Magnitude Of Genetic Variation Research Articles

Application of near-infrared spectroscopy for fast germplasm analysis and classification in multi-environment using intact-seed peanut (Arachis hypogaea L.)

Peanut is a worldwide oilseed crop and the need to assess germplasm in a non-destructive manner is important for seed nutritional breeding. In this study, Near Infrared Spectroscopy (NIRS) was applied to rapidly assess germplasm variability from whole seed of 699 samples, field-collected and assembled in four genetic and environment-based sets: one set of 300 varieties of a core-collection and three sets of 133 genotypes of an interspecific population, evaluated in three environments in a large spatial scale of two countries, Mbalmayo and Bafia in Cameroon and Nioro in Senegal, under rainfed conditions. NIR elemental spectra were gathered on six subsets of seeds of each sample, after three rotation scans, with a spectral resolution of 16 cm-1 over the spectral range of 867 nm to 2530 ​nm. Spectra were then processed by principal component analysis (PCA) coupled with Partial least squares-discriminant analysis (PLS-DA). As results, a huge variability was found between varieties and genotypes for all NIR wavelength within and between environments. The magnitude of genetic variation was particularly observed at 11 relevant wavelengths such as 1723 ​nm, usually related to oil content and fatty acid composition. PCA yielded the most chemical attributes in three significant PCs (i.e., eigenvalues >10), which together captured 93% of the total variation, revealing genetic and environment structure of varieties and genotypes into four clusters, corresponding to the four samples sets. The pattern of genetic variability of the interspecific population covers, remarkably half of spectrum of the core-collection, turning out to be the largest. Interestingly, a PLS-DA model was developed and a strong accuracy of 99.6% was achieved for the four sets, aiming to classify each seed sample according to environment origin. The confusion matrix achieved for the two sets of Bafia and Nioro showed 100% of instances classified correctly with 100% at both sensitivity and specificity, confirming that their seed quality was different from each other and all other samples. Overall, NIRS chemometrics is useful to assess and distinguish seeds from different environments and highlights the value of the interspecific population and core-collection, as a source of nutritional diversity, to support the breeding efforts.

Estimation of Nature and Magnitude of Genetic Variability, Heritability and Genetic Advance for Yield and Its Contributing Traits in Wheat (Triticum aestivum L.)

The present research investigation was conducted at AKS University, Satna, Madhya Pradesh during rabi Season of 2022. Altogether 20 wheat genotypes were grown under RBD design with three replications. In the present study various parameters of genetic variability, broad sense heritability and genetic advance estimates of wheat crop. Analysis of variance revealed that the mean sum of square showed significant due to genotypes for all the 12 characters studied. Analysis of variance for the design of experiment revealed highly significant difference for all the characters which expressed huge amount of diversity among 20 genotypes of wheat. Phenotypic coefficients of variation (PCV) were higher than genotypic coefficients of variation (GCV) for all the characters. The maximum GCV and PCV were observed for ear length (cm) (26.37 & 27.04) followed by number of productive tillers per plant (23.72 & 25.65) and test weight (21.76 & 22.57 g). The maximum value of heritability was shown by number of spikelets per ear (98.05), number of seed per spike (97.59), ear length (95.12cm), test weight (92.99 g), biological yield per plant (91.99 g), plant height (89.86 cm), seed yield per plant (87.28 g), days to maturity (86.67) and number of productive tillers per plant (85.56). The highest genetic advance was found for number of productive tillers per plant (45.20), number of seed per spike (43.60), test weight (43.24 g), seed yield per plant (37.37 g), no of ears par plant (34.99) and number of spikelets per ear (31.49). High heritability coupled with high genetic advance for the characters number of productive tillers per plant, no of ears per plant, ear length, number of spikelets per ear, number of seed per spike, test weight and seed yield per plant which indicated that above characters were governed by additive gene action and direct selection may be useful for further improvement program.

COMPARATIVE ASSESSMENT OF GENETIC DIVERSITY BETWEEN BRASSICA NAPUS AND BRASSICA JUNCEA BASED ON PHENOTYPIC TRAITS

Rapeseed and mustard crops’ extensive promotion for crop diversification and their potential to favorably respond to breeding programs depends on their existing nature and the magnitude of genetic variability. Therefore, the progressive research sought to estimate the genetic diversity of 40 genotypes of Brassica napus (20) and Brassica juncea (20) based on phenotypic characters. The material, grown in randomized complete block design, had three replications during winter 2020– 2021. The mean square from analysis of variance demonstrated significant differences for all the parameters among examined varieties, indicating that utilized material contained sufficient genetic variability. Regarding average performance, two mustard genotypes, Dhoom-I and Anmol Raya, performed better for seed yield plant-1 and can undergo assessment in upcoming breeding programs for enhancing seed yield. Meanwhile, high heritability occurred in oil content, silique length, 1000-seed index weight, and plant height. Diversity analysis, cluster mean, and total divergence contribution revealed maximum differences for various traits and possessed noteworthy sources for future breeding programs. The magnitude of cluster distance indicated that cluster VI comprised two mustard genotypes (Early Raya and Sindh Raya) and cluster IV consisted of three rapeseed genotypes (Rohi Sarson, hyola-401, and Kn-277), demonstrating that maximum distance is more diverse and helpful for upcoming heterotic recombination. Comparing genetic variation between rapeseed and mustard genotypes showed that rapeseed genotypes displayed more genetic variability in the first three components of PCA than its counterpart, yet expressing that mustard genotypes also have enormous valuable genetic resources. Similarly, genotypes Rohi Sarson, hyola-401, and Kn-277 resulted in the highest genotypic scores in three-dimensional graphs; hence, these genotypes are more diverse and can benefit future hybridization programs.

Genetic Variability for Micronutrient Content and Tuber Yield Traits among Biofortified Potato (Solanum tuberosum L.) Clones in Ethiopia.

Malnutrition is one of the global issues of public health concern, and iron and zinc deficiencies are at the top of the list. Iron deficiency affects more than 2 billion people in the world and is a major cause of anemia. Potato has the potential to be an important source of iron and zinc. This study assessed the nature and magnitude of genetic variability in Fe and Zn concentrations, tuber yield, and quality traits among biofortified tetraploid potato clones and their relationships through correlation and path analysis. A total of 45 potato genotypes, including the variety Gudanie, were grown in field trials in a 9 × 5 alpha lattice design with three replications. Significant differences in mineral, tuber quality, and yield traits were observed among the genotypes, and high broad-sense heritability was obtained for most traits, suggesting that progress through breeding can be achieved. However, negative correlations and direct effects on most of the traits with Fe and Zn contents are found both at genotypic and phenotypic levels. Therefore, attaining simultaneous genetic gain for yield and enhanced Fe and Zn concentrations will be challenging. Cluster analysis assembled them into five groups. Cluster II contained the most prominent genotypes, having better mean values compared to all other genotypes for micronutrient traits, viz., Fe (23.80 mg kg-1) and Zn (17.07 mg kg-1). The results of this study confirm the presence of sufficient genetic variation for iron and zinc mineral concentration and the possibility to make significant progress through breeding.

Genetic diversity of ayeyarmin mutant rice population revealed by quantitative traits

One of the most important aspects of selecting genotypes with desirable characteristics for a successful breeding program is knowledge of the nature and magnitude of genetic variability. The goal of this study was to estimate the level of genetic divergence among mutant rice genotypes. During the 2020 dry season, a field experiment was carried out using 550 mutant lines with parent Ayeyarmin. The experiment was carried out using a simple CRD design. Six divergent groups were discovered by cluster analysis. Cluster I had the highest cluster mean for grain yield per plant, and the majority of the plants in these clusters resembled the parent Ayeyarmin. Cluster V, which had the fewest mutant lines (9), exhibited dwarf stature, short growth duration, fewer effective tillers per hill, and moderate yielding varieties. Cluster VI, which contained 11 mutant lines, had the most effective tillers per hill and the longest panicle length, both of which were appropriate for yield improvement. Cluster V had the greatest intra-cluster distance (5.77). Cluster V and IV had the greatest inter-cluster distance, followed by Cluster III and V, Cluster II and V, Cluster I and V, and the smallest between Cluster I and IV. Hybridization of Cluster I with V, Cluster V and VI could result in genotypes with desirable characteristics such as dwarf stature, short growth duration, and high yielding rice. The first three eigenvalues were found to have 62% variation using principal component analysis (PCA). Because of the high genetic variability in this mutant rice population, selection could be used to obtain desirable genotypes.

Genetic Variability and Path Analysis for Yield and Associated Traits in Linseed Genotypes

An experiment was conducted to study the nature and magnitude of genetic variability with yield and related traits and characters association in linseed. Twelve diverse linseed (Linum usitatissimum L.) genotypes were evaluated in randomized block design withthree replications duringrabiseason 2020-21 in the experiment field of AICRP on oilseeds in the college of agriculture Tikamgarh. The higher phenotypic coefficient values than corresponding genotypic coefficient values depicted influence of environment in the expression of traits. The data were recorded for days to flowering initiation, days to 50 % flowering, plant stand per hectare, plant height, primary branches per plant, capsules per plant, number of seeds per capsule, biological yield per plant, days to maturity,1000 seed weight, yield per plant, yield per ha., protein and oil content.High to moderate magnitude of PCV and GCV were observed for the traits viz., 1000 seed weight, yield per plant, plant height, biological yield per plant, days to flower initiation indicating the presence of significant variability in the existing collection and in path coefficient analysis revealed the positive direct effect at both genotypic and phenotypic levels for the characters for days to 50% flower, plant height, number of capsule per plant, 1000 seed weight and primary branches per plant respectively.

Genetic variability studies in carrot (Daucus carota L.) under low hill regions of Himachal Pradesh

The purpose of this study was to determine the nature, extent and magnitude of genetic variability, as well as estimate of the coefficient of variability, heritability and genetic advance as a percentage of the mean. During the rabi, 2020-21, twenty-three diverse genotypes of carrot were laid out in RCBD design at the Experimental Farm of the Department of Vegetable Science, College of Horticulture and Forestry, Neri, Hamirpur, Himachal Pradesh. Observations were recorded on sixteen economic traits. For all traits, significant differences were found among all genotypes. PCV was greater than the corresponding GCV for all the traits, indicating that the environment has a significant impact on character expression. GCV, heritability and genetic advance as per cent of mean were high for root: shoot ratio, plant height at harvest, carotene content and total yield per plot, indicating that selection for these traits would be beneficial in improving carrot yield. Keywords: Carrot, Daucus carota L., Variability, Heritability, Genetic Advance, Genetic gain  

Genetic variability, character association and path analysis in fenugreek (Trigonella foenum-graecum L.) under normal and staggered irrigation regimes

The present study was conducted to identify the nature and magnitude of genetic variability, correlation and path coefficient analysis among forty eight fenugreek genotypes under normal and moisture stress conditions in a randomized block design with three replications. The pooled analysis of variance indicated a significant interaction between genotypes and environments for majority of the traits. The analysis of variance for individual environments indicated the existence of significant variability for all the characters, justifying the selection of genotypes for the study. The values of phenotypic coefficient of variation were higher than the genotypic coefficient of variation indicated effect of environment on expression of all characters. The satisfactory estimates of coefficients of variation were recorded for pods per plant and seed yield per plant. High heritability coupled with high genetic advance as a percentage of mean was observed for pods per plant in both environments. The correlation and path coefficient analysis showed that pods per plant had a positive correlation with a high direct effect on seed yield. The results indicated that selection may be worthwhile for pods per plant due to lesser influence of environment and predominance of additive gene action in the genotypes for increasing seed yield. Keywords: Correlation, Fenugreek, Genetic Variability, Moisture Stress, Path, Seed Yield

Genetic Variability, Heritability, Correlation Analysis, Genetic advance, and Principal Component Analysis of Grain Yield and Yield Related Traits of Quality Protein Maize (Zea mays L) Inbred lines Adapted to Mid-altitude Agroecology of Ethiopia

To establish effective breeding techniques for the creation of nutritionally enhanced maize cultivars, reasonable information of the extent of genetic diversity, heritability, genetic advance, correlation analyses, and interrelationships of yield and yield related variables is essential. As a result, the goal of this study was to determine the nature and magnitude of genetic variability, heritability, Correlation Analysis, genetic advance, and principal Component analysis of grain yield and yield-related traits in quality protein maize inbred lines adapted to Ethiopia's mid-altitude agroecology. During 2019/2020, the experiment was done on 36 inbred lines, including four checks at Bako and Jimma. The genotypes were tested three times in an alpha lattice arrangement. For all parameters except days to maturity, the mean square due to genotypes was extremely significant, according to the analysis of variance. The level of phenotypic and genotypic variation among all eleven characteristics showed that the environment influenced the expression of features in some way. Grain yield, kernels per ear, ear diameter, and thousand kernels weight all showed a moderately greater heritability. The estimated genetic progress as a percent of mean for grain production, kernels per row, and ear per plant was extremely high, indicating the control of additive gene of action and a better hope for selection of these traits. Grain yield has a high heritability mixed with a high genetic advance, indicating that additive gene action is dominant in controlling the variable. Days to maturity, plant and ear height, ear diameter, ear per plant, and thousand kernel weights all exhibited extremely significant positive associations with grain yield. The eigenvalue of the first main component was 6.16, and it accounted for 4.60 of the total variances. The PC7 had large ear weights per plant, which most likely reflected yield. Finally, in future quality protein maize breeding efforts, special ......

Genetic variation in mineral profiles, yield contributing agronomic traits, and foliage yield of stem amaranth

The study was evaluated to estimate mineral profiles and find out selection criteria for high foliage yielding cultivars by assessing the magnitude of genetic variability, heritability, genetic advance, association, and contribution of characters of sixteen stem amaranth genotypes in a randomized block design with three replications. Based on high heritability and high GA and GAPM and close values between Vg vs. Vp and GCV vs. PCV, all the traits could be selected to improve the foliage yield of stem amaranth. A significant and desirable positive correlation was observed for Fe, Ca, Mn, K, and leaves plant-1 both at genotypic and phenotypic levels. These five traits could be selected for improving the foliage yield of stem amaranth as these traits exhibited less influence on the environment. The insignificant genotypic correlation values were observed between mineral vs. mineral and mineral vs. foliage yield and yield contributing agronomic traits, which indicate that selection for high mineral content might be possible without compromising yield loss. A high to moderate direct effect along with a significant correlation was found in Fe, K, Ca, and Mn. Fe, K, Ca, and Mn had the most significant contribution to foliage yield of stem amaranth as these traits exhibited considerable positive direct effects and significant correlation coefficients on foliage yield. The accessions AS7, AS4, AS5, AS14, and AS16 had high foliage yields containing moderate to high mineral profiles. These five accessions could be selected as high-yielding cultivars. Selection could be made based on Fe, K, Ca, and Mn content to improve stem amaranth. The accessions AS7, AS4, AS5, AS14, and AS16 could be used as high foliage yielding and mineral profiles enrich cultivars.

Exploring variability and genetic diversity among rice genotypes in Eastern Uttar Pradesh

The genetic improvement of any crop mainly depends on the amount of genetic variability present in the population. To explore this variability, an effort was made to classify, understand the nature and magnitude of genetic variability and diversity among 112 rice genotypes for 16 quantitative traits using Mahalanobis D2 statistics. Analysis of variance revealed a wide and significant variation for all the 16 traits studied. A slight difference between PCV and GCV was found, suggesting that genetic control of traits is higher than environmental influence. Characters such as harvest index, days to first flowering, days to 50% flowering, and plant height showed high heritability coupled with high genetic advance as per cent of mean suggesting that selection for the improvement of these traits may be rewarding. Cluster analysis indicated that the 112 rice genotypes were grouped into 7 clusters, wherein cluster I had the highest number of genotypes (73) followed by cluster III with 22 genotypes. The maximum inter-cluster distance was recorded between clusters V and VII with a D2 value of 58981.07, followed by clusters II and V (51875.13). The number of spikelets per panicle (52.17%) and the number of grains per panicle (27.26%) were found to be the most contributing traits towards total genetic diversity. Hence, information on the nature and degree of divergence would help the plant breeder in the selection and hybridization procedure for choosing the right type of parents to improve yield and other traits. Key words: Genetic diversity, Heritability, Mahalanobis D2, Rice, Variability.  

English

Durum wheat is the second most important Triticum species next to bread wheat. Ethiopia is one of the centers of diversity for durum wheat. The aim of this study was to assess variability, heritability and genetic advance for some yield and yield-related traits. A total of 97 durum wheat accessions along with 3 improved varieties were evaluated in 10 x 10 simple lattice designs during the 2018 main cropping season at Mata Subsite of Haro Sabu Agricultural Research Center. Twenty parameters were collected and analyzed. Statistically significant (p≤0.01) variation was observed among materials tested for important quantitative and qualitative traits. Genotypic coefficient of variation (GCV) ranged from 3.77 to 44.81% for days to maturity and grain yield (tons ha-1), respectively. Broad sense heritability ranged from 72.33 to 99.95% for plant height and number of kernels per spike, respectively. The highest genetic advance as percent of mean recorded for grain yield (88.80%) and the least for moisture (5.22%). Generally, the magnitude of genetic variability among the studied durum wheat accessions showed great variations for desirable traits and thus confident enough to expect genetic progress if further breeding activities are carried out. Key words: Coefficient of variation, durum wheat (Triticum turgidum L.), genetic advance, heritability.

The performance of agronomic traits, genetic variability, and correlation studies for yield and its components in some red rice (Oryza sativa) promising lines

Abstract. Sadimantara GR, Yusuf DN, Febrianti E, Leomo S, Muhidin. 2021. The performance of agronomic traits, genetic variability, and correlation studies for yield and its components in some red rice (Oryza sativa) promising lines. Biodiversitas 22: 3994-4001. Improving a new variety commonly depends on the nature and magnitude of genetic variability and its utilization, followed by selection and evaluation before being released into new superior types. The present study aims to estimate the genetic variability and relation between yield and its related traits of the red rice promising lines. The experiment was arranged based on a randomized complete block design (RCBD) with three replications. Analysis of variance revealed significant differences among rice lines for 12 quantitative traits. The phenotypic coefficient of variation (PCV) value was higher than the genotypic coefficient of variation (GCV), indicating a negligible environmental influence in the phenotypic expression of traits. High heritability estimates coupled with high genetic advance were recorded for grain total per panicle and grain yield per hill. Grain yield observed a highly significant positive correlation with panicle length (0.63), percentage of filled grains (0.53), grain weight per panicle (0.54), and thousand-grain weight (0.52). It correlated negatively with days to 50% flowering (-0.61) and days to maturity (-0.48). The study indicated that panicle length, percentage of filled grains, grain weight per panicle, and thousand-grain weight are important yield-related traits and could be used for selection to improve the genetic potential of rice yield.

Estimation of the Coefficient of Variation and Some Genetic Parameters of Some Local Varieties of Turnip and Radish

Since there are no (or few) formal Egyptian (registered) cultivars of turnip and white radish, So, this investigation was carried out for studying the coefficient of variation and genetic differences within and between nine native landraces of turnip and white radish, unregistered cultivars, which were collected from different regions (nine governorates) of Egypt as a first step towards registering them, if they were genetically pure or including them in breeding programs to improve and establish new cultivars. This investigation was carried out at a private farm in Arab Elsabha, Dar Elsalam, Sohag governorate, during the winter seasons of 2017/2018 and 2018/2019. Results indicated that both turnip and radish Genotypes exhibited obvious differences among the native landraces of them for most of the studied characters. On the other hand, coefficients of variations (C.V.%) of the nine Balady landraces both of turnip and radish were less than 25 % for all the studied characters except a few exceptions. These results indicate that there were no significant differences within the nine Balady landraces for turnip and radish, separately. Consequently, these Balady landraces are largely genetically identical. Mean squares of genotypes were found significant or highly significant for all characters except for both of No. of leaves/plant and weight of 1000 seeds regarding turnip and for the weight of 100 seeds concerning radish. With regard to the genotype × year component of variance, it was highly significant in only weight of 1000 seeds for turnip and it was insignificant for the studied traits of radish. The insignificance of this component showed that the selected genotypes succeeded to possess the same good performances in the two years of the test. The partitioning of variance into its various components that a large portion of total variances of most studied traits, in all turnip and radish genotypes, would be attributed to genotypes. It should be mentioned here that genetic variance would be biased upward since it contains a non-partitioned genotypic × location source of variance; so, these results could be accepted under the designed conditions of this investigation and any wider implications warrant further research. The estimated broad-sense heritability of the various studied characters reflected high values (> 70%) in most studied traits of all turnip and radish genotypes These results gave information on the magnitude of genetic variation.

Revealing genetic diversity of Indian mustard (Brassica juncea) for yield improvement

The study was carried out during rabi 2015-17 to understand the nature and magnitude of genetic variability and character association of 45 accessions of Indian mustard. These accessions were evaluated for 16 quantitative traits under standard package of practices. The results indicated high PCV and GCV for 1000 seed weight, stover nitrogen uptake (STNU) and seed nitrogen uptake (SNU) while it was low for NUE. High heritability coupled with high genetic advance as percent of mean was observed for 1000 seed weight, STNU and oil content which indicates the involvement of additive gene action, thus feasibility of improvement through simple selection. Seed yield had a positive and significant correlation with seed uptake efficiency, nitrogen harvest index and NUE. First five principal components gave eigenvalues >1.0 and cumulatively expressed 80.67% of the total variation (Table 2). PCA exhibited that plant height, NBP, number of siliquae in the main branch, nitrogen (%) in seed, total nitrogen (%), SNU and seed yield (Kg/ha) were among the most important traits accounting for more than 50% phenotypic variation. Therefore, these quantitative traits should be considered to enhance yield potential as they will be beneficial to develop promising varieties. Accessions such as IC67693, IC277700, IC268336 and RH-30 were identified to be distantly plotted on the dendrogram, thus more diverse in nature. Donors for various traits were also determined based on their pooled performance e.g. IC267693, IC338494, IC571625, IC339605 and IC571654 for seed yield.

Variance components in recombinant inbred lines of Tef [Eragrostis tef (Zucc.) Trotter L.]: Estimation and their implications in selection

Tef [Eragrostis tef (Zucc.) Trotter L.] is an indigenous and important cereal crop in Ethiopia. Its improvement is dependent on the presence and magnitude of genetic variation among traits in a giv...

Genetic variability studies in chilli (Capsicum annum L.)

A study was conducted to evaluate the nature and magnitude of genetic variability in 15 Chilli genotypes in a randomized block design with three replications. The analysis of variance revealed significant difference among 15 genotypes for all the character studied indicating the presence of sufficient variability in the studied material. Results revealed the presence of wide genetic variability. The genotypes were grouped into 5 clusters based on Mahalanobis D2 statistics using Torcher’s method. The clustering pattern of genotypes revealed that the genetic diversity was independent of the geographical diversity. Among the 5 clusters, maximum numbers of genotypes were found in cluster II, while clusters IV and V was found to be mono-genotypic. Among the 14 quantitative characters studied, number of seeds/fruits constituted a maximum of 26% contribution to the divergence, followed by fruit weight(g). Ranking of genotypes based on intra-cluster mean performance for these characters which are major contributors of genetic diversity revealed its usefulness in selecting parents for heterosis breeding.

Genetic Analysis on Yield and Yield Components Traits in the Segregating Populations of Blackgram[Vigna mungo (L.) Hepper

The magnitude of variability and association among various traits in F2 populations of three crosses viz., MDU 1 x TU68, VBN6 x TU68, and VBN8 x TU68 of blackgram were studied. The experiment was conducted at the National Pulses Research Centre, Vamban, during Rabi 2019. The genotypic coefficient of variability was lower than the values of phenotypic coefficient of variability, which revealed the influence of the environment in deciding the expression of these populations.The traits viz., plant height, number of branches per plant, number of clusters per plant, number of pods per plant, and seed yield per plant has recorded high heritability and high genetic advance as per cent of mean for the majority of the crosses. It indicated that these traits were less influenced by the environment and possessed with high magnitude of genetic variability. Association studies revealed that the traits viz., number of clusters per plant, and number of pods per plant in all the three crosses recorded significant and positive association with seed yield per plant. Hence, based on the present investigation, it can be concluded that the number of clusters per plant and number of pods per plant should be given due importance in framing the selection indices for seed yield improvement in blackgram. However, separate selection indices are required for each population as the association of traits differs among populations.

Morphological characterization and genetic analysis in bread wheat germplasm: A combined study of heritability, genetic variance, genetic divergence and association of characters

Abstract. The present study was conducted to assess the nature and magnitude of genetic variability and traits association of bread wheat genotypes for yield and related traits. A total of 180 genotypes were evaluated in alpha lattice design with three replications in 2017/18 cropping season. Data for 10 quantitative traits were collected and subjected to analysis of variance. The result from the analysis of variance revealed highly significant variability observed among genotypes for all traits studied. Phenotypic coefficient of variation (PCV) is superior over genotypic coefficient of variation (GCV) for most traits but narrow variations were found between PCV and GCV for most of the traits. Heritability in broad sense and genetic advance as percent of the mean (GA%) were relatively higher for Kernels per spike and grain filling period. Grain yield showed positive and highly significant (p≤0.01) association with number of tillers, kernel per spike and plant height both on genotypic and phenotypic levels.The path coefficient analysis showed that spike length, plant height and kernels per spike had positive direct effect on grain yield on both genotypic and phenotypic levels. Divergence analysis (D2) grouped the total test germplasm into 10 clusters. Among those, clusters IV and IX showed the highest genetic distance and thus the possibility to develop segregating populations upon the crossing of widely related genotypes in those clusters. The results could help researches to utilize the most promising wheat genotypes of this study in future breeding programmes for enhancing desirable traits.

APPLICATION OF SOME SELECTION PROCEDURES FOR IMPROVING OF SOME ECONOMIC CHARACTERS IN COTTON (G. BARBADENSE L.)

The main objective of this study was to estimate and compare the genetic gain obtained from Simith-Hazel index model of selection index with direct and indirect selection to enhance selection efficiency of superior promising families in early segregating generations of the cotton cross Giza 86 x Karshenky. The data revealed increase in mean values for all characters with advanced generations' from F2 to F4 except micronaire reading which showed lower values (desirable values). This shifting in mean values in desirable direction could largely be attributed to the possible accumulation of favorable alleles as a result of selection procedures adapted in this study. The range was comparatively wider in F2 generation as compared with the later generationsF3 and F4 for all studied characters. The advanced generations (F3 and F4 generations) showed reduction in PCV and GCV values as compared with F2, this may due to reduction in genetic variability and heterozygosity as a result of using different selection procedures which exhausted a major part of variability. Most characters showed high heritability values over 60% over generations indicating high magnitude of genetic variability. Significant desirable correlations between boll weight and each of seed/boll and seed index were existed over the three generations. The significant undesirable association existed between seed cotton yield with most traits in F2 generation were broken up and converted to desirable relation in later generations. Principal component analysis grouped estimates variables into six main components. In the first PC1 yield characters (lint yield followed by (x1) and seed cotton yield/plant showed negative loading and more contributed than the other fiber characters which gave negative loadings. The PC2 was great influenced by seed index followed by lint/seed and boll weight which had positive loadings, in same time micronaire reading and fiber strength showed negative loadings. Ten out eleven selection indices were more efficient than direct selection for improvement of lint yield in F2 population. The highest predicted genetic gain from F2 generation for lint yield/plant was observed when selecting for lint yield/plant with bolls/plant (IW1) followed by (I12) selecting for boll/plant with seed/boll and selection index in involving selection index involving lint yield/plant, bolls/plant, seeds/boll and lint/seed. The highest actual genetic gains from F3 generation for lint yield/plant occurred when selecting directly for lint yield/plant followed by selecting for boll/plant. However the indices IW12 (selection index involving lint yield/plant, bolls/plant and seeds/boll) followed by IW13 (selection index involving lint yield/plant, bolls/plant and lint/seed) and IW3 (selection index involving lint yield/plant and lint/seed) were superior to all selection procedures in amount of actual gain. Most indices showed high discrepancy between predicted and actual genetic gain as lint yield/plant, this was due to non-additive gene effect and large effect of environmental factor. However maximum actual genetic advance from F4 generation for lint yield/plant were achieved when selecting for lint yield/plant, seeds/boll and lint/seed followed by selection indices containing lint yield/plant, boll/plant, seed/boll. The direct selection for lint yield and pedigree selection for boll/plant followed by selection for lint/ seed gave desirable actual values and surpassed most indices. selection index involving lint yield/plant and boll/plant surpassed all selection procedures for predicted gain followed by Selection index involving lint yield/plant, bolls/plant, seeds/boll and lint/seed. However direct selection for lint yield followed by pedigree selection for boll/plant appeared to be most effective for the improvement lint yield and gives reasonable actual gains. The predicted and actual advances determine from F3 generation were higher than F4 generation for most selection procedures. On the basis of various selection procedures, six selected families were isolated from F4 generation by superiority of these families from better parents, F3 families and point start of F2 plants mean. The breeder may utilize such selected families in breeding programs aiming to improve yield and quality.