Wide Genetic Diversity Research Articles

Agronomic performance, genetic variability estimation and mutant selection in M3 generation of sorghum under optimum condition

Abstract The population resulting from mutations in the M3 generation generally has a diversity that can be selected to obtain mutants with the desired character. This study aimed to observe the agronomic performances of the M3 generation of sorghum and to estimate its genetic parameters as information for selection. The genetic materials used in this research were 242 sorghum mutant lines of the M3 generation, and six comparison genotypes, namely Numbu, Samurai-1, Kawali, Pahat, B-35, and Watar Hammu Putih (parent). This experiment used an augmented design. The result analysis revealed that the genotype treatments affected the differences in performance of panicle length, stem diameter, and chlorophyll content characters. Significant differences were also seen between the control genotypes on all the observed characters. The appearance of sorghum mutant lines and control genotypes showed substantial differences in panicle length, stem diameter, panicle weight, biomass weight, leaf chlorophyll content, and seed yield characters. The wide genetic diversity and high heritability values were indicated by plant height, panicle length, panicle weight, and chlorophyll content characters. Using panicle weight as a selection character in M3 populations has increased the differential selection of stem diameter, leaf chlorophyll content, biomass, and seed yield characters.

First detection and diversity of astroviruses in wild migratory birds of Sakhalin Island, North Pacific.

Researchers have identified Avastrovirus as a significant genus of bird viruses, linked to various avian diseases such as enteritis, growth retardation, nephritis and hepatitis. These infections can cause substantial economic losses in agrocultureand have a widespread impact on global food production. Although there have been numerous studies on these viruses, most of them-mainly focuses on poultry. Research on astroviruses in wild bird populations has revealed a wide genetic diversity of these viruses, yet our understanding of their biological and ecological characteristics remains limited. In this study, we for the first time detected avastrovirus in wild migratory birds of the families Anatidae and Columbidae from Sakhalin Island, North Pacific Ocean. Phylogenetic analysis revealed the presence of Avastrovirus 2 in wild doves and Avastrovirus 3 in wild ducks. These findings provide valuable insights into the circulation of astroviruses in wild bird populations of Sakhalin Island, which lies along the East Asian-Australasian Flyway.

Research note: Genetically diverse avian hepatitis E virus identified in chickens with hepatitis-splenomegaly syndrome in Guangdong Province, China

Avian hepatitis E virus (HEV) is recognized as the primary causative agent of big liver and spleen disease, hepatitis-splenomegaly syndrome, and hepatic rupture hemorrhage syndrome, resulting in substantial economic losses within the global poultry industry. Since its discovery in 1991, diverse strains of avian HEV have been extensively identified worldwide. Epidemiological investigations have demonstrated the wide distribution and genetic diversity of avian HEV strains in China. In this study, avian HEV strains were identified in chickens exhibiting hepatitis-splenomegaly syndrome in Guangdong province, China. Sequence analysis indicated that these strains shared the highest nucleotide sequence identities with genotype 3 strains, and phylogenetic analysis demonstrated that they clustered with strains belonging to avian HEV genotype 3. Moreover, a statistically supported recombination event was detected within one of the avian HEV strain identified in this study. These findings significantly enhance our understanding of the genetic diversity and evolution of avian HEV in chickens, providing new insights for disease prevention and control strategies.

Spinocerebellar ataxia type 10 and Huntington disease-like 2 in Venezuela: Further evidence of two different ancestral founder effects.

The American continent populations have a wide genetic diversity, as a product of the admixture of three ethnic groups: Amerindian, European, and African Sub-Saharan. Spinocerebellar ataxia type 10 (SCA10) and Huntington disease-like 2 (HDL2) have very ancient ancestral origins but are restricted to two populations: Amerindian and African Sub-Saharan, respectively. This study aimed to investigate the genetic epidemiological features of these diseases in Venezuela. In-phase haplotypes with the expanded alleles were established in seven unrelated index cases diagnosed with SCA10 and in 11 unrelated index cases diagnosed with HDL2. The origins of remote ancestors were recorded. The geographic origin of the ancestors showed grouping in clusters. SCA10 had a minimal general prevalence of 1:256,174 families in the country, but within the identified geographic clusters, the prevalence ranged from 5 per 100,000 to 43 per 100,000 families. HDL2 had a general prevalence of 1:163,016 families, however, within the clusters, the prevalence ranged from 31 per 100,000 to 60 per 100,000 families. The locus-specific haplotype shared by all families worldwide, including the Venezuelans, supports a single old ancestral origin in each case. Knowing the genetic ancestry and geographic origins of patients in Ibero-American mixed populations could have significant diagnostic implications; thus, both diseases in Venezuela should always be first explored in patients with a suggestive phenotype and ancestors coming from the same known geographic clusters.

Assessment of genetic diversity among upland cotton for earliness, fiber quality and yield-related traits using correlation, principal component and cluster analysis

A field experiment was conducted at Cotton Research Farm, Gazipur in Kharif season 2017 with 100 genotypes to evaluate their genetic diversity. The results of the study showed a significant positive link between the number of bolls and seed cotton output, as well as between maturity and boll split. Cluster analysis, Principal Component Analysis (PCA), and correlation were used to categorize the major characters that account for the variation in yield contributing traits. Data were recorded at maturity, bolls plant-1, seed cotton yield, ginning outturn, fiber length and fiber strength. The first four PCs with Eigen value >1 contributed 65.15% variability among the cotton accessions. The genotypes were grouped into ten clusters through multivariate analysis. Cluster III contained a maximum number of genotypes (29) while clusters I (15), II (9), IV (23) and V (13) contained genotypes, cluster VII (4), VI, VIII and X contained genotypes (2) and cluster IX contained only 1 genotype. In all cases, the inter-cluster distances were greater than those of intra-cluster distances, which indicate a wider genetic diversity among the genotypes. Cluster I and IX had the largest inter-cluster distance (35.13), while cluster VI and VIII had the smallest (1.68)-. The results revealed a diverse and close relationship among the genotypes of those clusters. The single boll weight and days to boll split showed a higher contribution to the genetic divergence among 14 characters. Based on genetic diversity results and early-maturity, VII (BC-0451, BC-0456, BC-0491 and BC-0495), VIII (SR-16), IX (BC-0479) and X (BC-0493 and BC-0459) genotypes could be used to develop the short-term cotton variety as following the standard procedure.

Morpho–Molecular Characterization of Brazilian Common Bean Landraces Varieties and Commercial Cultivars

This study aimed to characterize forty genotypes (31 landrace varieties and nine commercial cultivars) of common bean (Phaseolus vulgaris L.) morphologically and molecularly. Morphological descriptors were evaluated during seedling, flowering, physiological maturation and post-harvest stages. Ten microsatellite markers were used for molecular screening. The markers were analyzed according to the number of alleles per locus, the allele frequency per locus and the polymorphism in content (PIC). Genetic distances and cluster analysis were performed using Bayesian inference and the UPGMA method. All black beans evaluated have anthocyanin in the cotyledons, hypocotyls and stems, and their flowers are purple. For the growth habit, 50% of the evaluated genotypes belong to type III, and at the physiological maturation stage, yellow color is predominant in the pods (85%). Through the genetic dissimilarity, three groups were observed for the likelihood reason, and five groups were observed through the UPGMA method, a strong indication of the wide genetic diversity among the evaluated genotypes. All genotypes from the Andean center of origin were grouped into the same cluster.

Whole-genome comparative analysis of the genetic, virulence and antimicrobial resistance diversity of Campylobacter spp. from Spain

Whole-Genome Sequencing has the potential to be an effective method for surveillance of foodborne diseases. This study aims to determine the genetic relatedness and prevalence of virulence-associated genes and antimicrobial resistance determinants in 135 Campylobacter jejuni, seven Campylobacter coli and three Campylobacter lari isolates from the poultry supply chain and a hospital in Spain. The isolates showed a wide genetic diversity between and within species with Clonal Complex 21 the most frequent lineage found. Among species, C. jejuni showed the highest prevalence of virulence genes (287/333) in which a high occurring variability was observed in the capsule biosynthesis and transport, O-linked flagellar glycosylation and lipooligosaccharide biosynthesis loci, with a great impact of phase-variation that led to 72 different virulence gene patterns among all isolates. High prevalence (> 90 %) of blaOXA-type β-lactamase genes and mutations in DNA gyrase gene associated with fluoroquinolones resistance were observed, and at a frequency similar to the tet(O) gene in C. jejuni (93 %) and C. coli (86 %), both of which also harboured resistance determinants to aminoglycosides with a higher occurrence rate in C. coli (43 %), that was the only species in which mutations in the 23S ribosomal subunit conferring resistance to erythromycin were identified (43 %). The present study constitutes the largest genomic survey of Campylobacter isolates in Spain providing insight into the prevalence and diversity of the pathogen along the poultry supply chain in the country.

PRODUCCIÓN Y RENTABILIDAD DE MAÍCES NATIVOS AZULES BAJO DIFERENTES DENSIDADES DE POBLACIÓN Y RÉGIMENES HÍDRICOS

<p><strong>Background:</strong> It is necessary to increase maize production due to the increase in global food demand. Producers in Mexico prefer to grow native varieties of maize, which have a wide genetic diversity that has not been fully studied. These native maize are being lost due in part to their low yields, as well as their low or no profitability. Despite this, in this germplasm it is possible the presence of genotypes that show high grain production and economic gains. Increasing plant density can be a viable strategy that contributes to improving the production systems of these native maize. <strong>Objective</strong>: To analyze the agronomic behavior and profitability of blue native maize genotypes in two population densities and two water regimes. <strong>Methodology</strong>: The study was carried out in the spring summer 2022 cycle in Nuevo León, Mexico (24°19'11.4"N, 99°56'34.8"W, 1980 m.a.s.l.). The treatments were the combination of four genotypes (Mimbres, Ascensión, Siberia and a Hybrid as a control), two water regimes (irrigated and rainfed) and two population densities (62,500 and 83,333 plants ha<sup>-1</sup>), which were distributed in a random complete block design with split-split plot design. Analysis of variance, Pearson correlation and principal components were carried out to understand the behavior and relationship between variables. <strong>Results</strong>: Grain yield was 38% higher in irrigation compared to rainfed. Increasing the density to 83,333 plants ha<sup>-1</sup> also contributed to increasing grain yield and economic profitability, only in native maize. The number of grains per m<sup>2</sup> and grain weight per ear were the components that were mostly associated with the benefit-cost ratio and grain yield. <strong>Implications</strong>: The native maize studied are important genetic resources with a favorable response to high plant density, therefore, increasing the density to 83,333 plants ha<sup>-1</sup> is a strategy that could be explored to increase grain production and profitability of native maize, in addition, this proposal could be more easily adopted by producers, since it would not significantly affect their production cost. <strong>Conclusions</strong>: It was feasible to cultivate native maize at a density of 83,333 plants ha<sup>-1</sup> both under irrigation and rainfed conditions, since only with this density and such maize genotypes was it possible to obtain the highest grain yield and economic gains.</p>

Unusual BA222-like strains of Rotavirus A (Sedoreoviridae: Rotavirus: Rotavirus A): molecular and genetic analysis based on all genome segments.

Rotavirus infection is the major cause of severe dehydrating diarrhea requiring hospitalization in young children worldwide. Due to their segmented genome, rotaviruses are capable of gene reassortment, which makes the emergence and spread of genetically novel strains possible. The purpose of this study was to search for unusual rotaviruses circulating in Nizhny Novgorod in 2021‒2023 and their molecular genetic characterization based on all genome segments. Rotavirus-positive stool samples of children were examined by PCR genotyping and electrophoresis in PAAG. cDNA fragments of each of the 11 genes (VP1‒VP4, VP6, VP7, NSP1‒NSP5), 570 to 850 nucleotide pairs in length were sequenced for the selected strains. The phylogenetic analysis was performed in the MEGA X program. In the study period 2021‒2023, 11 G[P] combinations with a predominance of G3P[8] (59.5%) were identified. Six atypical Rotavirus А (RVA) strains were identified: 2 strains of the G2P[4] genotype (G2-P[4]-I2-R2-C2-M2-A3-N2-T3-E2-H3, G2-P[4]-I2-R2-C2-M2-A3-N2-T3-E3-H2) and 4 G3P[9] strains (all strains had the genotype G3-P[9]-I2-R2-C2-M2-A3-N2-T3-E3-H3). Phylogenetic analysis based on all genes showed an evolutionary relationship between rotaviruses similar to rotaviruses of cats and dogs (BA222-like) and unusual strains of the G2P[4] genotype, for which a mixed combination of genotypes was identified and characterized for the first time. The results obtained expand the understanding of the diversity of reassortant RVAs, as well as complement the data on the genotypic structure of the rotavirus population in Nizhny Novgorod. The wide genetic diversity of reassortant RVA can help rotaviruses overcome the immunological pressure provided by natural and vaccine-induced immunity. In this regard, to control the emergence of new variants and assess changes in the virulence of rotaviruses after reassortment processes, continuous molecular monitoring for circulating RVA is necessary.

Caracterización morfoagronómica de poblaciones de maíz criollo (Zea mays L.), provincia de Manabí, Ecuador

Ecuador is a country with a wide genetic diversity of maize and there are populations of native maize conserved by farmers that have not yet been characterized. These genetic resources could be conserved and used in plant breeding programs. The objective of this research was to characterize the morpho-agronomic diversity of 38 populations of native maize from the province of Manabí, Ecuador, using 19 quantitative and 11 qualitative morpho-agronomic descriptors. During the dry season of 2022 (July - December) at the Portoviejo Experimental Station of the National Institute of Agricultural Research (INIAP), plots of 8 m2 were established for each population of native maize, with 0.3 m between plants and 0.8 m between furrows and each furrow was 5 m long. Cluster analysis showed the formation of four groups, where the populations of hard kernels with large ears and soft kernels with short ears were separated into different groups. The quantitative variables ear height, panicle length, percentage of lodging, number of kernels per row and biomass of the inflorescence rachis recorded "D" indices of 0.75, showing themselves as discriminant variables in the formation of the groups, while the most discriminating qualitative variables were kernel type (χ2 = 49.09***, P= 0.742, V= 0.64), kernel color (χ2= 51.955***, P= 0.75, V=0.64), row arrangement (χ2= 18.11*, P=0.56, V=0.39), and kernel surface shape (χ2 = 20.52*, P=0.58, V=0.41). The native maize races identified were Candela, Cubano, Tuxpeño, Tusilla, and Uchima, observing significant genetic diversity in the populations studied. It was concluded that the characterized native maize populations were a valuable genetic resource for the conservation and use of this cereal. Keywords: genotypes, landraces, genetic variability, conservation of genetic resources.

First Report on Detection and Molecular Characterization of Astroviruses in Mongooses.

Applying a pan-astrovirus (AstV) RT-hemi-nested PCR assay, we report here high detection rates (28.3%, 15/53) of AstVs in the small Indian mongoose (Urva auropunctata) on the Caribbean Island of St. Kitts. Based on deduced amino acid (aa) identities and phylogenetic analysis of long RNA-dependent RNA polymerase (RdRp) sequences (~315 aa, partial RdRp), the AstVs detected in the mongooses (designated as Mon-AstVs) were classified into two distinct groups (deduced aa identities of 66.45-67.30% between the groups). The putative RdRps of the Mon-AstVs shared low deduced aa identities with those of AstVs from other host species (<69%, <54%, and <50% identities with reptilian/amphibian AstVs, avastroviruses, and mamastroviruses, respectively). Phylogenetically, the group-I and group-II Mon-AstVs formed two distinct clusters, near the cluster of reptilian/amphibian AstVs, and were distantly related to avastroviruses and mamastroviruses. Since the mongooses were apparently healthy during sampling, we could not establish if the Mon-AstVs infected the animal or were of dietary origin. Although we could not ascertain the true host of the Mon-AstVs, phylogenetic analysis indicated that these viruses might have originated from lower vertebrates. To our knowledge, this is the first report on the detection and molecular characterization of AstVs in mongooses, highlighting the wide host range and significant genetic diversity within the family Astroviridae.

Genetic divergence and truncation and simultaneous selection in inbred families (S1) of elephant grass for bioenergetic purposes via mixed models

The State University of North Fluminense Darcy Ribeiro (UENF) has been developing for fifteen years a breeding program that aims at the development of new cultivars of elephant grass due to its high potential and the low availability of cultivars developed by genetic breeding programs that meet the needs of producers in the State of Rio de Janeiro. In this sense, inbred families were also obtained as a way of fixing potential alleles for traits related to production, as the inbreeding process apparently does not strongly affect elephant grass in aspects related to inbreeding depression. This study aimed to estimate genetic diversity, variance components and prediction of genotypic values in 11 (S1) elephant grass families, and perform the truncation and simultaneous selection of traits using the selection index, by mixed models. The experimental design consisted of randomized blocks with 11 (S1) families, three replications, and six plants per plot. For variables dry matter production, percentage of dry matter, plant height, stem diameter, number of tillers and leaf blade width, was performed the estimation of genetic parameters and selection of the best genotypes based selection index using mixed model. The descriptors were subjected to correlation analysis, distance matrices were generated by the Mahalanobis method, and individuals were grouped by the UPGMA method. In the selection via mixed models (REML/BLUP), families 6, 11, 8, 1, 3, 7, and 9 contributed most of the genotypes selected for the evaluated traits, indicating their high potential to generate superior genotype. The selection indices via mixed models indicated that the multiplicative index presented a greater selection gain.The phenotypic correlations showed the possibility of performing an indirect selection from six evaluated traits.The genotypes were separated into 18 groups by the Mahalanobis distance, allowing the observation of a wide genetic diversity. The most divergent and productive genotypes were self-fertilized to obtain the second generation (S2), continuing the development program.

Principal component analysis of foxtail millet accessions under rainfed condition

Foxtail millet (Setaria italica (L.) Beauv) is one of the earliest cultivated millet for grain, hay and silage. There is wide genetic diversity available in foxtail millet and characterization of available germplasm is a pre-requisite for the genetic improvement of any crop. Keeping the above fact in view 30 foxtail germplasm lines were evaluated during kharif 2020 and 2021 for morphological traits, stover yield, dry fodder yield and seed yield under rainfed conditions of Haryana. The results (based on pooled data of two years) revealed that enough variability was present among germplasm lines for further exploitation. High heritability and positive correlation was reported between traits like plant height, leaf length, leaf stem ratio, stover yield, grain yield etc. Principal component analysis also revealed that PC1, PC2, PC3, PC4 and PC5 contributed for 31.8%, 15.05%, 12.31%, 11.43% and 10.14%, respectively to the total variation. Five foxtail accessions viz., SEA8, SEA12, SEA48, SEJ184 and SEA37 were identified promising for yield and related traits under rainfed conditions of Haryana.

Genetic Diversity and Population Structure of a Large USDA Sesame Collection.

Sesame, Sesamum indicum L., is one of the oldest domesticated crops used for its oil and protein in many parts of the world. To build genomic resources for sesame that could be used to improve sesame productivity and responses to stresses, a USDA sesame germplasm collection of 501 accessions originating from 36 countries was used in this study. The panel was genotyped using genotyping-by-sequencing (GBS) technology to explore its genetic diversity and population structure and the relatedness among its accessions. A total of 24,735 high-quality single-nucleotide polymorphism (SNP) markers were identified over the 13 chromosomes. The marker density was 1900 SNP per chromosome, with an average polymorphism information content (PIC) value of 0.267. The marker polymorphisms and heterozygosity estimators indicated the usefulness of the identified SNPs to be used in future genetic studies and breeding activities. The population structure, principal components analysis (PCA), and unrooted neighbor-joining phylogenetic tree analyses classified two distinct subpopulations, indicating a wide genetic diversity within the USDA sesame collection. Analysis of molecular variance (AMOVA) revealed that 29.5% of the variation in this population was due to subpopulations, while 57.5% of the variation was due to variation among the accessions within the subpopulations. These results showed the degree of differentiation between the two subpopulations as well as within each subpopulation. The high fixation index (FST) between the distinguished subpopulations indicates a wide genetic diversity and high genetic differentiation among and within the identified subpopulations. The linkage disequilibrium (LD) pattern averaged 161 Kbp for the whole sesame genome, while the LD decay ranged from 168 Kbp at chromosome LG09 to 123 Kbp in chromosome LG05. These findings could explain the complications of linkage drag among the traits during selections. The selected accessions and genotyped SNPs provide tools to enhance genetic gain in sesame breeding programs through molecular approaches.

Biologically effective dose of diflufenican applied preemergence for the control of multiple herbicide-resistant waterhemp in corn

Abstract Waterhemp is a dioecious species which contributes to a wide genetic diversity that has enabled it to evolve resistance to several commonly used Herbicide Groups (G) in North America. Five field trials were established in Ontario to ascertain the biologically effective doses (BED) of diflufenican, a new Group 12 herbicide applied preemergence (PRE) for control of multiple herbicide-resistant (MHR) waterhemp in corn. Based on regression analysis, the predicted diflufenican doses to elicit 50, 80, and 95% MHR waterhemp control were 99, 225, and 417 g ai ha-1 at 2 WAA; 73, 169, and 314 g ai ha-1 at 4 WAA, and 76, 215, and “–“ (the effective dose was beyond the set of doses in this study) g ai ha-1 at 8 WAA, respectively. The diflufenican doses that caused a 50, 80, and 95% decrease in MHR waterhemp density were 42, 123, and ”–“ g ai ha-1, and MHR waterhemp biomass were 72, 167, and 310 g ai ha-1, respectively at 8 WAA. Diflufenican PRE at 150 g ai ha-1 controlled MHR waterhemp 64, 79, and 73%; isoxaflutole + atrazine PRE at 105 + 1060 g ai ha-1 controlled MHR waterhemp 98, 98, and 97%; and S-metolachlor/mesotrione/bicyclopyrone/atrazine PRE at 1259/140/35/588 g ai ha-1 controlled MHR waterhemp 100, 100, and 99% at 2, 4, and 8 WAA, respectively. Diflufenican PRE reduced MHR waterhemp density and biomass by 83%; in contrast, isoxaflutole + atrazine and S-metolachlor/mesotrione/bicyclopyrone/atrazine reduced MHR waterhemp density and biomass by 99%. All treatments evaluated caused either no or minimal corn injury and provided yield comparable to weed-free control. Results indicate that diflufenican applied PRE alone does not provide superior MHR waterhemp control than the commonly used herbicides isoxaflutole + atrazine or S-metolachlor/mesotrione/bicyclopyrone/atrazine; however, there is potential for the utilization of diflufenican as a part of an Integrated Weed Management (IWM) strategy for the control of MHR waterhemp control in corn.

Understanding the molecular mechanisms of drought tolerance in wild soybean (Glycine soja) through multi-omics-based alternative splicing predictions

The absence of adequate moisture resulting from drought poses a significant threat to both the viability and productivity of soybean cultivation. Genetic variation in common soybeans has been noticeably reduced through continuous breeding, and wild relatives with wider genetic diversity are one of the best tools in the search for new tolerance genes. In this study, we selected 139 genes co-expressed at transcript and protein levels in response to drought in Glycine soja through a multi-omics analysis. Drought stress induced co-expression of transcripts and proteins involved in dopamine synthesis within tyrosine metabolism. Polyphenol oxidase, involved in the dopamine synthesis process, was uniquely identified in both DEGs and DEPs, with its protein abundance increased. Co-expression of 9-lipoxygenase during linoleic acid metabolism was confirmed, along with consistent protein accumulation. The co-expression profiling of transcripts and proteins suggests that they may influence their regulatory feedback loops or unknown regulatory mechanisms. Additionally, we predicted the regulation of alternative splicing (AS) in response to drought. AS was predicted for 139 co-expressed genes, and four drought-tolerance-related gene candidate groups were selected. The expression levels of four genes, FT1, CCR1L, RPL18, and uncharacterized LOC114422617, varied depending on their transcript isoforms under drought stress. The occurrence of AS under drought stress may play a role in eliminating susceptibility genes or inducing tolerance genes to adapt to drought stress. Overall, this study reveals a novel mechanism of drought adaptation in wild soybean by predicting the regulation of metabolic pathways and AS events at the transcriptome and proteome levels and presents potential targets for soybean breeding.

Potential of increasing yield of spring Brassica napus canola by using Brassica rapa gene pool with emphasis on yellow sarson

Context Broadening the genetic base of canola (Brassica napus) is needed to develop improved hybrid cultivars. Wide genetic diversity is present in its parental species B. rapa and B. oleracea. In the case of B. rapa, the yellow sarson type from Asia is genetically distinct from all other types. Aims The objective of this research was to investigate the prospect of using yellow sarson to improve the performance of hybrid canola cultivars. Methods Inbred B. napus canola lines derived from an B. napus × B. rapa interspecific cross, and their F1 hybrids with the B. napus parent, as a tester, were compared on agronomic and seed quality traits; the inbreds were also evaluated for genetic diversity by using molecular markers. Key results Seed yield of the hybrids was significantly greater than the inbreds and the B. napus parent and exhibited more than 15% mid-parent heterosis (MPH). Genetic diversity did not show significant correlation with seed yield in the inbred population; however, it showed a positive correlation with MPH. Inbred yield as well as MPH showed a positive correlation with hybrid yield. For other traits, the performance of the inbreds showed a significant positive correlation with the performance of the hybrids; the average MPH for these traits was low or close to zero. Conclusions The yellow sarson gene pool showed great potential for use in the breeding of hybrid canola. Implications The knowledge gained and germplasm developed from this research can be used by breeders and researchers to develop improved canola cultivars.

Evaluation of Genetic Divergence among Different Okra Genotypes

Mahalanobis D2 statistics were used to analyse the genetic divergence of thirty different okra genotypes, and the results showed that there was a significant amount of genetic variety. The clustering, inter and intra-cluster distances, and trait contributions provided insights into the genetic variability and diversity within the studied okra population. Thirty diverse genotypes were grouped into five clusters with the highest of eighteen genotypes in the cluster I, five in the cluster III &amp; V and one each genotype in the cluster II and IV. Inter and intra cluster D2 values ranged from 8.00 to 16.7 and 0.0 to 7.4, respectively. It showed that inter cluster distance was higher than the intra cluster distance indicating wide genetic diversity among the genotypes of different groups. The cluster means of 11 characters among five clusters indicated that high genetic variability ranged present for yield per plant (222.1-253.1), number of fruits per plant (31.8-38.9), plant height (59.0-100.7) and days to fifty percent flowering (42.8-54.0). The per cent contribution of yield and its attributing characters in genetic divergence were reported maximum for number of fruits per plant (46.4%) and first fruit node (16.3%). The genotypes HB-691-08, HBT-49-1, Hisar Unnat, Hisar Naveen, HBTC-6-7-1, Varsha Uphar, Arka Abhay were superior for overall yield and yield attributing characters. These genotypes were used to exploit genetic variation for further breeding programme.

Genotyping of Croatian Olive Germplasm with Consensus SSR Markers

Leaf samples of 226 cultivated olive trees were collected from traditionally managed olive orchards and genotyped with eleven consensual SSR markers. The proportion of shared allele distance was used for the estimation of distances between olive genotypes. Cluster analyses were performed using a Fitch–Margoliash least-squares algorithm. The number of different genetic subgroups of olive genotypes (K) was investigated using STRUCTURE analysis. The standardization of allele lengths was performed to enable the comparison SSR profiles of Croatian olive genotypes with olive profiles obtained with the same SSR primers in OleaDB and WOGB databases. Overall, 73 SSR profiles of known Croatian varieties and 53 profiles of unknown olive genotypes were differentiated. Synonyms were detected in 18 varieties, and we found intra-varietal differences in 15 varieties. Three genetic subgroups of olive genotypes were determined. Following allele length standardization achieved using nine referral samples, the genetic profiles of 126 cultivated olive genotypes were compared to OleaDB and WOGB databases, out of which 92 genotypes were found to be unique to Croatian olive germplasm. The results revealed the wide genetic diversity of olive germplasm beyond the known, registered varieties. The FAZ_oliveDB database containing the profiles of 126 Croatian olive genotypes was created and made available for public use.

Diversity studies in Assam rice genotypes for ratooning ability and perennation

AbstractThe objective of the research was to assess diversity among 50 rice genotypes for ratooning and perennation which refers to ability of a plant to regrow from stubble remaining after harvesting. Results showed that 30 genotypes exhibited different degree of ratoon production and ratoon yield. Diversity analysis revealed that all the ratooning genotypes could be assigned to ten clusters. Clusters III (Binadhan-11 and Sayjihari) and VI (IR-64, DRR-44) were the best performing for ratoon yield. Maximum inter-cluster distance was observed between genotypes falling under clusters III and X followed by genotypes under clusters III and II indicating wider genetic diversity between these genotypes. Thus, these genotypes may be useful for future breeding to develop superior varieties with respect to ratooning ability and ratoon yield.