Commercial Genotypes Research Articles

Morphological and pathogenic characterization of Fusarium oxysporum in lulo (Solanum spp.)

Fusarium oxysporum is one of the most limiting fungal pathogens of lulo crop. To determine its pathogenicity, this work morphologically and pathogenically characterized F. oxysporum isolates from different lulo-growing municipalities of the Department of Nariño. Twenty isolates were evaluated through a completely randomized design with two factors and three replicates per treatment, including a control. The first factor corresponded to 20 isolates of F. oxysporum and the second to 10 lulo genotypes. The morphological characterization involved determining growth rate (GR), color (CO), mycelial type (MT), medium coloration (Mc), shape (Sh), size (S), number (N) of macroconidial (Ma) and microconidial (Mi) septa, presence of chlamydospores (PC), and chlamydospore shape (CS). Moreover, the pathogenic characterization was based on the incubation period (IP), absolute growth rate (AGR), disease severity (DS), disease incidence (I), and vascular discoloration (VD). The morphological characterization demonstrated that all isolates corresponded to F. oxysporum. For IP, genotype G1 showed the lowest average at 18 days. For AGR, genotype G2 had the lowest height increase at 0.05 cm.day-1. For DS, genotype G1 reached the highest severity level (level 9) and a disease incidence of 100%. This study provides the first report of the special form of F. oxysporum f. sp. quitoense in Nariño. Solanum hirtum, Solanum sessiliflorum, and Solanum estramonifolium were resistant to the isolates evaluated, demonstrating that wild species should be considered as sources of resistance for breeding programs aiming to obtain resistant commercial genotypes.

Can heat stress and water deficit affect cotton fiber wax content in field-grown plants?

Climate modelling predicts a warmer climate for cotton growing regions in the future. This will impose stresses on cotton plants that may impact on cotton fiber cuticle wax levels, and in turn may make cotton textile products more challenging to scour and dye. While previous research has measured the effect of abiotic stress on cuticle wax in cotton leaves and bracts, no research is known to have been undertaken specifically measuring the impact of abiotic stress on cotton fiber wax content. Five Upland (Gossypium hirsutum L.) cotton genotypes with known different tolerances to abiotic stress, were subjected over two growing seasons, to heat stress and or water deficit during the period when fiber cuticle wax deposition occurred. Total ethanol soluble wax content was determined in mature fiber using a standard protocol. Across all genotypes and treatments, fiber wax content varied between 0.2 and 1.6 %. For Sicot 71, a standard Australian commercial genotype, and for Siokra L23 and CIM-448 two genotypes known to be tolerant to abiotic stress, fiber wax content was either unaffected or decreased following the application of abiotic stress. For CS 50, a genotype with a poor tolerance to water deficit stress, fiber wax content increased following abiotic stress. For Sicala V-2, a genotype with less tolerance to abiotic stress, fiber wax content decreased following either heat stress or water deficit treatments alone, while wax content markedly increased following the combined application of both stress treatments. The genotypic variations observed in fiber wax content and the differences in the direction of the response to stresses suggest that conventional breeding could be used to generate new genotypes with acceptable fiber wax levels adapted to future extreme climates.

Establishment of Regional Phytoremediation Buffer Systems for Ecological Restoration in the Great Lakes Basin, USA. II. New Clones Show Exceptional Promise

Poplar tree improvement strategies are needed to enhance ecosystem services’ provisioning and achieve phytoremediation objectives. We evaluated the establishment potential of new poplar clones developed at the University of Minnesota Duluth, Natural Resources Research Institute (NRRI) from sixteen phytoremediation buffer systems (phyto buffers) (buffer groups: 2017 × 6; 2018 × 5; 2019 × 5) throughout the Lake Superior and Lake Michigan watersheds. We divided clones into Experimental (testing stage genotypes) and Common (commercial and/or research genotypes) clone groups and compared them with each other and each NRRI clone (NRRI group) at the phyto buffers. We tested for differences in clone groups, phyto buffers, and their interactions for survival, health, height, diameter, and volume from ages one to four years. First-year survival was 97.1%, with 95.5%, 96.2%, and 99.6% for the 2017, 2018, and 2019 buffer groups, respectively. All trees had optimal health. Fourth-year mean annual increment of 2017 buffer group trees ranged from 2.66 ± 0.18 to 3.65 ± 0.17 Mg ha−1 yr−1. NRRI clones ‘99038022’ and ‘9732-31’ exhibited exceptional survival and growth across eleven and ten phyto buffers, respectively, for all years. These approaches advance poplar tree improvement efforts throughout the region, continent, and world, with methods informing clonal selection for multiple end-uses, including phytotechnologies.

Resistance of landrace and commercial cowpea genotypes to Callosobruchus maculatus attack

In the northern and north-eastern regions of Brazil, the cultivation of cowpea (Vigna unguiculata L.) is socially and economically important. However, attack by weevils makes storage difficult. Landrace genotypes exhibit high genetic variability, which can confer resistance to pest attacks. In this study, the susceptibility of landrace genotypes of cowpea to the attack of the weevil (Callosobruchus maculatus (Fabr., 1775)) was assessed. A total of 13 genotypes were used (11 landraces and two commercial genotypes). Biological parameters (number of eggs; daily, accumulated, and final emergence; the instantaneous rate of population increase) of C. maculatus, and loss of cowpea seed mass were analysed. The treatments were composed of 30g of each genotype and 20 adult insects in an entirely randomised design with ten replicates. A principal component analysis and grouping analysis were performed due to the similarity between the genotypes, and three groups were described. Group 3 (‘BRS Pujante’, ‘Ligeiro’, and ‘Tardão’ genotypes) had the highest oviposition/number of eggs, daily emergence, number of emerging insects, and instantaneous rate of population increase. Group 2 (‘Azulão’, ‘Costela de Vaca’, and ‘Rabo de Tatu’ genotypes) showed intermediate values, and group 1 (‘Bala’, ‘Canapú’, ‘Corujinha’, ‘Manteiguinha’, ‘Moita’, ‘Seridó’, and ‘Sempre Verde’ genotypes) had the lowest values for all those variables. The commercial genotypes were grouped in groups 1 (‘Sempre Verde’) and 3 (‘BRS Pujante’) and showed similar behaviour to the landrace genotypes of those groups. This study demonstrated that the genotypes in group 3 are susceptible to the attack of C. maculatus, while those in group 1 showed antibiosis resistance. Utilization of insect-resistant genotypes can reduce cowpea infestation and synthetic insecticide application, leading to a positive economic impact.

Morpho-Biometrical, Nutritional and Phytochemical Characterization of Carrot Landraces from Puglia Region (Southern Italy)

The explorations as a part of the regional BiodiverSO Programme of vegetable genetic resource rescue revealed that in the arenili (sandy shores) of “Salterns of Margherita di Savoia” (SMS), a coastal landscape area of Puglia region (southern Italy), along the commercial genotypes of small rooting species, landraces are still cultivated. The morpho-biometrical, nutritional and phytochemical properties of two carrot landraces (“Carota a punta lunga” and “Carota a punta tonda”) and a commercial carrot hybrid (“Presto”) collected from the SMS area are examined. The study highlighted that the pedological conditions of the arenili of the SMS area are the main driving force in controlling the nutritional and nutraceutical characteristics of carrot, conferring to genotypes grown in this area a high profile in comparison with literature data. In the site of cultivation of arenili, a large variability in the morpho-qualitative traits emerged among carrot genotypes. “Carota a punta tonda” stands for a promising genotype being very rich in phenols (209.8 mg kg−1 fw) (mainly di-caffeic acid derivative and chlorogenic acid), ß-carotene (21,512 µg 100 g−1 fw), and high antioxidative proprieties. “Carota a punta tonda” could be considered as a healthy product for consumers and also amenable to selection for breeding purpose. Increasing the knowledge about nutritional and nutraceutical properties of local landraces may push the preference of consumers beyond the local community and, at the same time, farmers can be stimulated to continue their cultivation. Thus, the promotion of their on-farm/in situ conservation (cultivation) could represent an efficient strategy for agro-biodiversity preservation.

Rice seedlings showed a higher heat tolerance through the foliar application of biostimulants

The use of biostimulants is an agronomic tool to improve plant tolerance to abiotic stress in plants. This study explored the effect of foliar biostimulants sprays such as brassinosteroids (BR), amino acids (AA), nitrophenolates (NP) or a biostimulant based on botanical extracts (BE) on leaf gas exchange parameters [photosynthesis (PN), stomatal conductance (gs) and transpiration (E)], leaf photosynthetic pigments, lipid peroxidation of membranes and proline content of two commercial rice genotypes [‘Fedearroz 67’ and ‘Fedearroz 60’] under heat stress conditions. The established treatments were: i) plants without heat stress and foliar applications of biostimulants (C), ii) plants under heat stress and without foliar applications of biostimulants (HT), and iii) plants with heat stress and three foliar applications with BR (1 mL·L-1), AA (30 mL·L-1), NP (15 mL·L-1) or BE (15 mL·L-1). The results showed that the application of BR, AA, NP or BE increased the values ​​of PN (~14.5 µmol CO2·m-2·s-1), gs (~0.46 mmol·m-2·s-1) and E (~43.9 H20 day-1·plant-1) compared to plants (both genotypes) not treated with biostimulants under heat stress (9.9 µmol CO2·m-2·s-1 for PN, 0.31 mmol·m-2·s-1 for gs, and 27.3 H20 day-1·plant-1 for E). Foliar biostimulant sprays also caused a lower malondialdehyde and proline production in rice genotypes under heat stress. In conclusion, the biostimulants BR, AA, NP, or BE can be considered an agronomic strategy to help mitigate the adverse effects of heat stress in rice areas where periods of high temperatures are expected during the day in Colombia.

Genetic analysis of bacterial wilt resistance in eggplant (Solanum melongena L.)

Bacterial wilt triggered by Ralstonia solanacearum is one of the major devastating diseases causing significant yield reduction in eggplant. F1 hybrids (18 CARI-1 based F1 hybrids and 12 publicly available hybrids/varieties) were evaluated for bacterial wilt resistance, yield, and yield attributing traits. CARI-1 based F1 hybrids showed superiority in yields, however showed a varied level of resistance to bacterial wilt. Further, inheritance and gene action involved in resistance to Ralstonia solanacearum was studied. CARI-1 was crossed with two susceptible parents, Arka Neelachal Shyama and Pusa Purple Long to develop six generations for both the combinations. The genetic control of resistance to bacterial wilt was found to be polygenic in the case of the Arka Neelachal Shyama x CARI-1 derived population. While di-genic with complementary gene action in the case of Pusa Purple Long x CARI-1 F2 population, however deviation in expected ratios was observed in back cross populations. Generation mean analysis revealed the presence of epistasis. For Arka Neelachal Shyama x CARI-1 derived population, owing to the prevalence of additive × additive non-allelic interaction with a negative sign, delaying of selection to later generations, otherwise inter mating between the selected segregates accompanied by selfing for one or more generation(s) is advised for the aggregation of favorable alleles for enhancement of resistance. Similarly, for Pusa Purple Long x CARI-1 population, the simple selection can be efficient due to the prevalence of additive gene action. The inheritance details accumulated in this study would facilitate the introgression of bacterial wilt resistance into elite commercial genotypes.

Allelic and genotype frequencies of major CYP2B6 polymorphisms in the Pakistani population.

BackgroundCytochrome P450 (CYP2B6) is an important enzyme that metabolizes about 3.0% of therapeutic drugs. Drugs metabolized mainly by CYP2B6 include artemisinin, bupropion, cyclophosphamide, efavirenz, ketamine, and methadone. The genetic polymorphisms in the CYP2B6 gene have earlier been studied in many populations, but the data are lacking for the Pakistani population. This research study aimed to determine the frequencies of the three of the most important variant alleles and genotypes of the CYP2B6 gene in the Pakistani population.MethodsBlood was withdrawn from healthy volunteers after taking informed consent. DNA was extracted using commercial kits, and allelic and genotype frequencies were determined after PCR amplification followed by restriction fragment length polymorphism (RFLP) and gel electrophoresis.ResultsOur results show a minor allele frequency of 33.8% for CYP2B6*6, 25.8% for CYP2B6*4, 6.5% for CYP2B6*3, whereas wild‐type genotype frequency was 48.57% for CYP2B6*6, 59.79% for CYP2B6*4, and 90.20% for CYP2B6*3. A significant interethnic variation was also observed.ConclusionsOur results suggest that the frequency of poor metabolizers of CYP2B6, especially *6 variant, is significant enough in the Pakistani population to be given an important consideration when drugs metabolized by this enzyme are prescribed.

Comparing bacterial properties in relation to the virulence factors of Xanthomonas citri subsp. citri strains and evaluating resistance of subtribe Citrinae cultivars to the most virulent strain

Citrus Bacterial Canker disease, caused by Xanthomonas citri subsp. citri (Xcc), is one of the most devastating diseases that attacks citrus, especially in the southern areas of Iran. The objective of this investigation was to analyze several characteristics involved in Xcc virulence in relation to strain aggressiveness. To achieve this, swarming motility, biofilm formation, resistance to H2O2, and production of xanthan were evaluated considering 44 local strains causing citrus bacterial canker disease in Iran. All strains showed differential swarming motilities, biofilm formation abilities, and xanthan production. The most virulent strain, Xcc-KVXCC1, exhibited the greatest capability to form biofilm on solid surfaces, xanthan production, and pathogenicity on detached leaves of Citrus aurantifolia as well as positive chemotaxis toward C. aurantifolia extract. In this study, a total of 14 common and commercial citrus genotypes were evaluated for resistance to Xcc-KVXCC1. Genotypes were categorized into susceptible and resistant groups based on lesion number per inoculation site. Based on our results, C. aurantifolia was the most susceptible citrus cultivar to Xcc-KVXCC1. In contrast, C. aurantium, C. jumbhori, and C. reticulata cv. ponkan demonstrated high and moderately high resistance against Xcc-KVXCC1.

Transcriptomic analysis reveals key transcription factors associated to drought tolerance in a wild papaya (Carica papaya) genotype.

Most of the commercial papaya genotypes show susceptibility to water deficit stress and require high volumes of irrigation water to yield properly. To tackle this problem, we have collected wild native genotypes of Carica papaya that have proved to show better physiological performance under water deficit stress than the commercial cultivar grown in Mexico. In the present study, plants from a wild Carica papaya genotype and a commercial genotype were subjected to water deficit stress (WDS), and their response was characterized in physiological and molecular terms. The physiological parameters measured (water potential, photosynthesis, Fv/Fm and electrolyte leakage) confirmed that the papaya wild genotype showed better physiological responses than the commercial one when exposed to WDS. Subsequently, RNA-Seq was performed for 4 cDNA libraries in both genotypes (susceptible and tolerant) under well-watered conditions, and when they were subjected to WDS for 14 days. Consistently, differential expression analysis revealed that after 14 days of WDS, the wild tolerant genotype had a higher number of up-regulated genes, and a higher number of transcription factors (TF) that were differentially expressed in response to WDS, than the commercial genotype. Thus, six TF genes (CpHSF, CpMYB, CpNAC, CpNFY-A, CpERF and CpWRKY) were selected for further qRT-PCR analysis as they were highly expressed in response to WDS in the wild papaya genotype. qRT-PCR results confirmed that the wild genotype had higher expression levels (REL) in all 6 TF genes than the commercial genotype. Our transcriptomic analysis should help to unravel candidate genes that may be useful in the development of new drought-tolerant cultivars of this important tropical crop.

Performance of the double-cross tomato hybrids from a partial diallel

ABSTRACT Knowledge of the combining ability of genotypes, genetic diversity, and heterosis play the paramount role in obtaining double-cross hybrids with high productivity. This study was aimed at evaluating these parameters in tomato genotypes using partial diallel crosses among the commercial single-cross hybrids, which verified the possibility of using double-cross hybrids for commercial purposes. Tomato genotypes included 15 double-cross hybrids, their genitors, and two commercial genotypes as checks. Of the fifteen double-cross hybrids of tomato, two crosses exhibited superiority, such as Aguamiel × Compack and Dominador × Compack, mainly for the total and commercial fruit yields. The phenotypic expression of the trait is controlled by the genes with non-additive effects, whereas the genes with additive effects account for the genotypes of fruit mass, horizontal diameter, vertical diameter, and bunch insertion height. Regarding the genetic diversity, molecular analyses pointed out polymorphism for 79 percent of the evaluated loci evidencing a high genetic variability among the genitors. The heterosis values were low for most of the crosses, except for Forty × Plutão that represented 107 percent of heterosis for the total fruit yield. As compared with the commercial checks, the diallel cross generated superior quality hybrids, which inferred the possibility of obtaining double-cross hybrids of tomato with significant heterosis.

Salt stress genotypic response: Relative tolerance of wheat cultivars to salinity

The commercial wheat genotypes released for cultivation under timely sown irrigated conditions in Punjab along with known salt tolerant genotypes and few advance breeding lines were evaluated for salt stress tolerance at seedling stage under simulated stress conditions and at adult plant stage in actual saline fields at Rattakhera, Sri Mukatsar Sahib (Punjab), to find out the best suitable wheat variety for the salt affected areas. Twelve wheat varieties, seven advance breeding lines, one wheat genotype popular in salt stressed regions of Punjab and Kharchia, a universal donor for stress tolerance to salt were tested. PBW 765 and PBW 780 had highest tolerance among advance germplasm, HD 3086, HD 2967, KRL 210 could be categorized in one group whereas PBW 725 showed moderate tolerance to salt stress. These identified genotypes are most suitable for regions having moderate to high salinity stress as these were less affected due to salinity.

Zucchini lineages with levels of resistance to ZYMV and SqMV viruses

Zucchini (Cucurbita pepo L.) is a horticultural plant species of great socioeconomic value in tropical countries such as Colombia and Brazil. The production of zucchini is qualitatively and quantitatively affected by many diseases, especially viruses belonging to the Potyvirus (Zucchini yellow mosaic virus - ZYMV) and Comovirus (Squash mosaic virus - SqMV) groups. The primary strategy to reduce the spread of potentially damaging plant viruses is the development of genotypes with genetic tolerance; however, there are not many zucchini genotypes with multiple tolerance. Therefore, this study evaluated 66 zucchini genotypes to find sources of tolerance to the ZYMV and SqMV viruses. This experiment was conducted in a completely randomized design using genotypes from the germplasm bank of the Federal University of Uberlândia, including the genotypes: Emanuela (common commercial genotype) ‘Tronco Caserta’ (susceptible genotype) and PX 13067051 (resistant genotype). Leaf extracts containing viral particles were used as inoculant, and the distribution of grades of tolerance was recorded at the seedling stage. The lineages UFU-C×UFU-A#18#3;1, UFU-C×UFU-F#19#11;3, UFU-F#4#9;1, and UFU-D×UFU-F#7#21;1 and the Emanuela cultivar are alternatives for the production of new zucchini genotypes or hybrids with tolerance to the viruses ZYMV and SqMV. More severe symptoms were observed, as well as a larger number of susceptible genotypes for the ZYMV virus, indicating that this virus has great potential for causing damage and losses to zucchini crops.

Environment quality, sowing date, and genotype determine soybean yields in the Argentinean Gran Chaco

The Argentinean Gran Chaco is one of the global regions with the highest recent rates of agricultural expansion due to soybean production. The area has been heavily deforested during the last 30 years. Despite the economic relevance of soybean for this region, studies that provide options for sustainable management of these production systems are scarce. The objectives of this study were (i) to identify and to quantify key management and environmental soybean yield predictors, and (ii) to explore interactions with maturity group (MG) selection, since farmers are sowing genotypes ranging from MGs V to VIII. We evaluated commercial genotypes in 112 multi-environment on-farm trials (METs) consisting of 14–19 genotypes each during 11 consecutive years (from 2008 to 2019).We first analyzed a single genotype sown in 106 METs to identify environmental and management yield predictors with good explanatory power for yield, which ranged from 435 to 5117 kg ha−1. Relevant environmental variables were, in order of importance, rainfall from 30 days before sowing to physiological maturity (R7), years after land conversion to agriculture, reference evapotranspiration from sowing to R7, and the number of 2-day periods with maximum temperatures above 35 °C from beginning of flowering (R1) to R7. Based on variable relative importance (RI) sowing date was the most important management variable (RI = 0.99), followed by phosphorous availability (RI = 0.59). Genotype selection also had a strong significant effect. There was an interaction between MG and sowing date, yield reductions with delayed sowings ranked as MG VIII > VII > VI = V. The largest yield differences between MGs were observed under environments with high soil organic matter (explored range from 1.64 to 4.05 %). These results illustrate specific management variables to guide farmers and advisors to optimize regional soybean cropping systems. The negative yield effect promoted by years after land conversion and reductions in soil organic matter suggest a decline in the environmental quality of the region and the need for new production alternatives to halt these trends.

Biochemometric Analysis of Fatty Acid Amide Hydrolase Inhibition by Echinacea Root Extracts.

Recent research demonstrates that Echinacea possesses cannabimimetic activity with potential applications beyond common contemporary uses for relief of cold and flu symptoms. In this study, we investigated the in vitro inhibitory effect of root extracts of Echinacea purpurea and Echinacea angustifolia on fatty acid amide hydrolase, the main enzyme that degrades the endocannabinoid anandamide. The objective was to relate variation in bioactivity between commercial Echinacea genotypes to their phytochemical profiles and to identify determinants of activity using biochemometric analysis. Forty root extracts of each of species were tested for inhibition of fatty acid amide hydrolase and analyzed by HPLC-DAD/MS to identify and quantitate alkylamides and caffeic acid derivatives. Fatty acid amide hydrolase inhibition ranged from 34 - 80% among E. angustifolia genotypes and from 33 - 87% among E.purpurea genotypes. Simple linear regression revealed the caffeic acid derivatives caftaric acid and cichoric acid, and the alkylamide dodeca-2E,4Z-diene-8,10-diynioc acid 2-methylbutylamide, as the strongest determinants of inhibition in E. purpurea (r* = 0.53, 0.45, and 0.20, respectively) while in E. angustifolia, only CADs were significantly associated with activity, most notably echinacoside (r* = 0.26). Regression analysis using compound groups generated by hierarchical clustering similarly indicated that caffeic acid derivatives contributed more than alkylamides to in vitro activity. Testing pure compounds identified as determinants of activity revealed cichoric acid (IC50 = 45 ± 4 µM) and dodeca-2E,4E,8Z,10E-tetraenoic acid isobutylamide (IC50 = 54 ± 2 µM) as the most active. The results suggest that several phytochemicals may contribute to Echinacea's cannabimimetic activity and that ample variation in genotypes exists for selection of high-activity germplasm in breeding programs.

Identification of the SHINE clade of AP2/ERF domain transcription factors genes in Carica papaya; Their gene expression and their possible role in wax accumulation and water deficit stress tolerance in a wild and a commercial papaya genotypes

Climate change has resulted in alterations in temperature, soil salinity and droughts in many parts of the world. Carica papaya is one of the most important tropical fruits worldwide, although it is considered as a tolerant crop, water deficit stress affects its production. The aim of the present work was first to identify genes of the SHINE clade of AP2/ERF domain in the genome of C. papaya also, to characterize and compare the physiological performance, the total content of waxes and the expression levels of genes involved in wax biosynthesis in two papaya genotypes of contrasting tolerance (Maradol and Yuc1), when exposed to water deficit stress. Two genes (CpSHN1 and CpSHN2) were identified in C. papaya. It was clear that under water deficit stress, Yuc1 (a wild genotype collected at its center of origin), accumulated more cuticular waxes and had higher expression of both CpSHN1 and CpSHN2 genes than Maradol. This increased wax content might partly contribute to the higher water-deficit stress tolerance observed in Yuc1. Our results suggest that in response to water-deficit stress, CpSHN genes are involved in wax biosynthesis in C. papaya, allowing the accumulation of waxes (particularly alkanes). Both genotypes, showed tolerance to water stress, however the ability of Yuc1 to upregulate stress tolerance related genes faster than Maradol, might have favored an increased amount of waxes in leaves, contributing partly to its greater water-deficit stress tolerance than its commercial counterpart Maradol. The expression levels of CpSHN1 increased 30-fold in Yuc1 in response to water deficits and this was correlated with its superior ability to accumulate waxes. Although more studies are needed to further evaluate the functionality of CpSHN in water-limiting environments, our results suggest that CpSHN1 might be a good candidate gene to increase the water-deficit stress tolerance of this important tropical species.

CARACTERIZAÇÃO E DIVERGÊNCIA GENÉTICA DE GENÓTIPOS DE MILHO COM POTENCIAL FORRAGEIRO AVALIADOS EM REGIÃO SEMIÁRIDA

A produção de milho para consumo animal segue duas aptidões em relação à produção de ração em regiões semiáridas: grãos e silagem. No entanto, o alto sertão Sergipano, região comumente com baixa disponibilidade hídrica, apresenta escassez de alimentos. Desta forma, a obtenção de variabilidade genética, oriunda de cruzamentos específicos, podem auxiliar na seleção de genótipos de milho com potencial forrageiro. Objetivou-se caracterizar genótipos comerciais e experimentais de milho para obtenção de blocos de cruzamentos com potencial forrageiro avaliados em região semiárida. O experimento foi realizado na Fazenda Experimental da Embrapa – Semiárido, em delineamento em blocos incompletos em látice quadrado reticulado 6x6, com duas repetições, totalizando36 tratamentos. Analisou-se as variáveis altura de planta, diâmetro do colmo, peso de parcela, massa fresca, massa seca e massa de forragem. Os dados foram submetidos a análise de correlação fenotípica, contribuição relativa de cada variável e divergência genética. Indicou-se a formação de pelo menos três blocos de cruzamentos: bloco I, com aptidão para massa fresca; bloco II, com aptidão de peso de parcela e massa de forragem; bloco III, para aptidão de altura de planta, diâmetro do colmo e massa seca.

Digital Image Analysis Using FloCIA Software for Ornamental Sunflower Ray Floret Color Evaluation.

As an esthetic trait, ray floret color has a high importance in the development of new sunflower genotypes and their market value. Standard methodology for the evaluation of sunflower ray florets is based on International Union for the Protection of New Varieties of Plants (UPOV) guidelines for sunflower. The major deficiency of this methodology is the necessity of high expertise from evaluators and its high subjectivity. To test the hypothesis that humans cannot distinguish colors equally, six commercial sunflower genotypes were evaluated by 100 agriculture experts, using UPOV guidelines. Moreover, the paper proposes a new methodology for sunflower ray floret color classification – digital UPOV (dUPOV), that relies on software image analysis but still leaves the final decision to the evaluator. For this purpose, we created a new Flower Color Image Analysis (FloCIA) software for sunflower ray floret digital image segmentation and automatic classification into one of the categories given by the UPOV guidelines. To assess the benefits and relevance of this method, accuracy of the newly developed software was studied by comparing 153 digital photographs of F2 genotypes with expert evaluator answers which were used as the ground truth. The FloCIA enabled visualizations of segmentation of ray floret images of sunflower genotypes used in the study, as well as two dominant color clusters, percentages of pixels belonging to each UPOV color category with graphical representation in the CIE (International Commission on Illumination) L∗a∗b∗ (or simply Lab) color space in relation to the mean vectors of the UPOV category. Precision (repeatability) of ray flower color determination was greater between dUPOV based expert color evaluation and software evaluation than between two UPOV based evaluations performed by the same expert. The accuracy of FloCIA software used for unsupervised (automatic) classification was 91.50% on the image dataset containing 153 photographs of F2 genotypes. In this case, the software and the experts had classified 140 out of 153 of images in the same color categories. This visual presentation can serve as a guideline for evaluators to determine the dominant color and to conclude if more than one significant color exists in the examined genotype.

Sowing date, genotype choice, and water environment control soybean yields in central Argentina

AbstractSoybean [Glycine max (L.) Merr.] is one of the most important crops worldwide, and Argentina is the third largest global grain producer and the worlds´ largest meal exporter. Under the continuous challenge of increasing crop yields, especially in the central temperate region of the country, there is a growing need to optimize management in relation to the environment that each specific farm and paddock presents. Understanding the impact of available technologies and management options can help optimize crop design. Here, we identify and quantify the effect of the most relevant variables affecting soybean yield by analyzing a database that includes 53 field trials with four common commercial genotypes, reporting 50 management and environmental variables. Linear mixed‐effect models revealed that two management decisions (genotype and sowing date selection) and three environmental variables (rainfall during the reproductive crop period from R1 to R7, soil type [Hapludoll vs. Argiudoll], and water table presence above or below 2 m of depth from the surface) helped explain ∼40% of total yield variability, which ranged from 1,675 to 7,226 kg ha−1 and averaged 5,133 kg ha−1. Water table presence generated higher and more stable yields particularly in coarse‐textured Hapludolls and under low‐rainfall conditions. Results highlight specific management and environmental conditions that affect soybean crop yields in the region, pointing to effective pathways toward yield gap reductions.

Genetic diversity, population structure and ancestral origin of KwaZulu-Natal native chicken ecotypes using microsatellite and mitochondrial DNA markers

South African native chicken breeds are no exception to the declining of local domestic breeds that has long been recognised and found associated with the commercialisation of breeding in domestic animals. The aims of the study were: (i) to provide a comprehensive view of genetic variation in four KwaZulu-Natal indigenous chicken populations (Jozini, Newcastle, Pietermaritzburg, and Port Shepstone), and (ii) to estimate the extent of differentiation of the village populations from three conserved South African indigenous pure breeds (Potchefstroom koekoek, Ovambo, and Venda) by genotyping individuals at 19 autosomal microsatellite loci. Finally, (iii) new information to the history of KwaZulu-Natal indigenous chicken populations was made available by exploring their phylogenetic relationship and their possible maternal origin through the mitochondrial DNA. The results suggested noticeable genetic diversity within and between ecotypes with clear sub-structuring between them. The indigenous populations had high genetic diversity (observed heterozygosity ranging from 0.61 in Pietermaritzburg to 0.70 in Jozini) while conserved populations showed considerable within population inbreeding coefficient (from 0.01 in Potchefstroom koekoek to 0.18 in Ovambo). Median-joining network analyses indicated the dominance of haplogroup E suggesting a likely Southeast Asia and/or Indian subcontinent origin. The presence of haplogroup B and C not only emphasises multiple maternal origin but also highlights genetic introgression of local chickens with commercial genotypes. These results highlighted the importance of local breeds as a genetic reservoir; moreover, the conservation of local breeds may play an important role in the local economy as a source of high-quality products for consumers. Highlights The genetic variation and differentiation of KwaZulu-Natal indigenous chicken populations and pure South African chicken breeds is investigated. The village populations showed a noticeable genetic variability with clear sub-structuring between them. The results can be used to improve a sustainable breeding and conservation programs to control possible genetic dilution with commercial genotypes.