Variation In Agronomic Traits Research Articles

Genetic performance, heritability, and correlation of traits in new plant type of rice lines for highland ecosystem

Rice cultivation is crucial in providing global food needs, particularly in highland areas with distinct environmental conditions. Adapting promising rice lines suitable for highland ecosystems is essential to ensure sustainable rice production in such regions. This study assesses the agronomic performance, heritability, and correlation of traits in new promising rice lines adapted to highland ecosystems. The latest promising rice lines are designed with the unique environmental conditions of highland regions in mind. This research was conducted in Buntu Barana’ Village, Tikala Sub-district, with an elevation of 858.4 m above sea level. The study was carried out in rain-fed semi-irrigated paddy fields. The research was conducted from May 2023 to January 2024. The research methodology involves testing various agronomic traits for yield production components of the new type of promising rice lines at different highland locations. The research procedures included the selection of viable seed strains, seeding, fertilization, balanced irrigation, control of plant pest organisms, harvesting, and post-harvesting. Evaluated agronomic traits encompass plant height, days to maturity, number of productive tillers, length of panicles, number of filled grains per panicle, and grain yield. Additionally, heritability analysis is performed to assess the extent to which observed trait variations are attributed to genetic factors. Research findings reveal significant variations in agronomic traits among the new type of promising rice lines. The highest grain yield is achieved in genotype UKIT102-2-056, which is 8.3 tons per hectare of paddy rice. These lines exhibit objective adaptation to the highland ecosystem, with some lines demonstrating superior performance in specific parameters, especially early maturity, namely 97 days after planting. Heritability analysis indicates that certain traits have high heritability levels, suggesting a significant role of genetic factors in controlling these traits. Furthermore, this study unveils correlation patterns among the observed agronomic traits. Significant positive and negative correlations among several traits indicate complex interrelationships among these agronomic characteristics. These findings offer further insights into the relationships between these traits and can be utilized to develop more adaptive rice lines in highland environments.

IIIVmrMLM Provides New Insights into the Genetic Basis of the Agronomic Trait Variation in Chickpea

Chickpea is a staple crop for many nations worldwide. Modeling genotype-by-environment interactions and assessing the genotype’s ability to contribute adaptive alleles are crucial for chickpea breeding. In this study, we evaluated 12 agronomically important traits of 159 accessions from the N.I. Vavilov All Russian Institute for Plant Genetic Resources collection. These included 145 landraces and 13 cultivars grown in different climatic conditions in Kuban (45°18′ N and 40°52′ E) in both 2016 and 2022, as well as in Astrakhan (46°06′ N and 48°04′ E) in 2022. Using the IIIVmrMLM model in multi-environmental mode, we identified 161 quantitative trait nucleotides (QTNs) with stable genetic effects across different environments. Furthermore, we have observed 254 QTN-by-environment interactions with distinct environment-specific effects. Notably, five of these interactions manifested large effects, with R2 values exceeding 10%, while the highest R2 value for stable QTNs was 4.7%. Within the protein-coding genes and their 1 Kb flanking regions, we have discerned 22 QTNs and 45 QTN-by-environment interactions, most likely tagging the candidate causal genes. The landraces obtained from the N.I Vavilov All Russian Institute for Plant Genetic Resources collection exhibit numerous favorable alleles at quantitative trait nucleotide loci, showing stable effects in the Kuban and Astrakhan regions. Additionally, they possessed a significantly higher number of Kuban-specific favorable alleles of the QTN-by-environment interaction loci compared to the Astrakhan-specific ones. The environment-specific alleles found at the QTN-by-environment interaction loci have the potential to enhance chickpea adaptation to specific climatic conditions.

Morphological and cytological assessments reveal pollen degradation causes pollen abortion in cotton cytoplasmic male sterility lines

BackgroundUnderstanding the mechanism of male sterility is crucial for producing hybrid seeds and developing sterile germplasm resources. However, only a few cytoplasmic male sterility (CMS) lines of cotton have been produced due to several challenges, like inadequate variation of agronomic traits, incomplete sterility, weak resilience of restorer lines, and difficulty in combining strong dominance. Therefore, the morphological and cytological identification of CMS in cotton will facilitate hybrid breeding.ResultsTwo F2 segregating populations of cotton were constructed from cytoplasmic male sterile lines (HaA and 01A, maternal) and restorer lines (HaR and 26R, paternal). Genetic analysis of these populations revealed a segregation ratio of 3:1 for fertile to sterile plants. Phenotypic analysis indicated no significant differences in traits of flower bud development between sterile and fertile plants. However, sterile plants exhibited smaller floral organs, shortened filament lengths, and anther atrophy on the flowering day in comparison with the fertile plants. When performed scanning electron microscopy (SEM), the two F2 populations revealed morphological variations in the anther epidermis. Cellular analysis showed no significant differences in pollen development before pollen maturation. Interestingly, between the pollen maturation and flowering stages, the tapetum layer of sterile plants degenerated prematurely, resulting in abnormal pollen grains and gradual pollen degradation.ConclusionThe results of this study suggest that fertility-restoring genes are controlled by a single dominant gene. Sterile plants exhibit distinctive floral morphology, which is characterized by stamen atrophy and abnormal anthers. Pollen abortion occurs between pollen maturity and flowering, indicating that premature tapetum degradation may be the primary cause of pollen abortion. Overall, our study provides a theoretical basis for utilizing CMS in hybrid breeding and in-depth investigation of the dominant configuration of cotton hybrid combinations, mechanisms of sterility, and the role of sterile and restorer genes.

Development and characterization of an EMS-mutagenized population of wheat (Triticum aestivum L.) for agronomic trait variation and increased micronutrients content

Development and characterization of an EMS-mutagenized population of wheat (Triticum aestivum L.) for agronomic trait variation and increased micronutrients content

Dissecting Genotype by Environment Interactions in Moroccan Wheat: An Advanced Biplot and Heatmap Analysis Unveiling Agronomic, Quality Traits, and Genotypic Stability for Tailored Breeding Strategies.

This five-year study (2016-2021) across diverse Moroccan agro-climatic zones investigated genotype by environment (G × E) interactions in wheat, focusing on variations in agronomic traits and quality attributes such as protein and gluten content. Significant environmental effects were observed on key traits, like yield, thousand kernel weight (TKW), and spikes per square meter (Spk/m2), highlighting environmental factors' role in wheat yield variability. In the Tassaout (TST) location, notable genotypic effects emerged for traits like biomass, underscoring genetic factors' importance in specific contexts, while in Sidi El Aidi (SEA) and Marchouch (MCH), genotypic effects on yield and its components were predominantly absent, indicating a more substantial environmental influence. These findings illustrate the complexity of G × E interactions and the need for breeding strategies considering genetic potential and environmental adaptability, especially given the trade-offs between yield enhancement and quality maintenance. Insights from the biplot and heatmap analyses enhanced the understanding of genotypes' dynamic interactions with environmental factors, establishing a basis for strategic genotype selection and management to optimize wheat yield and quality. This research contributes to sustainable wheat breeding in Morocco, aligning with global efforts to adapt wheat breeding strategies to changing climatic conditions.

Genotypic Variation in Agronomic Traits and Molecular Markers among Chinese Luobuma (Apocynum spp.) Germplasm Accessions

Apocynum spp., known as Chinese Luobuma species, are perennial herbaceous plants that not only have good ecological characteristics, such as drought resistance, salt resistance, freezing resistance, high-temperature resistance and wind sand resistance, but also have good medicinal and textile value. However, studies on the genetic variation in Chinese Luobuma are rare. In this study, the genotypic variation in the agronomic traits and molecular markers among eight germplasm accessions (referred to as genotypes) of Apocynum spp. was investigated. The accessions were evaluated at two locations in China, Altay and Yuzhong, during a three-year period. Analysis of the variance in yield-related traits revealed significant genotypic variation (p < 0.05) among the eight genotypes at the early flowering and full flowering stages. There were also significant (p < 0.05) genotype × year and genotype × location × year interactions for all the traits except leaf dry weight. In comparison to those evaluated at Yuzhong, the plant height, number of branches, leaf dry weight and stem dry weight at the early flowering stage were greater in Altay, with averages of 991.0 mm, 5.52, 26.41 g and 25.35 g, respectively. There were significant (p < 0.05) differences among genotypes in terms of the quality traits measured at the early and full flowering stages. The crude protein and crude fat content for each genotype at different locations at the early flowering stage in different years ranged from 8.64 to 10.07%. The average flavone (FLA) content was 2.31 mg/100 g. Principal component analysis (PCA) revealed that the G1 genotype in Altay had a higher neutral detergent fiber content and leaf dry weight, and the G2 genotype had a larger stem thickness, branch number and stem-to-leaf ratio. Five DNA sequences, ITS, matK, psbA-trnH, rbcL and trnL-F, were selected for analysis of the molecular variance in Chinese Luobuma. Analyses of molecular variance (AMOVA) based on the nuclear DNA sequences and chloroplast DNA sequences showed that most of the variation occurred within species. Our study indicated the significant genetic variation in Chinese Luobuma for future cultivar domestication. Genotypes with high leaf dry weights and many branches are beneficial for tea production, while tall plants with long internode lengths are valuable for the production of hemp.

Micropropagation of banana genetic resources adapted to the Argentine environment and generation of new variability for agronomic traits through somaclonal variation

Micropropagation of banana genetic resources adapted to the Argentine environment and generation of new variability for agronomic traits through somaclonal variation

Responses of elite sorghum (Sorghum bicolor [L.] Moench) lines developed via gamma-radiation for grain yield, component traits and drought tolerance

Induced plant mutagenesis is a powerful technique to create genetic variation for agronomic traits and drought tolerance selection programs. The objective of this study was to determine the response of elite sorghum (Sorghum bicolor [L.] Moench) lines developed via gamma-radiation for grain yield, component traits, and drought tolerance to select best performing lines for cultivation in water-stressed environments. Ten newly developed mutant lines and four check varieties were evaluated in two growing seasons under drought-stressed (DS) and non-stressed (NS) conditions in Namibia. Mutant lines were evaluated using a factorial experiment laid out in a randomized complete block design with three replications in custom-made rainout-shelter facility. Data on grain yield and yield-related traits were collected and drought tolerance selection indices were computed using mean genotype yield under non-stressed condition and drought-stressed condition. Data were subjected to standard analysis of variance, correlation and principal component analyses. The interaction effect of genotype × drought stress × season was non-significant for most assessed traits suggesting the relatively stable performance of the test lines for selection. Grain yield response of test genotypes varied from 0.55 to 2.27 t/ha under DS and 1.84 to 4.05 t/ha in NS conditions. Grain yield positively and significantly (P < 0.05) correlated with harvest index (r = 0.79), panicle weight (r = 0.75) and panicle length (r = 0.37), and negatively correlated with days to flowering (r = −0.35) under DS condition. Principal component (PC) analysis identified two PCs accounting for 96.35 % of total genotypic variation based on drought tolerance selection indices. Biplot analysis using a combination assessed traits allowed selection of drought tolerant mutant lines designated as ML4, ML10, ML6, and ML5 with mean grain yield of 2.27, 2.05, 1.89 and 1.67 t/ha under DS conditions, in that order. The selected lines are recommended for further multi-environment evaluations for release and large-scale production in Namibia or other related agro-ecologies.

A comprehensive lettuce variation map reveals the impact of structural variations in agronomic traits

BackgroundAs an important vegetable crop, cultivated lettuce is grown worldwide and a great variety of agronomic traits have been preserved within germplasm collections. The mechanisms underlying these phenotypic variations remain to be elucidated in association with sequence variations. Compared with single nucleotide polymorphisms, structural variations (SVs) that have more impacts on gene functions remain largely uncharacterized in the lettuce genome.ResultsHere, we produced a comprehensive SV set for 333 wild and cultivated lettuce accessions. Comparison of SV frequencies showed that the SVs prevalent in L. sativa affected the genes enriched in carbohydrate derivative catabolic and secondary metabolic processes. Genome-wide association analysis of seven agronomic traits uncovered potentially causal SVs associated with seed coat color and leaf anthocyanin content.ConclusionOur work characterized a great abundance of SVs in the lettuce genome, and provides a valuable genomic resource for future lettuce breeding.

Plant trait relationships are maintained within a major crop species: lack of artificial selection signal and potential for improved agronomic performance.

The exploration of phenotypic spaces of large sets of plant species has considerably increased our understanding of diversification processes in the plant kingdom. Nevertheless, such advances have predominantly relied on interspecific comparisons that hold several limitations. Here, we grew in the field a unique set of 179 inbred lines of durum wheat, Triticum turgidum spp. durum, characterized by variable degrees of artificial selection. We measured aboveground and belowground traits as well as agronomic traits to explore the functional and agronomic trait spaces and to investigate trait-to-agronomic performance relationships. We showed that the wheat functional trait space shared commonalities with global cross-species spaces previously described, with two main axes of variation: a root foraging axis and a slow-fast trade-off axis. Moreover, we detected a clear signature of artificial selection on the variation of agronomic traits, unlike functional traits. Interestingly, we identified alternative phenotypic combinations that can optimize crop performance. Our work brings insightful knowledge about the structure of phenotypic spaces of domesticated plants and the maintenance of phenotypic trade-offs in response to artificial selection, with implications for trade-off-free and multi-criteria selection in plant breeding.

The effect of silicon fertilizers on agronomic performance of bread wheat under drought stress and non‐stress conditions

AbstractDrought is one of the major constraints of wheat production, especially in rainfed wheat production systems. The objective of this study was to evaluate the effects of different silicon fertilizer formulations on the agronomic performance of diverse wheat genotypes under drought‐stressed conditions. Twenty wheat genotypes were evaluated in field and greenhouse environments under non‐stressed and drought‐stressed and two silicon fertilizer formulations (granular and liquid potassium silicate) and untreated control. The four‐way interaction involving genotype, environment, water regime and silicon formulation had a significant effect (p &lt; .05) for aboveground biomass, productive spike number, hundred seed weight and grain yield. Granular silicon application was the most effective treatment both under non‐stressed and drought‐stressed conditions compared to the liquid and control treatments. Under field and drought conditions, the highest yielding genotype was MC18, which exhibited a mean grain yield of 4.17 t ha−1 with granular silicon, 2.56 t ha−1 with liquid silicon and 2.18 t ha−1 without silicon. The yield of genotype MC18 improved by 91.3% using granular silicon under drought‐stressed and by 44.6% under non‐stressed conditions compared with the untreated control. Granular silicon positively affected the drought stress tolerance indices compared to the liquid silicon and untreated control. The principal component biplot analysis revealed that liquid and granular silicon positively impact yield response for all test genotypes under drought‐stressed and non‐stressed conditions compared with the control. Silicon application reduced genotype variation for agronomic traits and enhanced agronomic trait relationships under drought‐stressed conditions. Drought stress tolerance indices are influenced by silicon application. The effect of silicon has a direct and indirect effect on yield and yield components. Silicon fertilization can be considered as a mitigation measure to cope with the adverse effect of drought stress on wheat.

Five improved sesame reference genomes and genome resequencing unveil the contribution of structural variants to genetic diversity and yield-related traits variation.

Five improved sesame reference genomes and genome resequencing unveil the contribution of structural variants to genetic diversity and yield-related traits variation.

Efficacy of transplant insecticides against black cutworm Agrotis ipsilon (Lepidoptera: Noctuidae) in tobacco

The black cutworm, Agrotis ipsilon (Lepidoptera: Noctuidae), is a critical soil pest of tobacco (Nicotiana tabacum) in the early season. Although numerous studies have shown that chemical insecticides through soil-surface or foliar application provide adequate management of black cutworms, relatively little is known about the efficacy of transplant applications. Here, we evaluated the efficacy of insecticide transplant treatment against black cutworm in tobacco in pots and in the field. We also investigated the impact of chlorantraniliprole on tobacco, including dynamic residue concentrations in tobacco and variation in agronomic traits of treated seedlings. Bioassays showed that LC50 of chlorantraniliprole was 0.28 mg AI/L against black cutworm. In a potted plant experiment, chlorantraniliprole treatment at 15, 30, and 75 g AI/ha reduced the number of damaged tobacco seedlings and increased the mortality of black cutworm within 30 d. When tobacco seedlings were treated with chlorantraniliprole 24 h before transplanting in the field, the control efficacy of chlorantraniliprole treatment at 75 g AI/ha was 45.5%–59.6% at 20 d after treatment. The concentration of chlorantraniliprole in tobacco seedlings treated with 15 g AI/ha was found to degrade to 0.033 mg/kg after 28 d (t1/2 = 2.54 d), which affected the height of seedlings but not the number of leaves after 28 d. Chlorantraniliprole treatment of seedlings during transplanting is a practical and effective strategy to manage black cutworm in tobacco.

Assessment of Genetic Diversity in Bupleurum spp. Basing Agronomic Traits, Medicinal Components and ISSR Markers.

Radix bupleuri is one of the bulk medicinal materials in China and it is widely adopted in clinical applications and drug discovery. The investigation of agronomic traits, active component content and genetic diversity in diverse Radix bupleuri germplasms may provide evidence to promote the selection of better strains. In this research, 13 germplasms from various sources were used to investigate the variations between different Radix bupleuri germplasms. Nine biological characteristics were noted in the field, and the levels of the two primary active ingredients were determined using high performance liquid chromatography (HPLC). Moreover, the molecular marker technique of inter-simple sequence repeat (ISSR) and the unweighted pair group method with arithmetic means (UPGMA) were employed to evaluate the molecular genetic diversity. The findings showed that there was a wide range of variation among the many varieties of Radix bupleuri, with coefficients of variation for agronomic traits and active component content ranging from 7.62% to 41.54% and 36.47% to 53.70%, respectively. Moreover, there are different degrees of relationship between the two. Since there was a significant correlation between root weight and saikosaponin content, it was possible to classify a plant based on its weight and anticipate its saikosaponin content. The 13 species were divided into four groups based on their germplasm by genetic markers-based cluster analysis. This indicated the possibility that the component content would not necessarily be related to germplasm and might easily be influenced by environmental factors. The use of ISSR marker technology made it possible to precisely identify the various Radix bupleuri provenances and its counterfeit products. There may be a way to prevent the misunderstandings caused by the appearance and composition of Chinese medicinal substances. In our study, the germplasm of Radix bupleuri that was widely circulated in the market was comprehensively evaluated in terms of agronomic traits, active components and molecular level, and identified by simple means, to provide a theoretical basis for the evaluation and screening of fine germplasms of Radix bupleuri.

Combined evaluation of agronomic and quality traits to explore heat germplasm in celery (Apium graveolens L.)

Existing celery germplasm resources must be evaluated prior to celery biological research and application of germplasm resources. In this study, 14 agronomic and quality traits, and heat-resistance of 50 celery cultivars were analyzed. The results showed that the coefficients of variation of the 14 traits ranged from 1.73% to 64.69%, 50 samples of celery could be divided into 5 groups by cluster analysis. The primary sources of variation in agronomic traits were petiole color, hollow/solid, and yield per plant, and the primary sources of variation of quality traits were apigenin and cellulose. The photosynthetic parameters and heat damage index was investigated, and the correlation between celery germplasm resources and heat-resistance was analyzed. The result showed that heat-resistance was correlated with its hollow/solid and color. This study analyzed the genetic diversity of celery germplasm resources, screened heat-resistant and heat-sensitive varieties, and performed an association analysis with the germplasm resources, which laid the foundation for the subsequent selection of heat-resistant celery varieties.

Development of 12 sets of chromosome segment substitution lines that enhance allele mining in Asian cultivated rice.

Many agronomic traits that are important in rice breeding are controlled by multiple genes. The extensive time and effort devoted so far to identifying and selecting such genes are still not enough to target multiple agronomic traits in practical breeding in Japan because of a lack of suitable plant materials in which to efficiently detect and validate beneficial alleles from diverse genetic resources. To facilitate the comprehensive analysis of genetic variation in agronomic traits among Asian cultivated rice, we developed 12 sets of chromosome segment substitution lines (CSSLs) with the japonica background, 11 of them in the same genetic background, using donors representing the genetic diversity of Asian cultivated rice. Using these materials, we overviewed the chromosomal locations of 1079 putative QTLs for seven agronomic traits and their allelic distribution in Asian cultivated rice through multiple linear regression analysis. The CSSLs will allow the effects of putative QTLs in the highly homogeneous japonica background to be validated.

Grain Nutrients Variability in Pigeonpea Genebank Collection and Its Potential for Promoting Nutritional Security in Dryland Ecologies.

Pigeonpea, a climate-resilient legume, is nutritionally rich and of great value in Asia, Africa, and Caribbean regions to alleviate malnutrition. Assessing the grain nutrient variability in genebank collections can identify potential sources for biofortification. This study aimed to assess the genetic variability for grain nutrients in a set of 600 pigeonpea germplasms conserved at the RS Paroda Genebank, ICRISAT, India. The field trials conducted during the 2019 and 2020 rainy seasons in augmented design with four checks revealed significant differences among genotypes for all the agronomic traits and grain nutrients studied. The germplasm had a wider variation for agronomic traits like days to 50% flowering (67–166 days), days to maturity (112–213 days), 100-seed weight (1.69–22.17 g), and grain yield per plant (16.54–57.93 g). A good variability was observed for grain nutrients, namely, protein (23.35–29.50%), P (0.36–0.50%), K (1.43–1.63%), Ca (1,042.36–2,099.76 mg/kg), Mg (1,311.01–1,865.65 mg/kg), Fe (29.23–40.98 mg/kg), Zn (24.14–35.68 mg/kg), Mn (8.56–14.01 mg/kg), and Cu (7.72–14.20 mg/kg). The germplasm from the Asian region varied widely for grain nutrients, and the ones from African region had high nutrient density. The significant genotype × environment interaction for most of the grain nutrients (except for P, K, and Ca) indicated the sensitivity of nutrient accumulation to the environment. Days to 50% flowering and days to maturity had significant negative correlation with most of the grain nutrients, while grain yield per plant had significant positive correlation with protein and magnesium, which can benefit simultaneous improvement of agronomic traits with grain nutrients. Clustering of germplasms based on Ward.D2 clustering algorithm revealed the co-clustering of germplasm from different regions. The identified top 10 nutrient-specific and 15 multi-nutrient dense landraces can serve as promising sources for the development of biofortified lines in a superior agronomic background with a broad genetic base to fit the drylands. Furthermore, the large phenotypic data generated in this study can serve as a raw material for conducting SNP/haplotype-based GWAS to identify genetic variants that can accelerate genetic gains in grain nutrient improvement.

Genetic variation in agronomic traits of Erianthus germplasm under multiple‐ratoon crops in Thailand

AbstractErianthus species have potential as breeding materials for sugarcane and as a biomass crop for fiber production. However, limited information about their genetic variation in agronomic traits hinders their practical utilization. Thus, in this study, we evaluated genetic variation and genetic correlations among 11 agronomic traits in plants grown as multiple‐ratoon crops (plant crop to the third ratoon crop) for 98 clones of E. arundinaceus and 32 clones of E. procerus collected across Thailand. Among the clones tested, large genetic variation was observed in the 4‐yr average, range, and genetic coefficient of variation of dry matter yield for both E. arundinaceus (12.1, 2.2 to 30.6 kg stool−1, and 41.7%, respectively) and E. procerus (8.0, 2.7 to 16.3 kg stool−1, and 25.5%, respectively). Many clones provided better dry matter yield and lower yield reductions in ratoon crops than a sugarcane cultivar (Saccharum spp. hybrid, 5.2 kg stool−1) and Napier grass (Pennisetum purpureum, 6.6 kg stool−1). Genetic variation was observed for stalk number, stalk length, stalk diameter, single stalk weight, Brix, dry matter content, and proportions of both pith and stem parts in stalks, which are important traits in sugarcane breeding. The dry matter yield showed the highest genetic correlation with stalk number (.958 in E. arundinaceus and .700 in E. procerus). Based on the results, clones with various combinations of advantageous traits were identified as promising genetic resources. These results provide important agronomic information that can be used to exploit this Erianthus germplasm for sugarcane improvement and fiber production in Thailand.

Evaluasi Galur-galur Padi Sawah Dihaploid Hasil Kultur Antera Menggunakan Seleksi Indeks

Plant breeders performed multi-trait selection using a suitable method, one of which is selection index. A multivariate analysis may be used for developing a selection index model. The objective of this experiment was to select doubled haploid rice lines with high yield potential and good agronomic characters based on the selection index. The experiment was carried out using a single factor completely randomized design with three replications, from August 2018 to December 2019. The study included 89 doubled haploid (DH) lines derived from anther culture as well as four check varieties (Ciherang, Inpari 30 Ciherang Sub1, Inpari 41, and Inpari 35 Agritan). Development of selection index model considered the results of analysis of variance, correlation analysis, path analysis, principal component analysis, and aimed plant ideotype. The findings revealed that there was variation in agronomic traits and yield among the DH lines tested. The selection index model can be formulated as I (index value) = 3*0.75 yield + 0.85 total grain per panicle – 0.85 plant height. Based on this model, 85 lines had index value and yield higher than Inpari 41. The selected DH lines were included in the subsequent field evaluation.&#x0D; Keywords: correlation, heritability, path analysis, variability

Intraspecific crosses and agronomic evaluation of hybrid progenies of bahiagrass

Paspalum notatum Flügge (bahiagrass) is one of the most common native grasses found in southern Brazil and have become one of the most promising forage species considering their value for beef cattle production in the tropics and subtropics. The breeding program has been possible through intraspecific hybridization among sexual and apomictic clones, generating progenies with variability for agronomic traits. Hybrid materials with superior agronomic performance can be selected, registered and protected to be made available as a commercial cultivar. The objective of this work was to evaluate 24 intraspecific hybrids and select them for the superior agronomic traits, as well analyze correlations between forage traits that can assist in the selection of genotypes. Based on the three years of evaluation, hybrids KD9, KF1, KF4, and KD5 produced higher total dry mass than other genotypes. The hybrid KF4 too had greater leaf dry matter; KF1 and KF4 were the more cold tolerant. These genotypes were selected for new cycles of hybridization and field evaluations, such as seed production, fertilizer use efficiency and animal performance. The high correlation of the total dry mass with the other forage components might be useful for indirect select criteria in bahiagrass improving strategies.