Diversity and characterization of antagonistic bacteria against Pseudomonas syringae pv. actinidiae isolated from kiwifruit rhizosphere.

Kiwifruit bacterial canker caused by Pseudomonas syringae pv. actinidiae (Psa) is a severe global disease. However, effective biological control agents for controlling Psa are currently unavailable. This study aimed to screen potential biological control agents against Psa from the kiwifruit rhizosphere. In this study, a total of 722 isolates of bacteria were isolated from the rhizosphere of kiwifruit orchards in five regions of China. A total of 82 strains of rhizosphere bacteria showed antagonistic effects against Psa on plates. Based on amplified ribosomal DNA restriction analysis (ARDRA), these antagonistic rhizosphere bacteria were grouped into 17 clusters. BLAST analyses based on 16S rRNA gene sequence revealed 95.44%-100% sequence identity to recognized species. The isolated strains belonged to genus Acinetobacter, Bacillus, Chryseobacterium, Flavobacterium, Glutamicibacter, Lysinibacillus, Lysobacter, Pseudomonas, Pseudarthrobacter, and Streptomyces, respectively. A total of four representative strains were selected to determine their extracellular metabolites and cell-free supernatant activity against Psa in vitro. They all produce protease and none of them produce glucanase. One strain of Pseudomonas sp. produces siderophore. Strains of Bacillus spp. and Flavobacteria sp. produce cellulase, and Flavobacteria sp. also produce chitinase. Our results suggested that the kiwifruit rhizosphere soils contain a variety of antagonistic bacteria that effectively inhibit the growth of Psa.

Nesting behaviour and foraging characteristics of Andrena cineraria (Hymenoptera: Andrenidae).

The current studies were carried out in the three experimental locations of Kashmir valley during 2013 to 2016. The species Andrena cineraria formed the dense nest aggregations in plan grounds, barren lands and hilly areas near the fruit orchards and other landscapes with clay loam soil type. The species start flying and foraging in the orchards from April till July. The nests were allodalous, 29-36 cm in depth, with cells located obliquely around the main barrow. The nests were dense with a maximum density of 11.09 nests/m2 observed in landscapes of Budgam. The barrow diameters were found varying with depth from main entrance. The maximum barrow diameter recorded was 2.05 mm. At certain depth, the female constructs the first cell and the upper nest burrow is vertical and lower is oblique. The nest entrance is generally hidden under the tumulus. In the depth of average 30.48 cm, each cell directly opens to main burrow either alternately or unilaterally. The cell number, diameter, and length varied with depth. Foraging behaviour of A. cineraria on various fruit crops and other shrubs and social forestry trees were determined and the abundance, visitation rate, total visits and time spend per flower were found significant, especially on fruit crops. The significance of the studies is important for the melittologists, as it will help in the conservation of bee fauna. The study is also important in using this species for pollination purpose and would also help to detect and understand the possible pre-adaptation of species in temperate region of Kashmir valley.

Mating behaviour and behavioural ecology of a Predatory Wasp, Symmorphus allobrogus (de Saussure) (Hymenoptera: Eumeninae).

This paper represents an attempt to investigate the mating behaviour of Symmorphus allobrogus, explaining the willingness of male to mount and copulate. The male displays including mode and frequency of antennation and position while copulating, the displays further comprises of intensity and frequency of rejecting behaviour. The presence of the male's copulatory and postcopulatory courtship studies, understands the maintenance of monandry. The wasp has numerous secondary sexual characters, and the mating behaviour follows a phyletic and the specific sexual mating characters in context of sexual selection. The duration of mating phases and the number of male antennation series during precopulatory, copulatory and postcopulatory phases of mounting, differs significantly. Mating success depends mostly on the activities of male in the premounting phase and the behaviour of both sexes has a roughly equal importance for it in precopulatory phase. While during copulation, activity of male has little influence on its duration; however, behaviour of female has crucial effect, inducing its earlier termination.

Native and invasive ants affect floral visits of pollinating honey bees in pumpkin flowers (Cucurbita maxima).

Global pollinator decline is a major concern. Several factors-climate change, land-use change, the reduction of flowers, pesticide use, and invasive species-have been suggested as the reasons. Despite being a potential reason, the effect of ants on flowers received less attention. The consequences of ants being attracted to nectar sources in plants vary depending upon factors like the nectar source's position, ants' identity, and other mutualists interacting with the plants. We studied the interaction between flower-visiting ants and pollinators in Cucurbita maxima and compared the competition exerted by native and invasive ants on its pollinators to examine the hypothesis that the invasive ants exacerbate more interference competition to pollinators than the native ants. We assessed the pollinator's choice, visitation rate, and time spent/visit on the flowers. Regardless of species and nativity, ants negatively influenced all the pollinator visitation traits, such as visitation rate and duration spent on flowers. The invasive ants exerted a higher interference competition on the pollinators than the native ants did. Despite performing pollination in flowers with generalist pollination syndrome, ants can threaten plant-pollinator mutualism in specialist plants like monoecious plants. A better understanding of factors influencing pollination will help in implementing better management practices.

Histopathological abnormalities of prolonged alloxan-induced diabetes mellitus in rabbits.

The objective of this study was to investigate the prolonged complications of untreated diabetes on histomorphology of rabbits. Diabetes mellitus was experimentally induced in one group of New Zealand white male rabbits by intraperitoneal administration of four doses of alloxan @ 80 mg/kg b.w. at weekly intervals following 12 h fasting. Other group of rabbits served as healthy controls that received isotonic saline in a similar manner. The establishment of diabetes mellitus was confirmed by fasting blood glucose levels. For histomorphological study of different organs, 50% of the animals were killed after 7 weeks and the rest after 26 weeks. Routine haematoxylin and eosin stain and Gomori's modified stain were used. The blood glucose level of diabetic rabbits increased significantly throughout the experimental period. The peak values for blood sugar were on the sixth week of the study. Further, histomorphological alterations were recorded in pancreas, kidneys, lungs, heart and brain in diabetic rabbits. However, mild changes were observed in gastrointestinal tract with proliferation of yeasts in the stomach. With the progress of untreated diabetes, the histoanatomical alterations intensify and extend to almost all organs of the body and appear to increase the susceptibility of gastric mucosa to yeast cell proliferation.