Correlation Of Grain Yield Research Articles

ASSESSMENT OF WHEAT GENOTYPES FOR THEIR LOW NITROGEN USE EFFICIENCY UNDER SEMI-ARID CONDITIONS OF PUNJAB, PAKISTAN

Nitrogen is one of the most important and critical macronutrients needed by plants for their optimal growth and development. The current experimental study was designed to examine the response of wheat variety Akbar-2019 under different nitrogen levels keeping the levels of phosphorus and potassium constant. The study was conducted in Chak No. 169/7.R Fort Abbas, District Bahawalnagar under the supervision of the Department of Soil Fertility (Field) during the crop year 2022-23. The experimental material was comprised of a wheat variety Akbar-2019 and five different treatments of nitrogen consisted of (i) N = 160 kg ha-1 (ii) N = 145 kg ha-1 (iii) N = 131 kg ha-1 (iv) N = 117 kg ha-1 and (v) N = 103 kg ha-1. The experiment was laid out under a randomized complete block design with three replications and 170 m² net plot size par treatment per replication. The results revealed the presence of highly significant variations among nitrogen treatments in wheat variety based on the agronomic and morpho-physiological parameters including flag leaf area, thousand-grain weight, grains per spike, relative water contents, stomatal conductance, net photosynthetic rate, biological yield and gain yield. Furthermore, the results also unveiled that treatments with higher nitrogen dosage produce better results for almost all the study parameters including grain yield. These results were also confirmed through correlation coefficient analysis and bar graph graphical representation based on mean data, where correlation coefficient analysis showed a strong positive correlation of grain yield with studied plant traits except biological yield for which the correlation was positive but non-significant. The results suggest that nitrogen in higher amounts up to a certain level is necessary for obtaining maximum output from wheat crops under semi-arid conditions.

Understanding of G × E interactions of yield attributes in soybean MAGIC population and characterization for charcoal rot resistance

AbstractMulti‐parent advanced generation inter‐cross (MAGIC) populations have been developed and utilized in crop improvement programs in several economically important crops. In the current study, soybean (Glycine max L.) MAGIC population was evaluated at four locations to identify stable and high‐yielding MAGIC RILs (recombinant inbred lines) and to understand the genotype and environmental interaction for grain yield and attributing traits. For different traits under study, pooled analysis of variance indicated the significant genotype × environmental interactions at p < 0.01. RILs such as G236, G455, G159, G493, and G488 found ideal for grain yield across the four environments. Through multi‐trait genotype‐ideotype distance index ideotype‐MAGIC RILs have been identified for each location. Significant positive correlation of grain yield with pods per plant, 100‐seed weight, plant height, number of nodes per plant, and branches per plant has been identified. Under field conditions, screening of F2:3 generation of MAGIC population revealed that only 59 progenies exhibited adult plant resistance for charcoal rot disease (caused by Macrophomina phaseolina). Although under controlled conditions parental genotypes EC 572136 and EC 572109 found to be partially resistant with least mean necrosis length, MAGIC RILs (F2:8) showed variable reaction. Thus, the study established diverse genetic resources useful for both mapping and varietal development program.

Character Association Studies for Yield, Nutritional and Cooking Quality Characters in Coloured Rice (Oryza sativa L.)

In the present study 35 coloured rice genotypes along with three checks were evaluated in Randomized Complete Block Design for yield, nutritional and cooking quality traits to study association between the yield, nutritional and cooking quality traits. Correlation studies showed positive and significant correlation of grain yield per plant with yield contributing characters like ear bearing tillers per plant, panicle length, test weight, number of filled grains per panicle and some nutritional characters like protein content and anthocyanin content. The path analysis revealed that traits like ear bearing tillers per panicle, test weight, number of filled grains per panicle, alkali spreading value and anthocyanin content showed not only positive direct effect but also positive correlation with grain yield suggesting the importance of direct selection for above characters. The residual effect in the present study was 0.3696 and 0.2348 at phenotypic and genotypic levels respectively, indicating that the characters included in the present study clearly explained the direct and indirect effects on the dependent variable to some extent.

Agro-morphological analysis of yield and yield attributing traits of wheat under heat stress condition

Wheat is the most important cereal crop worldwide and ranks third in Nepal. Improvements in wheat yield can be done effectively by selection for yield attributing traits. In this experiment, twenty wheat genotypes were evaluated in the terai region of Nepal at Paklihawa, Rupandehi in Alpha lattice design under heat stress conditions. The characters were evaluated to find their correlation and direct and indirect effects on yield. Positive significant correlation of grain yield with No. of spikes m-2 (0.405) and harvest index (0.647) were found whereas Spike weight (-0.322) showed a significant negative correlation with grain yield. Similarly, Path analysis showed that the Harvest index (0.5511) and No. of spikelets per spike (0.3365) had a high direct effect, whereas Thousand kernel weight, Spike m-2, and Plant height showed a lower positive direct effect on grain yield. Ten spikes weight, spike length, and No. of grains per spike showed low negative direct effects. The conclusions drawn from this analysis can be useful for breeding programs under heat stress by providing information on which characteristics significantly affect the yield. However, multi-locations and multi-year trials need to be done for further verifications on the selection of such traits for improving yield.

Heritability, Genetic Advance and Correlation Analysis for Grain Yield and Yield Components of Chickpea (Cicer arietinum L.)

The experiment was performed to evaluate heritability, genetic advance and genetic correlation for grain yield and its components, in F1 populations by line x tester fashion. The results showed that most traits demonstrated high heritability, except for days to maturity (49%), which displayed moderate heritability. The traits like pods per plant (2.848), 100 seed weight (2.772), number of nodules per plant (2.529), grain yield per plant (3.081) and harvest index (3.786) exhibited a significant genetic advance. Grain yield exhibited positive and significant genetic correlations with pods per plant (0.878), root length (0.878), 100 seed weight (0.929), number of nodules per plant (0.913), and harvest index (0.964) but negative correlations with traits like days to maturity (-0.492) and plant height (-0.266). Correlated response analysis highlighted traits that positively influenced grain yield and suggested indirect selection or index selection for improvement.

Evaluation of Germplasm for Reproductive Stage Salinity Tolerance in Rice (Oryza sativa L.)

The current study was carried out to identify salt tolerant genotypes by screening 76 rice germplasm at reproductive stage salinity stress. The test entries were subjected to salt stress under field conditions and salinity was noted at different intervals of crop growth period i.e., 30 and 67 days after sowing and at the time of harvesting with the pH value of 5.4 and electrical conductivity of 4.3 dSm-1, 5.3 dSm-1and 7.2 dSm-1 respectively. The characters namely, salinity score, days to 50 percent flowering, plant height, panicle length, productive tillers/plant, number of filled grains/panicle, total number of grains/panicle, spikelet fertility and grain yield/plant were studied under saline conditions. Variability, heritability and genetic advance as percent of mean showed high genotypic and phenotypic coefficient of variation for grain yield plant-1indicating the presence of considerable amount of variation among the genotypes for potential yield improvement through selection. The trait grain yield per plant had high heritability coupled with high genetic advance as percent of mean indicating that it is regulated by additive gene action and therefore selection could be practiced based on phenotypic performance. Association studies under saline conditions, revealed favorable and significant correlation of grain yield per plant with days to 50% flowering, panicle length, plant height, total number of grains per panicle, number of filled grains per panicle and productive tillers per plant whereas, spikelet fertility and plant height on the other hand, recorded negative non-significant correlation, indicating the undesirable causes of salinity on plant growth and yield potential.

ESTIMATION OF HERITABILITY, GENOTYPIC VARIABILITY AND CORRELATIONS ANALYSIS FOR YIELD AND YIELD ATTRIBUTING TRAITS AMONG BREAD WHEAT (Triticum aestivum L.) GENOTYPES

To find out genetic variability, heritability, and trait association among yield and yield-related traits among bread wheat genotypes, an alpha lattice design was used in triplicate manner where 50 wheat genotypes were evaluated at the University of Agriculture Peshawar during rabbi growing season 2021-22 along with a regional check genotype. Data were taken on ten parameters. All the genotypes showed significant variation among them, signifying the possibility of enhancing genetic improvement through breeding programs. Highly significant differences were found in days to heading, days to maturity, plant height, spike length, grain filling duration, number of grains per spike, biological yield and grain yield these traits indicating diversity in yield potential. Moderate to low heritability values were noted for most of the traits. The study exhibits positive correlations for plant height with grain yield, spike length with biological yield, and harvest index with grain yield. On the basis of high heritability and positive correlation of grain yield with other traits, it is recommended that G-41, G-3, G-12, G-37, G-34 and G-14 genotypes which have the potential to be incorporate in further breeding programs.

Genetic analysis of tolerance to combined drought and heat stress in tropical maize.

Simultaneous occurrences of heat and drought stresses have a detrimental effect on growth, development and yield of maize. Heat and drought is expected to worsen maize yield losses under climate change. Selecting CDHS tolerant maize hybrids creates great opportunity for sustainable maize improvement in the tropics. The objective of current investigation was to dissect the genetic basis of CDHS tolerance in tropical maize and to determine performance of single cross hybrids under CDHS. Ninety six single-cross hybrids resulted from crossing 12 tassel blast tolerant and 12 tassel blast susceptible lines along with two Striga resistant commercial hybrids, a heat tolerant and a heat susceptible check hybrids were evaluated under FIRR, MDRTS and CDHS using 25x4 alpha lattice design with two replications. The results showed significant genetic variation for FIRR, MDRTS and CDHS tolerance among maize hybrids. The majority of single crosses that showed improved grain yield over their respective standard checks under MDRTS also exhibited improved grain yield over the same checks under CHDS, indicating development of CHDS tolerance hybrids. Significant and positive genotypic and phenotypic correlation of grain yield under MDRTS and CDHS implicated common genetic mechanisms controlling yield under MDRTS and CDHS. Stress tolerance indices YI, GMP, MP, HM and STI were identified as best selecting indices under both stresses. GCA variances were larger than SCA variances in each testing environment for most studied traits indicating the impotence of additive gene action than non-additive gene action to control these traits. Majority of stress indices and SCA effects demonstrated that hybrids HB18, HB41, HB91 and HB95 were high yielder under MDRTS and CDHS. Hybrids HB41, HB91 and HB95 and their parents' scored minimum tassel blast. Parents 19 and 7 were well general combiner for grain yield and early maturity under MDRTS and CDHS indicting their valuable source of genes for hybridization. The current findings revealed that CDHS tolerance hybrids can reduce expected yield losses and maintain maize productivity in CDHS prone areas. Promising hybrids should be tested further under various drought and CHDS for commercialization.

MORPHOMETRIC, PHYSIOLOGICAL AND BIOCHEMICAL CHARACTRIZATION OF LOCAL AND EXOTIC MAIZE HYBRID UNDER HEAT AND WATER-STRESS STRESS CONDITIONS AT POST-ANTHESIS STAGE

The research project was carried out at the Maize and Millets Research Institute in Yusafwala-Sahiwal during the crop season of 2022) using a split-plot design. The present investigation explored the effects of individual and combined effects of water stress and heat stresses on morpho-phenological, physiological and biochemical traits in eight local (YH-5482, YH-5427, YH-5407, FH-1046, YH-5399, JPL-1908, SB-9663 and YH-1898) and two exotic maize hybrids (NK-8441 and P-1543). Significant variations were observed among maize hybrids under discrete and shared effects of water stress and heat stresses for key morphometric and other agronomically important, grain-related traits. Correlation analysis exposed strong positive correlation of grain yield with SPAD value (r= 0.88**), Proline (r= 0.79**), transpiration rate (r= 0.78**), superoxide dismutase (r= 0.73**), stomatal conductance (r= 0.72**) while negatively correlated with hydrogen peroxide (r= -0.87**). Cluster analysis grouped local and exotic maize hybrids into three groups under stress conditions and exposed that local maize genotypes/hybrids, predominantly YH-5427, YH-5482 and YH-5395 were the maximum stress tolerance under individual as well as combined heat + water-stress conditions.

Skipping irrigation at pre- and post-anthesis stages influences grain yield and starch contents of bread wheat derived from synthetic or landraces

This study aims to evaluate the role of genetic diversity originated from three-way crosses of landraces and synthetic bread wheat derivatives attempted with elite cultivars to identify the genotypes having better grain yield as well as better starch contents under flowering stage drought stress. In total, 50 genotypes comprised of 47 derivatives of landraces and synthetics, and three standard varieties were grown in the fields of CIMMYT, Obregon following alpha lattice design with two replications. Drought stress was imposed by stopping the irrigation before anthesis and post-anthesis stages. Different traits related to physiological adaptations, earliness, grain yield and starch contents were decreased under drought stress except amylose which increased significantly. Canopy temperature depression was not significantly affected by drought stress. Further, we identified strong correlation of grain yield with plant height, normalized difference in vegetation index, plant maturity, spike length, grain number and thousand grain weight but negative with canopy temperature depression. Non-significant correlation of amylose and amylopectin was recorded with grain yield. Results revealed that genetic diversity derived from landraces and synthetic bread wheat can improve grain yield and starch contents but simultaneous improvement of both is elusive.

Acidity and nutrient management practices for enhancing soil nutrient availability, nutrient uptake and grain yield of rice in Vaikom kari soils in Kuttanad, Kerala

A field investigation was conducted during August to December 2015 and 2016 in farmers` fields in Thalayazham panchayat in Kottayam district. The experiment was laid out in randomized block design having 16 treatments in three replications with rice (Oryza sativa L.) var. Uma. The treatments were dolomite, lime + MgSO4 or RHA (rice husk ash) + MgSO4 along with 100% package of practice (POP) alone or with 100% POP + foliar spray of 13-0-45 N-P-K (KNO3) (1%) or borax (0.5%) or 13-0-45 + borax at PI (panicle initiation) stage. Lime + MgSO4 + 75% POP + 13-0-45 + borax as well as lime without MgSO4 + 100% POP combined with 13-0-45 or borax or both were also included as treatments. Higher grain yield of 5.42 and 5.57 t ha-1 during 2015 and 2016 respectively were produced by dolomite + POP + 13-0-45 followed by dolomite + POP + 13-0-45 + borax and lime + POP + MgSO4 + 13-0-45. The treatments involving dolomite and lime with or without MgSO4 produced taller plants, higher tiller number m-2 and higher Leaf Area Index during both the years. Dolomite + POP + 13-0-45 produced the highest number of panicles m-2. Higher test weight and lower percentage of unfilled grains were observed with dolomite + POP + 13-0-45 and dolomite + POP + 13-0-45 + borax. Lime and dolomite treatments were more effective in reducing soil acidity and improving dehydrogenase activity and nutrient availability in the soil than RHA treatments during both the years. However, the effect of liming materials applied as basal and at 30 DAS diminishes after the crop and this necessitates application of liming materials in every crop season. Availability of soil N improved by treatments involving lime + POP without MgSO4 at PI and harvest stages. The treatments involving dolomite + POP and lime + POP with or without MgSO4 recorded higher available P during PI stage. In general, higher status of available K was registered by the treatments involving dolomite or lime application and lower K status registered by the treatment with 75% POP fertilizer. All treatments involving lime or dolomite registered higher soil available Ca and those involving dolomite or lime + MgSO4 showed higher availability of Mg in the soil. The treatments involving dolomite registered lower status of soil available Fe and higher status of available B. Higher status of available Zn was registered by the treatments involving dolomite or lime + MgSO4. Soil pH was significantly and positively correlated with available P, Ca and Mg and significantly and negatively correlated with available Fe in the soil. In general, higher uptake of macronutrients was observed with dolomite or lime + MgSO4 treatments along with 100% POP during both the years. Foliar spray of 13-0-45 recorded higher N and K uptake. Significant and positive correlation of grain yield with uptake of macro nutrients was also observed.

Spatiotemporal Variation and Influencing Factors of Grain Yield in Major Grain-Producing Counties: A Comparative Study of Two Provinces from China

The exploration of the spatiotemporal variations and influencing factors of grain yield in major grain-producing regions is greatly important to maintain stable and sustainable agriculture. Taking Henan Province and Heilongjiang Province as examples, this study reveals the spatiotemporal characteristics of grain yield at the county level by using multisource data on the economy, society, and natural geography from 2000 to 2021 and employing methods such as coefficients of variation, standard deviational ellipses, and spatial autocorrelation analysis. Moreover, geographical detector and geographically weighted regression models are combined to explore the differences in significant influencing factors between these provinces and the spatial heterogeneity of regression coefficients, respectively. The following findings are drawn: (1) Grain yield in both provinces gradually increased, with notable differences in the annual growth rate, the proportion, and at the county level. (2) The number of high-yield counties significantly increased and their spatial distribution became more concentrated, indicating a notable shift in the main regions. (3) The overall spatial correlation of grain yield steadily increased, and the local spatial correlation transitioned from random distribution to gradual aggregation. (4) There were significant differences in the influencing factors, where geographical environment, socio-economic factors, and input factors all affected both provinces. In summary, this study provides a scientific reference for governments worldwide to formulate rational and effective food production policies, thereby contributing to global food security and sustainable social development.

IRON-ZINC BASED GENETIC DIVERSITY ASSESSMENT IN MAIZE (ZEA MAYS L.) GENOTYPES

Hidden hunger is one of the most important challenges of the current era, and genetic biofortification is the most feasible, cheapest, and sustainable way to provide a balanced diet to the community. Given the value of biofortification in food grains, the relevant study sought to screen maize inbred lines for kernel Fe and Zn contents and estimate their bioavailability using molar ratios. One hundred maize inbred lines planted during spring 2018 in soil contained optimal levels of Fe and Zn. Maize genotypes evaluation comprised plant height, days to tasseling, silking, maturity, cob length, number of rows per cob, grains per row, grains per cob, 100-grain weight, grain yield per plant, grain Fe, Zn, and phytic acid contents. Significant differences emerged for all the studied traits. The results of the correlation study indicated that grain Fe and Zn contents had a positive genetic link with each other while a non-significant negative association with phytic acid and grain yield. A substantial positive correlation of grain yield occurred with rows per cob, grains per row, and grains per cob. Cluster and principal component analyses ran through, with PA/Fe and PA/Zn molar ratios calculated to estimate the mineral bioavailability. Based on the genetic variability for grain yield, Fe, Zn, and PA contents, four clusters resulted, and the first two PCs had an eigenvalue of more than one and depicted 76.91% of the total variance. Genotypes M-11, M-41, M-45, M-56, M-60, M-61, M-66, M-80, M-96, and M-98 showed high Fe and Zn contents with low molar ratios and are potential to benefit further breeding programs to develop biofortified maize hybrids.

Character Association Analysis on Morpho-physiological and Yield Parameters of Rice (Oryza sativa L.) under Water Stress

The present character association study aims to understand the correlation between morphological, physiological and yield traits of rice genotypes under water stress and non-stress conditions, so as to identify the differentially expressing traits under both the conditions. Such differentially expressed traits with positive influence on yield can serve as selection criteria for selection of stress tolerant plants. The experiment was carried out using randomized complete block design with three replications at the department of plant breeding and genetics, college of agriculture, Kerala Agricultural University between December 2021 and March 2022. Sixteen characters pertaining to morphological, physiological and yield of three rice genotypes were recorded under reproductive stage water stress and non-stress conditions. The intensity of trait correlations varied significantly under drought and non-drought conditions. The results of correlation studies indicate positive and significant correlation of grain yield with number of tillers, 1000 grain weight, photosynthetic rate, inter cellular CO2 content and water use efficiency under well-watered condition and of these, 1000 grain weight, and inter cellular CO2 content had significant positive influence on grain yield under drought stress. Principal component analysis results indicated two principal components i.e., PC1 and PC2 accounted for 70.5% and 29.5% of the total variation in grain yield under drought and 89% and 11% respectively under non drought conditions. Correlation and principal component analysis concluded that plants with higher grain weight along with improved high internal carbon dioxide content in leaves can be selected for attaining high yield potential under drought and non-drought conditions and will serve as climate adaptive crops under varying soil moisture levels.

Harnessing High Yield Potential in Wheat (Triticum aestivum L.) under Climate Change Scenario

Wheat is a major staple food crop for food security in India and South Asia. The current rate (0.8-1.2%) of genetic gain in wheat is significantly shorter than the 2.4% needed to meet future demand. The changing climate and increased yield loss due to factors such as terminal heat stress necessitate the need for climate-resilient practices to sustain wheat production. At ICAR-Indian Institute of Wheat and Barley Research in Karnal, Haryana, India, a new High Yield Potential Trial (HYPT) was conceptualized and subsequently conducted at six locations in the highly productive North Western Plain Zone (NWPZ). An attempt was made to harness higher wheat yields through the best pipeline genotypes suitable for early sowing and modified agronomic practices to explore the feasibility of a new approach that is profitable to farmers. The modified agronomic practices included like early sowing, application of 150% recommended dose of fertilizers, and two sprays of growth regulators (Chlormaquate chloride and Tebuconazole) to prevent lodging. The mean yield in the HYPT was 19.4% superior compared to the best trials conducted during the normal sowing time. A highly positive and significant correlation of grain yield with grain filling duration (0.51), biomass (0.73), harvest index (0.75), normalized difference vegetation Index (0.27), chlorophyll content index (0.32), and 1000-grain weight (0.62) was observed. An increased return of USD 201.95/ha was realized in the HYPT when compared to normal sowing conditions. This study proves that new integrated practices have the potential to provide the best profitable yields in wheat in the context of climate change.

Study of correlation and path coefficient analysis for yield attributing traits in selected rils of diverse wheat (Triticum aestivum L.) genotypes for heat tolerance

Rising temperature has adversely affected wheat production globally. In this realm we studied various morpho-physiological traits governing heat tolerance using thirty bread wheat RILs developed via crossing LOK-1 x HUW- 468, LOK 1 x HUW 234 and Raj-4014 x PBN-51. Correlation studies reflected that traits like number of tillers per plant, plant height, and chlorophyll content were significantly positive correlated with grain yield per plant, on the other hand, path coefficient analysis revealed that the chlorophyll content (0.362) and tillers per plant (0.222) showed a significant positive correlation with grain yield per plant, whereas significant negative correlation for grain yield was exhibited with relative water loss (-0.392) and canopy temperature (-0.402) at genotypic level.

STABILITY ANALYSIS OF WHEAT THROUGH GENOTYPE BY ENVIRONMENT INTERACTION IN THREE REGIONS OF KHYBER PAKHTUNKHWA, PAKISTAN

Genotype-by-environment (GEI) interaction provides the basic information that helps breeders to select stable and superior genotypes for targeted environments. Climate change also alters the recommendations of the genotype for a specific condition. The field study carried out during the cropping seasons of 2015–2016 determined the performance of 16 wheat genotypes (13 lines and three cultivars) at three different locations: The University of Agriculture, Peshawar (UAP), Nuclear Institute of Food and Agriculture, Peshawar (NIFA), and Cereal Crops Research Institute (CCRI), Pirsabak-Nowshera, Khyber Pakhtunkhwa, Pakistan. Data on yield contributing parameters (days to heading, spike length, spikelets spike-1, grain weight spike-1, 1000-grain weight, and grain yield) were collected and analysed using analysis of variance (ANOVA) and stability analysis. Mean square values revealed highly significant results for all the traits under consideration for genotypes (G) and locations (L). Likewise, interactions (GEI) were highly significant for all the traits except grain weight spike-1. The performance of genotypes under different locations indicated no similarity. However, the overall performance of genotypes displayed better under environmental conditions of the Cereal Crops Research Institute (CCRI- Location No: 03). According to the Eberhart and Russell approach, the genotypes K-87, PR-113, Pak-13, PR-112, NR-449, and KT-338 were confirmed stable under tested locations for yield contributing traits as their regression coefficient (bi) value exhibited close to unity. Correlations of grain yield with yield contributing traits considered were significant and positive except for days to heading.

Evaluation of panicle architecture traits in rice genotypes using PTRAP

An experiment was conducted with the objective of evaluating panicle architecture traits of different genotypes of rice in relation to yield during June to November 2020. The experiment was conducted in randomized complete block design with three replications and forty-two treatments. The graphical user interface used image analysis tool Panicle Trait Phenotyping (PTRAP) was used to record architecture and yield related traits. Among genotypes, the highest yield was found in high yielding late variety Sampurna (6.1t/ha) with highest number of both primary (16.33) and secondary branches (53.33). Four different types of panicle size-irregular, conical, diamond like and pyramid shaped panicle were identified in 42 genotypes. Correlation analysis revealed significant (p=0.05) and positive correlation of grain yield with architecture traits i.e., number of primary branches (r=0.88), length of primary branches (r=0.89), number of secondary branches(r=0.69), number of nodes (r=84). The correlation between spikelet number and other variables related to number of primary branches was higher than correlation with variables related to length of primary branch. The increase in number of panicle rachis length, number of primary and secondary branches and length of primary branches resulted in increased spikelet number per panicle and grain yield. It can be concluded the architectural traits like rachis length, number of primary secondary branches, and secondary branches and length of primary branches were the most important in improving panicle architecture and crop yield.

Study of Gene Action and Correlation for Grain Yield and its Attributing Characters in F1 Generation of Bread Wheat (Triticum aestivum L.)

Wheat is one of the most important cereal crop both in regard to its antiquity and its use as a source of human food. It is a major staple food crop of the world. The experimental materials consisted of 36 genotypes (28 F1s + 8Parents) were sown in Randomized Block Design with 3 replications. The estimated values of additive genetic component (D ˆ) were significant for days to 75% heading, But dominance variance (1 H ˆ) was significant ear length (cm), no. of grains ear, 1000 grain weight (g), grain yield / plant (g). In the present study, correlation coefficients for parents and F1s at phenotypic and genotypic levels among the grain yield and other characters have been worked out. The grain yield per plant showed positive and highly significant association with no. of tillers per plant and 1000 grain weight.

English

The yield of rice landraces in the Sudan has been low due to genetic ceiling in the existing varieties. It is necessary to carry out breeding programs that deal with the production of high yielding, adaptable new varieties. Therefore, this study aimed to estimate genetic variability, heritability, genotypic performance and interrelationships among the traits. 18 upland rice genotypes and two checks evaluated at White Nile Research Station Farm, Kosti, of the Agricultural Research Corporation (ARC), Wad Medani Sudan were planted in a randomized complete block design with three replications during the two seasons of 2017 and 2018. All evaluated genotypes exhibited a wide and significant variation in the 13 measured traits. Genotypic coefficient of variation and genetic advance were recorded for days to 50% flowing, panicle length (cm), number of filled grain/panicle and 1000 grain weight in both seasons. High heritability and genetic advance were recorded for the number of tillers/plant, number of unfilled grains/panicle, biomass yield (t/ha) and grain yield (t/ha). Moreover, there was a highly significant and positive correlation of grain yield with biological yield (0.764), number of tillers per plant (0.439) and number of filled grain per panicle (0.423). The highest yielding five genotypes across the seasons were NERICA3 (5.2 t/ha), NERICA4 (5.1 t/ha), NERICA6 (4.9 t/ha), PAKIST-ck (4.7 t/ha) and NERICA12 (4.6 t/ha). It is recommended to be grown in White Nile state under irrigation upland condition after testing for seed yield stability. Key words: Genetic variability, NERRICA, rice, yield.