Banko Janakari

Calanthe longipes Hook.f., a new record of Orchidaceae for the flora of Nepal

Rashika Kafle — 2024-05-31

Not available

Monitoring, reporting & verification of carbon emission and its trading

Kiran Kumar Pokharel — 2024-05-31

Not available

Duckweed (Lemna minor D0158): a promising protein source for food security

Ramesh Basnet — 2024-05-31

Duckweeds, recognized as the fastest growing aquatic flowering plants, exhibit substantial biomass production. Recently, they have been emerged as a potential industrial crop for efficient and eco-friendly protein production and nutrient recovery compared to conventional crops. The objective of the study was to determine the biomass accumulation rate, protein content and amino acid analysis of duckweeds (Lemna minor D0158).We cultured L. minor D0158 from its preserved state in the gene bank into both aseptic (in-vitro) and open condition at controlled room. The medium was Hoagland Solution (HS) mixed with sucrose in in-vitro condition while 1/5 concentration of HS (without sucrose) was in the open condition. Subsequently, we determined the dry biomass growth by calculating the weight difference adopting the Bergmann Method, and then calculated the protein percentage following the Kjeldahl Method. Moreover, the amino acid profiling was obtained using the Hydrolysis and Liquid Chromatography Technique. Later on, we compared the results with those of the other duckweeds and soybean together with the FAO requirements. We found that L. minor D0158 possessed the dry biomass growth rate of 6.72 g/m²/d with 33.13% protein content within 7-day cultivation period. Moreover, it exhibited significantly higher levels of branched chain amino acids (BCCAs) than soybean and met the FAO requirements. However, methionine (Met) content was found to be slightly low. The study suggested that L. minor D0158 might offer a sustainable solution for protein food security in future.

Pattern of plant biomass and carbon stock along different elevational forests in eastern Nepal

Pramila Kumari Gachhadar — 2024-05-31

The primary aim of this investigation was to determine the biomass and carbon stock distribution pattern among different forest stands of diverse elevations in the Morang district of East Nepal. It is noteworthy to estimate carbon stock and biomass of relatively least underexplored forests in east Nepal. The data for estimating the biomass and carbon stocks of the five different forest sites, viz. Bhaunne, Raja-Rani, Murchungi, Adheri, and Sagma located between 100-1300m above the mean sea level, were acquired through the measurement of inventory plots selected randomly. Altogether, 50 sample plots were established within five forest stands located on different elevational zone; within each forest site, 10 sample plots of 20m × 20m size, were laid out for the measurement of trees. In the case of shrubs and herbs, nested plots of 5m × 5m and 1m ×1m, respectively were established. Calculation of the biomass of trees and shrubs was facilitated through the application of an allometric equation, while the biomass of herbs was determined by the harvest method. The carbon concentration in the plant materials was estimated using ash content method. The comprehensive analysis of the stand biomass in the Bhaunne, Raja-Rani, Murchungi, Adheri, and Sagma forest sites were: 815.86 Mg ha^-1, 414.19 Mg ha^-1, 606.81 Mg ha^-1, 519.20 Mg ha^-1, and 299.96 Mg ha^-1, respectively, with minimum at the Sagma site (high-altitude forest) and maximum at the Bhaunne site (low-altitude forest). As per the variation in stand biomass, the carbon stocks in the forest sites also showed the same trend, but the values ranged from 140.19 Mg C ha^-1to 333.63 Mg C ha^-1, with the minimum in the Sagma site and the maximum in the Bhaunne site. The application of the Friedman Test revealed statistically significant variation in the tree biomass between the Murchungi and Sagma sites and also in the shrub biomass between the Adheri and Sagma sites. Similarly, noteworthy variations were observed in the herb biomass of the Bhaunne, Raja-Rani, Murchungi, and Adheri sites as compared to that of the Sagma site. The present study contributes to the understanding of forest ecosystems in context to carbon management.

In vitro selection and characterization of cadmium-tolerant calli of Tagetes erecta and Gomphrena globosa

Gauri Lama — 2024-05-31

Ornamental plants (OPs) are beneficial to remove, control and reduce heavy metals (HMs) in a process called 'phytoremediation'. This study evaluated the in vitro system-based phytoremediation properties of Tagetes erecta and Gomphrena globosa calli. Leaves from in vitro seed-grown T. erecta and G. globosa were used as an explant source for callus culture. Callus culture was found optimal in MS medium supplemented with 8 μM BAP + NAA for T. erecta and 2 μ M 2, 4-D for G. globosa. These plants were grown in their respective optimized (controlled) medium enriched with different amounts (50, 100, 150, 200, and 250 μM) of Cadmium (Cd) added in the form of Cadmium chloride (CdCl₂). The in vitro calli developed were evaluated for Cd stress tolerance based on callus diameter, growth tolerance index (GTI) and catalase (CAT) activity. Over four weeks, the callus diameters of T. erecta and G. globosa grown in different concentrations of Cd had lower growth than that of the controlled one. On the other hand, the GTI measured were greatest at 150 μM of Cd for both T. erecta (130.95%) and G. globosa (149.32%) suggesting a potential Cd tolerance. However, the CAT activity in T. erecta callus increased with the Cd concentration peaking at 150 µM then started declining while G. globosa callus showed the highest CAT activity at 50 μM of Cd. Thus, T. erecta callus showed greater Cd tolerance with the prospect of utilizing it for phytoremediation. The study also suggests growing T. erecta at 150 μM Cd for tolerant calli.

Population structure and regeneration of Tsuga dumosa and Abies spectabilis across altitudinal gradient in Rasuwa district, central Nepal

Badri Prasad Dhungana — 2024-05-31

In Nepal, Tsuga dumosa thrives well between 2,100-3,600 m altitudes above the mean sea level, mostly in the temperate region while Abies spectabilis occurs between 3,000-4,200 m altitude above the mean sea level in the sub-alpine region. Research on mature T. dumosa-A. spectabilis forests in Nepal is limited. This study aimed to analyze the population structure and regeneration status of T. dumosa and A. spectabilis in the high-altitude mixed forests of Rasuwa, central Nepal. Conducted in 2023, a total of 61 concentric circular sample plots were laid out following a stratified systematic sampling method. The population-structure-curve displayed a consistent upward trend showing abnormality. The abnormal population structure with a lack of young trees and poor regeneration status in both species points towards potential threats like grazing and wildfires. The highest DBH class ranged from 90 cm to 120 cm DBH for T. dumosa while from 60 cm to 90 cm DBH for A. spectabilis. The study found that the seedling condition of T. dumosa species was ‘fair’ in the lower (2800-3100 m) and middle stratum (3100-3400 m), while it was ‘poor’ in the upper-elevation stratum (3400-3600 m). On the other hand, the seedling condition of A. spectabilis was found to be ‘poor’ in all the three elevation strata. Furthermore, the sapling condition of both the species were found to be ‘poor’. Therefore, the studied forest requires sustainable management along with a comprehensive strategy combining controlled grazing, zonation, monitoring, community engagement, regulation enforcement, restoration, ongoing research, and public awareness.