High Broad Sense Heritability Research Articles

Spectral Reflectance Indices as a High Throughput Selection Tool in a Sesame Breeding Scheme

On-farm genotype screening is at the core of every breeding scheme, but it comes with a high cost and often high degree of uncertainty. Phenomics is a new approach by plant breeders, who use optical sensors for accurate germplasm phenotyping, selection and enhancement of the genetic gain. The objectives of this study were to: (1) develop a high-throughput phenotyping workflow to estimate the Normalized Difference Vegetation Index (NDVI) and the Normalized Difference Red Edge index (NDRE) at the plot-level through an active crop canopy sensor; (2) test the ability of spectral reflectance indices (SRIs) to distinguish between sesame genotypes throughout the crop growth period; and (3) identify specific stages in the sesame growth cycle that contribute to phenotyping accuracy and functionality and evaluate the efficiency of SRIs as a selection tool. A diversity panel of 24 sesame genotypes was grown at normal and late planting dates in 2020 and 2021. To determine the SRIs the Crop Circle ACS-430 active crop canopy sensor was used from the beginning of the sesame reproductive stage to the end of the ripening stage. NDVI and NDRE reached about the same high accuracy in genotype phenotyping, even under dense biomass conditions where “saturation” problems were expected. NDVI produced higher broad-sense heritability (max 0.928) and NDRE higher phenotypic and genotypic correlation with the yield (max 0.593 and 0.748, respectively). NDRE had the highest relative efficiency (61%) as an indirect selection index to yield direct selection. Both SRIs had optimal results when the monitoring took place at the end of the reproductive stage and the beginning of the ripening stage. Thus, an active canopy sensor as this study demonstrated can assist breeders to differentiate and classify sesame genotypes.

Performance Evaluation of Ethiopian Bread Wheat (Triticum aestivum L.) Genotypes in Southern Ethiopia

Ethiopia is not self-sufficient to meet its increasing wheat demand from domestic production partly due to a lack of improved seeds. Efforts are undertaken to fill the gap through off-season production of wheat using supplemental irrigation and modern cultivars adapted to arid areas. This study was carried out to evaluate the genetic variability and adaptability of 15 Ethiopian bread wheat genotypes at different agroecologies in Wolaita and Dawuro zones, Ethiopia. The field experiment was conducted at three locations using a randomized complete block design with three replications during the 2019/2020 main cropping season. Analysis of variance based on 11 morphological agronomic traits and two major wheat diseases revealed that there were highly significant differences ( P < 0.01 ) among the genotypes for all the traits studied at each location and combined over locations. The top three cultivars viz. Alidoro, Galema, and Honqolo exhibited higher average grain yield (GY) of 4.54 t/ha, 4.36 t/ha, and 4.0 t/ha, respectively, combined over locations. Eight of the traits (72.73%) exhibited moderate (30–60%) to high broad-sense heritability ( h b 2 > 60%) values. High h b 2 associated with high genetic advance as percent of mean was observed for the severity of both stem and yellow rust diseases combined over locations. GY was significantly related to aboveground biomass at all locations. This study depicted that cultivar Alidoro had wider adaptability for grain yield and resistance to wheat rusts.

Agronomic performance, genetic variation and heritability of yield and related traits in rice genotypes under upland conditions

Although rice production potential under rain fed ecology doubles that of irrigated lowland in Kenya, there has been little advancement in identifying suitable varieties adapted to upland rice ecology. This study was carried out to appraise the agronomic performance, heritability, grain yield components, genetic variability, and correlations for grain yield and identity of suitable varieties for the upland ecology. Eight rice genotypes were evaluated in a randomized complete block design alongside three replicates under upland conditions. Collection of data included days to 50% flowering, height of the plant, productive tillers-1, panicle length, grain length, panicle weight, grains panicle-1, spikelet fertility, grain yield weight of one thousand grains, grain breadth and breadth/ length ratio of the grain. Data analysis involved Analysis of variance, broad sense heritability estimates determination and principal component analysis. Genotype’s variation was significant for all traits measured. The first three principal components accounted for 94.67% of the sum variation among 12 traits under study. The outcome of heritability estimates and the PCA indicated that the characters 50% flowering days, weight of a thousand grains, spikelet fertility, length of the panicle, grain breadth, length of the grain and breadth/length ratio, accounted for most of variance in the variables observed and showed average to high broad sense heritability. Therefore, for these traits, early generation selection was effective in identifying superior genotypes following hybridization. From the eight cultivars used in the study, NERICA 10 and NERICA 2 varieties had better indicators for coastal lowlands of Kenya.

Genomic Insights Into Sclerotinia Basal Stalk Rot Resistance Introgressed From Wild Helianthus praecox Into Cultivated Sunflower (Helianthus annuus L.).

Crop wild relatives of the cultivated sunflower (Helianthus annuus L.) are a valuable resource for its sustainable production. Helianthus praecox ssp. runyonii is a wild sunflower known for its resistance against diseases caused by the fungus, Sclerotinia sclerotiorum (Lib.) de Bary, which infects over 400 broadleaf hosts including many important food crops. The objective of this research was to dissect the Sclerotinia basal stalk rot (BSR) resistance introgressed from H. praecox ssp. runyonii into cultivated sunflower. An advanced backcross quantitative trait loci (AB-QTL) mapping population was developed from the cross of a H. praecox accession with cultivated sunflower lines. The AB-QTL population was evaluated for BSR resistance in the field during the summers of 2017–2018 and in the greenhouse in the spring of 2018. Highly significant genetic variations (p < 0.001) were observed for the BSR disease in the field and greenhouse with a moderately high broad-sense heritability (H2) ranging from 0.66 to 0.73. Genotyping-by-sequencing approach was used to genotype the parents and the progeny lines of the AB-QTL population. A genetic linkage map spanning 1,802.95 cM was constructed using 1,755 single nucleotide polymorphism (SNP) markers mapped on 17 sunflower chromosomes. A total of 19 BSR resistance QTL were detected on nine sunflower chromosomes, each explaining 2.21%–16.99% of the phenotypic variance for resistance in the AB-QTL population. Sixteen of the 19 QTL had alleles conferring increased BSR resistance derived from the H. praecox parent. SNP markers flanking the identified QTL will facilitate marker-assisted breeding to combat the disease in sunflower.

Estimation of Genetic Variances and Stability Components of Yield-Related Traits of Green Super Rice at Multi-Environmental Conditions in Pakistan

Identifying adopted Green Super Rice (GSR) under different agro-ecological locations in Pakistan is crucial to sustaining the high productivity of rice. For this purpose, the multi-location trials of GSR were conducted to evaluate the magnitude of genetic variability, heritability, and stability in eight different locations in Pakistan. The experimental trial was laid out in a randomized complete block (RCB) design with three replications at each location. The combined analysis of variance (ANOVA) manifested significant variations for tested genotypes (g), locations (L), years (Y), genotype × year (GY), and genotype × location (GL) interactions revealing the influence of environmental factors (L and Y) on yield traits. High broad-sense heritability estimates were observed for all the studied traits representing low environmental influence over the expression of traits. Noticeably, GSR 48 showed maximum stability than all other lines in the univariate model across the two years for grain yield and related traits data. Multivariate stability analysis characterized GSR 305 and GSR 252 as the highest yielding with optimum stability across the eight tested locations. Overall, Narowal, Muzaffargarh, and Swat were the most stable locations for GSR cultivation in Pakistan. In conclusion, this study revealed that G×E interactions were an important source of rice yield variation, and its AMMI and biplots analysis are efficient tools for visualizing the response of genotypes to different locations.

Radial variations of broad-sense heritability in wood properties and classification of load\u2013deflection curves in static bending for six half-sib families of Chamaecyparis obtusa

Wood properties (annual ring width, tracheid length, microfibril angle [MFA], basic density, and air-dry density) and mechanical properties (modulus of elasticity [MOE], modulus of rupture [MOR], bending work, and compressive strength) in 34-year-old Chamaecyparis obtusa trees of six half-sib families were measured from pith to bark to clarify radial variations in inheritance of these traits and the relationships between wood properties and mechanical properties. In addition, within-tree and among-family differences in the load–deflection curves were discussed. Radial variations of all wood properties were fitted to linear or nonlinear mixed-effects models with random effects of families. The MFA was correlated with MOE in all radial positions, whereas air-dry density correlated with all mechanical properties in mature wood. Radial variations in broad-sense heritability differed between wood properties. A relatively higher broad-sense heritability was recognized in almost all wood properties for mature wood. Based on the results, it was concluded that mechanical properties in mature wood can be effectively improved using MFA and air-dry density as criteria. In addition, the types of load–deflection curve in mature wood differed from those in juvenile wood, suggesting that not only elastic properties, but also plastic properties in C. obtusa are affected by genetic controls, especially in mature wood.

Assessment of the Yam Landraces (Dioscorea spp.) of DR Congo for Reactions to Pathological Diseases, Yield Potential, and Tuber Quality Characteristics

Yams (Dioscorea spp.) possess the potential to contribute to food security and poverty alleviation in DR Congo; however, yam production is limited by several constraints, including the lack of yam improvement programs to address challenges relating to yield improvement, resistance to foliar diseases, and post-harvest tuber quality. Identification of a superior genotype for these traits and reservoirs of genes for improvement would guide yams’ improvement. This study aims to evaluate and identify landraces with superior performance for farmers and consumers. We evaluated 191 accessions from six yam species, and significant variation in the performances was observed at p &lt; 0.05. Accessions of D. alata were superior for tuber oxidative browning (−0.01), D. cayenensis for high yield potential (29 t/ha), D. bulbifera for yam mosaic virus (YMV) tolerance (AUDPC = 3.88), and D. rotundata for tuber dry matter content (37%). A high genotypic and phenotypic coefficient of variation (&gt;40) was observed for tuber yield, number of tubers per plots, tuber flesh oxidative browning, and tuber flesh texture. High broad-sense heritability estimates (&gt;60) were similarly observed for all the assessed parameters except number of tubers per plot. Tuber size was identified as the best predictor for tuber yield (b = 2.64, p &lt; 0.001) and tuber dry matter content (b = 2.21, p &lt; 0.001). The study identified twenty stable landrace accessions from three Dioscorea species (D. alata (7); D. cayenensis (2); D. rotundata (11)). These accessions combined high yield potential, high tuber dry matter, high tolerance to YMV and YAD, and low tuber flesh oxidation. The accessions could be considered for the establishment of a yam improvement program in DR Congo.

The Effects of Frost Cracks and Large Poplar Borer Damage on Stem Rot in Hybrid Aspen (Populus tremula L. × Populus tremuloides Michx.) Clones

Hybrid aspen (Populus tremula L. × Populus tremuloides Michx.) plantations may produce valuable sawlogs for the growing timber market and contribute to carbon sequestration. However, environmental risks such as stem rot, the spread of which is facilitated by insect or frost damage, may reduce the proportion of valuable timber. It is important to understand the various factors affecting the spread of aspen rot to mitigate negative impacts with tree breeding. This study aimed to assess the impact of frost cracks and large poplar borer on stem rot in hybrid aspen clones in two clonal trials in Latvia. Genetic parameters for the traits were also estimated. The presence of insect passages substantially increased the probability of stem rot without distinct clonal differences. A negative and mainly insignificant correlation was observed between rot and stem cracking. The highest broad-sense heritability (H2 = 0.21) and strong site-site genotypic correlation (0.86) showed that the probability of stem rot is genetically determined in the study material. Significant differences in diameter at breast height, the presence of stem rot, and its severity were found among the clones, albeit without undesirable positive correlation between growth and presence of decay. This indicated its potential to improve both productivity and rot resistance.

Estimating Genetic Variability and Diversity for Vein Density, Photosynthesis and Yield in Rice Genotypes

Understanding the physiological and leaf anatomical traits having positive association with higher yields is critical to utilize these traits effectively in breeding programs for yield improvements in stable food crops. In rice, this would help in improving the productivity to feed the ever growing population. Therefore, the experiment was conducted to evaluate the variability and diversity of ninety-nine rice genotypes for photosynthesis, vein-related characters, and yield. The field trial was carried out in a wetland in Tamil Nadu Agricultural University, Coimbatore during Rabi, 2020. To investigate the genetic variability, efforts were made to estimate the percent of genotypic and phenotypic variation, heritability, and genetic advance likewise genetic diversity was estimated for twelve traits using Mahalanobis (D2) statistics. Analysis variance elucidates the existence of significant variation among the genotypes for all the twelve characters studied. The difference between GCV and PCV was narrow for all the characters studied which shows these characters are less influenced by environmental factors. The highest GVC and PCV was observed in yield and biomass simultaneously the high heritability in broad sense along with high genetic advance as percent mean was estimated in biomass, photosynthetic rate, yield, interveinal distance between major vein, leaf width, total number of veins, and total number of minor veins. These characters are considered to be inherent in nature and selection for improving these traits may be effective in the genetic improvement program. Based on the D2 value ninety-nine genotypes were diversified into five clusters in which Cluster II is the largest containing 37 genotypes followed by cluster I. The highest inter-cluster distance was estimated between cluster II and cluster IV whereas the highest intracluster distance was observed in cluster V indicating that genotypes in this cluster are highly diversified. Subsequently, the higher cluster means of most of the characters including vein characters, leaf width, and photosynthetic rate along with optimum yield and biomass fell in cluster II. Whereas in cluster IV the highest cluster means for biomass and yield was recorded. The traits biomass, yield, photosynthetic rate, interveinal distance between major veins, the total number of minor vein is the major contributors of total divergence in this population. Based on the trait contribution percentage for genetic diversity and genetic distance this study suggests that the genotypes from cluster II and cluster IV can be selected as parents for genetic improvement programs. Hence, information on the nature and degree of divergence in this population would help the plant breeder in the selection and hybridization procedure for choosing the right type of parents to improve vein characters, photosynthetic rate, yield, and biomass.

Genetic variability and multivariate studies on the grain physical properties of rice (Oryza sativa L.) landraces

Thirty rice landraces were evaluated during the 2020 wet season for the estimation of the genetic variability of six grain physical properties, viz. grain length (GL), grain breadth (GB), milled grain length (MGL), milled grain breadth (MGB), milled grain length breadth ratio (MGL/MGB), and 1000-grain weight (TGW), at the Bangladesh Institute of Nuclear Agriculture Substation, Sunamganj, Bangladesh. The relative contribution of these traits to variability was estimated by using principal component analysis (PCA), and the landraces were clustered by using Mahalanobis distance (D2) statistics. The TGW and MGL/MGB ratio exhibited high estimates of the phenotypic coefficient of variation and genotypic coefficient of variation. The high broad-sense heritability and genetic advance of all the traits indicated that the environmental effect had a weak involvement in the expression of these traits. PCA revealed six principal components, among which two were significant and contributed up to 96.9% of the total variance cumulatively. GL, GB, MGL, and TGW contributed to PC1 to create the variation among the landraces, whereas MGL/MGB ratio, GL, and MGL contributed to PC2. The landraces were grouped into six clusters. Cluster analysis revealed that the maximum and minimum intracluster distances were found in cluster III (235.11) and cluster VI (0.00), respectively. The longest intercluster distance was found between clusters IV and VI, and the shortest distance was found between clusters I and III. The maximum mean values for GL and TGW were observed in cluster VI. The mean values for GB and MGB were highest in cluster V, whereas the MGL/MGB ratio and MGL were highest in cluster II. ‘Madhumala’/‘Sada Madhumala’ and ‘Pankhuraj’ could be used in hybridization programs to exploit maximum heterosis for rice grain size and shape and for the direct selection of superior quality traits because these traits are less affected by the environment than other traits.

Dynamics of Fertility-Related Traits in Tomato Landraces under Mild and Severe Heat Stress.

Studies on the reproductive dynamics under heat stress are crucial to breed more tolerant cultivars. In tomato, cultivars, breeding lines, and wild species have been evaluated for their response to heat stress. Here, we addressed the study to a panel of selected landraces representing traditional genotypes that usually show high adaptation to local environments. In two experiments, spaced by 12 years, we set-up an identical experimental design with plants transplanted at two different dates to expose the second field to thermic stress with natural fluctuations. Such a strategy resulted in both a mild and severe stress in the two years. The landraces showed wide variation for both vegetative and reproductive traits; all traits were affected by heat, mostly with a significant Genotype*Environment interaction. A high broad-sense heritability was estimated for plant height, stigma position, pollen viability, and fruit weight. Low heritability estimates were found for the number of flowers, fruit set, and yield. Despite the interaction, traits recorded under control and heat conditions were positively correlated. Multivariate analysis located the genotypes in a topography that was stable under all conditions, except under the harshest temperatures. The study revealed that landraces present a wide variability for the response of reproductive traits to thermic challenges and that such a variation could be useful to dissect the traits with higher heritability and identify quantitative trait loci for breeding more resilient varieties.

Genetic Parameters of Soybean [Glycine max (L.)] Genotypes Tolerant to Salinity

Background: Saline land can be used to increase soybean planting area. Adaptive varieties is one of technology to utilize saline land for soybeans. The objective of this study was to determine the phenotype and genotype performance of the F3 generation soybean lines in saline soil of Indonesia. Methods: A total 247 soybean genotypes, including four check varieties, were planted in augmented design in 2018. The field electrical conductivity (EC) value before planting soybean was 10.4 dS/m and soil acidity was 8.1 which was classified as high saline land based on Jones (2002). Result: The number of selected plants were 172 single plants. GH K13/Anjasmoro lines has an opportunity to further selection. Average height of GH K13/Anjasmoro selected lines was 26.4 cm, number of fertile nodes was 11, number of filled pods was 27 and seeds weight per plant was 4.8 g. GH K13/Anjasmoro lines has a high broad sense heritability for plant height, number of branches and number of filled pods, also high genetic advance for all characters.

Genetic Variability, Correlation, and Path Analysis of Thai Commercial Melon Varieties

In the selection phase of melon breeding programs, genetic variability is a critical component for yield improvement. The goals of this study were to discover the variables that affect melon fruit weight and examine genetic variability, correlation, and path analysis of eight melon varieties. The experiment was arranged as a completely randomized block design with 4 blocks. It was conducted between July and September 2021 at the School of Agricultural Technology, Walailak University, Nakhon Si Thammarat, Thailand. The result found that stem diameter and length, leaf length, width, number, and chlorophyll, day to 50% male and female flowering, and fruit perimeter, height, and weight were highly significant across the varieties. The genotypic coefficients of variation (GCV) of observed variables were all lower than phenotypic coefficients of variation (PCV). Fruit weight (15.462 and 19.865%) had the highest GCV and PCV. High broad-sense heritability was linked to high (H) or moderate (M) genetic advance as a percentage of the mean from stem length (67.606%: H and 21.992%: H), fruit weight (60.586%: H and 24.793%: H), fruit perimeter (76.395%: H and 12.258%: M), and fruit height (69.828%: H and 12.122%: M). The maximum and significant genotypic correlation value was obtained between leaf length and leaf width (r = 1.000). Fruit weight is positively correlated with fruit perimeter (r = 0.940) and fruit height (r = 0.831). According to correlation and path analyses, stem diameter and length, leaf chlorophyll, and fruit perimeter and height were considered variables for fruit weight improvement in the breeding programs. It suggests that the increase in traits with a favorable direct influence on fruit weight may directly contribute to fruit weight.

Genetic Variability Studies for Yield and Yield Attributing Traits of Wheat (Triticum aestivium L.)

Diversity analysis was carried out in 93 wheat genotypes including three checks with help of cluster analysis, path analysis, heritability in broad sense, genetic advance as per cent of mean, coefficient of variation and correlation coefficient. D2 statistics showed existence of 10 clusters which clearly indicated presence of considerable genetic divergence in the experimental material. In Path analysis, traits viz., tillers per plant, spike length and grains per spike displayed positive and direct effect on yield per plot; indicating that selection of those traits can be practiced to improve yield. Grain yield per plot showed positive correlation with days to maturity, plant height, tillers per meter, tillers per plant, spike length and grain per spike. All traits show high heritability in broad sense. Genetic advance in percent of mean estimates were high in all traits except days to maturity and days to fifty percent heading; which recorded low and moderate estimates of genetic advance, respectively. The difference between PCV and GCV was less indicating less impact of environment in the expression of various yield contributing traits.

Performance and Genetic Variability of Okra (Abelmoschus esculentus (L.) Moench) Genotypes in Ethiopia for Agromorphology and Biochemical Traits

No research has been done to assess the genetic diversity of Okra (Abelmoschus esculentus) genotypes in Ethiopia based on the combination of agromorphology and biochemical traits of the crop. Such an assessment would assist in the development of high fruit yield and nutritionally good cultivars. Therefore, 36 okra genotypes were evaluated for 29 agromorphological and biochemical traits at the Melkassa Agricultural Research Center (Ethiopia) during the 2018 main rainy season, using a 6 × 6 simple lattice design. Analysis of variance showed significant differences among genotypes for all the studied traits, except number of flower epicalyxes and fruit diameter. Genotypic coefficients of variation and phenotypic coefficient of variation were high for number of branches, internode length, fresh fruit weight, number of mature pods, fruit yield per plant, fruit yield per hectare, seed yield per plant, seed yield per hectare, and seed protein content. Heritability values ranged between 33.63 and 99.81%, while the genetic advance as percentage of mean ranged between 4.29 and 95.45%. High broad sense heritability was coupled with high GAM for plant height, branch, internod length, fruit length, panicle length, fresh fruit weight, number of fruits per plant, number of mature pods, seed yield per plant, seed yield per hectare, and fibre and protein content. In conclusion, this study showed the presence of genetic variation among genotypes for fruit yield, seed yield, and nutritional content, indicating the potential success of developing okra varieties for high fruit yielding and good nutritional content.

Agronomic Performance of F3 Populations of Tomato for Hydroponic Cultivation at Lowland Greenhouse

Tomatoes consumption continues to increase, but it’s constrained by low productivity in central production, so a plant breeding program is needed to improve the yield and adaptability of tomatoes in urban areas. This study aimed to analyze the agronomic performance of F3 tomato populations for hydroponic cultivation in a lowland greenhouse. The F3 populations derived from crosses of commercial variety Rewako x Tantyna (Rw.Ta-4-7U, w.Ta-4-10U, and Rw.Ta-1-14U) and Agatha x Ultima (Ag.Ul-5-7U &amp; Ag.Ul-5-14U). The research was conducted at the Gunadarma University’s experimental greenhouse in Depok City, West Java, from March to August 2020. Twenty-fifth-day-old seedlings from each population were planted in a planter bag. The experiment was carried out using a single plant design for F3 generation and a randomized complete block design (RCBD) for the commercial varieties. The result showed that a number of fruit per plant, and fruit weight per plant had wide genetic variabilities among F3 populations. All characters had a high broad-sense heritability except for flowering days and harvesting days. The high advance genetic, along with high mean values, was shown by the F3 populations of Rw.Ta-4-10U, Rw.Ta-4-7U and Ag.Ul-5-14U. The high value of genetic variability, heritability, and genetic advance will help to select the program for the next generation.

Correlation and Heritability Studies of Yield and Yield Related Traits in F5 Triticum aestivum Lines from a Cross Cv Fsd-08 × Cv S-24

The heritability estimates give information about traits which are transferred from one generation to another generation, and it has important role in selection criteria to enhance the yield potential. The purpose of current study was to estimate heritability and genetic advance of F5 wheat lines derived from a cross of Faisalabad 2008 and S-24. Eight yield parameters were evaluated during the year 2019-20 in complete randomize design with five replicates. The results of ANOVA showed significant difference (P ≤0.001) in all studied traits. High broad sense heritability was observed for grain yield per spike (82.49%) followed by tillers per plant (81.77%) and spikelet per spike (76.65%). Moderate to low genetic advance was observed for all the traits except plant height (79.47%), and grain yield per spike have 73.10%. Grain yield have positive correlation with fertile tiller, 100 seed weight and grain yield per spike. The traits grain yield per spike, tillers per plant and spikelet per spike deserve more attention in future breeding programs for evolving better wheat yield.

Agro-Morphological Characterization and Genetic Dissection of Linseed (Linum usitatissimum L.) Genotypes

Linseed is a multipurpose crop and the crop needs further improvement to increase production and yield due to its high value and demand. This study aimed to assess the extent and pattern of genetic variability of forty linseed genotypes based on diverse agro–morphological and yield attributes. The field experiment was conducted following a Randomized Complete Block Design with three replications. Linseed germplasm showed a wide range of phenotypic expression, genetic variability and heritability for 30 studied traits. A low to high phenotypic coeffi- cient of variation (PCV) and genotypic coefficient of variation (GCV) were observed. The lowest genotypic (σ2 g) and phenotypic variances (σ2 p) were found in capsule diameter (CD), length of calyx (LC), capsule length (CL), seed length (SL), and seed breadth (SB). High broad-sense heritability (h2b) with high genetic advance as a percentage of mean (GAM) were observed in days to germination started (DGS), days to 80% emergence (DE), plant height at 28 and 40 DAS, number of flowers (NFPP), filled capsules (NFCPP) and yield per plant (YPP) indicating additive gene action exists for these characters. Hierarchical cluster analysis separated 40 genotypes into five clusters, where Clusters I to V assembled with 13, 4, 4, 5 and 14 genotypes, respectively. Considering yield and yield attributes, Cluster-IV (G3, G4, G6, G10 and G31) genotypes showed promising while, Cluster-II (G2, G16, G35, G36) and Cluster-III (G1, G33, G39 and G40) genotypes were dominant on plant morphological traits. Based on principal component analysis (PCA), few characters such as YPP, NFPP, NFCPP, days to first flowering and capsule formation, early emergence, days to branch initiation and plant heights at different growth stages revealed important and effective traits for consideration in the selection of linseed breeding programs.

Comparative performance of top cross and population cross hybrids in white Maize using a common tester

Improved maize populations and cross hybrids can be beneficial alternatives for commercial single-cross hybrids and good elite sources for diverse inbred lines. A set of 22 genotypes comprised 10 population crosses, 10 top crosses, and two check cultivars were evaluated at Cereal Crop Research Institute, Pirsabak-Nowshera, in a randomized complete block design with three replicates in 2014. This research's major aims were to determine the magnitude of heterosis and the degree of character association between yield and its attributes to select superior genotypes from the breeding material. Data were recorded on maturity, and yield associated traits, where significant genetic variability was observed among the genotypes for all the studied traits except days to silking. Mean values for the studied traits ranged from 44 to 52 days for tasseling, 48 to 54 days for anthesis, 49 to 54 days for silking, -1.33 to 2.33 for the anthesis-silking interval, 2.53 to 8.47 kg for fresh ear weight, 12 to 16 rows for kernel rows cob-1, 27.15 to 37.49 g for 100-kernel weight and 2830 to 7649 kg ha-1 for grain yield. Days to silking, anthesis silking interval, and kernel rows cob-1 showed low broad sense heritability (12.08%, 24.84%, 27.59%), days to tasseling, days to anthesis revealed moderate heritability (40.53%, 36.62%), while fresh ear, 100-kernel weight, and grain yield exhibited high broad-sense heritability (94.89%, 82.33%, 90%). Negative and significant heterotic values were observed for maturity traits, while heterotic values were positive and significant for yield-associated traits. Correlation analysis revealed that characters like fresh ear weight (r = 0.93) and 100-kernel weight (r = 0.50) manifested a strong positive and significant association with grain yield. Based on mean performance and grain yield, promising hybrids were 3008F3 x 2007-WC and 3008F3 x 2010. The current study revealed significant genetic variability among the tested hybrids; hence, it can be used in future breeding programs to produce early maturing and high-yielding maize hybrids.Days to tasseling, genetic variability, heterosis, population cross, top cross Keywords: HBV, HCV, ICT, PCR, Risk factors, Mansehra

Heritable Variation, Genetic and Phenotypic Correlations for Tuber Traits and Host Plant Resistance to Late Blight for Potato Breeding in Scandinavian Testing Sites

Potato breeding aims to improve crop productivity, quality and resilience based on heritable characteristics. Estimating the trait heritability and correlations—both genetic and phenotypic—among characteristics in a target population of environments allows us to define the best breeding method that leads to selection gains. Breeding clones (47) and released cultivars (209) were grown using simple lattice designs at three testing sites in northern and southern Sweden to estimate the best linear unbiased predictors (BLUPs) derived from mixed linear models for characteristics such as tuber weight (total and according to sizes), host plant resistance to late blight (caused by the oomycete Phytophthora infestans) and tuber quality (starch percentage based on specific gravity measurements and reducing sugars). There was significant heritable variation for all the characteristics investigated. Tuber starch percentage and total tuber weight were the traits with the highest broad-sense heritability (H2), while the weight for the smallest size (&lt;40 mm) had the highest H2 among the different tuber categories. These results show the potential for further improving these traits for Scandinavia through recombination and selection in segregating offspring. The genetic and phenotypic correlations among the tuber weight characteristics were significant (p ≤ 0.05) irrespective of their sizes, but none were significant (p &gt; 0.05) with tuber starch percentage. Host plant resistance to late blight was negatively and significantly associated with tuber weight and starch percentage, thereby showing the strong effects of this disease on the productivity and quality of the potatoes.