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Coordinated Varietal Trial (CVT) on different genotypes of potato received from National Potato Research Program (NPRP), Khumaltar, Lalitpur was carried out at Horticultural Research Station, Rajikot, Jumla at an altitude of 2396 m above mean sea level during two consecutive years 2019 and 2020 to evaluate potato genotypes suitable for the high hills of Karnali province of Nepal. Nine different potato genotypes with two checks i.e. Desiree and Jumli Local were tested on Randomized Complete Block Design (RCBD). Each treatment was replicated four times. Compost was used at the rate of 20 tons per hectare. There was no use of chemical fertilizer. Well sprouted tubers of 25-50 g were planted with 60cm x 25cm spacing. The effects of different genotypes were recorded for both vegetative as well as yield parameters. Tested genotypes differed significantly for vegetative (emergence percentage at 30 days after planting & 45 days after planting, uniformity, ground coverage, plant height, number of main stems) as well as yield parameters (total number of tubers and tuber yield per ha). The highest tuber yield (20.9 t/ha) was harvested from CIP 392797.22. Result of consecutive years showed that potato genotype CIP 392797.22 is suitable for cultivation in high hills of Karnali province for food as well as nutritional security.

An on-farm varietal trial was carried out to evaluate promising genotypes of potatoes received from the National Potato Research Program (NPRP), Khumaltar at Urthuchautara settlement of Patrashi Rural Municipality of Jumla, Nepal at an altitude of 2430 meters above mean sea level during two consecutive years 2019 and 2020. Four promising potato genotypes: PRP 226567.2, PRP 136769.1, CIP 395077.242, CIP 393617.1 and two check cultivars i.e. Desiree and Jumli Local were tested in Randomized Complete Block Design (RCBD). Each treatment was replicated four times. Compost was used at the rate of 20 tons per hectare (t/ha) and there was no chemical fertilizer used. Well-sprouted tubers of 25-50 g were planted at 60cm x 25cm spacing. Observations were recorded on vegetative parameters as well as yield attributes. Among different parameters observed most all the vegetative as well as yield and yield attributing parameters were found significant among each other whereas emergence at 45 DAP and plant height during 2020 were found non-significant. The highest tuber yield (30.88 t/ha) was recorded in PRP 226567.2 followed by PRP 136769.1 (23.89 t/ha). Based on the average of two-year results, PRP 226567.2(30.88 t/ha) and PRP 136769.1 (23.89 t/ha) were superior for the purpose of variety recommendation for high hills of Karnali province.

On-farm varietal trial was carried out to evaluate promising genotypes of potato received from International Potato Centre (CIP), Lima, Peru through National Potato Research Program (NPRP), Khumaltar at Guthichaur Rural Municipality in the high hills of Jumla during two consecutive years 2017 and 2018. Five promising potato genotypes and two check cultivars i.e. Desiree and Jumli Local were tested in Randomized Complete Block Design (RCBD). The treatments were replicated three times. Compost was used at the rate of 20 t/ha. Well sprouted tubers of 25-50 g were planted at 60cm x 25cm spacing. Observations were recorded on vegetative parameters and yield attributes. Tested genotypes differed significantly for emergence percentage at 30 days after planting, uniformity, ground coverage, plant height, number of main stems, total number of tubers and tuber yield per hectare. The highest tuber yield (26.14 t/ha) was recorded in CIP393073.179 followed by CIP 395112.32 (24.56 t/ha) and CIP 390478.9 (23.12 t/ha). The average results of both years showed that potato genotypes CIP393073.179, CIP 395112.32 and CIP 390478.9 were promising for commercial cultivation in Jumla and in the similar agro-ecological domains of Karnali province.

The trial was carried out to identify suitable potato genotypes for high hills of Karnali province of Nepal. The genotypes were received from International Potato Centre (CIP), Lima, Peru through National Potato Research Program (NPRP) and evaluated for two consecutive years 2017 and 2018 at Horticulture Research Station (HRS), Rajikot, Jumla, Nepal (2396 masl). Nine nutrient dense potato genotypes with two checks i.e. Desiree and Jumli Local in on-station trial were tested in Randomized Complete Block Design (RCBD) with three replications. Fertilizer was used at the rate of 100:100:60 kg NPK/ha and 20 t/ha compost. Well sprouted tubers of seed size (25-50 g) were planted at a spacing of 60cm x 25cm. The effects of different genotypes were recorded for both vegetative as well as yield parameters. There is a significant difference among tested genotypes for vegetative (emergence percentage at 30 days after planting & 45 days after planting, uniformity, ground coverage, plant height, number of main stems) as well as yield parameters (total number of tubers and tuber yield per ha). The highest tuber yield (46.93 t/ha) was recorded from genotype T 304351.109 followed by genotype T 304368.46 (41.46 t/ha) and genotype T 302498.7 (32.69 t/ha) among the nutrient dense potato genotypes. Similarly, late blight scoring was minimum (score 1) in all these three genotypes. The results of both years showed that potato genotypes T 304351.109, T 304368.46 and T 302498.7 are promising for cultivation in high hills of Karnali province to combat the malnutrition as well as ensure nutritional security.

The present study analyses the gaps and issues in the production and distribution system of potato seeds in Nepal. Households’ survey combined with focus group discussions (FGDs) and key informant interviews (KII) were carried out to collect the information. Gross benefit and descriptive statistics were employed for the analysis of the data. Results revealed that National Potato Research Program (NPRP) and some private companies were responsible for the zero generation Pre-Basic Seeds (PBS) production. National Centre for Potato, Vegetables and Spice Crops Development Program (NCPVSCDP) collects the seed demand and helps in potato seed certification at the farmers’ level. The current production is inadequate to meet the demand. As the present potato productivity is 16.72 mt ha-1 which is less than projected by National Seed Vision (NSV), reducing the yield gap is one of the important ways to meet the demand. The Gross benefit per hectare of first-generation basic potato seed (BS1) was NRs 14, 66,667 ($ 12,759) and second-generation basic potato seed (BS2) was NRs 9, 20, 667 ($ 8,009). However, the potato seed system is not working effectively in Nepal. Therefore, the adoption of improved potato varieties should be extensive through a strong mechanism for maintaining the full seed cycle and its proper distribution. Further, it is equally important to change the perception of farmers by showing the comparative benefit of growing ware potato and seed potato.

This paper aims to introduce the $k$-Mersenne and $k$-Mersenne-Lucas octonions. We give the closed form formulae for these octonions and obtain some well-known identities like Cassini's identity, d'Ocagne's identity, Catalan identity, Vajda's identity and generating functions of them. As a consequence k=1 yields all the above properties for Mersenne and Mersenne-Lucas octonions.

We evaluate some types of infinite series with balancing and Lucas-balancing polynomials in closed form. These evaluations will lead to some new curious series for $\pi$ involving Fibonacci and Lucas numbers. Our findings complement those of Castellanos from 1986 and 1989., Comment: 16 pages, 5 tables

In this article, we have proposed a public key cryptography using Affine-Hill cipher with a generalized Fibonacci matrix(called multinacci matrix). Also proposed a key establishment(exchange of key matrix $K=Q_{\lambda}^{k}$ of order $\lambda\times\lambda$ for encryption-decryption) scheme with the help of multinacci sequences under prime modulo. In this scheme, instead of exchanging key matrix, we need to exchange the only pair of numbers $(\lambda, k)$, which reduces the time complexity as well as space complexity and comes with a large key-space., Comment: Construction, development and efficiency

Saabunud / Received 19.06.2020 ; Aktsepteeritud / Accepted 18.09.2020 ; Avaldatud veebis / Published online 18.09.2020 ; Vastutav autor / Corresponding author: Kalika Prasad Upadhyay e-mail: kalikaupadhyay@yahoo.com The response of five types of biochar (Lantana camara, Ipomoea carnea, rice husk, sawdust, no biochar) on growth and yield attributes of potato was evaluated. The experiment was laid out in randomized complete block design with six replications in rainfed areas of two different environments (Jiri in 2018 and Pawati in 2019) of Nepal. The popular early maturing potato variety 'Desiree' was used in the experiment. The spacing was maintained 60 cm between rows and 25 cm between plants in the plot size of 7.2 m2. Seed tubers were planted in the 1st week of February and harvested in the 4th week of May. Recommended fertilizers (100:60:60 kg ha–1 NPK + 20 t ha–1 farmyard manure) and biochars at 2 t ha–1 were applied to the soil. Seed tubers were completely covered with an equal amount of biochar before covering with the soil. The results revealed that the total yield and marketable yield of potato varied with biochars types. The potato tuber yield was found higher and red ants infestation was lower in plots applied with biochars as compared to control plots (without biochars). The use of biochars derived from Lantana camera produced the highest number of tubers (6.1 tubers plant–1), the greatest weight of tubers (286.1 g plant–1) and the least damage of red ants on tubers (4.7%) followed by sawdust (6.0 tubers plant–1, 263.6 g tuber weight plant–1 and 7.8% damaged tubers by red ants). The findings provide new information on the understanding of biochar effect on increased marketable yield of potato in rainfed lands by reducing damage from red ants.

A split-plot experiment was conducted to determine the response of potato to application rate of biochar (0, 2, 4 and 6 t/ha , main plots) and number of irrigations (once, twice and thrice a month, sub-plots) in 3 replications as a pot trial in a screen house at Khumaltar during winter season of 2018 and 2019. Biochar was produced from Lantana camara by semi-pyrolysed technique in a Kon Tiki drum. Plastic pots with 26 cm of diameter were used to meet the 25 cm plant spacing of potato recommended in Nepal. The early maturing (90 days) released variety ‘Desiree’ was used for the trial. Observations were recorded on plant and tuber attributes. The results revealed that the influence of biochar rates was positive over zero biochar on plant height, root fresh weight, root dry weight, stem fresh weight and tuber dry weight. The effect of biochar @ 2/ha had similar effects to the rates of 4 t/ha and 6 t/ha rates. Irrigation treatments were significantly different for plant height, number of tubers per plant, root fresh weight, stem and leaf fresh weight, tuber fresh weight, root dry weight and tuber dry weight. Among the irrigation schedules, irrigating twice and thrice a month had similar effects but they were different from one irrigation. Interactions of biochar @ 2 t/ha with one, two or three irrigations were superior to the interactions of biochar @ 0 t/ha with one and two irrigations for tuber dry weight and total dry weight.

Plants display extraordinary ability to revive tissues and organs lost or damaged in injury. This is evident from the root tip restoration and classical experiments in stem demonstrating re-establishment of vascular continuity. While recent studies have begun to unravel the mechanistic understanding of tissue restoration in response to injury in underground plant organs, the molecular mechanisms of the same in aerial organs remain to be ventured deeper. Here, we discuss the possibility of unearthing the regulatory mechanism that can confer universal regeneration potential to plant body and further provide a comprehensive understanding of how tissue and organ regeneration gets triggered in response to mechanical injury and later gets terminated after re-patterning and regaining the appropriate size.

Eastern hill region is one of the high potato producing areas of potato in Nepal. There are many traditional potato production systems existing in the region. Among them, 'Bung' and 'Lhose' are very popular systems. There are some under-proven views of naming to this unique cultivation practice. Field observations, key informants' interview, and group discussion were carried out at three sites of Okhaldhunga and Solukhumbu districts in July 2019 to explore the basic information on the bung system. The results of this investigation revealed that the century-old practice utilized marginal sloppy lands of mountains for cultivation of potatoes. Farmers left land fallow for 4-5 years to grow weeds and herbs. Thereafter, they slashed them with a thin layer of soil, stacked them over winter, burned and mixed with the soil making a raised pit. They planted 15-25 potato seed tubers into these pits depending upon the pit size. No additional fertilizer is added to these pits. No intercultural operations are carried out until harvesting. It was explained that the yield of potato from the bung was significantly higher 15-20 kg) than that of general local practice called lhose system (5-7 kg) from the area equivalent to Bung . Some interventions such as high yielding varieties, easy-to-handle equipment for bung preparation and introduction of fast-growing non-hazardous weeds, etc. were the demands of the farmers to increase profit from the bung system.

Shoot-borne adventitious/crown roots form a highly derived fibrous root system in grasses. The molecular mechanisms controlling their development remain largely unknown. Here, we provide a genome-wide landscape of transcriptional signatures - tightly regulated auxin response and in-depth spatio-temporal expression patterns of potential epigenetic modifiers - and transcription factors during priming and outgrowth of rice (Oryza sativa) crown root primordia. Functional analyses of rice transcription factors from WUSCHEL-RELATED HOMEOBOX and PLETHORA gene families reveal their non-redundant and species-specific roles in determining the root architecture. WOX10 and PLT1 regulate both shoot-borne crown roots and root-borne lateral roots, but PLT2 specifically controls lateral root development. PLT1 activates local auxin biosynthesis genes to promote crown root development. Interestingly, O. sativa PLT genes rescue lateral root primordia outgrowth defects of Arabidopsis plt mutants, demonstrating their conserved role in root primordia outgrowth irrespective of their developmental origin. Together, our findings unveil a molecular framework of tissue transdifferentiation during root primordia establishment, leading to the culmination of robust fibrous root architecture. This also suggests that conserved factors have evolved their transcription regulation to acquire species-specific function.

In this paper, we define new generalized k-Mersenne numbers and give a formula of generalized Mersenne polynomials and further we study their properties. Moreover, we define Gaussian Mersenne numbers and obtain some identities like Binet Formula, Cassini's identity, D'Ocagne's Identity, and generating functions. The generalized Gaussian Mersenne numbers are described and the relation with classical Mersenne numbers are explained. We also introduce a generalization of Gaussian Mersenne polynomials and establish some properties of these polynomials., 16 pages

Summary: A wide variety of multicellular organisms across the kingdoms display remarkable ability to restore their tissues or organs when they suffer damage. However, the ability to repair damage is not uniformly distributed throughout body parts. Here, we unravel the elusive mechanistic basis of boundaries on organ regeneration potential using root tip resection as a model and show that the dosage of gradient-expressed PLT2 transcription factor is the underlying cause. While transient downregulation of PLT2 in distinct set of plt mutant backgrounds renders meristematic cells incapable of regeneration, forced expression of PLT2 acts through auto-activation to confer regeneration potential to the cells undergoing differentiation. Surprisingly, sustained exposure to nuclear PLT2, beyond a threshold, leads to reduction of regeneration potential despite giving rise to longer meristem. Our studies reveal dosage-dependent role of gradient-expressed PLT2 in root tip regeneration and uncouple the size of an organ from its regeneration potential. : Durgaprasad et al. show that dosage of a gradient-expressed transcription factor orchestrates the regeneration competence in developing root tip. Interestingly, the regeneration potential of root meristem can be separated from its size. Keywords: multicellular organism, Arabidopsis, organ regeneration, PLETHORA gradient, stem cells, autoregulation, root meristem, lateral root, organ size, dosage dependent

Unlike dicots, the robust root system in grass species largely originates from stem base during postembryonic development. The mechanisms by which plant hormone signaling pathways control the architecture of adventitious root remain largely unknown. Here, we studied the modulations in global genes activity in developing rice adventitious root by genome-wide RNA sequencing in response to external auxin and cytokinin signaling cues. We further analyzed spatiotemporal regulations of key developmental regulators emerged from our global transcriptome analysis. Interestingly, some of the key cell fate determinants such as homeodomain transcription factor (TF), OsHOX12, no apical meristem protein, OsNAC39, APETALA2/ethylene response factor, OsAP2/ERF-40 and WUSCHEL-related homeobox, OsWOX6.1 and OsWOX6.2, specifically expressed in adventitious root primordia. Functional analysis of one of these regulators, an auxin-induced TF containing AP2/ERF domain, OsAP2/ERF-40, demonstrates its sufficiency to confer the adventitious root fate. The ability to trigger the root developmental program is largely attributed to OsAP2/ERF-40-mediated dose-dependent transcriptional activation of genes that can facilitate generating effective auxin response, and OsERF3–OsWOX11–OsRR2 pathway. Our studies reveal gene regulatory network operating in response to hormone signaling pathways and identify a novel TF regulating adventitious root developmental program, a key agronomically important quantitative trait, upstream of OsERF3–OsWOX11–OsRR2 pathway.

Red ant is the most destructive insect pest of potato tubers in the field. Utilization of varietal resistance is the best option to control the pest. The resistance of five released and nine promising genotypes of potato were evaluated against red ant (Dorylus orientalis Westwood) under natural infestation in red ant prone field. Potato resistance was evaluated based on tuber damage index value (0.00 to 1) which was calculated on the bases of the percentage of damaged tubers and number of injuries on per kilogram of tubers made by the pest. Based on the results of combined data, the levels of varietal damage were categorized to be less damaged (TDI value ranging from 0.35 to 0.49), moderately damaged (TDI value ranging from 0.50to 0.64) and highly damaged (TDI value ranging from 0.65 to 0.79) types. Among the 14 genotypes compared for levels of tuber damage, the fivegenotypes: IPY-8 (TDI value: 0.35), Khumal Seto (TDI value: 0.39), PRP-056267.1 (TDI value: 0.40), Janak Dev (TDI value: 0.44) and PRP-25861.1 (TDI value: 0.49) were determined to be the less damaged types. The less damaged potato genotypes can be used by farmers as the relatively resistant genotypes against red ant.

Plants encompass unparalleled multi-scale regenerative potential. Despite lacking specialized cells that are recruited to injured sites, and despite their cells being encased in rigid cell walls, plants exhibit a variety of regenerative responses ranging from the regeneration of specific cell types, tissues and organs, to the rebuilding of an entire organism. Over the years, extensive studies on embryo, shoot and root development in the model plant species

Plants encompass unparalleled multi-scale regenerative potential. Despite lacking specialized cells that are recruited to injured sites, and despite their cells being encased in rigid cell walls, plants exhibit a variety of regenerative responses ranging from the regeneration of specific cell types, tissues and organs, to the rebuilding of an entire organism. Over the years, extensive studies on embryo, shoot and root development in the model plant species Arabidopsis thaliana have provided insights into the mechanisms underlying plant regeneration. These studies highlight how Arabidopsis, with its wide array of refined molecular, genetic and cell biological tools, provides a perfect model to interrogate the cellular and molecular mechanisms of reprogramming during regeneration.

The versatile regeneration capability of leaves enable even a detached Arabidopsis leaf to yield two kinds of regenerative responses namely, wound healing at the cut end in form of callus formation or de novo root regeneration (DNRR). Using various experimental approaches, we show that the factor favouring DNRR over callus formation seems to be a mechanical cue, possibly touch, at the cut end of the detached leaf. Here, we show that the forced expression of a PLETHORA transcription factor can bypass the need for touch to initiate DNRR. Our findings provide a genetic frame-work for touch dependant DNRR and suggest that a core PLT transcription regulatory module acts in response to mechano-sensing stimuli.

Recurring damage to the aerial organs of plants necessitates their prompt repair, particularly their vasculature. While vascular regeneration assays for aerial plant parts such as the stem and inflorescence stalk are well established, those for leaf vasculature remain unexplored. Recently, we established a new vascular regeneration assay in growing leaves and discovered the underlying molecular mechanism. Here, we describe the detailed stepwise method for the incision and regeneration assay used to study leaf vascular regeneration. By using a combination of micro-surgical perturbations, brightfield microscopy, and other experimental approaches, we further show that the age of the leaf as well as the position and size of the injury determine the overall success rate of regeneration. This easy-to-master vascular regeneration assay is an efficient and rapid method to study the mechanism of vascular regeneration in growing leaves. The assay can be readily combined with cellular and molecular biology techniques.

BackgroundRecurring damage to aerial organs of plants necessitates their prompt repair, particularly their vasculature. While vascular regeneration assay in aerial plant parts such as stem and inflorescence stalk are well established, those on leaf vasculature remained unexplored. Recently we established a new vascular regeneration assay in growing leaf and discovered the underlying molecular mechanism.ResultsHere we describe the detailed stepwise method of incision and the regeneration assay used for studying the leaf vascular regeneration. By using a combination of micro-surgical perturbations, brightfield microscopy and other experimental approaches, our new findings show that the regeneration efficiency decreases with aging of the leaf, and increases with the nearness of the wound towards the proximal end of the leaf.ConclusionThis easy-to-master vascular regeneration assay is an efficient and rapid method to study the mechanism of vascular regeneration in growing leaves. It can be readily adapted for other plant species and can be combined with cellular and molecular biology techniques.

Shoot borne adventitious/crown roots (AR/CR) shape up the root architecture in grasses. Mechanisms underlying initiation and subsequent outgrowth of CR remain largely unknown. Here, we provide genome-wide modulation in the landscape of transcriptional signatures during distinct developmental stages of CR formation in highly derived grass species, rice. Our studies implicate the role of potential epigenetic modifiers, transcription factors and cell division regulators in priming the initiation of CR primordia followed by progressive activation of conserved transcription regulatory modules to ensure their outgrowth. In depth analysis of spatio-temporal expression patterns of key cell fate determinants and functional analyses of rice WUSCHEL RELATED HOMEOBOX10 (OsWOX10) and PLETHORA (OsPLT1) genes reveal their unprecedented role in controlling root architecture. We further show that OsPLT1 activates local auxin biosynthesis and forms an integral part of ERF3-OsWOX11-OsRR2 regulatory module during CR primordia development. Interestingly, OsPLT genes, when expressed in the transcriptional domain of root-borne lateral root primordia of Arabidopsis plt mutant, rescued their outgrowth demonstrating the conserved role of PLT genes in root primordia outgrowth irrespective of their developmental origin. Together, these findings unveil the molecular framework of cellular reprogramming during trans-differentiation of shoot tissue to root leading to culmination of robust root architecture in grass species which got evolutionary diverged from dicots.

WUSCHEL-RELATED HOMEOBOX 11 establishes the acquisition of pluripotency during callus formation and accomplishes de novo shoot formation by regulating key transcription factors in poplar. De novo shoot regeneration is a prerequisite for propagation and genetic engineering of elite cultivars in forestry. However, the regulatory mechanism of de novo organogenesis is poorly understood in tree species. We previously showed that WUSCHEL (WUS)-RELATED HOMEOBOX 11 (PtWOX11) of the hybrid poplar clone 84K (Populus alba × P. glandulosa) promotes de novo root formation. In this study, we found that PtWOX11 also regulates de novo shoot regeneration in poplar. The overexpression of PtWOX11 enhanced de novo shoot formation, whereas overexpression of PtWOX11 fused with the transcriptional repressor domain (PtWOX11-SRDX) or reduced expression of PtWOX11 inhibited this process, indicating that PtWOX11 promotes de novo shoot organogenesis. Although PtWOX11 promotes callus formation, overexpression of PtWOX11 and PtWOX11-SRDX also produced increased and decreased numbers of de novo shoots per unit weight, respectively, implying that PtWOX11 promotes de novo shoot organogenesis partially by regulating the intrinsic mechanism of shoot development. RNA-seq and qPCR analysis further revealed that PtWOX11 activates the expression of PLETHORA1 (PtPLT1) and PtPLT2, whose Arabidopsis paralogs establish the acquisition of pluripotency, during incubation on callus-inducing medium. Moreover, PtWOX11 activates the expression of shoot-promoting factors and meristem regulators such as CUP-SHAPED COTYLEDON2 (PtCUC2), PtCUC3, WUS and SHOOT MERISTEMLESS to fulfill shoot regeneration during incubation on shoot-inducing medium. These results suggest that PtWOX11 acts as a central regulator of the expression of key genes to cause de novo shoot formation. Our studies further provide a possible means to genetically engineer economically important tree species for their micropropagation.

Plants display an extraordinary ability to regenerate complete shoot systems from a tissue fragment or even from a single cell. Upregulation of the determinants of pluripotency during a precise window of time in response to external inductive cues is a key decisive factor for shoot regeneration. A burst of recent studies has begun to provide an understanding of signaling molecules that are instrumental in the making of the regenerative mass, as well as the developmental regulators that are seminal in shaping the pluripotent state. Here, we discuss how signaling molecules, waves of mutually exclusive stem cell regulators and epigenetic modifiers could contribute to cellular heterogeneity in an island of regenerative mass, thus leading to de novo shoot regeneration.

The initial view that regeneration can be a continuum in terms of regulatory mechanisms is gradually changing, and recent evidence points towards the presence of discrete regulatory steps and intermediate phases. Furthermore, regeneration presents an excellent example of a process generating order and pattern, i.e. a self-organization process. It is likely that the process traverses a set of intermediate phases before reaching an endpoint. Although some progress has been made in deciphering the identity of these intermediate phases, a lot more work is needed to derive a comprehensive and complete picture. Here, we discuss the intermediate developmental phases in plant regeneration and compare them with the possible intermediate developmental phases in animal regeneration.