Stem Number Research Articles

Exploring the interplay between within-stand variation and thinning practices in southern Sweden

The state of within-stand variation (WSV) in boreal, coniferous production forests and how it is dealt with in thinning operations is a scarcely researched topic. In the autumn of 2018, we surveyed a series of Norway spruce (Picea abies (L.) Karst) or Scots pine (Pinus sylvestris L.) dominated production stands scheduled for first commercial thinning from below. Here, we evaluate the potential causes of WSV in basal area, how WSV was addressed in the thinning operations, and finally how the stands and subsequent thinning practice conformed with the basal area target specified in the thinning guidelines. WSV in the yield attributes was defined as the dispersion in a stand attribute within a stand and quantified using the Qn scale estimator (a robust measure of dispersion). First, WSV in basal area at the time of first thinning was evaluated as a function of WSV in stem number and WSV in site index. Next, yield attributes before and after thinning were compared using paired t-tests, and the future development of WSV in basal area was evaluated using linear mixed-effects models. Finally, the thinning practice was evaluated before and after thinning by modelling the compliance with the basal area target as a function of stem number and dominant height, also using linear mixed-effects models. WSV in basal area appeared to be influenced by WSV in site index and WSV in stem number for Norway spruce, but not for Scots pine. Thinning reduced the WSV in basal area, standing volume, and stem number, while dominant height, quadratic mean diameter and basal area weighted mean height remained unaffected. At first thinning, compliance with the thinning guideline increased with increasing stem density and dominant height. However, moderate to high compliance with the basal area target in the thinning guidelines was only reached for plots with elevated dominant height (>15 m) in combination with high stem number (>2250 N ha-1). Thus, the recommended range in dominant height (12–14 m) for first thinning was generally exceeded, which may be attributed to the generally low stem number at the time of thinning. This study suggests that sub-optimal regeneration efforts and management of young forests can lead to WSV across a wide range of stand attributes, and likely also reductions in yield. Thinning decreased WSV in basal area, standing volume and stem number, however, the plots were heavily thinned to such a degree that it could potentially cause production losses.

Performance of Cocoa Graft Seedlings as a Result of Different Number of Lower Stem Leaves and Entry Defoliation Time

This research aims to see the effect of the number of leaves left on the rootstock and the best defoliation time to improve the performance of cacao shoot connection seedlings. The research was conducted in the experimental garden of Politeknik Pertanian Negeri Payakumbuh from March to July 2023. Cocoa clone ICS was used as rootstock and clone TSH as scion. The experimental design was 4x4 factorial with 3 replications, the environmental design was completely randomized design. Data were analyzed statistically using F test and DNMRT further test at 5% level. From the research and data processing, it was found that there is an interaction between the treatment of different number of rootstock leaves and different defoliation times on the performance of cocoa shoot grafting seedlings based on the variables of percentage of grafted seedlings, number of shoots, number of leaves, leaf area and weight of seedling scion. It can be concluded that defoliation of the rootstock six days before splicing with rootstock having four leaves produces the best performance of cacao shoot grafting seedlings

Effects of tillage and maturity stage on the yield, nutritive composition, and silage fermentation quality of whole-crop wheat.

Whole-crop wheat (Triticum aestivum, WCW) has a high nutritional value and digestibility. No-tillage (NT) can reduces energy and labor inputs in the agricultural production process, thus decreasing production costs. There are many studies on planting techniques of WCW at present, few being on no-tillage planting. This study aimed to compare the effects of different tillage methods and maturity stages on the yield, nutritive value, and silage fermentation quality of WCW. The experiment included two tillage methods (NT; conventional tillage, CT), two maturity stages (flowering stage; milk stage), and three years (2016-2017; 2017-2018; 2018-2019). Years had a strong influence on the yield and nutritional composition of WCW. This was mainly related to the amount of rainfall, as it affects the seedling emergence rate of wheat. Although tillage methods showed no significant effects on the yield, plant height, and stem number per plant of WCW (P > 0.05), compared to CT, the dry matter (DM) and crude protein (CP) yields of NT decreased by 0.74 t/ha and 0.13 t/ha. Tillage methods showed no significant effects on the nutritive composition of WCW (P > 0.05). The WCW at the milk stage had greater DM (5.25 t/ha) and CP (0.60 t/ha) yields than that at the flowering stage (3.19 t/ha and 0.39 t/ha) (P< 0.05). The acid detergent fiber concentration of WCW decreased by 34.5% from the flowering to the milk stage, whereas water-soluble carbohydrates concentration increased by 50.6%. The CP concentration at the milk stage was lower than that at the flowering stage (P< 0.05). The lactic acid concentration of NT (17.1 g/kg DM) silage was lower than that of CT (26.6 g/kg DM) silage (P< 0.05). The WCW silage at the milk stage had a lower NH3-N concentration (125 g/kg TN) than that at the flowering stage (169 g/kg TN) (P< 0.05). Wheat sown by NT and CT was of similar yield and nutritional value, irrespective of harvest stages. WCW harvested at the milk stage had greater yield and better nutritional composition and silage fermentation quality than that at the flowering stage. Based upon the results of the membership function analysis, no-tillage sowing of wheat was feasible and harvesting at milk stage was recommended.

Phosphorus addition increases stability and complexity of co-occurrence network of soil microbes in an artificial Leymus chinensis grassland.

Understanding the response of cross-domain co-occurrence networks of soil microorganisms to phosphorus stability and the resulting impacts is critical in ecosystems, but the underlying mechanism is unclear in artificial grassland ecosystems. In this study, the effects of four phosphorus concentrations, P0 (0 kg P ha-1), P1 (15.3 kg P ha-1), P2 (30.6 kg P ha-1), and P3 (45.9 kg P ha-1), on the cross-domain co-occurrence network of bacteria and fungi were investigated in an artificial Leymus chinensis grassland in an arid region. The results of the present study showed that phosphorus addition significantly altered the stem number, biomass and plant height of the Leymus chinensis but had no significant effect on the soil bacterial or fungal alpha (ACE) diversity or beta diversity. The phosphorus treatments all increased the cross-domain co-occurrence network edge, node, proportion of positively correlated edges, edge density, average degree, proximity to centrality, and robustness and increased the complexity and stability of the bacterial-fungal cross-domain co-occurrence network after 3 years of continuous phosphorus addition. Among them, fungi (Ascomycota, Basidiomycota, Mortierellomycota and Glomeromycota) play important roles as keystone species in the co-occurrence network, and they are significantly associated with soil AN, AK and EC. Finally, the growth of Leymus chinensis was mainly due to the influence of the soil phosphorus content and AN. This study revealed the factors affecting the growth of Leymus chinense in artificial grasslands in arid areas and provided a theoretical basis for the construction of artificial grasslands.

Slope aspect of a mountainous grassland landscape shapes the structure of an encroaching shrub (Euryops floribundus N.E. Br): insights from communal grazing sites located at varying distances from rural homesteads

Mountainous grassland landscapes are severely threatened by the proliferation of shrub encroachment. So far, it remains unclear though how slope aspect coupled with land disturbances linked to the proximity of homesteads to communal grazing sites affects the distribution, density and structure of the encroaching shrubs in these grassland ecosystems. In this study, we investigated the role that slope aspect plays in determining the density and structure of an encroaching shrub species Euryops floribundus N.E. Br in three communal grazing sites located at varying distances from rural homesteads in a semi-arid mountainous grassland in the Eastern Cape Province of South Africa. Three sites were strategically chosen in Cala communal grazing lands in an encroached mountainous grassland landscape that depicted north and south-facing slope aspects. The selected sites were Tsengiwe; a site located in close proximity to homesteads at a distance of less than 100 m, Upper Mnxe situated at an intermediate distance ranging from 200 to 800 m away from homesteads and Manzimdaka, which was located furthest from homesteads at a distance greater than 1600 m. In each site and corresponding slope aspect, the density and structure of the shrub E. floribundus were evaluated on 36 randomly distributed plots, yielding a total of 108 plots across all sites. We found that shrub density was significantly higher (50%) on the north-facing slope compared to the south-facing slope in Tsengiwe, the site located near homesteads. Shrub height was significantly higher (53 and 17%) on the north-facing slope compared to the south-facing slope at Upper Mnxe and Manzimdaka, which were located at intermediate and furthest distances from the homesteads. Notably, shrub height was significantly lower (37%) in the north-facing slope compared to the south-facing slope in Tsengiwe. Following a similar pattern to shrub height, total stem number was significantly higher (20 and 85%) in the north-facing slope compared to the south-facing slope at Upper Mnxe and Tsengiwe, respectively. Shrub crown area was higher (33 and 11%) in the north-facing slope compared to the south-facing slope at Upper Mnxe and Manzimdaka, respectively. A strong positive relationship was established between the height of shrubs and their longest crown diameter, shortest crown diameter and shrub crown area across all sites, suggesting that the investigated shrub species E. floribundus employs its structural characteristics to survive, and thrive and this was more evident in the north-facing slope. The results highlight the importance of considering the proximity of homesteads into account in ecological studies, and puts emphasis on improved understanding of the vegetation patterns shaped by shrub encroachment in mountainous grasslands, which is crucial in the development of effective land management strategies.

Overexpression of P5CDH from Cleistogenes songorica improves alfalfa growth performance under field drought conditions

Water stress affects the metabolic regulation and delays the growth and development of alfalfa, causing a reduction in biomass. New alfalfa germplasm was created with improved drought tolerance in greenhouse conditions by introducing the key gene P5CDH1 from C. songorica, a xerophytic grass. However, the field adaptability and response mechanism of new drought-tolerant alfalfa germplasms under water stress are still unclear. In the present study, the yield and quality traits of transgenic CsP5CDH1 alfalfa lines under water stress and normal irrigation conditions were measured and analyzed for two years. The genetic variance components of the tested traits were calculated from the data fitted by the mixed linear model. The plant height of all lines showed significant genotypic variation (σ2g) (P < 0.05), and the stem diameter, stem number, and dry weight of all lines had a significant genotype × environment interaction (σ2ge) (P < 0.05). The heritability (H) of plant height, stem diameter, stem number, dry weight and leaf-to-stem ratio of alfalfa lines were 0.87, 0.52, 0.59, 0.52 and 0.50, respectively. There were significant genotype × environment interactions (σ2ge) (P < 0.05) for the quality traits of all lines. The heritabilities (H) of acid detergent fiber and neutral detergent fiber were 0.65 and 0.64, respectively. The results of transcriptional expression analysis with RNA-seq showed that the genes MsProDH1, MsProDH4, MsProDH5, MsP5CDH1, MsP5CS5, MsP5CS9, and MsP5CR1, which are involved in the proline metabolism pathway, played an important role in the drought tolerance of innovative alfalfa germplasm. Under water stress, with the regulation of key genes in the proline metabolism pathway, the proline content of all alfalfa lines increased to varying degrees. Among them, the proline content in the shoots and roots of transgenic line L6 was 7.29 times and 12.22 times that under normal irrigation conditions, respectively. The present study helped to clarify that the new germplasm of alfalfa transformed with the CsP5CDH gene synthesized a large amount of proline under water stress, and effectively slowed leaf water loss, thus improving the drought resistance of alfalfa.

COP9 signalosome component CSN-5 stabilizes PUF proteins FBF-1 and FBF-2 in Caenorhabditis elegans germline stem and progenitor cells.

RNA-binding proteins FBF-1 and FBF-2 (FBFs) are required for germline stem cell maintenance and the sperm/oocyte switch in Caenorhabditis elegans, although the mechanisms controlling FBF protein levels remain unknown. We identified an interaction between both FBFs and CSN-5), a component of the constitutive photomorphogenesis 9 (COP9) signalosome best known for its role in regulating protein degradation. Here, we find that the Mpr1/Pad1 N-terminal metalloprotease domain of CSN-5 interacts with the Pumilio and FBF RNA-binding domain of FBFs and the interaction is conserved for human homologs CSN5 and PUM1. The interaction between FBF-2 and CSN-5 can be detected in vivo by proximity ligation. csn-5 mutation results in the destabilization of FBF proteins, which may explain previously observed decrease in the numbers of germline stem and progenitor cells, and disruption of oogenesis. The loss of csn-5 does not decrease the levels of a related PUF protein PUF-3, and csn-5(lf) phenotype is not enhanced by fbf-1/2 knockdown, suggesting that the effect is specific to FBFs. The effect of csn-5 on oogenesis is largely independent of the COP9 signalosome and is cell autonomous. Surprisingly, the regulation of FBF protein levels involves a combination of COP9-dependent and COP9-independent mechanisms differentially affecting FBF-1 and FBF-2. This work supports a previously unappreciated role for CSN-5 in the stabilization of germline stem cell regulatory proteins FBF-1 and FBF-2.

Examining the relationship between Hispanic Serving Community college Title III grants and STEM associate degree completion

AbstractHispanic‐Serving Community Colleges enroll and educate a large share of Hispanic postsecondary students. Due to work trends and demographic changes, Hispanic and other historically underrepresented students play a crucial role in shaping the next generation of Science, Technology, Engineering, and Math (STEM) scholars and practitioners. We use data from the National Center for Education Statistics and a difference‐in‐differences technique to estimate the association between federal capacity building grants aimed at improving STEM degree attainment outcomes and associate degree completion. We find receipt of a Title III grant was associated with about a 30% increase in the total number of STEM associate degrees awarded. Further, the grants nearly doubled the number of STEM associate degrees awarded to Hispanic students, on average. This positive relationship is driven by institutions receiving more than one grant. We conclude by discussing these findings and providing federal and institutional recommendations.

3D Reconstruction of Wheat Plants by Integrating Point Cloud Data and Virtual Design Optimization

The morphology and structure of wheat plants are intricate, containing numerous tillers, rich details, and significant cross-obscuration. Methods of effectively reconstructing three-dimensional (3D) models of wheat plants that reflects the varietal architectural differences using measured data is challenging in plant phenomics and functional–structural plant models. This paper proposes a 3D reconstruction technique for wheat plants that integrates point cloud data and virtual design optimization. The approach extracted single stem number, growth position, length, and inclination angle from the point cloud data of a wheat plant. It then built an initial 3D mesh model of the plant by integrating a wheat 3D phytomer template database with variety resolution. Diverse 3D wheat plant models were subsequently virtually designed by iteratively modifying the leaf azimuth, based on the initial model. Using the 3D point cloud of the plant as the overall constraint and setting the minimum Chamfer distance between the point cloud and the mesh model as the optimization objective, we obtained the optimal 3D model as the reconstruction result of the plant through continuous iterative calculation. The method was validated using 27 winter wheat plants, with nine varieties and three replicates each. The R2 values between the measured data and the reconstructed plants were 0.80, 0.73, 0.90, and 0.69 for plant height, crown width, plant leaf area, and coverage, respectively. Additionally, the Normalized Root Mean Squared Errors (NRMSEs) were 0.10, 0.12, 0.08, and 0.17, respectively. The Mean Absolute Percentage Errors (MAPEs) used to investigate the vertical spatial distribution between the reconstructed 3D models and the point clouds of the plants ranged from 4.95% to 17.90%. These results demonstrate that the reconstructed 3D model exhibits satisfactory consistency with the measured data, including plant phenotype and vertical spatial distribution, and accurately reflects the characteristics of plant architecture and spatial distribution for the utilized wheat cultivars. This method provides technical support for research on wheat plant phenotyping and functional–structural analysis.

The Effect of Different Rates of Farm Yard Manure Application on the Growth of Irish Potato (Solanum tuberosum L.) Production in Offa District, Southern Ethiopia

Background: The highlands of North America are where the potato (Solanum tuberosum L.) first appeared. Potato is the most important vegetable crop. Farm Yard Manure undoubtedly boosts crop output because it contains large amounts of plant-growth-critical nutrients that aren’t always available in appropriate levels in the soil and the investigation is aimed to establish the ideal level of farmyard manure for increasing potato tuber production. Methods: During the 2019-2020 agricultural season, the experiment was conducted in the Offa District W/Dekeya kebele Irrigation site under irrigation and rainfall circumstances for ten months. The experiment was created on the spot using the randomized complete block design. There were three replications and four treatments (0 t/ha-1, 2.5 t/ha-1, 5 t/ha-1 and 7.5 t/ha-1). Result: The data analysis of variance showed that varying FYM nutrient rates had significant effects on potato tuber spread and stem diameter. But the effect of FYM nutrient showed a non-significant difference (P less than 0.05) on plant height, leaf area and number of stems. The longest plant height (45.187 cm), wider leaf area (45.417 cm2) and maximum plant spread (42.317) were recorded by the application of 5 t/ha-1 FYM nutrient-applied plot. Whereas the maximum stem number (3.4333) obtained by control plot and stem diameter (3.667 cm) were obtained by the application of 7.5 t/ha-1 FYM nutrient.

Floristic and structural distinctness of monodominant Gilbertiodendron dewevrei forest in the western Congo Basin

Background and aims – The forests of the Congo Basin contain high levels of biodiversity, and are globally important for carbon storage. In order to design effective conservation strategies, and to accurately model carbon stocks, a fine-scale understanding of the different forest types that make up this forest block is needed. Monodominant Gilbertiodendron dewevrei forest covers large areas of the Congo Basin, but it is currently unclear whether it is sufficiently distinct from adjacent mixed terre firme forest to warrant separate treatment for conservation planning and carbon calculations. This study aimed to compare the structure and diversity of monodominant and mixed forest, and ask whether there is a unique vascular plant community associated with G. dewevrei forest. Material and methods – We utilised a combination of plot data and herbarium specimens collected in the Sangha Trinational (a network of protect areas in Cameroon, Central African Republic, and the Republic of Congo). Plot inventories were used to compare G. dewevrei forest and mixed forest for stem density, basal area, above ground biomass, stem size distribution, species diversity, and species composition. In addition, a database of 3,557 herbarium specimens was used to identify species of vascular plant that are associated with G. dewevrei forest. Key results – Gilbertiodendron dewevrei forest is distinct in both structure and species composition from mixed forest. Gilbertiodendron dewevrei forest has a lower stem number (of trees ≥ 10 cm), but a greater proportion of larger trees (&amp;gt; 70 cm), suggesting higher carbon stocks. The species composition is distinct from mixed forest, with 56 species of vascular plant significantly associated with G. dewevrei forest. Conclusion – Monodominant G. dewevrei forest in the Sangha Trinational is both compositionally and structurally distinct from mixed forest. We therefore recommend this forest type be considered separately from mixed forest for conservation planning and carbon stock calculations.

Ecological Restoration in Eastern Canada Using Four Early-Successional Species on Severely Degraded Sites Using a Factorial of Site-Preparation Treatments: Growth and Biomass over Two Years

Barren sites that lack soil are exposed to some of the harshest elements, which include high temperatures, solar radiation, wind, extreme temperature changes, and low soil moisture and nutrient conditions. An ecological restoration experiment was conducted using three site-preparation treatments, straw (S), Meri-Crusher (MC), and coarse woody debris (CWD), in a site-/no site-preparation 2 × 2 × 2 factorial on sites that had been barren for 25 years. In addition, four early successional deciduous species, white birch (WB, Betula papyrifera Marshall), gray birch (GB, Betula populifolia Marshall), green alder (GA, Alnus viridis Vill. subsp. crispa Ait), and speckled alder (SA, Alnus incana L. subsp. rugosa Du Roi), were examined. The two- and three-way interactions were almost all magnitude effects and not rank changes. Gray birch had the greatest overall first-year height growth, followed by GA, SA, and WB, with 12.1, 9.7, 9.6, and 5.6 cm, respectively. Straw doubled first-year growth, while CWD and MC increased first-year height growth by 43 and 31%, respectively. Straw’s ability to retain moisture in the dry summer provided the greatest benefit. In the second year, GA had the greatest height growth, followed by SA, GB, and WB, with 42.5, 30.5, 13.4, and 13.0 cm, respectively. Alders form symbiotic relationships with N-fixing bacteria and, although this was observed in some first-year roots, they did not fully express this advantage at these severely degraded sites until the second year, which allowed them to surpass birches in growth. Site-preparation treatments furthered their height growth affect, with S, and CWD doubling second-year height growth and MC, with an increase of 25%. Alders and birches had, on average, three and one stems, respectively, and the mean stem number of alders increased under S and CWD. After two years, overall stem dry mass had very large genus and species differences with GA, SA, GB, and WB, with 58.4, 30.3, 5.4, and 4.0 g, respectively. The N-fixing ability of alders under these conditions resulted in a 13-fold stem dry mass production increase compared with birches. Straw tripled, CWD doubled, and MC increased stem dry mass by 40%. For WB, site-preparation combinations had an additive effect, whereas GB, GA, and SA had several combined site-preparation treatments showing synergistic results, which were greater than the additive effects of single treatments. Under the control (no site prep.), second-year stem dry masses for WB, GB, GA, and SA were 0.7, 1.4, 17.8, and 0.5 g, respectively. Under the three combined treatments, MC × S × CWD, WB, GB, GA, and SA had 6.6, 12.3, 115.7, and 70.6 g stem dry masses, respectively. SA is ecologically a lowland species, hence the low 0.5 g under the control; however, the result under the three combined treatments demonstrates their combined effectiveness on these barren sites. Green alder seems to be the best adapted to the sites, having the greatest stem dry mass under control, although that was considerably magnified under the site-preparation treatments. This study using combinations of treatments with these early successional species introduces a novel research concept, and similar studies in the literature are currently lacking, creating an opportunity for future exploration.

FEATURES OF THE MANIFESTATION OF BIOMETRIC INDICATORS IN VARIETIES AND BREEDING LINES OF WINTER BREAD WHEAT AT SPRING RENEWAL OF VEGETATION DATE IN THE FOREST STEPPE OF UKRAINE

The growth, development, and yield formation of winter bread wheat depends on renewal of vegetation date (RVD). This is one of the environmental factors most affecting the production process of plants. Purpose. To identify the peculiarities of the manifestation of biometric indicators in the genotypes of winter bread wheat at renewal of spring vegetation date in the conditions of the central Forest-Steppe of Ukraine. Methods: field, laboratory, statistical. Results. It was established that biocenosis formation of winter wheat at renewal of spring vegetation date significantly depended on growing conditions, sowing date, genotype and their interaction. Weather conditions were the dominant (25.2÷69.5%) significant for the influence. It was determined that after renewal of spring vegetation the influence of genotype (its ability to intensive growth and adequate response to changes in environmental conditions) and its interaction with the growing season conditions on all biometric indicators significantly increased. It was noted that under favorable hydrothermal regime, the level of realization of plant potential was maximum, while under conditions of soil and air drought it was minimum. This must be taken into account in breeding process, study of the source material, and selection of genotypes with specified parameters. The breeding line LUT 55198 had the highest biomass on average according to the experiment, which at the RVD formed phytocenosis with stem number per plant 2.60 pcs, leaf number per plant 7.74 pcs, plant height 16.51 cm, and plant weight 0.80 g. The level of variability in plant height was moderate (Cv = 14.08%) and for leave number, stem number, and plant weight it was significant (Cv = 18.39%; Cv = 21.54% and Cv = 29.89%, respectively).

Avaliação precoce da interação genótipo x safras na cultura da mandioca sob déficit hídrico

ABSTRACT The aim of this study was to evaluate the effect of genotype x harvest interactions on different agronomic traits, the genetic correlation between traits in early selection under water stress, and early selection in cassava. 25 cassava genotypes were evaluated in a randomized block experimental design with four replications. The variables root weight (RW), root number per plant (RN), root diameter (RD), root length (RL), root dry matter content (DMC), stem number per plant (SN), plant height (PH), stem diameter (SD), mite severity (MS), and harvest index (HI) were evaluated under water stress conditions in two harvests. Broad-sense heritability (h²), realized heritability ( ( h R 2 )), and the index of coincidence (IC) were estimated. Accuracy estimates ranged from 0.62 for RL to 0.86 for DMC. A significant genotype effect was identified on all traits, except for RW, RL and SD. Significant genotype x harvest interactions occurred for the variables SN, PH, SD, and HI. (h²) estimates ranged from 0.27 for RL to 0.79 for SN. The estimates of the index of coincidence ranged from 100% to 25%. A positive correlation was observed between all variables under study, except for MS, RN and SN, and the other traits. The genotypes showed similar performance in the two harvests for most variables, except for SN, PH, SD, and HI.

Growth and Yield Traits of Potato Genotypes Grown under Different Cultivation Practices in Dailekh, Nepal

Variable rainfall and recurrent drought in spring season limit the potato production at Dailekh. To address this problem, a two-year (2019-2020) field experiment was conducted at HRS, Dailekh to investigate 12 potato genotypes (T-304347.6, T-393371.58, T-304350.1, T-304351.109, T-302498.7, T-304405.47, T-303381.3, T-396311.1, T-397029.1, T-304368.46, Desiree and Cardinal) along with different growing practices (Partial Irrigation (PI), rain-fed and straw mulch) for their growth, and yield traits. The experiment was laid out in split-plot design, where three different growing practices were allotted as main plot and 12 potato genotypes were placed as sub-plot treatment, and it was replicated three times. The combined analysis revealed that growing practices significantly affected the ground cover, plant height, stem number, marketable tuber number and weight, and yield. Potato genotypes showed the significant effect on all the plant and yield traits. Straw mulch produced 28.7% and 21.6% higher marketable tuber yield than PI and rain-fed potato, respectively. Genotypes T-304351.109 and T-397029.1 imparted 22.9% and 17.4% higher marketable tuber yield than Desiree, check variety, respectively. Therefore, growing of high yielding genotypes T-304351.109 and T-397029.1 along with straw mulch can be the best option to increase the potato productivity at rain-fed condition of Dailekh.

MORPHOLOGICAL, AGRONOMIC, AND QUALITY PROPERTIES OF THE TWO DEVELOPED POPULATIONS OF ALFALFA (Medicago sativa L.) UNDER NON-IRRIGATED CONDITIONS OF SEMIARID REGIONS

Alfalfa is the most important crop in Turkey but there is no alfalfa cultivar developed for rainfed conditions under the semiarid regions in Turkey. For this reason, new cultivars are needed for using of rangeland improvement, artificial pasture establishment, and hay production. For this reason, the two alfalfa populations were developed by the mass selection method in the breeding project. These two advanced populations (L-533, and L-1739) were examined with the three control cultivars of alfalfa (Bilensoy-80, Savaş and Kayseri) for morphological, yield and quality traits in two various regions of Turkey in three experimental years. The present study results demonstrated that there were significant differences in terms of the plant height, but no differences in stem diameter, and stem number among the study genotypes. When evaluating all genotypes, the L-533 and Kayseri had the highest yield value, but the Savaş cultivar was the lowest. As compared to Bilensoy-80 cultivar, the L-533, and L-1739 populations gave higher at 22.27 and 11.57% in green forage yield; 18.30 and 10.13% in dry forage yields, respectively.&#x0D; In addition, statistically significant differences were found for ADF, NDF, and digestible dry matter yield among the study genotypes, except crude protein contents. Moreover, the highest crude protein content and digestible dry matter yield were obtained from the L-533 and L-1739, but the L-533 had also the lowest NDF content. The present study result showed that the L-533, and L-1739 had high adaptation capability, excellent yield, and good quality performance in dry conditions under semi-arid regions and could be used as commercial cultivars.

Status of Native Tree Diversity in Relation to Land-Use in the Merhabete District, Ethiopia

Abstract Most studies undertaken on native fodder and fruit species have focused on planting preferences and socioeconomic importance. The focus has been less on diversity aspects. This study aimed to make a comparative investigation on the status of native fodder and fruit tree /shrub diversity and their management in three land types in Merhabete district, North Shewa Zone, Ethiopia. A total of 127 households were randomly selected for interviews on management practices and threats to the targeted species. Furthermore, 90 sampling plots representing three land use types were used for vegetation data collection. Altogether, a total of 34 tree /shrub species were recorded from three land use types in the study area. Out of the 34 tree/shrub species identified, 31 (91.2 %) species were native fodder and fruit tree/shrub species, and the remaining 3 (8.8 %) were exotic tree/shrub species. The mean tree/shrubdiversity, species richness, and species density were significantly higher in the remnant natural forest than in homegarden and parkland (p≤0.05). Likewise, the highest tree basal area was recorded in remnant natural forest, followed by homegarden and parklands. The common management practices for native fodder and fruit species were pollarding, thinning, pruning, lopping, and fencing. Based on the findings, it is concluded that species diversities and stem numbers were lower in parkland than in other land-use types. Therefore, it is recommended that planting native fodder and fruit tree/shrub species on parkland is essential to enhance the conservation and domestication process of the targeted species.

Loss of Aspm causes increased apoptosis of developing neural cells during mouse cerebral corticogenesis.

Abnormal spindle-like microcephaly associated (ASPM) is a causative gene of primary autosomal recessive microcephaly. Microcephaly is considered to be a consequence of a small brain, but the associated molecular mechanisms are not fully understood. In this study, we generated brain-specific Aspm knockout mice to evaluate the fetal brain phenotype and observed cortical reduction in the late stage of murine cortical development. It has been reported that the total number of neurons is regulated by the number of neural stem and progenitor cells. In the Aspm knockout mice, no apparent change was shown in the neural progenitor cell proliferation and there was no obvious effect on the number of newly generated neurons in the developing cortex. On the other hand, the knockout mice showed a constant increase in apoptosis in the cerebral cortex from the early through the late stages of cortical development. Furthermore, apoptosis occurred in the neural progenitor cells associated with DNA damage. Overall, these results suggest that apoptosis of the neural progenitor cells is involved in the thinning of the mouse cerebral cortex, due to the loss of the Aspm gene in neocortical development.

Serum Amyloid A1 (SAA1) Secreted By the Stromal Microenvironment Drives Malignant Clonal Proliferation in Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML)

Drivers of malignant hematopoietic stem cell clonal proliferation from age-related clonal hematopoiesis (ARCH) to Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML) are not well understood. However, a pro-inflammatory and immune tolerant aging bone marrow (BM) microenvironment is thought to contribute to disease development. Serum Amyloid A1 (SAA1) has been identified as a novel pro-inflammatory oncoprotein the levels of which progressively increase with MDS and AML progression. SAA1 also selectively promotes growth of patient-derived MDS and AML cells independent of cytogenetic or mutational profile. We aimed to characterize the mechanism by which SAA1 drives oncogenesis within the microenvironment. Herein we further stratified the disease marking properties of SAA1 by clarifying the association of its BM levels with disease progression in MDS and AML. SAA1 levels were significantly elevated in BM aspirates from MDS and AML patients as compared to those from healthy age-matched subjects (p=0.0002 and p=0.0052, respectively). The effects of SAA1 on mutated hematopoietic cells were assessed in a model of age-related clonal hematopoiesis (ARCH). Utilizing a CRISPR-Cas9 system, ASXL1-mutant CD34+ hematopoietic stem cells (HSCs) were generated; the replating capacity of both mutated and healthy CD34+ cells were assessed in the presence or absence of SAA1. Notably, SAA1 increased the replating capability assessed by an increase in the number of colonies formed on serial replating of ASXL1-mutant CD34+ cells, but not those of SAA1-treated healthy CD34+ or vehicle treated ASXL1-mutated CD34+ cells, suggesting that the presence of SAA1 favors stemness of mutated HSCs, and implicating SAA1 as a driver of malignant clonality. To investigate the mechanism of action of SAA1 BM mononuclear cells from AML patients or healthy age-matched subjects were treated with SAA1 or vehicle overnight and single-cell RNA sequencing analysis was performed. Seurat and cell cluster annotation analysis showed that AML samples treated with SAA1 had increased numbers of hematopoietic stem and progenitor cells (HSPCs) and plasmacytoid dendritic cells as compared to matched untreated AML samples. Further, Enrichr analysis showed that pathways upregulated by SAA1 in AML samples included pro-inflammatory molecules, anti-apoptotic, and antiviral defense mechanisms (p&amp;lt;0.0001). Shared genes upregulated in these pathways in HSPCs include interferon-induced signals including JAK2, STAT1, and OAS3, and genes implicated in resistance to chemotherapy, including CD44 and CD36, as well as the anti-phagocytosis signal CD47. Lastly, we initiated the development of a blocking monoclonal antibody against SAA1 as a means of inhibiting its potent oncogenic effects on malignant HSCs and examining its potential therapeutic activity. Utilizing a RAW 264.7 NFκB-luciferase reporter cell line, we screened 51 clones for their ability to selectively block SAA1-mediated NFκB activation. 7 optimal candidates were identified which demonstrated dose-dependent reduction in NFκB activity upon SAA1 challenge. Importantly, these candidate clones were specific for SAA1 and did not affect NFκB activation mediated by lipopolysaccharide (LPS)-mediated activation. We observed up to an 85% reduction of SAA1-mediated activity using supernatants from further subcloning of previously selected candidates. Moreover, cell proliferation of a human AML cell line (OCI-AML3) stimulated by SAA1 was markedly reduced in the presence of candidate antibodies, suggesting anti-proliferative activity. Our findings show that SAA1 levels correlates with disease severity in MDS and AML progression, selectively promotes stemness and proliferative potential of ASXL1-mutant cells, and demonstrates unique immune-related mechanisms selecting for malignant clonality. Further development and purification of a novel inhibitory antibody against SAA1 for future in vivo and ex vivo testing is underway as a promising novel target to reduce SAA1-mediated, niche-driven effects with broad implications in the treatment of hematological malignancies.

Inactivation of Group 1B Phospholipase A2 Enhances Disease Recovery and Reduces Experimental Colitis in Mice.

Phospholipase A2 (PLA2) enzymes influence inflammatory bowel disease in both positive and negative manners depending on the type of PLA2 that is expressed. This study explored the influence of the abundantly expressed Group 1B PLA2 (PLA2G1B) on ulcerative colitis. Wild-type C57BL/6J mice and Pla2g1b-/- mice were treated with dextran sulfate sodium (DSS) for 5 days to induce epithelial injury, followed by another 5 days without DSS for recovery. The Pla2g1b-/- mice displayed significantly less body weight loss, colitis pathology, and disease activity indexes compared to the wild-type mice. The differences in colitis were not due to differences in the colonic lysophospholipid levels, but higher numbers of stem and progenitor cells were found in the intestines of Pla2g1b-/- mice compared to the wild-type mice. The DSS-treated Pla2g1b-/- mice also showed higher expressions of genes that are responsible for epithelial repair and lower expressions of proinflammatory cytokine genes in the colon, as well as reduced inflammatory cytokine levels in the plasma. In vitro experiments revealed the PLA2G1B stimulation of inflammatory cytokine expression by myeloid cells. PLA2G1B inactivation protects against DSS-induced colitis in mice by increasing the intestinal stem cell reservoir for epithelial repair and reducing myeloid cell inflammation in the diseased colon. Thus, PLA2G1B may be a target for colitis management.