Influence of Environmental Parameters, Pinching, and Ethephon Application on Growth and Branching of Potted Stevia

Stevia (Stevia rebaudiana) is an herb grown commercially for the extraction of intensely sweet-tasting, non-caloric, steviol glycosides produced primarily in the leaves and used as a sugar substitute. While most stevia production occurs as an industrial field crop, more recently, consumer demand for stevia for home gardens and patio containers has increased. Research on how environmental inputs impact growth, branching, and flowering of stevia under greenhouse conditions for potted plant production is currently lacking. A series of experiments was conducted to quantify how methods to promote branching, fertilizer concentration, photoperiod and temperature impact branch production, growth and development, and flowering of stevia. Both manual decapitation and ethephon application increased lateral branch production, though hard pinching (cutting plants back to leave four nodes) yielded a more desirable plant architecture. Neither temperature nor fertilizer concentration impacted the number of branches produced by plants given a hard pinch. Shoot dry biomass was similar at fertilizer concentrations (applied at each watering) of 50, 100, and 200 mg⋅L−1 N, but decreased at 300 or 400 mg⋅L−1 N. Stevia responded to photoperiod as a facultative short-day plant, with earliest flowering occurring, both in days to flower and the number of nodes produced before flowering, at photoperiods <13 hours. The number of nodes produced on the longest branch increased as temperature increased from 17 to 26 °C. Plant height and longest branch length were shorter at 17 °C than at higher temperatures. The results of these studies indicate that for potted plant production, stevia should be grown under a photoperiod of 14 hours or longer with moderate nutrient levels, a minimum temperature of 20 °C, and plants should receive one or more manual pinches to promote branching.

Path analysis based on genetic association of yield components and insects pest in upland cotton varieties

Gossypium hirsutum L. is also called upland cotton or Mexican cotton. It is the most widely cultivated species of cotton in the whole world. Globally, about 90% of all cotton production comes from the cultivars derived from this species. Some genetic parameters like monopodial branches per plant, sympodial branches per plant, sympodial branch length, bolls per plant, boll weight, sympo-boll distance, Ginning Out Turn%, staple length (rg = 0.9199**), and fiber strength along with seed cotton yield were evaluated for their potential utilization via selection in seed cotton yield improvement. Significant positive genetic correlations were estimated for monopodial branches per plant (rg = 0.9722**), sympodial branches per plant (rg = 0.7098**), sympodial branch length (rg = 0.617**), bolls per plant (rg = 0.8271**), boll weight (rg = 0.8065**), sympo-boll distance (rg = 0.6507**), Ginning Out Turn (GOT)% (rg = 0.7541**), staple length (rg = 0.9199**), and fiber strength (rg = 0.7534**) with seed cotton yield. A path analysis of all the yield traits under study revealed strong positive direct effects of monopodial branch length (1.1556), sympo-boll distance (0.8173) and staple length (0.7633), while plant height exerted a highly strong direct negative effect (-1.2096) on yield. It is concluded that a direct selection based on monopodial branch length and sympo-boll distance, and staple length is effective, whereas, monopodial branch length, and sympodial branch length are good selection indicators via bolls per plant for yield improvement in cotton.

Sensitivity of A Frequency-Based Alignment-Free Approach For Phylogeny Rreconstruction.

Background: Phylogenies enrich our understanding of how genes, genomes, and species evolve. Traditionally, alignment-based methods are used to construct phylogenies from genetic sequence data; however, this process can be time-consuming when analyzing the large amounts of genomic data available today. Additionally, these analyses face challenges due to differences in genome structure, synteny, and the need to identify similarities in the face of repeated substitutions resulting in loss of phylogenetic information contained in the sequence. Alignment Free (AF) approaches using k-mers (short subsequences) can be an efficient alternative due to their indifference to positional rearrangements in a sequence. However, these approaches may be sensitive to k-mer length and the distance between samples.Results: In this paper, we analyzed the sensitivity of an AF approach based on k-mer frequencies to these challenges using cosine and Euclidean distance metrics for both assembled genomes and unassembled sequencing reads. Quantification of the sensitivity of this AF approach for phylogeny reconstruction to branch length and k-mer length provides a better understanding of the necessary parameter ranges for accurate phylogeny reconstruction. Our results show that a frequency-based AF approach can result in accurate phylogeny reconstruction when using whole genomes, but not stochastically sequenced reads, so long as longer k-mers are used. Conclusions: In this study, we have shown an AF approach for phylogeny reconstruction is robust in analyzing assembled genome data for a range of numbers of substitutions using longer k-mers. Using simulated reads randomly selected from the genome by the Illumina sequencer had a detrimental effect on phylogeny estimation. Additionally, filtering out infrequent k-mers improved the computational efficiency of the method while preserving the accuracy of the results thus suggesting the feasibility of using only a subset of data to improve computational efficiency in cases where large sets of genome-scale data are analyzed.

Cell twisting during desiccation reveals axial asymmetry in wall organization

Plant cell size and shape are tuned to their function and specified primarily by cellulose microfibril (CMF) patterning of the cell wall. Arabidopsis thaliana leaf trichomes are responsible for protecting plants against environmental elements and are unicellular structures that employ a highly anisotropic cellulose wall to extend and taper, generating pointed branches. During elongation, the mechanisms by which shifts in fiber orientation generate cells with predictable sizes and shapes are unknown. Specifically, the axisymmetric growth of trichome branches is often thought result from axisymmetric CMF patterning. Here, we analyzed the direction and degree of twist of branches after desiccation to reveal the presence of an asymmetric cell wall organization with a left-hand bias. CMF organization, quantified using computational modeling, suggests a limited reorientation of microfibrils during growth and maximum branch length limited by the wall axial stiffness. The model provides a mechanism for CMF asymmetry, which occurs after the branch bending stiffness becomes low enough that ambient bending affects the principal stresses. After this stage, the CMF synthesis results in a constant bending stiffness for longer branches. The resulting natural frequency of branches after a length of 200 μm falls within the range of the sounds associated with many insects.

Putative novel avian paramyxoviruses identified from wild bird surveillance (United States, 2016?2018) and retrospective analysis of APMV-2s and APMV-6s in GenBank

Avian paramyxoviruses (APMVs) (subfamily Avulavirinae) have been isolated from over 200 species of wild and domestic birds from around the world. The International Committee on Taxonomy of Viruses (ICTV) currently defines 22 different APMV species, with Avian orthoavulavirus 1 (whose viruses are designated as APMV-1) being the most frequently studied due to its economic burden to the poultry industry. Less is known about other APMV species, including limited knowledge on the genetic diversity in wild birds and there is a paucity of public whole genome sequences for APMV-2 to -22. The goal of this study was to use MinION sequencing to genetically characterize APMVs isolated from wild bird swab samples collected during 2016–2018 in the United States. Multiplexed MinION libraries were prepared using a random strand-switching approach using 37 egg-cultured, influenza-negative, hemagglutination-positive samples. Thirty-five APMV isolates that had complete polymerase coding sequences were speciated using ICTV’s current Paramyxoviridae phylogenetic methodology. Viruses from APMV-1, -4, -6, -8 were classified, one putative novel species (Avian orthoavulavirus 23) was identified from viruses isolated in this study, two putative new APMV species (Avian metaavulavirus 24 and 27) were identified from viruses isolated in this study and from retrospective GenBank sequences, and two putative new APMV species (Avian metaavulavirus 25 and 26) were identified solely from retrospective GenBank sequences. Furthermore, co-infections of APMVs were identified in a subset of the samples. The potential limitations of the branch length being the only speciation criterion and the potential benefit of a group pairwise distance analysis are discussed.

New Tools for Mechanical Thinning of Apricot Fruitlets

In this study, the thinner machine with yellow rod equipment was tested in relation to tree branch length and orientation in April 2019, in a narrow-canopied apricot orchard of Emilia Romagna Region, Italy. The trees were mechanically thinned with manual finishing, and comparative tests were carried out simultaneously with the ordinary hand thinning (control). Three groups of two plants were identified as replication for a total of six plants per row. Three rows were checked, considering field uniformity average. The branches were grouped into four classes according to their length: <30 cm, 30–60 cm, 60–90 cm and >90 cm. Branch inclination on the plant, radial or longitudinal with respect to the row, was evaluated. Fruit number before the thinning, after the first and the second machine intervention, after three days of the mechanical thinning and after the hand finishing was recorded. This experience showed satisfactory results in terms of thinning efficiency and reduced damage to both fruits and branches, as a function of the class length and insertion point in the main branch of the plant. Thinning efficiency was always kept above 37% of the left load after hand finishing, and on average between the treatments close to 44%. Fruit damages always remained below the economic thresholds to marketable production or to the plant.

May the trophy evaluation variables be utilized as population indices in cervids

The most frequently utilized population quality indices in cervids were a fluctuating asymmetry or a branch length in yearlings. Nevertheless, unlike bovids, there has not been a reliable quality index so far that could also be applied at a later age. Therefore, an application reliability testing pertaining to certain elements of trophy measurement for the sake of difference detection between the cohorts was performed on a sample numbering 225 trophies of red deer stags from 11 cohorts. Although each of the nine trophy variables tested has succeeded in finding certain differences, the most reliable are the overall trophy value and circumferences (circumference of coronets, lower beam circumference and upper beam circumference). Since various trophy evaluation systems have been applied in the world, the implementation of the overall trophy value is limited only to the trophies evaluated pursuant to the CIC system. Hence, the most reliable indices are those based upon circumferences.

Response of Seeds, Oil Yield and Fatty Acids Percentage of Jojoba Shrub Strain EAI to Mycorrhizal Fungi and Moringa Leaves Extract

Jojoba seeds have a unique storage lipid wax which is suitable as a basic feedstock in the chemical industry. For saving both human health and the environment, there is a continuous need to search for alternative safe natural sources of plant nutrients. Therefore, in this study the effect of mycorrhizal fungi and Moringa oleifera leaves extract on growth, flowering, fruits set, yield and the chemical composition of the jojoba shrub was studied. The application of a combination of treatments of 20 g L−1 mycorrhizal fungi plus 30 g L−1Moringa oleifera leaves extract recorded the maximum mean values of main branch length, length of secondary branches, number of branched nodes, number of secondary branches, flowering percentage, final fruit set percentage, seeds yield per shrub and per hectare, percentage of minerals, proteins as well as oil yield per shrub and per hectare, chlorophyll a and b, N, P, K percentage with a minimum mean value of the number of days until full bloom in both seasons. The maximum percentage of Gadoleic fatty acid was found with the combination treatment of uninoculation plus 10 g L−1Moringa oleifera leaves extract.

Evolutionary dynamics of Begomoviruses causing Papaya leaf curl disease in India

The genus begomovirus represents a group of multipartite viruses that significantly damages many agricultural crops, including papaya and drastically influence the overall production. Understanding the genetic variations, mutations and recombination of the begomovirus population infecting papaya has several important implications in alleviating substantial losses, mainly in developing countries, including India. In an attempt for a bioinformatics driven study of diversity and variability of papaya leaf curl disease in India, a total of thirty-two (32) DNA-A and sixteen (16) betasatellite sequences were retrieved from GenBank. An uneven distribution of evolutionary divergence has been observed across the branch length, which triggered the estimated recombinational event. Interestingly, a maximum of the begomoviruses were found to be intra-species recombinants. Further genetic variability, selection pressure, and substitution rate acting on the population were estimated and found to be high enough to support the evolution of geminiviruses. Genetic divergence composition in all begomovirus datasets revealed predominance of nucleotide diversity driven by mutation. The analysis indicates that even though a significant fraction of the genetic variations might be due to recombination but, it was constantly lower than the mutation rate. Thus, the diversification of the begomovirus population is principally impelled by mutational dynamics.