate metastases after subcutaneous injection and gave rise to very few metastatic lung nodules after intravenous injection. These data demonstrate that a fully malignant cell with metastatic potential, as measured in an immunodeficient animal, can be obtained from early passage embryo cells by the transfection of the ras oncogene alone.     

A MADS-box gene necessary for fruit ripening at the tomato ripening-inhibitor (rin) locus

Tomato plants harboring the ripening-inhibitor (rin) mutation yield fruits that fail to ripen. Additionally, rin plants display enlarged sepals and loss of inflorescence determinacy. Positional cloning of the rin locus revealed two tandem MADS-box genes (LeMADS-RIN and LeMADS-MC), whose expression patterns suggested roles in fruit ripening and sepal development, respectively. The rin mutation alters expression of both genes. Gene repression and mutant complementation demonstrate that LeMADS-RIN regulates ripening, whereas LeMADS-MC affects sepal development and inflorescence determinacy. LeMADS-RIN demonstrates an agriculturally important function of plant MADS-box genes and provides molecular insight into nonhormonal (developmental) regulation of ripening.     

Formal and informal relations to rice seed systems in Kerala,India: agrobiodiversity as a gendered social-ecological artifact

Agrobiodiversity is an evident outcome of a long-lasting human–nature relationship, as the continuous use, conservation and management of crops has resulted in biological as well as cultural diversity of seeds and breeds. This paper aims to understand the interlocking of formal and informal seed supply routes by considering the dynamic flow of seeds within networks across the intersections of gender, ethnicity and age in South India as social categories structuring human–nature relations. This changing relationship under formal and informal institutional settings has consequences on performance for men and women in rice seed systems. Undertaking an empirical analysis of the organization of seed management and exchange, we seek to shed light on the gendered organization of agrobiodiversity as a social network. The study builds on Net-Map interviews conducted in 2012, embedded in the larger BioDIVA project in the district of Wayanad in Kerala, India. Based on network analysis, the interactive method employed has enabled identification of important actors in the seed system and the characteristics of their relationships. We look into the gendered structure of information exchange regarding seed varieties and actual seed transactions, while also examining clusters of actors collaborating regarding seed supply. Finally, we identify the institutional gap concerning seed sources left by formal and informal institutions, like the availability of varieties. We show how informal and formal seed systems coexist and overlap due to actors moving between systems and argue that the degree and areas of overlap are shaped by gendered human–nature relations.     

Modulation of growth hormone-releasing factor-induced release of growth hormone from bovine pituitary cells

Growth hormone (GH)-releasing factor (GRF) at concentrations of 10−¹² through 10−⁷M for 6 hr linearly increased GH release (b₁ = 10.4 ± .3) from bovine anterior pituitary cells in culture. Maximum release of GH (262% above controls) occurred at 10−⁷M GRF. In contrast, GH release-inhibiting factor (SRIF) at 10−¹² through 10−⁵M had no effect on basal concentrations of GH. In a second experiment, as the proportion of SRIF relative to GRF increased. SRIF suppression of GRF-induced GH release from anterior pituitary cells increased. In a third experiment, anterior pituitary cells cultured in media containing fetal calf serum (FCS) were treated with cortisol (0 or 10 ng/ml media) for 24 hr before exposure to 10−¹³ through 10−⁷M GRF. GRF linearly increased GH secretion (b₁ = 7.4 ± .3) and cortisol augmented this response (b₁ = 10.5 ± .6). However, when cells were cultured in media containing dextran-charcoal treated FCS, cortisol did not alter GRF-induced GH release. Our results demonstrate that GH response of bovine anterior pituitary cells to GRF was modulated negatively by SRIF. However, augmentation of GRF-induced GH release by cortisol was evident only when cells were cultured in media supplemented with untreated FCS.