Good Combination Research Articles

Assessment of Combining Ability for Yield and Yield Contributing Traits in Rice (Oryza sativa L.)

The current study was carried out with an objective to study Combining ability studies for yield and yield contributing traits in Rice (Oryza sativa L.) to identify superior crosses for commercial cultivation after testing over years band locations. Rice production plays an integral role in the national economy of India and has the maximum share in grain production, accounting for 22% of the world’s rice production. Agricultural Polytechnic, Polasa, Jagtial, during Kharif, 2021 and Rabi, 2021-22. Where, crossing programme was carried out during Kharif, 2021 and evaluation of the crosses was taken up during Rabi, 2021-22. Twenty-four (24) experimental hybrids were developed using eight lines and three testers and randomized block design was utilized for the evaluation studies. The variance due to the crosses, variance due to the parent’s vs crosses were also found highly significant for all the characters. Lines, testers and line x tester effects, the interaction effects (lines x testers) were found to be significant for all the traits studied. This indicates that the material under investigation has adequate variability. The study revealed that the line, CMS 46B and KNM 7787 among the testers were identified as good general combiners for grain yield per plant while, JMS 18A x RNR 21278 were identified as best specific combiners for the trait.

EFFECT OF Q-P PROCESS PARAMETERS ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF SECURE 400 STEEL

SECURE 400 steel is used for basic ballistic protection of armoured vehicle chassis against the pressure energy of exploding mines, IEDs and grenades. It is a low-alloy high-strength steel with a manufacturer's declared hardness of 380 to 430 HB, which is characterized by a good combination of high strength and toughness. As standard, this steel is processed by quenching followed by tempering, but new possibilities for improving its mechanical properties are constantly being sought. A modern heat treatment process, the so-called Q-P process, leads to the formation of a multiphase structure, which positively influences the mechanical properties. Therefore, this paper focuses on describing the influence of Q-P process parameters on the development of the microstructure and mechanical properties. During the experimental program, it was found that the Q-P process increased the ultimate tensile strength by up to 300 MPa and increased the hardness by up to 68 HV10 compared to the post-delivery condition where tensile strength and hardness values of 1354 MPa and 438 HV10, corresponding to 414 HB, were measured. Redistribution of the carbon from the supersaturated martensite stabilised the austenite and a finer grained microstructure was achieved.

Combining ability studies in desi cotton (Gossypium arboreum L.) genotypes

BackgroundStudies on genetic variation and combining ability are essential tools to employ the suitable breeding programme, particularly for hybrid production, to exploit the heterosis in cross-pollinated crops like cotton. Thus, combining ability studies in desi cotton (Gossypium arboreum L.) was carried out using 13 diverse parents through diallel mating design, evaluating 78 F1 hybrids along with their parents, without reciprocals using Griffing’s and Hayman’s approaches.ResultsGenotypes H 509, AC 3265, AKH 496, and PBN 565 exhibited superior per se performance, indicating their potential use as parents in future breeding programs to develop superior hybrids. The general combining ability (GCA) effect of the genotypes revealed that AC 3097 and AKA 13-SP1 were good general combiners for most traits in this study. Genotypes PBS 1127-SP1, AKH 496, H 509, N11-54–31-32, and AKA 13-SP1 exhibited strong combining ability, contributing to a significant specific combining ability (SCA) effect in seven selected crosses (AC 3265 × PBS 1127-SP1, AKH 496 × H 509, AKH 496 × AC 3097, PBS 1127-SP1 × N11-54–31-32, AC 3216 × AKA 13-SP1, H 503 × N11-54–31-32, and H 509 × AKA 13-SP1) for yield improvement. These crosses showed positive heterosis in a positive direction.ConclusionFrom the present study, five genotypes (AC 3097, AKA 13-SP1, N11-54–31-32, AC 3265, and H 509) were identified as good general combiners for producing hybrids, and seven combinations showed a promising hybrid for future breeding programs.

Inheritance, heterosis and combining ability analysis in line × tester crosses of cotton

Abstract. The aim of this research was to study heterosis, combining ability and genetic control of most important traits in line × tester crosses. It was found that the non-additive variance (σ2D) was larger than the additive variance (σ2A) for productivity per plant and fiber length revealing the greater importance of non-additive gene action in the inheritance of both traits and the selection of desirable forms should be conducted in the later hybrid generations. Non-additive genetic variance was also more important for boll weight, whereas additive gene action was of greater importance for lint percentage and the selection for this trait can be effective in early segregated generations. Line 266 was identified as a good general combiner for productivity per plant and fiber length, line 346 for lint percentage and fiber length. The Turkish cultivar Nazili 954 can be used in crosses to improve productivity, while the Spanish cultivar FR-H-1001 can be used to increase lint percentage and fiber length. The hybrids 191 × Nazili 954 and 266 × FR-H-1001 exhibited the highest productivity per plant with high SCA effects and the highest heterosis of 30.7-31.7%. The highest lint percentage of 42.1-42.3% was achieved in hybrids from the crosses Nazili 954 × 266 and 346 × FR-H-1001 showing significant positive heterosis of 2.4 - 9.0%. Hybrids from the crosses FR-H-1001 × 266 and 346 × FR-H-1001 had the longest fiber and exhibited heterosis of 8.4% and 5.7%, respectively. The cross combination 346 × FR-H-1001 was very promising for lint percentage and fiber length showing high mean levels for both traits with high SCA effects and positive heterosis.

High strength‐ductility combination in low‐density dual phase high entropy alloys

High strength and good ductility combination make it appealing for advanced structural and functional applications. However, enhancing strength typically reduces ductility due to their inverse correlation. FCC, BCC, L12, and B2 phases are most commonly found in high-entropy alloys (HEAs), which are the subject of extensive research to tweak their mechanical properties. We present a systematic microstructure-oriented mechanical property investigation for a newly developed low-density dual-phase high entropy alloy (LDDP-HEA) with varying phase fractions. In this study, Al15Cu20Fe25Ni30Ti10 HEA was designed by phase formation rules and heat treated at 800, 900, and 1000 °C for 24 h, followed by water quenching to investigate phase stability and their effect on mechanical properties. A combination of FESEM, EBSD, EDS, XRD, microhardness, and compression tests were carried out to investigate the microstructural characteristics and mechanical properties of the HEAs. The LDDP-HEA exhibited an excellent combination of mechanical properties with a high yield strength of ∼1675 MPa, ultimate compressive strength of ∼2250 MPa, and elongation to fracture of ∼10 % in the as-cast condition. The strength and low density of the alloy lead to superior specific compressive yield strength of 240 MPa g−1 cm3 and 121.70 MPa g−1 cm3 in as-cast and heat treated at 1000 °C conditions, respectively.

Exposure the role of hydrogen with algae spirogyra biodiesel and fuel-borne additive on a diesel engine: An experimental assessment on dual fuel combustion mode

This investigation is focused on the study of the overall performance of a single-cylinder diesel engine with the use of 99.99 % pure elemental hydrogen (H2), as a gaseous fuel and algae Spirogyra biodiesel 30 % (SBD30) with 1.5 % Di-tert Butyl Peroxide (1.5%DTBP) as cetane improver and 2 % Algae Residual Carbon Nanoparticle (2%ARCNP). During the investigation, the hydrogen flow rate was controlled by an electronic gas injector and varied in the range of 5–20 lpm in the increment of 5 lpm. Among the fuel blends SBD30 + 1.5%DTBP+2%ARCNP+15H2 acted as a good combination to reduce ID and CD; and to boost HRR, BTE, and EGT. Additionally, this resulted in a drastic decline in the emission components such as HC, CO, and smoke. However, a surge in NO was observed for all the fuel sampled by the induction of H2. For SBD30 + 1.5%DTBP+2%ARCNP+15H2 a shorter ID and CD were observed at 7.2°CA and 34.5 °CA than diesel respectively at full load. The MCP for SBD30 + 1.5%DTBP+2%ARCNP+15H2 was 81 bar which occurred at 9.2°CA, however, the HRR was 61.3 J/°CA which was 1.2 % lower than that of 20 LPM hydrogen flow rate, at full load respectively. By using hydrogen + DTBP + ARCNP, the BSFC was overall lower by about 22 % and the BTE was improved by about 36.1 %. The CO, HC, and smoke for SBD30 + 1.5%DTBP+2%ARCNP+15H2 was 64.8 %, 38.8 %, and 29.2 % lower than diesel however, the NO emission was 32.6 % higher than diesel at full load respectively.

Breeding Brassica juncea hybrids with higher seed weight and oil content: Defining criteria for selection of parents

Most of the released high-yielding hybrids of Brassica juncea have a low 1000-seed weight (TSW) with no increment in the percent oil content (OC), and, therefore, these hybrids have poor acceptance among the farmers in India. It is, thus, imperative to understand the genetic basis of these traits and deploy them in commercial hybrid breeding programs. The present study utilized a set of 15 diverse B. juncea genotypes with TSW and OC ranging from 1.32 to 8.26 g and 31.93–43.39 %, respectively, to generate 210 hybrids following a full diallel mating scheme. These hybrids along with their parents, were evaluated in three different environments. Inheritance of TSW suggests the predominance of additive gene action, whereas non-additive gene action was observed to regulate OC. Further, TSW and OC were reported to be influenced by maternal and non-maternal effects, respectively. Parents with bold seeds viz., NPJ 253, RH 761 and EC 223389 were identified as good general combiners for both the traits. Hybrid generated from the cross NPJ 253 x NPJ 161, with both parents having high seed weights, exhibited the highest mean values (8.43 g) and heterobeltiosis (17.2 %) for TSW. Whereas, hybrid between parents NPJ 253 and IC 426372, possessing high and low seed weights, respectively, observed the highest mean value (44.95 %) and heterobeltiosis (14.89 %) for OC. Keeping both TSW and OC together, hybrids viz., NPJ 253 x EC 223389 (H1), NPJ 253 x NPJ 161 (H2) and NPJ 253 x Pusa Tarak (H4) were identified as promising using the Multi-trait Genotype-Ideotype Distance Index. Lines with higher TSW and better combining ability for OC shall be converted to male and/or female lines for generating commercial hybrids. The scheme for deploying higher seed weight and improved oil content in B. juncea hybrids is discussed.

Extrusion-Based Additive Manufacturing of WC-10Co Cemented Carbide Produced with Bimodal Ultrafine/Micron WC Particles

This article researches the effect of ultrafine (submicron) tungsten carbide powder addition on the microstructure and mechanical properties of WC-10Co cemented carbide produced by the extrusion of a highly filled polymer. This addition aims to develop a material with a good combination of toughness, hardness, and yield strength. The results demonstrate that increasing the ratio between ultrafine and micron WC particles from 0/100 to 45/55 in the initial powder results in successive decreases in average grain size from 2.61 µm to 1.75 µm. When 45% of ultrafine powder is introduced into the mixture, a high number of fine tungsten carbide grains is produced. This promotes inter-grain contact and reduces the free path of the binder phase, which results in a more rigid structure and in the material becoming more brittle. The best mechanical characteristics are achieved in WC-10Co cemented carbide with 15% content of ultrafine powder in the total weight of WC. Here, a microstructure with a bimodal distribution of tungsten carbide grains in a virtually non-intermittent cobalt phase was formed. This allowed us to achieve a compressive strength of 2449 MPa at the deformation of 6.69%, while the modulus of elasticity was 38.8 GPa. The results indicate a good combination of strength and ductility properties in the developed cemented carbide.

Investigation on tensile property and mechanism of partially recrystallized Al0.1CoCrFeNi high-entropy alloy after cold rolling and annealing treatment

Processing partially recrystallized microstructure has been proved effective to improve tensile property in high-entropy alloys (HEAs), however, a systematic understanding about the relation among processing parameter, partially recrystallized microstructure and tensile behavior is lacking. Here, five types of recrystallized fractions, 12.5 %, 45.7 %, 77.4 %, 87.0 % and 100 %, were obtained after cold rolling and annealing at 600 °C for 1 h, 3 h, 6 h, 12 h and 120 h in Al0.1CoCrFeNi HEA. All partially recrystallized structures were comprised of non-recrystallized region with strong {111} <112> texture and recrystallized region with a nearly similar scale of fine grain (∼1.22–1.57 μm). The partially recrystallized specimens exhibited a good strength-ductility combination, i.e., yield strength increased from ∼547.1 MPa to ∼881.0 MPa with decreasing recrystallized fractions, while ductility still remained above ∼20 %. Based on the law of mixtures, the calculated results of the contributions from multiple strengthening mechanisms to yield strength closely matched the experimental data. It is found that increasing recrystallized fraction leads to enhancing contribution of grain boundary strengthening but weakening contribution of dislocation strengthening and synergistic strengthening. TEM results revealed that plastic deformation in partially recrystallized specimens was dominated by high-density dislocations and deformation twins in grain interior, as well as dislocation planar slip and pile-up near heterogeneous interface; for comparison, dislocation cells and more deformation twins were formed in fully recrystallized specimens.

Development of Faba Bean Genotypes for Broomrape Tolerant and Foliar Diseases Resistance in F\(_2\) Factorial Crosses

Two field experiments were conducted at Sakha Agricultural Research Station, Kafr El-Sheikh, Egypt. The first experiment was in a naturally Orobanche- free field and the second one was in a naturally Orobanche-infested field. In each experiment sixteen F2 crosses and their parents were sown. The sixteen F2 crosses were produced by a 4 x 4 factorial mating design in F1 and selfed to give F2-crosses. The data were then analyzed using a line x tester design. The main objective of this study was to develop new promising faba bean genotypes that are able to produce high yield, resistance to foliar diseases and broomrape tolerance. Significant differences among all genotypes mean square were observed for all studied traits under both growth conditions. The parents, crosses and their interaction mean squares were detected for all traits in the two environments. The mean squares of lines were significant and/or highly significant for flowering date and 100-seed weight under both conditions, while number of pods per plant was significant under normal condition, in addition to the number of seeds per plant and broomrape dry weight per plant under infested broomrape condition were significant and highly significant, respectively. Mean squares of testers were significant for chocolate spot at the two conditions; rust disease, plant height, number of pods and seeds, seed yield per plant and 100-seed weight under normal condition. Lines x testers mean squares were significant for all traits in both conditions, except for number of branches and 100-seed weight. L1 and L4 and the parental testers T4 were considered more resistance parents to foliar diseases under both environments. The crosses; L2 x T3, L2 xT4, L3 x T2, L3 x T4 and L4 x T4 were considered resistant to foliar disease and had an earlier flowering date. The testers, T3 and T4 showed significantly the highest values of number of seeds per plant, seed yield per plant and 100-seed weight under both conditions, while the crosses; L3 x T4 and L4 x T4 had the highest values for seed yield per plant and 100-seed weight under both conditions. The parental L2 and T4 were considered good combiners for chocolate spot and rust diseases under both environmental conditions, while L1 and T4 performed as good combiner parents for number of seeds and seed yield per plant. The cross; L2x T3 performed as good specific combiner cross for foliar diseases under both conditions. The crosses; L2x T3, L3xT4, L3 x T1and L4 x T4 had highly significant (sij) values for the No. of seeds and seed yield per plant under infested soil condition. The phenotypic coefficient of variation (PCV) values ranged from 5.52% to 84.01% and genotypic coefficient of variation (GCV) values ranged from 3.18% to 79.21%. Broad-sense heritability (H) ranged from 72.98% to 99.29%, and narrow sense heritability (h2) ranged from 2.3% to 21.38%. Expected genetic advance (Ga) ranged from 0.03 to 0.71, and predicted genetic advance (Ga%) ranged from 8.21% to 10.86%.

Identification of Best General and Specific Combiners for Soybean Improvement

The present study on general combining ability effects and specific combining ability effects involves 15 parents viz., lines RKS 18, RKS 113, AUKS 199, AUKS 200, AUKS 212, RVSM 2011-35, JS 20-98, AUKS 202, AUKS 208, AUKS 218, JS 21-72, NRC 165 and tester JS 20-34, NRC 138, SL 958 with their 36 F1 hybrid through Line x Tester mating system. The present investigation was undertaken using Randomized Block Design with three replications. The combining ability effects were estimated for thirteen characters viz., days to 50% flowering, days to maturity, plant height, number of branches per plant, number of pods per plant, pod length, number of seeds per pod, 100-Seed weight, seed yield per plant, biological yield per plant, harvest index, protein content and oil content. The result showed that gca effects of parents and sca effects of hybrids were significant differed. Among the parents, AUKS 212 was found to be good general combiner based on the per se performance and gca effects for seed yield and other contributing traits and four hybrids AUKS 113 x SL 958, RVSM 2011-35 x NRC 138, AUKS 199 x JS 20-34 and NRC 165 x JS 20-34 were superior high sca effects for seed yield and yield contributing traits. These crosses can be utilized in future breeding programmes and exploitation of better segregants through pedigree method or single seed descent method in advance generations for improvement of yield and yield attributes coupled with quality traits sound soybean genotypes.

Genetic Analysis of Yield, Protein, and Oil Traits in Soybean Diallel Crosses for Enhanced Crop Quality and Productivity

The study was conducted at Sakha Research Station, ARC, Egypt, during three successive seasons from 2021 to 2023. A half diallel cross of fifteen F1 and F2 generations in addition to the six soybean parental genotypes namely, Japanese 13, Giza 111, Crawford, H18L54, Nc92-2231 and Linford were evaluated to determine the genetic behavior of yield and its components traits in both F1 and F2 generations, as well as seed protein and oil contents in F1. Results indicated that mean squares of General Combining Ability (GCA) and Specific Combining Ability (SCA) were significant and highly significant for all the studied characters of soybean genotypes in F1’s and F2’s, except SCA for 100-seed weight in F2’s only. The GCA/SCA ratios were less than unity in all traits, indicating that, the non-additive gene effects seemed to be responsible for the inheritance of these traits. The parental genotypes; H18L54, Nc 92-2231 and Linford seemed to be excellent combiners for days to flowering and maturity; however, Giza 111 and Japanese 13 were good combiners for seed yield. Meanwhile, Giza 111 was a good combiner for protein and oil content; also, H18L54 and Nc 92-2231 were good combiners for protein content. The crosses C7, C9, C10, C11 and C13 were earlier for maturity date, and also showed the most negative significant desirable Ŝij effects. The best (Ŝij) values in F2 were shown in the C1, C5, C8 and C15 crosses for seed yield/plant, these crosses also had the highest seed yield values in F2. The crosses; C5 and C8 showed significant to highly significant positive heterotic effects relative to the better parent for protein% and seed yield per plant. In addition three crosses; C13, C14, and C15 had highly significant positive heterotic effects relative to the better parent for oil % and seed yield per plant.

Assessment of Combining Ability and Heterosis for Seed Yield and its Attributes in Sunflower (Helianthus annuus L.)

The present study employed three lines and fifteen testers to assess the combining ability and standard heterosis of forty-five hybrids developed through a line × tester mating design. The analysis of variance for combining ability revealed significant variation in the mean sum of squares of parents, testers and the interaction between lines and testers regarding seed yield per plant and its related traits. Among the parents, testers GMU 498 and RHA 378 exhibited superior performance for seed yield/plant. In the hybrids, COSF 6A×CSFI 1862, HA 89A×GMU 1000 and HA 89A×RHA 378 demonstrated significantly better seed yield per plant compared to the checks. The variance for specific combining ability (SCA) exceeded that for general combining ability (GCA), indicating that all traits were governed by non-additive gene action. Among the lines, COSF 12A was identified as a good general combiner for yield-contributing traits, while the testers CSFI 1862, GMU 1000 and GMU 498 were recognized as good general combiners for seed yield per plant. Five hybrids, namely HA 89A × RHA 378, HA 89A × GMU 1000, COSF 12A × CSFI 1855, COSF 6A × CSFI 1862 and COSF 12A × GMU 311, exhibited significantly positive SCA for seed yield per plant. Heterosis over the standard checks (DRSH 1, COH 3 and GK 2002) was estimated and the hybrids HA 89A × GMU 1000 and COSF 6A × CSFI 1862 showed positive significant heterosis for seed yield per plant and related traits. The promising hybrids HA 89A × GMU 1000, HA 89A × RHA 378 and COSF 6A × CSFI 1862 were selected based on their mean performance, SCA effects and standard heterosis for seed yield per plant and its attributes.

Effect of Co content on microstructure and properties of TiCN-TiB2 cermets prepared by spark plasma sintering from a TiCN-B4C-Ti-Co system

Series of TiCN-TiB2 cermets were in situ prepared from the TiCN-B4C-Ti-Co system via spark plasma sintering (SPS). The effects of Co content on the densification, microstructure, mechanical properties, and wear resistance of TiCN-TiB2 cermets were investigated. The results showed that the Co addition had little effect on the phase composition of the sintered cermets, but had significant influences on the densification, microstructure and mechanical properties. Appropriate addition of metal Co could enhance densification and promote the grain growth of ceramic phases, but excessive addition resulted in a decrease in hardness and wear resistance. When the Co content was 10 wt.%, the cermet obtained the optimal comprehensive performance (a hardness of 1757 HV and a fracture toughness of 7.02 MPa•m1/2). Meanwhile, the cermets with 10 wt.% Co addition exhibited optimum wear resistance properties due to a good combination of hardness and toughness and moderate grain size. In addition, the formation process and strengthening mechanism in present system were discussed in detail. Results from this work could provide valuable references for the fabrication of TiB2 reinforced TiCN-based cermets.

Deformation behavior of harmonic structure designed CoCrFeMnNi HE alloys

This paper presents the deformation behavior of CoCrFeMnNi high-entropy alloy (HEA) produced from plastically undeformed and deformed powders. The investigation commenced with the preparation of ball-milled HEA powder at 90ks and 180ks, with a ball-to-powder ratio of 2:1, to induce severe plastic deformation on the outer layer of the HEA powder. Subsequently, the plastically undeformed and deformed HEA powders were successfully consolidated in a spark plasma sintering (SPS) furnace. The SEM observations revealed that the sintered plastically undeformed HEA powder exhibited conventional homogeneous microstructures (Homo), while sintered deformed HEA powders exhibited a regulated bimodal grain distribution known as harmonic structure (HS). The mechanical properties of the materials were characterized by performing tensile tests at room temperature (RT) and a low temperature of 193 K. The HS HEA exhibited an increase in proof strength of 16%–40%, while the ultimate tensile strength (UTS) increased by 8%–20% compared to the Homo HEA. Moreover, the strain hardening rate (SHR) curve indicates that both Homo and HS HEA exhibited oscillatory behavior at low temperature. However, Homo HEA exhibited more pronounced oscillation than HS HEA. The current results indicate that oscillatory behavior in the SHR curve is indicative of twin deformation. At low temperatures, the high rate of twinning deformation in Homo HEA was attributed to its higher ductility, while a good combination of high strength and high ductility produced by HS material was found to be influenced by HS design in addition to twinning deformation.

Computational analysis for fractional model of coupled Whitham-Broer-Kaup equation

In this research paper, we study a semi analytical technique to solve the nonlinear partial differential equations. This technique is good combination of homotopy analysis method with Kharrat-Toma transform. Also, we present the numerical solution of nonlinear fractional coupled Whitham-Broer-Kaup equation using studied technique. The Whitham-Broer-Kaup model is broadly considered to study the tsunami wave dynamics under gravity. The regularized version of Hilfer-Prabhakar fractional derivative is used to model the problem. Some qualitative properties, existence and uniqueness of the considered model and its solution are also discussed.The obtained solutions are presented graphically to show the efficiency of studied technique. Error analysis tables are also given to demonstrate the accuracy of obtained results.

Optimization the selection of lint percentage and fiber length in cotton based on the combining effects of parental forms

Forty F1 crosses obtained from 5 × 8 line by tester mating design methodology were studied. The varieties Chirpan-539, Sirius, Darmi (Bulgarian selection), Nazili 954 (Turkish) and FR-H-1002 (Spanish) were used as female parents, selection lines 449, 489, 639, 535, 550, 572, 578 and 678 were used as male parents. The aim of the study was to identify the best F1 crosses for improving lint percentage and fiber length in new cotton varieties, by applying a new approach to select parents with the highest possible general combining ability (GCA) for both traits. Crosses and their parents were sown in one row, randomized in three replications. The highest values of the GCA effects of the two parental forms for each trait were taken as “ideal” and the Euclidean distances between them and the GCA effects of the two parents for each F1 cross were calculated. Combining ability analysis of variance showed that females and males differed in general and specific combining abilities. The cultivars Chirpan-539 and Nazili-954 from the females, and lines 550 (Tiara variety) and 578, from the males, appeared to be very good general combiners for lint percentage. The cultivar FR-H-1002 and Darmi variety, from the females, and lines 449, 572, and 578, from the males, appeared to be very good general combiners for fiber length. Some crosses showed high positive SCA effects and heterosis for both traits. Cross combinations FR-H-1002 × 578, Darmi × 578 and Nazili 954 × 578 had the highest possible GCA for both studied traits and are most valuable for selection programs. A total of seven crosses with short Euclidean distances to the “ideal” population in which desirable segregates are expected to occur were selected.

Optimizing toughness in high entropy alloys using a genetic algorithm: A combined computational and experimental approach

A genetic algorithm (GA) was developed to search for high entropy alloys (HEAs) with good combinations of mechanical properties. The algorithm was designed find single-phase face-centered cubic (FCC) HEAs, already known for their ductility, with high Hall-Petch constants (K) and high critical resolved shear stresses (τY). The objective was to develop a methodology that allows the design of HEAs in a multi-objective environment, focusing on alloys that exhibit enhanced ductility and strength, achieved through an increase in its yield point without significant loss of its ultimate deformation via adjustments of K and τY values, resulting in an alloy with high toughness. The most promising alloy suggested by the genetic algorithm was an unconventional composition (Co32.73Cu15.11Fe0.72Hf0.72Mn35.97Mo3.96Ni10.43Sn0.36), with eight different elements in non-equiatomic ratios with maximized K and τY values. This alloy was then experimentally produced and characterized by scanning electron microscopy (SEM), synchrotron x-ray diffraction (XRD), transmission electron microscopy (TEM) and microhardness, with the objective of validating the predictions made by the GA. An advantage of the proposed method is the possibility of more systematically identifying and exploring new compositions in the complex composition space characteristic of these multicomponent alloys, as it directs its search towards domains that can be used to solve challenging problems involving multi-objective optimization. However, the thermodynamic parameters used for single-phase FCC prediction, namely the valence electron concentration (VEC) and the dimensionless thermodynamic parameter φ, exhibited limitations. These limitations were further explored in the present study, as evidenced by the fact that the microstructure of the selected alloy was not single-phase, which hindered the study of the mechanical properties, predicted exclusively for monophasic FCC alloys. Therefore, this work highlights the necessity for the development of novel thermodynamic equations for phase prediction, or even the integration of the genetic algorithm with other methodologies, such as CALPHAD calculations, to achieve enhanced results.

Combining Ability and Heterosis Analysis in Maize: Insights from Line × Tester Hybridization

Fifty hybrids were obtained by crossing twenty five lines with two testers and were evaluated to study heterosis and combining ability for kernel yield per plant and its components traits. The experiment was laid out in simple lattice design with two replications during kharif 2019 at Agricultural Research Station, Peddapuram, East Godavari District, Andhra Pradesh. Heterosis studies revealed that twelve out of fifty crosses exhibited significant positive heterosis over the mid-parent, five crosses showed significant positive heterosis over the better parent and one cross exhibited significant positive heterosis over the standard check, DHM117, for kernel yield per plant. The cross PDM1732 × BML6 recorded significant heterosis over mid parent, better parent and standard check in desirable direction for kernel yield per plant. Out of the 25 lines evaluated in the present investigation, the line PDM1733 for protein content and kernel yield per plant was found to be good general combiner in desirable direction and can be utilized as parent for production of good hybrids by crossing with other divergent lines and can also be employed in the development of synthetic varieties. None of the fifty crosses recorded significant sca effect for kernel yield per plant.

Genetic Diversity of Maize (Zea mays L.) Genotypes under Low Level of Nitrogen

Maize (Zea mays L.) is India's second most significant crop, behind rice. As a cross-pollinated crop, hybrid vigour is commonly used to achieve the best production potential. The selection of various genotypes is a primary goal in the maize hybrid breeding programme. Maize is a voracious feeder and requires a lot of fertiliser. The biggest limits on maize production in India are low soil nitrogen and high fertiliser costs. Jharkhand consumes only 82.5 kg of total fertiliser nutrients per acre. In order to discover genetically varied maize genotypes for nitrogen usage efficiency, the current study evaluated 121 maize genotypes in a randomised block design with two replications at low nitrogen levels. Plant height, days to 50% pollen shed, days to 50% silk, anthesis-silking interval (ASI), days to75% maturity, number of leaves per plant, root length, stover yield per plant, grain yield per plant, and harvest index were all recorded. Statistical analysis was performed using the morphological trait data. Analysis of variance revealed substantial (p≤0.05) variations in morphological features between maize genotypes. For statistical analysis, a clustering method was used to locate various genotypes with greater genetic distance in order to develop good heterotic combinations. One hundred twenty one genotypes were divided into six clusters using the dendogram-by-ward minimum variance approach. Cluster III and V had the greatest inter-cluster distance (79.26), followed by cluster III and VI (74.77) and cluster II and III (73.80). The many heterotic combinations developed from these clusters can be employed in subsequent breeding programmes to produce low nitrogen-requiring hybrids with a low yield penalty.