The extent of genetic diversity among Vanilla species: Comparative results for RAPD and ISSR

Vanilla is a large genus of about 110 species in the orchid family (Orchidaceae), including the species Vanilla planifolia from which commercial vanilla flavoring is derived. Since most species of vanilla are considered rare and endangered there is an urgent need to conserve them through genetic analysis and propagation/conservation studies on this crop.The present study investigated the genetic diversity among nine leafy- and leaf-less Vanilla species employing 30 decamer RAPD primers and 10 ISSR primers. The species under study were diverse and displayed a range of variability (0–66% and 0–81% for RAPD and ISSR, respectively). A total of 154 RAPD polymorphic markers (83.24%, h = 0.378) and 93 ISSR polymorphic markers (86.11%, h = 0.363) were used to generate a genetic similarity matrix followed by the cluster analysis. Specific groupings were revealed by each cluster analysis with slight variation between two different markers. Among the nine species studied, V. planifolia, Vanilla aphylla and Vanilla tahitensis revealed very low level of variation within their collections, thus indicating a narrow genetic base. The large genetic distance of Vanilla andamanica from other species suggests its different origin. A close genetic affinity was observed between the pairs V. planifolia, V. tahitensis and Vanilla albida, V. aphylla. These are the first comparative results for RAPD and ISSR reporting inter-relationship among nine cultivated, wild and hybrid Vanilla species.     

Identification of a diverse mini‐core panel of Indian rice germplasm based on genotyping using microsatellite markers

Identification of a small core germplasm set representing the available genetic diversity is essential for its proper evaluation and subsequent utilization in rice improvement programmes. For constituting a small diverse mini‐core panel of Indian rice germplasm, a representative set of 6912 accessions drawn based on their geographic origin from the whole rice germplasm collection available in the National Gene Bank was genotyped using 36 microsatellite markers. Automated fragment analysis of amplicons yielded a total of 435 alleles, with an average 12.4 and range of 3–29 alleles per locus. Polymorphism information content (PIC) ranged from 0.08 (RGNMS190) to 0.86 (RM552) with an average of 0.528. Based on genotyping data, a mini‐core consisting of 98 genotypes was identified. Ninety‐four per cent of the alleles present in the core set were present in the mini‐core. The identified small but diverse panel will be useful for further intensive trait‐specific evaluation and utilization in allele mining.     

Effects of biofloc under different carbon sources and protein levels on water quality,growth performance and immune responses in black tiger shrimp Penaeus monodon (Fabricius, 1978)

A 75‐day 2 × 3 factorial experiment was conducted to evaluate the effect of two levels of dietary protein (32 and 40%) and two different carbon sources (rice flour–R and molasses‐M), and without carbohydrate (control–C) in black tiger shrimp Penaeus monodon juveniles (3.37 ± 0.04 g) at 100 nos. m^?3 in 100 L fibre reinforced plastic tanks. Biofloc volume and total suspended solid were higher in molasses added groups (32 + M and 40 + M) followed by rice flour (32 + R and 40 + R) and controls (32C and 40C). Molasses and rice flour addition significantly reduced (P < 0.01) the total ammonia–N compared to controls. The highest Vibrio, Bacillus and Lactobacillus counts were recorded in 40 + M, 32 + M and 32 + R respectively. Among the treatments, significantly higher (P < 0.01) final body weight was recorded in 40 + R (8.5 ± 0.3 g), 40 + M (7.8 ± 0.3 g) and 32 + R (7.5 ± 0.4 g) compared to control groups, 32C (6.1 ± 0.3 g), 40C (6.4 ± 0.3 g) and molasses added group, 32 + M (5.7 ± 0.4 g). Rice flour supplementation significantly increased (P < 0.01) the total haemocyte count (×10⁶ cells mL^?1) in 32 + R (45.7 ± 3.7) and 40 + R (44.3 ± 3.1) compared to controls, 32C (27.3 ± 3.4) and 40C (25.8 ± 0.9). Similarly, higher superoxide dismutase, catalase, serum protein and glucose were recorded in the rice flour added groups, 40 + R followed by 32 + R. Among the treatments, the highest level of prophenoloxidase (OD 490 nm, 0.3 ± 0.0) and survival after challenge with Vibrio harveyi (55.6%) was observed in 32 + R. The study elucidates that rice flour addition produces optimum level of biofloc with better growth and immune responses compared to molasses and control. Furthermore, rice flour addition at 32% protein level could replace 40% protein feed.     

Evaluation of growth,feed utilization efficiency and immune parameters in tiger shrimp (Penaeus monodon) fed diets supplemented with or diet fermented with gut bacterium Bacillus sp. DDKRC1. isolated from gut of Asian seabass (Lates calcarifer)

An experiment was conducted to assess the effect of supplementation of cellulolytic gut bacterium with plant protein‐based diet on growth, digestibility and digestive enzyme status of tiger shrimp, Penaeus monodon. Bacillus sp. DDKRC1. (JN641289), a potential cellulolytic bacterium, isolated from the gut of Asian seabass was used as feed supplement in this experiment. The shrimps of group I, II and III were fed with control diet (without bacterial supplement, D1), diet supplemented with live Bacillus sp. DDKRC1. at 2.94 × 10⁷ cfu per 100 g feed (D2) and diet fermented (48 hr) with same bacteria (D3) respectively. At the end of the 42 days experiment, shrimps of group II showed significantly better (p < .01) growth and protein efficiency ratio (PER) and lower (p < .01) feed conversion ratio (FCR) as compared to group I and III. Dry matter, cellulose, hemicellulose and lipid digestibilities were significantly (p < .01) higher in group II than other two groups. Cellulase, amylase and protease activities in the gastrointestinal (GI) tract were significantly (p < .01) higher in group II as compared to other two groups. Total heterotrophic count, amylolytic, cellulolytic and proteolytic bacterial counts in gut were significantly (p < .01) higher in group II as compared to other two groups. Haematological analysis indicated better (p < .05) immune response in groups II and III than control group. Diets D2 and D3 showed better effect on growth, digestibility, FCR, survival and immune response of P. monodon as compared to D1.     

Long-term manuring and fertilization influence soil inorganic phosphorus transformation vis-a-vis rice yield in a rice–wheat cropping system

A study on the rice–wheat cropping system was conducted at Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India, to assess the effects of long-term manuring and fertilization on transformation of the inorganic phosphorus (P) fraction in soil after 22 years of the crop cycle. Soil samples were collected after Kharif from seven treated plots having different types of organic amendments like farm yard manure, paddy straw and green manuring with 50% substitution of nitrogen levels in rice crop only. The result showed that the yield trend of rice was maintained due to the buildup of P from various organic inputs. Although cultivation for 22 years without adding any fertilizer caused a significant decrease in almost all the forms of P viz. avail-P, saloid P, iron phosphorus fraction (Fe–P), aluminum phosphorus fraction (Al–P), calcium phosphorus fraction (Ca–P) and total P in control. Partial substitution of inorganic fertilizer N (50%) with organics, however, caused a significant increase in almost all the P fractions in soil over the control. The relative abundance of all the fractions of inorganic P irrespective of treatments was as follows: Fe–P > reductant soluble P fraction > occluded P > Al–P > Ca–P > saloid P. Saloid and Fe–P were the dominating fractions responsible for 92% variation of available P and total P levels, respectively.     

Seroprevalence of brucellosis in yaks (Poephagus grunniens) in India and evaluation of protective immunity to S19 vaccine

The present study was carried out to explore the seroprevalence of brucellosis in yaks of North-Eastern hilly yak tracts of Arunachal Pradesh, India. Of 374 animals tested, 23.79, 21.11 and 18.98% were found positive for brucellosis using avidin-biotin ELISA (AB-ELISA), Rose-Bengal plate test (RBPT) and standard tube-agglutination test (STAT), respectively. The relative sensitivity and specificity for STAT were 79.77 and 100%, respectively and the same for RBPT were 88.76 and 100%, respectively in comparison to AB-ELISA. The alarming prevalence as recorded was highest among the yak cows (31.42%) followed by heifers (23.85%) and bulls (8.88%). The immune response in yaks following standard dose of calfhood vaccination with Brucella abortus strain 19 vaccine showed that protective antibody level persisted up to 210 days. This is the first report from India on prevalence of brucellosis and immunization with B abortus strain 19 vaccine in yaks. The present investigation would be a valuable guideline for future control measure and eradication programme of brucellosis in yaks.     

Molecular detection of important abortion-causing microorganisms in preputial swab of breeding bucks using PCR-based assays

Infectious diseases and aetiological agents related to female reproductive systems were extensively covered compared to its male counterpart. There needs a proper study to bridge this gap, where microflora and infectious agents of both male and female reproductive are mutually intelligible. With this study, we aimed to evaluate the microbial contamination of the preputial cavity and also screened for abortion-causing agents which are zoonotic as well. In goats, such types of abortions are caused by Brucella melitensis, Chlamydophila, Campylobacter and Coxiella etc. One of the major sources of contamination of semen is the preputial cavity, which is exposed to the external environment leading to spread of infection into the female via semen straws or by natural service. In the current study, good quality bucks (n = 32, Barbari = 12, Jamunapari = 10, Jakhrana = 10) which were routinely used for semen collection were screened for their preputial swabs, for the presence of the above pathogens. For detection of Brucella melitensis, OMP31 based TaqMan® probe real-time PCR assay was used, and for Chlamydia, 16srRNA gene based SYBR® green real-time PCR assay was employed for detection of Chlamydophila abortus. While for Campylobacter spp. and Coxiella burnetii, 16srRNA gene based conventional PCR and Trans-PCR were used, respectively. In the current study, of the screened preputial swabs, none of them showed positive for Brucella and Coxiella, but of the screened 32 samples 17 showed positive for Chlamydia (53.13%) and two (6.25%) showed positive for Campylobacter spp. The current study emphasizes on the farms and laboratories which were regularly involved in screening of brucellosis also often overlook the other potential non-brucella pathogens, causing abortions eventually incurring severe economic losses to the goat keepers.     

Carbon and water footprints of major crop production in India

Scarcity of water and emission of greenhouse gases (GHGs) are the two key environmental issues affecting crop production in India.Reducing the carbon footprint (CF) and water footprint (WF) of crop production can help to mitigate the environmental hazards that stem from GHG emissions and water scarcity.The CFs and WFs of three major cereal crops,rice,wheat,and maize,were estimated for the year 2014 under the environmental conditions in India,based on national statistics and other data sources.To...