Importance and genetic diversity of vegetable-infecting tospoviruses in India

A survey for Peanut bud necrosis virus (PBNV), Watermelon bud necrosis virus (WBNV), Capsicum chlorosis virus (CaCV), and Iris yellow spot virus (IYSV) was conducted between 2002 and 2009 in the major vegetable-growing areas in India. PBNV was documented widely in tomato and chili peppers in 14 states representing southern, north-western, north-eastern, and central regions and WBNV was predominantly detected in watermelons and cucurbits in all except north-eastern regions. In addition, the expanded host range of PBNV to watermelons and other cucurbits and WBNV to tomato and chili peppers was observed leading to natural mixed infection of the two viruses. IYSV was found in onion in southern, central, and north-eastern regions and CaCV in tomato and chili peppers in northern and southern regions, respectively. Phylogenetic analysis of the nucleocapsid gene revealed segregation of field isolates of PBNV and WBNV into two distinct subclades, whereas isolates of CaCV and IYSV each clustered into a single clade. A proposal for establishing WBNV as a distinct tospovirus species is made based on the molecular characterization of small- (S) and medium- (M) RNA segments.     

Genetic architecture, inter-relationship and selection criteria for yield improvement in rice (Oryza sativa L.)

This study has been conducted to determine the extent of genetic association between yield of Rice (Oryza sativa L.) and its components. The present experiment was carried out with 40 Rice (Oryza sativa L.) genotypes which were evaluated in a randomized block design with 3 replications during wet season of 2007 and 2008. Results showed that sufficient amount of variability was found in the entire gene pool for all traits studied. Higher magnitude of genotypic and phenotypic coefficients of variation was recorded for seed yield, harvest index, biological yield, number of spikelets per panicle, flag leaf length, plant height and number of tillers indicates that these characters are least influence by environment. High heritability coupled with high genetic advance as percent of mean was registered for seed yield, harvest index, number of spikelets per panicle, biological yield and flag leaf length, suggesting preponderance of additive gene action in the expression of these characters. Grain yield was significantly and positively associated with harvest index, number of tillers per hill, number of panicle per plant, panicle length, number of spikelet's per panicle and test weight at both genotypic and phenotypic levels. Path coefficient analysis revealed that harvest index, biological yield, number of tillers per hill, panicle length, number of spikelets per panicle, plant height and test weight had direct positive effect on seed yield, indicating these are the main contributors to yield. From this study it may be concluded that harvest index, number of tillers per hill, panicle length and number of spikelet per panicle and test weight are the most important characters that contributed directly to yield. Thus, these characters may serve selection criteria for improving genetic potential of rice.     

Cholinesterase activity in Thysaniezia giardi (Cestoda,Anoplocephalidae)

Summary

The activity of cholinesterase was determined separately in the mature and gravid proglottids of Thysaniezia giardi and its significance is discussed. The mean values of the enzyme in mature and gravid proglottids were respectively 225.60 ± 28.55 and 75.00 ± 11.64 units per gram of wet weight.     

First report on serological evidence of bovine viral diarrhea virus (BVDV) infection in farmed and free ranging mithuns (<Emphasis Type="Italic">Bos frontalis</Emphasis>)

Despite reports of BVDV infection in several domestic and wild ruminants, no information exists for mithun (Bos frontalis) species. Hence, this study was undertaken to determine prevalence of BVDV infection in mithuns, which contribute significantly to local economy in the North Eastern region of India. Blood and serum samples were collected between 2013 and 2016 from mithuns (n = 466) belonging to the states of Nagaland, Mizoram, and Arunachal Pradesh. Serum samples were tested for BVDV antibodies by a commercial ELISA and leukocytes were tested for BVDV by real-time RT-PCR. The overall true seroprevalence rate was 13.1% (95% confidence interval, CI: 6.9–17.8%) with higher prevalence in mithuns reared under semi-intensive system (27.5%) than in free-ranging mithuns (7.6%). Among the three states, seroprevalence (16.2%) was highest in Nagaland, while prevalence rates varied markedly among geographical locations. Age-wise data showed highest seroprevalence rate in >6-year-old animals (20.6%) than 2–6 years old (16.9%), 6 months–2 years old (8.5%), and <6-month-old animals (11.3%). The seroprevalence was higher in males (20.9%) than in females (12.1%). Among the four mithun strains, higher prevalence was evident in Manipur (30.3%) than Arunachal (21.3%), Nagaland (11.7%), and Mizoram strain (10.2%). However, no BVDV genomic RNA could be detected. The results provide first serological evidence of BVDV infection in mithun species and extend the knowledge on BVDV host range. The baseline data will help further investigations on epidemiology of BVD in mithun and its impact on mithun production.     

Rapid and convenient gel‐free screening of SCAR markers in wheat using SYBR green‐based melt‐profiling

Sequence characterized amplified region (SCAR) markers that are highly desirable in crop breeding for marker‐assisted selection (MAS) are routinely analysed by gel‐based methods that are low‐throughput, time‐consuming and laborious. In this study, we showed a rapid and convenient method for analysis of SCAR markers in a gel‐free manner. Seven SCAR markers, linked to rust resistance genes (Sr24, Sr26 and Sr31) and seed quality traits (Pina, Pinb and Glu‐D1) in wheat (Triticum aestivum), were amplified on a real‐time PCR machine using custom reaction mixture. Subsequently, melting curve analysis was performed, to assess the specificity of amplicons. Using the amplicon‐specific melt‐profiles, the presence/absence of SCAR markers was analysed in fifteen genotypes and five F₂ populations. Unlike the fluorescence‐based in‐tube detection methods, the present method used the amplicon‐specific melt‐profiles to evaluate the status of the SCAR markers, thus eliminating the need for gel‐based analysis. Results also showed feasibility of multiplex analysis of two markers with well‐separated melting profiles. Overall, the approach is a rapid, convenient and cost‐effective method for high‐throughput screening of SCAR markers.     

Effect of bypass fat supplementation on productive performance and blood biochemical profile in lactating Murrah (Bubalus bubalis) buffaloes

The study investigated the effect of dietary supplementation of bypass fat on productive performance and blood biochemical profile of lactating Murrah buffaloes (Bubalus bubalis). Fifteen multiparous buffaloes (2-4 lactation) of early to mid lactation were divided in three homogenous groups T(1) (control), T(2), and T(3) of five each. The animals in T(1) were fed with a basal diet consisting of a concentrate mixture, green sorghum, and wheat straw as per requirements, while the animals in group T(2) and T(3) were fed with same ration supplemented with 0.7 % (100?g/day) and 1.4 % (200?g/day) bypass fat (on dry matter intake (DMI) basis), respectively. The feed intake, milk yield, and milk composition were not influenced by supplemental bypass fat. However, fat-corrected milk (6.5 %) yield was higher (P?相似文献   

Sequence and topological characterization of Toll-like receptor 8 gene of Indian riverine buffalo (Bubalus bubalis)

In this study, buffalo (Bubalus bubalis) Toll-like receptor 8 (TLR8) gene has been characterized by sequence analysis and detecting polymorphism. Complete ORF of buffalo TLR8 gene was amplified using the RNA isolated from spleen tissue, which was found to be 3,102 nucleotides long encoding a 1,033 amino acid protein. Buffalo TLR8 had 10 nucleotide changes as compared to other livestock species resulting in six unique amino acid changes, four of them lying within leucine-rich repeat (LRR) domains. As compared to cattle (Bos indicus and Bos taurus), out of fifteen cysteine residues, fourteen were conserved and Cys at position 521 was replaced by Arg. Nine of the LRR domains had no amino acid change as compared to cattle, whereas LRR-C-terminus had maximum, five amino acid changes. Sequence characterization of 12 riverine and swamp buffaloes revealed presence of four polymorphic nucleotides, two of them were non-synonymous, one synonymous and one site in 3′UTR. PCR-RFLP genotyping of non-synonymous SNP 2758A>G (ILeu920Val) in Toll–interleukin-1 receptor domain of 463 swamp and riverine buffaloes showed a higher frequency of allele A in swamp (95 %) as compared to riverine (9.84 %) buffaloes.     

Genotypic variability among cotton cultivars for heat and drought tolerance using reproductive and physiological traits

Development of rapid and inexpensive screening tools for heat and drought stress tolerance is needed and will be helpful in cotton breeding programs and selecting cultivars for a niche environment. In this study, several pollen-based traits at optimum and high temperatures and physiological parameters measured during the boll-filling period were used to evaluate variability among the cultivars for heat and drought stresses. Principal component analysis and drought stress response index methods were used to categorize cotton cultivars into three heat and drought tolerant clusters. Based on the combined analysis, PX532211WRF has been identified as heat- and drought-tolerant, and would be expected to perform better under both heat- and drought-stressed environments. A poor correlation between reproductive and physiological indices indicates that screening breeders have to use different traits to screen cultivars for reproductive and vegetative tolerance. Identified traits could serve as valuable screening tools in cotton breeding programs aimed at developing genotypes to a changing climate. Moreover, cultivar-dependent relative scores will aid in the identification of cultivars best suited to niche environments to alleviate the influences of abiotic stresses at both vegetative and reproductive stages.     

Response of Maize (Zea Mays L.) to Phosphorus Fertilizers in Two Alfisols with Contrasting Phosphorus Availabilities and Sorption Capacities

Increase in phosphorus (P) availability with fertilizer addition is influenced by soil properties such as P sorption capacity. We investigated P availability changes and response of maize (Zea mays L) to four P fertilizers rates (0, 20, 30 and 40 kg ha^?1) in a two-site field experiment, having soils of contrastingly different available P (2.9 and 22.1 mg kg^?1) and P sorption capacities (171.9 and 54.2 mg kg^?1). Increase in available P was significantly greater in the soil with higher available P but lower P sorption capacity, than in the other; however, yield responses were similar in the two soils. Fertilizer P rates of 30 and 40 kg ha^?1 gave significantly greater maize yields than the unfertilized treatment in both soils. Results suggest the need to account for the P sorption capacity when deciding rates of P fertilizers to increase available P in soils.