Identification of sorghum genotypes with resistance to the sugarcane aphid Melanaphis sacchari under natural and artificial infestation

Sugarcane aphid, Melanaphis sacchari is an endemic pest of sorghum during postrainy season, and there is a need to develop cultivars with resistance to this pest. Evaluation of a diverse array of sorghum genotypes under natural and artificial infestation resulted in identification of seven lines (ICSB 215, ICSB 323, ICSB 724, ICSR 165, ICSV 12001, ICSV 12004 and IS 40615) with moderate levels of resistance to aphid damage. Under artificial infestation, 10 lines suffered <20% loss in grain yield as compared to 72.4% grain loss in the susceptible check, Swarna. The genotypes ICSR 165, ICSB 724, IS 40615, DSV 5 and ICSB 323 exhibited moderate levels of resistance to aphid damage (damage rating, DR <5.0) and also had high grain yield potential (>30 q/ha). In another experiment, ICSB 215, ICSB 695, ICSR 161, Line 61510, ICSV 12004, Parbhani Moti and IS 40618 exhibited high grain yield potential (>25 q/ha) and exhibited <50% variation in grain yield as compared to more than 80% in the susceptible check, in CK 60 B. The genotypes RSV 1211, RS 29, RSV 1338, EC 8‐2, PU 10‐1, IS 40617 and ICSB 695 though showed a susceptible reaction to aphid damage, but suffered relatively low loss in grain yield, suggesting that these lines have tolerance to aphid damage. Principal coordinate analysis suggested that the genotypes with aphid resistance are quite diverse and can be used to breed for aphid resistance and high grain yield potential and also in breeding for aphid resistance in sorghum with adaptation to the postrainy season.     

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.     

Soil Nutrient Status and Leaf Nutrient Norms in Oil Palm (Elaeis Guineensis Jacq.) Plantations Grown in the West Coastal Area of India

Oil palm (Elaeis guineensis Jacq.) is a heavy feeder of nutrients and requires balanced and adequate supply of nutrients for optimum growth and yield. Information regarding soil nutrient status and leaf nutrient concentration is very much required for proper fertilizer application. Therefore, a survey was conducted for assessment of soil nutrient status and leaf nutrient concentration in 64 oil palm plantations in the state of Goa lying in the west coastal region of India. Soil pH, electrical conductivity (EC), organic carbon (OC), available potassium (K) (ammonium acetate-extractable K) (NH₄OAc-K), available phosphorus (P) (Bray’s-P), exchangeable calcium (Ca) (Exch. Ca) and magnesium (Mg) (Exch. Mg), available sulphur (S) (calcium chloride-extractable S) (CaCl₂-S), and hot water soluble boron (B) (HWB) in surface (0–20 cm depth) soil layers ranged from 4.25 to 6.77, 0.05 to 1.06 dS m^–1, 5.07 to 48.4 g kg^–1, 58.1 to 1167 mg kg^–1, 1.80 to 415 mg kg^–1, 200 to 2997 mg kg^–1, 36.0 to 744 mg kg^–1, 3.00 to 87.7 mg kg^–1 and 0.09 to 2.10 mg kg^–1, respectively. Diagnosis and Recommendation Integrated System (DRIS) norms were established for different nutrient expressions and were used to compute DRIS indices. As per DRIS indices, the order of requirement of nutrients in the region was found to be P > Mg > K > nitrogen (N) > B. Optimum leaf nutrient ranges as per DRIS norms varied from 1.64 to 2.79%, 0.36 to 0.52%, 0.37 to 0.75%, 0.89 to 1.97%, 0.35 to 0.63%, 0.89 to 1.50%, 3.10 to 13.9 mg kg^?1, 7.50 to 32.2 mg kg^?1, 35.0 to 91.1 mg kg^?1, 206 to 948 mg kg^?1, and 895 to 2075 mg kg^?1 for N, P, K, Ca, Mg, S, B, copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) respectively. On the basis of DRIS-derived sufficiency ranges, 14, 5, 11, 6, 6, 6, 8, 2, 3, 6, and 16% of leaf samples had less than optimum concentrations of N, P, K, Ca, Mg, S, B, Cu, Zn, Mn, and Fe respectively. The optimum ranges developed can be used as a guide for routine diagnostic and advisory purpose for balanced utilization of fertilizers.     

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.