Host-specific influence on early growth and physiological attributes of sandal (Santalum album) grown in farmlands

Aim: The present study aimed to investigate the host- specific compatibility of sandal (Santalum album) for better root proliferation and boosting the growth of tree. Methodology: Sandal (Santalum album) was grown with 8 different leguminous and non-leguminous species at early stage to evaluate its biometric growth (height and basal diameter) and physiological (chlorophyll, photosynthesis rate and transpiration rate) performance under field conditions. Results: Sandal grown with Sesbania grandiflora recorded highest biometric observations, chlorophyll, photosynthesis and transpiration rate followed by Sandal + Albizia lebbeck and sandal + Casuarina junghuhniana. The sandal grown with leguminous host showed superior growth performance than sandal grown with non-leguminous host. Interpretation: The present study recommended that Sesbania grandiflora can be grown as transit host for boosting the growth of sandal.

Rhizobium-Linked Nutritional and Phytochemical Changes Under Multitrophic Functional Contexts in Sustainable Food Systems

Rhizobia are bacteria that exhibit both endophytic and free-living lifestyles. Endophytic rhizobial strains are widely known to infect leguminous host plants, while some do infect non-legumes. Infection of leguminous roots often results in the formation of root nodules. Associations between rhizobia and host plants may result in beneficial or non-beneficial effects. Such effects are linked to various biochemical changes that have far-reaching implications on relationships between host plants and the dependent multitrophic biodiversity. This paper explores relationships that exist between rhizobia and various plant species. Emphasis is on nutritional and phytochemical changes that occur in rhizobial host plants, and how such changes affect diverse consumers at different trophic levels. The purpose of this paper is to bring into context various aspects of such interactions that could improve knowledge on the application of rhizobia in different fields. The relevance of rhizobia in sustainable food systems is addressed in context.

Cyclic di-GMP signaling controlling the free-living lifestyle of alpha-proteobacterial rhizobia

Cyclic-di-GMP (c-di-GMP) is a ubiquitous bacterial second messenger which has been associated with a motile to sessile lifestyle switch in many bacteria. Here, we review recent insights into c-di-GMP regulated processes related to environmental adaptations in alphaproteobacterial rhizobia, which are diazotrophic bacteria capable of fixing nitrogen in symbiosis with their leguminous host plants. The review centers on Sinorhizobium meliloti, which in the recent years was intensively studied for its c-di-GMP regulatory network.

Use of genitalia preparations in the species determination of Leafminers (Agromyzidae: Diptera)

Morphological characters are not sufficient in the species determination of leaf miners. Preparing genitalia slides, making illustrations and their studies were used in the present investigation. 15 species of flies were redescribed and 13 more species were described and named as new, associated with leguminous host. Many species of leaf miners were also reared on various non-leguminous hosts from eastern Nepal. About 1500 genitalia slides were prepared for this work. Interspecific and intraspecific variations were illustrated. More variations were found in the interspecific group. Small variation was found in causing speciation.

Symbiosomes: temporary moonlighting organelles

Symbiosomes are a unique structural entity that performs the role of biological nitrogen fixation, an energy-demanding process that is the primary entryway of fixed nitrogen into the biosphere. Symbiosomes result from the infection of specific rhizobial strains into the roots of an appropriate leguminous host plant forming an organ referred to as a nodule. Within the infected plant cells of the nodule, the rhizobia are encased within membrane-bounded structures that develop into symbiosomes. Mature symbiosomes create an environment that allows the rhizobia to differentiate into a nitrogen-fixing form called bacteroids. The bacteroids are surrounded by the symbiosome space, which is populated by proteins from both eukaryotic and prokaryotic symbionts, suggesting this space is the quintessential component of symbiosis: an inter-kingdom environment with the single purpose of symbiotic nitrogen fixation. Proteins associated with the symbiosome membrane are largely plant-derived proteins and are non-metabolic in nature. The proteins of the symbiosome space are mostly derived from the bacteroid with annotated functions of carbon metabolism, whereas relatively few are involved in nitrogen metabolism. An appreciable portion of both the eukaryotic and prokaryotic proteins in the symbiosome are also ‘moonlighting’ proteins, which are defined as proteins that perform roles unrelated to their annotated activities when found in an unexpected physiological environment. The essential functions of symbiotic nitrogen fixation of the symbiosome are performed by co-operative interactions of proteins from both symbionts some of which may be performing unexpected roles.

Description of new species of leaf miners (Diptera Agromyzidae) associated with leguminous host described from northern India

A total of 28 species of agromyzid flies belonging to 7 genera have been reared and described on 34 different leguminous host -plants from Pantnagar, Nainital, Northern India. 13 agromyzid flies have been described as new species viz., Japanagromyza species nova (sp.n.) ex leaves of Pueraria phaseoloides (Roxb.) Benth; Liriomyza sp.n. ex leaves of Vicia sativa Linn.; Liriomyza sp.n. ex leaves of Vicia faba Linn.; Malanagromyza sp.n. ex stems of Cassia sp.; Melanagromyza sp.n. ex stems of Pisum sativum Linn. Melanagromyza sp.n. ex stems of Trifolium pratense Linn.; Melanagromyza sp.n. ex stems of Vicia faba Linn.; Ophiomyia sp.n. ex stems of Pueraria Phaseoloides (Roxb.) Benth; Ophiomyia sp.n. ex stems of Sesbania aculeata Pers.; Ophiomyiz sp.n. ex stem of Vigna mungo (Linn.) Heeper and Ophiomyia sp.n. ex stems of Vigna mungo (Linn.) Heeper. Large numbers of host plants have been recorded as new host for various agromyzid species. More than one thousand male genitalia slides have been prepared for this study. Variations in morphology and genitalia characters have also been illustrated within the species. DOI: http://dx.doi.org/10.3126/njbs.v1i0.7474 Nepalese Journal of Biosciences 1: 66-82 (2011)