International Journal of Applied Sciences and Biotechnology

403-409

Authors: Bikal Ghimire

Crop protection against pests and diseases is a major challenge in agriculture. Plant breeding is a key solution for the development of disease resistant cultivars. Gene editing is an indispensable part of plant breeding to obtain desirable traits in crops. CRISPR (Clustered Regular Interspaced Palindromic Repeats)/Cas9 (CRISPR- associated protein) is a recent breakthrough in gene editing technology. It can be utilized to exploit defensive mechanism in plants against pathogen attack with recognition and degradation of the invading pathogenic genes by bacterial immune system. Advances in plant breeding with integration of CRISPR/Cas9 have facilitated the production of cultivars with heritable resistance to viral and bacterial disease. CRISPR/Cas9 mediated genetically engineered resistance can be inherited to further generation of crops after segregation of Cas9/sgRNA transgene in F1 generation. The segregation of Cas9/sgRNA transgene prevents undesirable genome modification in successive generation and makes use of CRISPR/Cas9 safe in plant breeding. CRISPR/Cas9 proves itself as a fascinating tool to revolutionize plant breeding for the development of various disease resistant cultivars however, effects of CRISPR/Cas9 system on different physiological process of plants still needs to be studied.

415-422

Authors: Prakash Sarwa, Sanjay Kumar Verma

Two unicellular green microalgae, were isolated from Amani Shah Nallah (Jaipur, India) that receives discharge of dyeing industries. Preliminary morphological characterization using light microscopy showed ovoid, fusiform shape of cells with single to two celled coenobia in a culture suspension. Transmission electron microscopy (TEM) analyses depict abundant chloroplast located at the periphery of the cell, a pyrenoid as well as nucleus is visible in the centre. A well developed cell wall with many layers is also evident in TEM. Phylogenetic position and genetic variabilty among the isolated microalgal strains were investigated by 18S rDNA sequence analysis. The results suggest that the isolated microalgae belongs to family chlorophyceae and corresponds to genus Scenedesmus and genus Acutodesmus. Growth profile of both microalgal strains showed a typical sigmoid curve with specific growth rate of µmax, 0.839 day-1 and 0.654 day-1 for Scenedesmus sp. and Acutodesmus obliquus, respectively. The strains were allotted with MCC numbers by IARI, New Delhi as MCC26 for Scenedesmus sp. and MCC33 for Acutodesmus obliquus.

430-433

Authors: Ramchandra Pudasaini, Bigya Dhital

An experiment was conducted in IAAS, Livestock Farm, Rampur Chitwan, Nepal in order to assess the growth performance of kids feeding diets supplemented with probiotics. The experiment was laid out in Randomized Complete Block Design (RCBD) with four replications and five feeding supplemented diets with probiotics treatments. Parameters studied were live weight gain, body measurements and economic analysis. The result of this study showed the highest cumulative mean live weight (13.24 kg) in the treatment group feeding mixture of rice bran and wheat bran with probiotics. Fortnightly and daily body weight gains were also highest in the treatment group having mixture of rice bran and wheat bran with probiotics. The highest (11.74cm) overall mean monthly heart girth was observed in the treatment group feeding mixture of rice bran and wheat bran with probiotics. The mean monthly cumulative neck girth, body length and wither height of kids did not differ significant (p>0.05) among treatments. However, the highest overall mean monthly cumulative neck girth (6.71cm), wither height (10.14cm) and body length (14.62cm) was observed in probiotics supplemented treatment groups. Highest (1.61) benefit cost ratio was obtained from goats reared on feeding mixture of rice bran and wheat bran with Probiotics and lowest (1.008) in wheat bran without probiotics. The result of the study thus suggests that feeding of rice bran and wheat bran with probiotics is beneficial in terms of growth rate and cost of production.

442-448

Authors: Tulasi Prasad Paudel, Devi Prasad Adhikari, Ram Prasad Ghimire

Large numbers of species of tree fodder are being used as green roughage source for goats in several farming systems. A study was carried out at Goat Research Station, Bandipur, Nepal in order to compare the feeding value of commonly used tree fodder leaves in mid-hills of Nepal. Altogether five treatments; tree fodder leaves of Ficus semicordata, Shorea robusta, Ficus glaberrima and Ficus lacor and mixed fodder as the conventional practices of the farmers were evaluated in Randomized Complete Block Design (RCBD) with three replications. Total of 30 male goats were used for the experiment in five groups, 6 for each treatment. The subsequent experiment was carried out to determine the nutrient digestibility of the tree fodder leaves by using fecal collection method. Nutrient composition, voluntary intake and nutrient digestibility of the fodder leaves and growth performance of goats were monitored. Crude protein (CP), total ash (TA), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), hemicelluloses and cellulose proportion were better for F. glaberrima and F. lacor leaves, whereas the digestibility of those nutrients were better for F. semicordata leaves and moderate for F. glaberrima and S. robusta. Voluntary fodder dry matter intake was highest for F. glaberrima and least for mixed fodders. Growth performance of goats was higher for F. lacor and F. glaberrima than other tree fodder leaves and mixed fodders. The leaves of F. lacor and F. glaberrima had shown better feeding value than the conventional practices of farmers, mixed fodders. The leaves of S. robusta and F. semicordata were observed similar with the mixed fodders for their feeding value.

466-469

Authors: Shilu Sharma, Doj Raj Khanal, Yuvraj Panth

Brucellosis; a zoonotic disease which is caused by Brucella sp. viz; abortus, melitensis, ovis, canis, suis, in Nepal is regarded as one of the occupational and public health hazards for veterinarians, animal attendants, dairy man, slaughter-house workers, butchers and meat sellers. This study aimed to determine the prevalence of brucellosis in pigs of Bhaktapur, Kavre and Banke districts of Nepal. Serum samples of 231 pigs were collected purposively of which, 78 samples were from Bhaktapur, 85 from Kavre and 68 from Banke districts. Blood samples were collected from the jugular vein of the pigs and were centrifuged to separate the serum from the blood. The separated serum samples were stored at -20°C in the NARC lab till the test was done. Out of 231 samples, 3.90% (9/231) of samples were found to have sero-positivity towards brucellosis by using indirect ELISA test through ID Vet iELISA kit 2016. Fisher exact test was used to find association between variables. There was no significant differences (p>0.05) on sex-wise prevalence. This study shows a potential threat to the public health sector of the country along with the degradable impacts on animal health including the economy of farmers. Thus, timely implementation of appropriate preventive and control strategies should be adopted to eradicate the disease.

479-485

Authors: Ioanna Varkitzi, Kalliopi Pagou, Christina Pyrgaki, Ioannis Hatzianestis

Biotechnological applications of toxic marine dinoflagellates include seafood safety and biomedical, pharmaceutical and research purposes of their toxins among other bioproducts and bioactive compounds that they produce. The supply of sufficient quantities of phycotoxins for investigational uses remains in demand. Some of these toxins, available in small amounts, are quite expensive while their chemical synthesis is complex and costly. However, some quantities of these toxins could be produced with mass cultures of the appropriate dinoflagellates, which are however difficult to handle. Prorocentrum lima is a cosmopolitan marine dinoflagellate, which synthesizes toxins that cause a diarrheic syndrome to humans through the consumption of contaminated shellfish and fish (Diarrheic Shellfish Poisoning, DSP). The aim of this study was to design and develop a biomass upscale system for the production of the lipophilic toxins okadaic acid (OA) and dinophysistoxin 1 (DTX1) from the produced biomass of Prorocentrum lima. In our study, P. lima was grown in large scale semi-continuous cultures under controlled laboratory conditions. The maximum biomass produced was 20690 cells/mL. Maximum toxin production was 63.66 ng/mL for OA and 8.07 ng/mL for DTX1. Toxin quota in P. lima cells was 88.7% OA and 11.3% DTX1. The produced culture volume was 300 L and the total volume capacity of the upscale system could reach 500 L.

498-504

Authors: Ritesh Kumar Yadav, Amarjit Singh, Ajmer Singh Dhatt, Sandeep Jain

A total of forty one genotypes of onion were evaluated for their relative response to purple blotch complex caused by Alternaria porri and Stemphylium vesicarium under artificial epiphytotic condition in field during Rabi 2014-2015 and 2015-2016. Significant variation in disease severity among the onion genotypes was found over two years but the pooled analysis revealed that most of the variations were due to genotype x year interaction. None of the genotypes exhibited resistance to the disease complex. Of the test genotypes, eighteen were found moderately susceptible while twenty one were found susceptible to the disease complex. Two genotypes viz., Punjab Naroya and OSR-1364 exhibited highly susceptible reaction. However, six genotypes viz., P-96, P-30, P-121, OSR-1359, P-98 and OSR-1370 showed superior yield performance. Purple blotch complex exhibited highly significant negative correlation of 0.71 and 0.67 with fresh bulb yield and bulb size, respectively. Cluster analysis of onion genotypes was performed based on disease and yield variables and the genotypes were furthered grouped into five clusters based on average values of disease and yield variables.

511-522

Authors: Keshab Babu Koirala, Yagya Prasad Giri, Tirtha Raj Rijal, Pervez Haider Zaidi, Ajanahalli Ramaiaha Sadananda, Jiban Shrestha

Midhills, foot hills and river basin areas of are generally under spring maize cultivation. These areas along with the areas from Terai and Inner Terai where spring and early summer maize are grown are the most affected from heat stress. Identification and selection of suitable varieties and traits for high temperature tolerance is vital to produce heat resilient genotypes.With a view to identify high yielding heat stress resilient maize hybrids, genotypes received from International Maize and Wheat Improvement Centre (CIMMYT) were evaluated in alpha lattice design with two to three replications at Rampur, Nepalgunj and Surkhet in 2013/014, 2014/015 and 2015/016. Total 57 trials consisting of 7764 maize hyrbids were evaluated under heat stress conditions. At Nepalgunj and Surkhet, trials were planted in March/April. Out of the tested genotypes, 24 hybrids were found promising based on grain yield, plant and ear height. These 24 hybrids along with four National Maize Research Program (NMRP) developed and two multi-national companies’ hybrids as checks were tested in multilocation trials at Dumarwana, Nijgadh, Nawalparasi and Rampur in 2014/015. Out of these 24 hybrids, eight were selected and tested during 2015/016 in Dumarwana, Nijgadh, Nawalparasi, Anandapur and Rampur. Based on results combined over years and locations CAH-151 (8629 kg ha-1) and CAH-153 (8955 kg ha-1) were registered for general cultivation as Rampur Hybrid-8 and Rampur Hybrid-10, respectively. Other promising hybrids were CAH-1511 (8800 kg ha-1) followed by CAH-1515 (8678 kg ha-1), RML-95/RML-96 (8486 kg ha-1), CAH-1513 (8258 kg ha-1) and RML-86/RML-96 (7544 kg ha-1), respectively. Stability analysis revealed that CAH-151, CAH-153, CAH-1515, CAH-1511 and RML-95/RML-96 are stable hybrids having good performance.

532-536

Authors: Tirtha Raj Rijal, Keshab Babu Koirala, Mina Karki

Maize genotypes were screened at research field of National Maize Research Program, Rampur, Chitwan on 20 maize genotypes during 2015 and 2016 summer season with the objective of identification of resistant genotypes against southern leaf blight caused by Bipolaris maydis. Field experiment was laid out in randomized complete block design with three replications. Disease scoring was done as percentage of leaf area infected using 1-5 rating scale. In both the years among the tested genotypes, disease severity and grain yield varies significantly. None of the genotypes reacted for resistant whereas four genotypes; 05SADVI, BGBYPOP, RAMS03F08 and RML-32/RML-17 were moderately resistant over the years. For grain yield most of the tested genotypes produced comparatively lower grain yield however RML-32/RML-17 was superior for grain yield (3.1 t/ha) over the years.

542-547

Authors: Prakash Paneru, Birendra Kumar Bhattachan, Lal Prasad Amgain, Suman Dhakal, Bisheswar Prasad Yadav, Pankaj Gyawaly

Seed quality is the major concern for future crop production which largely depends on the nutrient we applied. To evaluate the effect of different doses of nitrogen and phosphorus on yield and seed quality of wheat an experiment was conducted during 2014/15 at agronomy research block of Agriculture and Forestry University. The experiment was designed on randomized complete block experiment with four levels of Nitrogen (0, 50, 100, and 150 kg N/ha) and Phosphorus (0, 25, 50, 75 kg P205/ha) Lab experiment was conducted to evaluate the germination and vigor test of the progeny seeds obtained from the mother plant. Highest grain yield (3.64t/ha) was associated with 100 kg N/ha which was statically similar with 150 kg N/ha, similarly highest grain yield (3.14t/ha) was associated with 75 kg P/ha which was at par with 50 kg P/ha and 25 kg P/ha. Highest germination percentage was associated with 150 kg N/ha (94.08) and 75 kg P/ha (93.66) Highest vigor was observed (36.5) at 100 kg N/ha which was at par with 150 kg N/ha whereas highest vigor was obtained at 50 kg P/ha (35.77) which was at par with 75 kg P/ha (35.71) Gross return, Net return and Benefit Cost ratio was highest at 100 kg N/ha which was at par with 150 kg N/ha. Similarly highest gross return (104.9 thousands) was observed at 75 kg P/ha, highest net income (54.81 thousands), and benefit cost ratio (2.105) was observed with 50 kg P/ha. Therefore for the better yield, good economic return and good seed quality application of nitrogenous fertilizers at 100 kg N/ha and phosphorus at 50 kg P/ha is useful under Chitwan condition.

554-565

Authors: Ritesh Kumar Yadav, Amarjit Singh, Sandeep Jain, Ajmer Singh Dhatt

Six systemic fungicides viz., Kitazin 48 EC (iprobenfos), Tilt 25 EC (propiconazole), Folicur 25 EC (tebuconazole), Score 25 EC (difenoconazole), Amistar Top 325 SC (azoxystrobin 18.2% + difenoconazole 11.4%) and Nativo 75 WG (trifloxystrobin 25% + tebuconazole 50%), and two non-systemic fungicides viz., Indofil M-45 75 WP (mancozeb) and Kocide 77 WP (copper hydroxide), were evaluated under in vitro and field conditions for their efficacy to manage purple blotch complex of onion caused by Alternaria porri and Stemphylium vesicarium. Field efficacy of the fungicides at different concentrations were determined in controlling the purple blotch complex of onion under artificial epiphytotic conditions on bulb and seed crop (cultivar PRO-6) during the Rabi season 2014-2015 and 2015-2016, respectively. The triazole fungicides, tebuconazole and difenoconazole proved superior in inhibiting growth of A. porri and S. vesicarium under in vitro conditions, respectively. Further, foliar sprays (3 for bulb crop and 4 for seed crop) of tebuconazole 25 EC (Folicur) @ 0.1 per cent at fortnightly interval most effectively managed purple blotch complex of onion under field conditions with highest Benefit: Cost ratio (8.75:1 and 88.7:1) in bulb and seed crop, respectively. Seed-to-seed method of onion seed production recorded significantly lower disease severity and higher seed yield than that of bulb-to-seed method under natural epiphytotic conditions. The present findings can be instrumental in devising strategy for the integrated management of A. porri, S. vesicarium singly as well as in complex, serious limiting biotic factors in onion production.