Improvement of rooting and growth in kiwifruit (Actinidia deliciosa) cuttings with organic biostimulants.

Seaweed extracts have shown profoundly positive effects on crop growth, quality and reproduction in diverse agricultural and horticultural crops. Seaweed extracts can be used to promote the rooting and growth of cuttings in perennial fruit species like kiwifruit (Actinidia deliciosa). In this study, the cuttings were treated with 1, 5, 10 and 50% solutions of G Sap (Gracilaria edulis), K Sap (Kappaphycus alvarezii), AN (Ascophyllum nodosum), EM (Ecklonia maxima), HA (Humic acid) and control (water) for 6 h as base dipping. Subsequently, the treatments of G Sap, K Sap, AN, EM, HA and control were repeated every 15 days for a period of six months as application of 50 ml solutions in the potted cuttings. All the treatments exhibited significant effects on the rooting percent in all the kiwifruit cultivars, namely 'Monty', 'Abott', 'Hayward', 'Allison' and 'Bruno' (P ≤ 0.01) as compared to the control. Shoot and root growth parameters including leaf number per cutting, number of roots per cutting, number of branches, plant height, shoot diameter, root length, root diameter and root weight were all positively increased with the application of seaweed extracts (P ≤ 0.05). Cuttings treated with seaweed extract exhibited significantly higher levels of pigments (chlorophyll a, chlorophyll b and total carotenoids), metabolites (total carbohydrates and soluble phenols) and less electrolyte leakage as compared to the control cuttings. Significant positive and negative correlations were observed between biochemical parameters combined with plant nutrient concentration. Principal component analysis (PCA) revealed that PC1 and PC2 (first two principal components) accounted for 75% of the entire variation. While, PC1 accounted for 63% of the total variation, PC2 accounted for 11% of the total variation. The leaves and the roots of kiwifruit cultivar 'Hayward' treated with G Sap at 10%, K Sap at 10%, AN at 10%, EM at 10%, HA at 10% exhibited higher expression of all four root promoting candidate genes (GH3-3, LBD16, LBD29 and LRP1) compared to the control. Therefore, it can be concluded that, seaweed extract and humic acid can be used as a suitable alternative to synthetic hormones for promoting the rooting and growth of kiwifruit cuttings.

Oral route of transmission: Trypanosoma evansi in a mice model experiment.

Twelve Swiss albino mice of either sex and equal body weight were randomly divided in 2 groups (I and II), consisting of 9 and 3 mice respectively and were used to conduct the study. A dose of 2.5 × 104 number of Trypanosoma evansi was instantly fed to each mouse of group I. Each mouse of group II was inoculated intraperitoneally with same dose of parasites through infected mice blood and kept separate. The tail blood of each mouse was examined daily up to 30 days post infection by examination of wet blood film and Giemsa-stained blood smears for presence of any trypanosomes. Out of 9 mice of group I those were infected orally, 3 (33.33%) mice became positive for presence of T. evansi both by examination of wet blood film and Giemsa-stained blood smears after 4, 6 and 7 days post infection. After 2 days post infection all intraperitoneally infected mice were found positive for T. evansi. Thus incubation period in orally infected mice was longer than the intraperitoneally infected mice. All the positive mice of both the groups died with high parasitaemia after 3-4 days of first appearance of parasitaemia. From the present study, it can be concluded that besides mechanical or parenteral means of transmission, T. evansi could also be transmitted through oral route. Thus zoo carnivores might be infected with T. evansi and develop disease by eating infected blood or flesh of the infected animals, as a prey and predator relationship.

Morphology, epidemiology, and phylogeny of Babesia: An overview.

Babesiosis is a tick-borne hemoprotozoan disease of domestic and wild animals. The disease is caused by various species of Babesia and some species of Babesia have also zoonotic significance. The parasite in vertebrate hosts' remains in erythrocytes and the morphology of Babesia spp. is not uniform in all vertebrate hosts. With the advancement of science, particularly the use of molecular techniques made it easy to study the evolution of parasites and thereby reclassifying Babesia spp. as per their phylogeny and to establish the relation of one isolate of Babesia spp. with isolates throughout the world. An attempt also made in this communication to enlighten the readers regarding relationship of one isolate of Babesia spp. of a particular area to another isolate of Babesia spp. of that area or other parts of the world and phylogenetic classification of Babesia spp. was also discussed. It has been concluded that as the study on Babesia is complex in nature so monitoring of the infection with the use of modern techniques is very much needed to control the infection. Second, more research work on phylogenetic relationship of Babesia spp. isolated from different hosts is needed, particularly in India to know the evolution of Babesia spp. of a particular area, as it has great importance to study the trans boundary diseases of animals.

Detection of Babesia bigemina infection in cattle from north-eastern India by polymerase chain reaction and its genetic relatedness with other isolates.

A total of 333 blood samples were collected from cattle suspected for haemoprotozoan infections from three states of north-eastern part of India. All the samples were examined for diagnosis of Babesia bigemina infection using PCR for detection of specific DNA. Out of these, 12 (3.60%) samples were found positive for B. bigemina DNA on PCR using the organism-specific primers derived from 18S ribosomal RNA (rRNA) gene of B. bigemina. An expected size of 1124-bp PCR product was visualized on agarose gel electrophoresis with all the 12 samples, and four of the products was further cloned and sequenced. Basic Local Alignment Search Tool (BLAST) analysis of B. bigemina sequences generated in the present study share 99.2 to 99.7% identity at 18S rRNA gene nucleotide sequence level. These Indian B. bigemina sequences were found to be closely related with the cognate gene nucleotide sequences of B. bigemina from Argentina and Kenya where 99.1 to 99.9% and 99.0 to 99.7% nucleotide identities were observed, respectively. Distant relationship of these Indian organisms was observed with few cognate gene sequences from China where more than 7% divergence was observed in the distance matrix.

Experimental studies on survivality and degenerative changes of Trypanosoma evansi after death of host.

Twenty adult Swiss albino mice, 20 rats and 10 rabbits were artificially infected with Trypanosoma evansi and killed at the peak of parasitaemia to know the period of survivality of T. evansi and degenerative changes of the parasite after death of these hosts. Examination of Giemsa stained blood smears and wet blood smears revealed the presence of parasites and live trypanosomes along with motility in the heart blood of mice and rats up to 14 h and in rabbits up to 13 h post death. Mouse inoculation test (MIT) conducted with heart blood up to 13 h post death of mice and rabbits became positive. MIT with both heart blood and portal blood of rats became positive up to 14 h post death. The liver and lung impression smears could detect the parasites up to 14 h of death of mice and rats and up to 13 h post death of rabbits whereas spleen impression smears revealed the presence of parasites up to 12 h post death of these animals. It is confirmed that T. evansi infection in animals may be diagnosed after post mortem examination of hosts by demonstration of parasites.

First report of establishment of Trypanosoma evansi infection in pigeon nestlings (Columba livia).

Trypanosomosis (surra) caused by Trypanosoma evansi is quite common among horses where the parasite is endemic. In the present study, T. evansi was isolated from an infected horse and maintained by subinoculation in Swiss albino mice. At the peak of parasitemia (5 x 10(6) parasites per ml of blood), 0.25 ml of the tail blood from infected mice was inoculated intraperitoneally and subcutaneously to 2 groups of adult pigeons and 2 groups of pigeon nestlings. Four days after inoculation, the trypanosomes occurred in the peripheral circulation of pigeon nestlings, but no parasitemia was observed in adult pigeons. The body temperatures of infected nestlings increased to 104 F, whereas uninfected controls remained steady at 102 F; thus, elevated temperatures coincided with parasite presence in the peripheral circulation. A decrease in hemoglobin concentration of blood also was observed in infected nestlings. On microscopic examination, increases in length and breadth of trypomastigotes and vigorous flagellar movement of the parasites were observed. The virulence and pathogenicity of the parasites after adaptation to nestlings remained unchanged for albino mice as proved by the death of all subinoculated mice. Furthermore, polymerase chain reaction studies confirmed that the genomic DNA of trypanosomes in pigeon blood was the same as that of T. evansi. This is the first report of the establishment of T. evansi infection in pigeon nestlings.