Isolation of Glucose Fermenting Nitrogen Fixing Gene (nifH) Containing Endophytic Bacteria from Seed and Roots of Wheat (Triticum aestivation l.)

The present study was conducted to study the nifH gene containing endophytic bacterial frequency in wheat seed and roots obtained from the soil of Chitwan and Kaski. One hundred and four isolates were studied for the presence of the nifH gene. There was a diversity in isolate characters obtained from root sample Root (R), direct seed sample (ds), and plant sample (P). None of the isolates from any sources showed indole-producing ability. About 18 isolates (15% of the total) contained the nifH gene through amplification of the gene by universal primers PolF and PolR. About 6 isolates from seed sample ds and 12 isolates from root sample R contained nifH gene. None of the isolates from root sample P manifested the presence of the nifH gene. Among 18 nifH- containing isolates, only 6 isolates manifested presence of cel3 gene of 400 bp, whereas, 11 isolates showed cel3 gene of 200 bp. All nifH gene containing isolates were confirmed to be bacteria by PCR amplification of 16s rRNA gene by universal primer 27F and 1492R and visualization of agarose gel matrix with bp range of approximately 530 under UV ray. Further research scope exists to use these microbes as a bio fertilizer in plant growth promotion studies by inoculation

Phenotypic characterization of wheat landraces from mid and far western districts of Nepal

The study was conducted to evaluate phenotypic variation in one hundred and sixty six wheat landraces from mid and far western districts of Nepal. They were sown in randomized complete block design with two replications at National Wheat Research Program in 2014/15. The observed traits were analyzed using descriptive statistics and multivariate analysis using MINITAB v. 14. The results showed a wide range of phenotypic variability in observed parameters. The results also showed that the highest value of the standard deviation from mean (Sd) was for grain yield (±290.10) followed by plant height (±7.21). Among the traits the lowest deviation from mean (Sd) was for thousand grain weight TGW (±2.68). Wheat landraces grouped in four clusters depending on similarity of the studied traits. The results in this cluster, showed that days to maturity ranged from 97 to111 days, TGW ranged from 16 to17 gm, plant height ranged from 76 to 85 cm, and grain yield ranged from 2800 to 3000 Kg ha-1. Wheat landraces under study are grouped depending on specific traits useful for wheat improvement program. Results of this study can be supportive to detect wheat landraces within species with similar traits. In addition it can be useful for sampling in successive studies and parental selection in wheat breeding program.International Journal of Environment Vol.4(4) 2015: 32-44</p

EFFECT OF CLIMATE CHANGE AND ASSOCIATED FACTORS ON THE PRODUCTION AND PRODUCTIVITY OF WHEAT (Triticum aestivum L.) OVER LAST 25 YEARS IN THE TERAI REGION OF NEPAL

 A study on the effect of climate change and associated factors on the production and productivity of wheat (Triticum aestivum L.) over last 25 years in the Terai region of Nepal was conducted. Three major wheat growing districts of Nepal (Kanchanpur, Rupandehi and Dhanusha) were focused. Climate and wheat management data were deployed. Farmers' feedback was taken through a set of semi-structured questionnaire followed by one day workshop cum seminar. Focus Group Discussion (FGD) was also conducted in the field. Comparison over 25 years showed that rainfall during wheat season declined significantly while maximum temperature increased by over 10C. Mean minimum temperature showed slight decline. Farmers' interaction indicated that growth period of wheat appeared to reduce over years, while new diseases/races and weeds have emerged. This led to increase in use of chemical pesticides. Use of inputs such as chemical fertilizers increased significantly leading to increased production cost by many folds. Despite limitations, wheat farming area and production has increased significantly in the past 25 years. The major issues for farmers were found to be a deficit of inorganic fertilizers, insufficient supply of quality seeds and an unsystematic market. The coping mechanism for climate change in wheat farming in all the three districts was not applied due to lack of knowledge, facilities and access to improved technologies. The farmers expected advanced technological know-how along with other facilities for climate resilient wheat farming.International Journal of Environment Volume-4, Issue-3, June-August 2015Page:</p

Wheat Variety Improvement for Climate Resilience

High temperature stress unfavorably affects plant growth and reduces grain yield (GY). This study was conducted with an aim to identify the terminal heat tolerance of one hundred and two wheat genotypes with three checks. They were sown under normal (non-stress) and late (stress) conditions at Regional Agricultural Research Station (RARS), Tarahara; RARS, Nepalgunj and National Wheat Research Program (NWRP), Bhairahawa, Nepal. The trial was sown in Augmented design during 2014/15 winter season as a Nepal heat tolerance wheat screening nursery (NHTWSN). Grain yield, maturity, stress susceptibility and tolerant indices were estimated to assess the heat tolerance of the genotypes. Combined analysis among the tested wheat lines (102 new entries + 3 checks) showed that KACHU//KIRITATI/WBLL1 ((Heat tolerance index (HTI) = 1.78) possessed the highest level of heat tolerance, followed by SLVS&nbsp; /3/ CROC_1/ AE.SQUARROSA (224)// OPATA/5/ VEE/LIRA//BOW/3/BCN/4/KAUZ/6/ 2*KA/NAC//TRCH (HTI=1.57) while SUP152/VILLA JUAREZ F2009 (HTI=0.83) appeared to be the least heat tolerant. Correlation analysis showed that yield under stress environment had positive (r=0.083) and significant (p&lt;0.05) association with that of non-stress environment. Grain yield (Kg/ha) under both environments had significant positive correlation with mean productivity (MP), geometric mean productivity (GMP) and HTI. Thirty seven wheat genotypes possessing heat tolerance will be considered in further heat tolerance trial and can also be used directly in varietal development and in the crossing program to breed more heat tolerant genotypes

FIELD BASED ASSESSMENT OF FOLIAR BLIGHTS DISEASE OF WHEAT (Triticum aestivum L.)

  Wheat, the third major staple crop of Nepal has been suffered from many diseases. Various diseases are the major limiting factors of considerable wheat production, one of them is Spot blotch. Spot blotch caused by Bipolaris sorokiniana is a major disease of wheat in warm and humid regions of the Nepal. The fungus has a worldwide distribution but as a pathogen it is the most aggressive under the conditions of high relative humidity and temperature associated with the low fertility of soils in South Asia, South America, Africa, and Australia. The yield loss due to the disease is very significant Nepal. This experiment was conducted to identify the genotypes (crossing) having good level of resistance against spot blotch. The experiment set was received from CIMMYT comprises 52 entries and arranged in alpha lattice design with two replication in 2012/13 at NWRP, Bhairahawa condition. Three times diseases scoring were done in double digit method and calculated the Area under disease progress curve (AUDPC). Heading days, days to maturity, plant height and test weight were found highly significant but the grain yield and AUDPC were not significant among the entries. However, the grain yield and test weight (50.5 gm) were found higher where the AUDPC was lower recorded in genotype 6719 (4046 kg/ha and AUDPC 488.33) followed by genotype 6737 (3765 Kg/ha and AUDPC 576.9) and genotype 6718 (3550 kg/ha and AUDPC 596.33). International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 140-150</p

Effect of Co-Inoculation of <i>Bacillus</i> sp. Strain with Bacterial Endophytes on Plant Growth and Colonization in Tomato Plant (<i>Solanum lycopersicum</i>)

Colonization of a biofertilizer Bacillus sp. OYK strain, which was isolated from a soil, was compared with three rhizospheric and endophytic Bacillus sp. strains to evaluate the colonization potential of the Bacillus sp. strains with a different origin. Surface-sterilized seeds of tomato (Solanum lycopersicum L. cv. Chika) were sown in the sterilized vermiculite, and four Bacillus sp. strains were each inoculated onto the seed zone. After cultivation in a phytotron, plant growth parameters and populations of the inoculants in the root, shoot, and rhizosphere were determined. In addition, effects of co-inoculation and time interval inoculation of Bacillus sp. F-33 with the other endophytes were examined. All Bacillus sp. strains promoted plant growth except for Bacillus sp. RF-37, and populations of the rhizospheric and endophytic Bacillus sp. strains were 1.4–2.8 orders higher in the tomato plant than that of Bacillus sp. OYK. The plant growth promotion by Bacillus sp. F-33 was reduced by co-inoculation with the other endophytic strains: Klebsiella sp. Sal 1, Enterobacter sp. Sal 3, and Herbaspirillum sp. Sal 6., though the population of Bacillus sp. F-33 maintained or slightly decreased. When Klebsiella sp. Sal 1 was inoculated after Bacillus sp. F-33, the plant growth-promoting effects by Bacillus sp. F-33 were reduced without a reduction of its population, while when Bacillus sp. F-33 was inoculated after Klebsiella sp. Sal 1, the effects were increased in spite of the reduction of its population. Klebsiella sp. Sal 1 colonized dominantly under both conditions. The higher population of rhizospheric and endophytic Bacillus sp. in the plant suggests the importance of the origin of the strains for their colonization. The plant growth promotion and colonization potentials were independently affected by the co-existing microorganisms

Plant Growth Promoting Effects of Nepalese Sweet Potato Endophytes

Endophytic bacteria form a symbiotic relation with plants and generally cause no harmful effects to the host plants. In a previous study, we isolated eight bacterial endophytes from sweet potato plants harvested in Salyan, Nepal. These endophytes showed plant growth-promoting properties as a mixed culture. In this study, we evaluated the ability of these strains to produce indole-3-acetic acid (IAA) and to fix nitrogen. Based on these results, we selected two strains, Klebsiella sp. Sal 1 and Enterobacter sp. Sal 3, and evaluated their ability to promote plant growth. IAA production activity peaked at 15&#8315;60 mg NH4NO3/L in plant-free medium. Similarly, acetylene reduction activity peaked at 0&#8315;6.25 mg NH4NO3/L. Both strains successfully colonized plants, promoted the growth of tomatoes, and induced phenotypes in plants consistent with IAA exposure. This suggests that these strains promote plant growth by producing IAA inside the plant, where nitrogen levels are expected to be low

Yield Interactions of Wheat Genotypes to Dates of Seeding in Eastern Mid Hills of Nepal

Wheat (Triticum aestivum L.) is one of the major cereal crops and staple food sources in Nepal. Wheat varieties being popular in mid hill regions are still in the early stages of adoption. Identification of appropriate date of seeding plays important role in enhancing the adoption rate ensuring the sustainable production. Therefore, three dates viz 15th November, 1st and 15th December for seeding and twenty eight wheat genotypes were evaluated in a split plot design with two replications for two consecutive seasons in 2011/12 and 2012/13 at an altitude of 2200 masl of eastern Nepal. The results showed genetic differences and interaction effect of genotypes with the dates of sowing on grain yield, panicle length and effective tillers per square meter. The wheat sown on 1st December showed the highest yield as compared to other sown dates. Similarly, WK1907, WK1911, WK1803, WK1915, WK1909, WK1714 and WK1803 produced highest yield among the tested genotypes with retaining maximum number of effective tillers and posed suitable maturity across all sowing date