Maximum Inter-cluster Distance Research Articles

Genetic Variability for Root and Shoot Morpho-physiological Traits Contributing to Seedling Drought Stress Tolerance in Parental Lines of Pearl Millet

Drought stress severely affects plant growth and development leading to substantial reduction in yield and biomass accumulation. Forty one Pearl millet parental lines were subjected to seedling drought stress and morpho–physiological attributes along with individual drought stress response indices were recorded. Significant genetic variability existed for all the traits and genotype ICMX 1410698-SB-11-1-1-2(B) ranked first based on combined drought stress response index. Principal component analysis indicated that first two PCs explained 86.4% of variation under drought conditions. GCV ranged from 13.84 to 23.47% under drought indicating genetic basis for variability. D2 statistics grouped the genotypes into seven clusters. The maximum inter-cluster distance was reported between the clusters III and VII while clusters III & I ranked second under drought stress. These are potential drought tolerant parental lines for hybrid breeding. Root/Shoot ratio has been the major contributor for genetic divergence under both control and drought stress.

Genetic characterization and diversity analysis of indigenous aromatic rice

Gangetic old alluvial zone in India has conserved many locally adapted aromatic rice landraces. In order to determine the extent of genetic divergence of ten morphological characters, the study was conducted to examine forty-eight aromatic rice genotypes for six Kharif seasons (2016–2021) at the Instructional Farm of Regional Research Station (Old Alluvial Zone), Uttar Banga Krishi Viswavidyalaya, Majhian, West Bengal, India. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. A considerable degree of variation was noted for all the traits being investigated. It was found that the total number of tillers per plant, panicle numbers per plant, number of grains per panicle, fertility percentage, test weight, and grain length/breadth ratio had significantly positive correlated with seed yield per plant. Based on D2 analysis values, all the genotypes were grouped into six clusters. Cluster III (Tulaipanji, Patnai, Basmati 1121, Jugal, and Bahurupi) and Cluster VI (Kanakchur), containing genotypes were found most divergent with maximum inter-cluster distance (6941.51). According to the cluster means, Cluster II had the largest intra-cluster distance (1937.52), and important attributes including test weight, number of grains per panicle, seed yield per plant, and fertility percentage made remarkably significant contributions to this cluster. In terms of principal component analysis, maximum variability was found in PC1 (23.88%), with high positive loading values for tillers per plant (0.459), panicle number per plant (0.441), seed yield per plant (0.408), fertility percentage (0.364), test weight (0.264), and grain length/breadth (L/B) ratio (0.263). On the basis of biplot analysis, four genotypes, namely Shakbhati, Sugandhi, Bahurupi and Kanakchur, were identified as the most divergent types for the yield-attributing traits of aromatic rice. The diverse genotypes could be used as potential donors in future breeding programmes.

Diversity studies in Assam rice genotypes for ratooning ability and perennation

AbstractThe objective of the research was to assess diversity among 50 rice genotypes for ratooning and perennation which refers to ability of a plant to regrow from stubble remaining after harvesting. Results showed that 30 genotypes exhibited different degree of ratoon production and ratoon yield. Diversity analysis revealed that all the ratooning genotypes could be assigned to ten clusters. Clusters III (Binadhan-11 and Sayjihari) and VI (IR-64, DRR-44) were the best performing for ratoon yield. Maximum inter-cluster distance was observed between genotypes falling under clusters III and X followed by genotypes under clusters III and II indicating wider genetic diversity between these genotypes. Thus, these genotypes may be useful for future breeding to develop superior varieties with respect to ratooning ability and ratoon yield.

Estimate the Genetic Diversity with PCA in Bread Wheat (Triticum aestivum L.)

The present investigation was carried out on bread wheat (Triticum aestivum L.) crop during rabi season with the aims of analysis of genetic diversity with the help of principle component analysis. The experimental sample size included 80 genotypes, in an augmented block design with three replications. Observation was based upon twenty-six quantitative characteristics. For all characteristics Cluster I had highest number of genotypes (28) followed by cluster II (5), cluster IV, cluster V and cluster VI had presented (4), cluster VII and VIII (3), cluster III, cluster IX, cluster X, cluster XI and cluster XII (2) whereas cluster had presented one entry in each group. The minimum intra cluster distance (0.00) was found for XIII to XXXI and maximum was found for cluster XII (2.10). The maximum inter-cluster distance was found between cluster XX to XXVII (11.08). The minimum inter- cluster D2 value found in case of cluster IV to XVI and XXX to XXXI (2.12). Cluster XVIII showed earliest mean value for day to 50 per cent flowering (75.24 day) and most important character maximum mean value for yield per plot (536.13). Principal component analysis (PCA) indicated that the five principal components (PC1 to PC5) showed 50.37 per cent of the total variability. The five different groups positive maximum variable loaded component PC I for grain yield per plant (23.2542), PC II flag leave area (19.4005), PC III for peduncle length (23.9893), PC IV grain length /width ratio (21.0627), PC V for physiological maturity (16.7492). As a result of the foregoing data, it is possible to conclude that there is great potential for effective crop modification for improved yield and yield-attributing traits in present wheat germplasm.

Genetic diversity studies for yield attributing characters in chickpea (Cicer arientinum L.) germplasm and their clusters

Genetic diversity is a prerequisite for undertaking any crop breeding programe for the development of high yielding crop varieties to enhance the national food production for the food security. Protein is an important component in the human diet, which is obtained for the vegetarian people from the pulses. Chickpea is an important source of protein for the Indian and African population. Therefore, breeding for high yielding chickpea varieties is a continuous process whose success is dependent on the availability of genetic diversity in the chickpea germplasm. In the present studies forty one genotypes of chickpeas were grouped into twelve clusters. The cluster I was with the highest number of genotypes (23) followed by cluster IV (09), II , III, V, VI, VII, VIII, IX, X, XI and XII which had only 1 genotype in each cluster, respectively.The intra cluster distance (D2) ranges from 68.72 to 90.06 while the inter cluster distance (D2) ranges from 49.00 to 1217.31. The maximum inter-cluster distance (D2 = 1217.31) was observed between cluster VI and cluster XII followed by cluster XII and VIII (D2 = 1069.94), cluster VI and cluster X (D2 = 962.24) and cluster V and cluster VI (D2 = 919.90). It was observed that, seed yield per plant (42.20%) contributed highest for divergence followed by plant height (16.83%), 100 seed weight (16.34%), days to maturity (6.83%), number of pods per plant (5.37%), number of primary branches (4.51%), number of secondary branches per plant (3.05%), harvest index (2.20%), number of seeds per pod (2.07%) and days to 50% flowering (0.61%).

Study on genetic diversity in Amaranthus (Amaranthus hypochondriacus L.)

Grain amaranth is a protein rich psuedocereal, assumes an important position in terms of quality breeding activities. Systematic characterization, evaluation and utilization of the potential genotype in the crop are prerequisite to any crop improvement. Genetic diversity study was conducted in one hundred fifty genotypes using Mahalanobis D2 Statistics during Kharif 2017 at College of Agriculture Badnapur. Based on D2 values, 150 genotypes were grouped into XII clusters. In the present investigation, the cluster II was with the highest number of genotypes (62) followed by cluster I (33), clusters VI (25), cluster VI (16), IX (3), X (3) and cluster III, V, VII, VIII, XI , XII had single genotype. The intra cluster distance (D) range from 4.74 to 48.64. The maximuminter cluster distance (D= 48.64) was observed between cluster XII and IX cluster, followed by cluster XI and IX (D= 46.25), cluster XI and cluster IV (D= 45.43), cluster IX and cluster VIII (D= 43.92), cluster IX and cluster II (D= 39.03) indicating that the genotypes falling in these clusters were highly divergent from each other implying large amount of diversity within and between groups, which could be exploited in breeding programmes. As crosses between genotypes belonging to the clusters with maximum inter cluster distance, may give high heterotic response resulting in better recombinants.

Genetic divergence in Chrysanthemum (Dendranthema x grandiflora Tzvelev) based on morphological traits

Genetic diversity of thirty-one genotypes of Chrysanthemum were analysed for various growth and flowering related traits. Analysis of variance revealed significant differences among the genotypes for all the morphological traits studied. The clustering pattern based on Mahalanobis D2 statistics categorised genotypes into six distinct clusters. The largest cluster i.e. cluster III composed of eleven genotypes followed by cluster II with nine genotypes, cluster I having eight genotypes and cluster IV, V, and VI with one genotype each. The maximum inter-cluster distance was recorded between clusters IV and cluster V (376.87) followed by clusters IV and cluster VI (344.96) and, cluster II and cluster IV (196.81). The maximum intra-cluster distance was observed for cluster III (56.57), followed by cluster II (46.87) and cluster I (29.52). Among all the clusters, genotypes in cluster II recorded highest cluster mean values for number of branches per plant (7.15), number of leaves (119.72) and flowers (91.69) per plant. Among nine characters, number of flowers per plant contributed maximum to divergence (32.26%). Therefore, for chrysanthemum improvement, highly diverse genotypes can be used as parents for crossing to generate high variability.

Genetic divergence studies of fodder yield and quality attributing characteristics in promising maize (Zea mays L.)composites

The objective of the current study was to assess the extent of genetic variation among twenty-seven maize varieties using morpho-agronomic data based on Principal Component Analysis (PCA) and to measure the genetic distance among these genotypes using hierarchical cluster analysis. Twenty-seven composites were grown in a randomised complete block design with three replications for two years. The experimental material was assessed for 15 morpho-agronomic traits. Green fodder yield depends on various other traits such as plant height, number of leaves, leaf length and fodder quality traits such as crude protein, acid detergent fibre and neutral detergent fibre. This study showed a positive correlation of green fodder yield with various such traits. A very high positive correlation was noticed between number of leaves and ear height (0.723) and between crude protein and dry matter digestibility (0.823). However, crude protein showed a significant in vitronegative correlation with acid detergent fibre (-0.739) and neutral detergent fibre (-0.678). Five principal components had more than one eigen value, contributing 75% variability among genotypes. PC contributes 125.1% followed by PC with 19.9%, PC with 12.5%, PC with 9.7% and PC with 7.8%. The scree plot revealed 2345that the experimental material could be divided into five clusters. The genotypes under cluster five could be used to improve green fodder yield. The minimum intra-cluster distance observed for cluster 1 was 48.008, and the maximum inter-cluster distance observed between clusters 2 and 5 was 259.45. The different groups obtained could be useful for deriving the inbred lines with diverse features, which could be used in various maize breeding programmes.

Genetic diversity analysis in soybean (Glycine max L.)

Using Mahalanobis D2 Statistics, genetic diversity research was carried out on 321 different genotypes of Soybean (Glycine max L.) at All India Coordinated Research Project on Soybean, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra. Total 321 genotypes were classified into ten clusters based on D2 values. Cluster II, cluster VII, cluster VI, cluster V and cluster IX had 74, 15, 9, 3 and 2 genotypes, respectively, whereas, cluster I had the maximum genotypes of 214. One genotype was present in clusters III, IV, VIII and X. Cluster VII (1230.69) had the greatest intra-cluster distance, followed by Cluster VI (1104.13), Cluster II (604.39), Cluster I (478.57), Cluster IX (209.08) and Cluster V (96.3). D2 Values across the clusters ranged from 128.81 to 15699.76.The maximum inter-cluster distance was noticed between cluster X and cluster III (15699.76); followed by cluster X and cluster V (15568.61); cluster X and cluster VI (12020.02) and cluster X and cluster I (11083.56). Plant height (37.1%), number of pod clusters/plant (28.83%), total number of pods/plant (21.48%) and number of nods/plant (5.95%) contributed the most to diversity. Genotypes included in Cluster X & Cluster III; Cluster X & Cluster V and Cluster X & Cluster VI were identified for diverse source in the hybridization programme for identification of desirable transgressive segregants for important Agronomic traits in soybean.

Divergence Studies for Early Seedling Vigour Related Traits, Yield and Yield Components in Rice (Oryza sativa L.)

The present study was carried out in the Autumn 2020-21 using a Randomized Complete Block Design (RCBD) with three replications. Forty-two different genotypes of rice were evaluated in this investigation. These genotypes were assessed based on 21 quantitative traits, which includes yield and yield related traits and early seedling vigour related traits. The Mahalanobis D2 statistic was used for characterizing the genotypes. Based on the D2 analysis, the 42 rice genotypes were grouped into seven clusters. Among these clusters, cluster I was the largest, consisting of 22 genotypes. Cluster III exhibited the highest intracluster distance (22.04), while the maximum inter-cluster distance was observed between clusters II and III (49.06), followed by clusters III and VII (45.84). These results highlight the significance of the genotypes present in these clusters for harnessing heterosis and exploiting the desirable traits associated with them.

Assessment of Genetic Diversity in Muskmelon (Cucumis melo L.) Genotypes Through D2 Statistics

One hundred and twenty-four diverse genotypes of muskmelon (Cucumis melo L.) were used for assessment of genetic diversity in muskmelon genotypes through Mahalanobis D2 technique in Randomized Complete Block Design with two replications during the summer 2019. D2 analysis indicated wider genetic diversity among 124 genotypes of muskmelon, which were grouped into 14 clusters. In general, intra-cluster distances were lower than inter-cluster distances, indicating that genotypes included within a cluster tended to diverse less from each other. The maximum inter-cluster distance (D = 1086.24) was found between cluster III and XIV. The minimum inter-cluster distance was observed between cluster I and II (D = 169.03). The intra-cluster distance (D) ranged from 0.0 (cluster- XIII and XIV) to 337.38 (cluster- XI). The cluster XI showed the highest mean values for most of the morphological parameters desirable for yield. The most productive hybrids and diverse segregating materials might come from high yielding parents with high genetic diversity. Therefore, based upon high yielding genotypes and large inter-cluster distances, crossing of the genotypes belonging to cluster XI and V might be used in hybridization programme to produce derived transgressive segregants for traits of interest to improve muskmelon.

Genetic Diversity Analysis for Yield and Yield Attributing Traits in Finger Millet (Eleusine coracana L.)

The present investigation was carried out to assess the genetic variability, heritability, genetic advance, genetic diversity in 37 finger millet genotypes for 15 quantitative traits during Kharif, 2022 at Field Experimentation Centre, Department of Genetics and Plant Breeding, Naini Agricultural Institute, Sam Higginbottom University of Agricxulture Technology and Sciences, Uttar Pradesh in Randomized Block Design with 3 replications. The analysis of variance for mean sum of squares due to genotypes showed significant differences for all the 15 quantitative characters. The genotype, IE-184 followed by IE-195, IE-185, IE-191, IE-199, IE-180 exhibited highest grain Yield per Plant, while IE-111, IE-150, IE-169, IE-170, IE-175, IE-168 genotypes are early in maturity. Whereas, genotypic and phenotypic coefficient of variation were found high for flag leaf length, number of productive tillers, number of fingers per ear, finger length. High heritability and high Genetic advance were recorded in plant height, flag leaf length, ear width, number of fingers per ear, finger width. Clustering by Tocher’s Method has grouped all 37 genotypes into 6 clusters, in which Cluster-I contains more (16) genotypes and Cluster-IV, Cluster-V, Cluster-VI contains less (1) genotypes. According to Mahalanobis Euclidean Distance (not to scale), the maximum Inter-Cluster distance is recorded between Cluster-I and Cluster-VI (10.52) followed by Cluster-II and Cluster-V (10.44), Cluster-II & Cluster-III (9.35), Cluster-II & Cluster-IV (9.21). Plant height followed by grain yield per plant and days to 50% flowering traits contributes the highest percentage towards the overall divergence among the genotypes. Hence the selection of genotypes based on the above-mentioned characters and Inter Cluster Distance will be useful for crop improvement in Finger Millet.

Genetic divergence analysis for qualitative and quantitative traits in groundnut (Arachis hypogaea L.)

In the present investigation, 60 genotypes of groundnut were grouped into 12 different clusters. D2analysis indicated existence of wider genetic variability in the population of sixty genotypes which were grouped in twelve clusters, based on their inter clusters distance. The maximum inter-cluster distance was found between cluster III and X carrying one and two genotypes from each cluster respectively followed by that between V and X and cluster III and XII. The minimum inter-cluster distance was observed between cluster VII and XI. The minimum intra-cluster distance (D) was found in cluster II which includes eight genotypes. Cluster III showed high genetic divergence with cluster X followed by cluster V. Therefore it is advisable to make crossing between the genotypes from cluster I with cluster X, cluster III, cluster V and cluster VIII for the generation of wide spectrum genetic variability and isolation of transgressive segregants for enhancement of pod yield in groundnut.

Multivariate analysis for yield and yield-related traits of oat (Avena sativa L.) genotypes in Ethiopia

The study aimed to generate information on agro-morphological variability among the 120 oat genotypes in the central highlands of Ethiopia. The result showed that the hierarchical clustering grouped the genotypes into four clusters. The highest number of genotypes grouped into the first cluster (38) followed by the second cluster (35) and the fourth cluster (33) while the lowest genotypes (14) were recorded in the third cluster. High forage yield-producing genotypes were grouped into the second cluster while high grain-producing genotypes were grouped into the third cluster. The intra-cluster genetic distance values ranged from 4.3 (C3) to 2.3 (C1). The minimum inter-cluster genetic distance was recorded at 11.7 (between C1 and C2), while the maximum inter-cluster distance was 63.2 (between C3 and C4). Principal component analysis showed that the first four principal components with eigenvalues greater than one contributed 78.3% of the variability among genotypes. The highest contributing traits in the first component were forage yield production rate, biological yield production rate, panicle length at grain harvest, forage dry matter yield, and number of spikelets per panicle. The traits with the greatest weight on the second component were harvest index, grain yield, number of leaves at forage harvest, and plant height at grain harvest. Proper selection of best yield performing genotypes coupled with high yield contributing traits is very important to yield improvement and future oat breeding program. Therefore, selection based on the traits that had a high contribution to the first two principal components would be effective for yield improvement in oat genotypes.

Genetic diversity analysis of Indian Cassava (Manihot esculenta Crantz) accessions using morphological and molecular markers

Thirty cassava accessions, including released and pre-release varieties in India were selected for morphological, statistical and molecular analysis to evaluate their genetic divergence. Based on ANOVA (Analysis of Variance), significant differences were observed in thirty genotypes for the fifteen characters used in the study. Most of the characters such as plant height, stem weight plant−1, number of leaves plant−1 and mean weight of tuber exhibited high GCV and PCV along with a positive correlation to tuber yield plant−1. Path analysis showed that stem weight plant−1, number of tubers plant−1, number of leaves plant−1, leaf dry matter content and number of nodes plant−1 directly affected tuber yield plant−1. The genotypes were then grouped into nine clusters following Mahalanobis’ D2 statistics with clusters IV and VIII recording the maximum inter-cluster distance, which gave an idea about the diversity prevailing among them. PCA analysis showed that stem girth, number of nodes and tuber yield plant−1 accounted for greater variability among the genotypes. Molecular analysis using SSR markers showed polymorphism for eighteen markers and molecular dendrogram clustering grouped the genotypes into three principal clusters with different subclusters. Overall, the study highlights the genomic diversity of cassava accessions and provides valuable insights into their characteristics and yield potential.

Principal Component Analysis and Genetic Divergence Studies for Yield and Yield-Related Trait of Groundnut (Arachis hypogaea L.) Genotypes at Pawe North Western Ethiopia

A study was conducted on sixty-four (64) groundnut genotypes at Pawe northwestern part of Ethiopia. And the analysis of variance revealed the existence of significant variation among the tested groundnut genotypes. Cluster analysis showed the existence of five (5) divergent groups and the maximum inter-cluster distance was observed between cluster (II) and cluster (V) D2=1419.77 and the shortest inter-cluster squared distance was found between cluster (I) and Cluster (III) D2=247.23. The first four principal components for (PCs) accounted for 70.03% of the total variation. Overall, the results of the current study depicted the presence of sufficient genetic diversity existed among tested groundnut genotypes for further use in breeding programs. However, a one-season experiment will not realize variability because quantitative traits are polygenic and highly influenced by the environment. So, further experiments must be conducted over location and seasons.

Estimation of Genetic Divergence in Garden Pea (Pisum sativum L.) Germplasm

Genetic diversity among thirty garden pea genotypes was worked out using Mahalanobis D2 statistics. Based on genetic distance, genotypes were grouped into ten clusters of the ten clusters, cluster I was the largest, having 11 genotypes, followed by cluster IV, cluster VIII, cluster III, cluster V and clusters II, VI, VII, IX and X, with one genotype in each. The average intra-cluster distance was maximum in cluster VIII (487.04) and minimum in cluster V (125.72). The maximum inter-cluster distance was observed between cluster VIII and cluster X (3439.67), indicating the genotypes in these clusters are more diverged and they can be used as parents in the hybridization program to obtain superior segregants. Cluster means for various traits revealed that cluster VIII was found superior for plant height at 60 DAS, number of branches per plant at 60 DAS, and number of pods per plant. Thus, genotypes from this cluster could be used as divergent parents to improve these particular characters. Pod yield per plant contributed the maximum (38.16 %) to the genetic diversity among the characters studied.

Genetic Divergence Study in Groundnut Genotypes (Arachishypogaea L.)

Employing the Mahalanobis D2 statistic, a divergence study was performed on 36 groundnut genotypes and 13 clusters were identified. Indicating that the genotypes of these groups may be more divergent from one another, the maximum inter-cluster distance (D) was found between cluster II and cluster XIII (315.56), followed by cluster III and cluster IX (289.56), cluster III and cluster XII (289.21), and cluster XII and cluster XIII (297.11). The genotypes in the mentioned clusters showed a significant difference in the means for traits that contribute significantly to yield, indicating that the genotypes in these clusters make ideal parents in a hybridization programme to produce transgressive segregants and improve groundnut.

Assessment of Genetic Diversity for Grain Yield in Rice (Oryza sativa L.) Genotypes under Humid South Eastern Plain of Rajasthan, India

Rice (Oryza sativa L.) is the most staple food source and grain for more than half of the world’s population, therefore identify the best suitable genotypes for proper crossing is important to produce high yielding potential varieties with best cooking and biochemical quality characters. Diversity helps the plant breeder in selecting the best parents for breeding programmes. The experimental material were evaluated in Randomized Block Design (RBD) with three replications. The 25 Rice genotypes were divided into 1 to 6 clusters grounded by Mahalanobis’s D2 statistics. Cluster II comprise with the highest number of (8) genotypes from differently originated and cluster I comprise of 7 cultivars exhibit supreme grain yield whereas cluster VI consisted with the least number of (1) genotypes. Maximum inter-cluster distance was recorded between cluster III and VI. Cluster I had the principle mean values for grain yield and Number of productive tillers per plant and Cluster VI had the head mean values for 1000-grain weight. These clusters of cultivars may serve as prospective donors for future hybridization programs to create high yielders if they possess the desired traits.

Genetic analysis and diversity studies in sesame (Sesamum indicum L.)

Genetic variability, path coefficient and diversitywere studied using 56 genotypes ofsesame [Sesamum indicum (L.)] in RBD with three replications at Agricultural Research Station, Mandor, Jodhpur during kharif 2019. Themean squares for all the characters were significant indicating the presence of wide genetic variability. The high magnitudes of PCV and GCV for seed yield and moderate values for primary branches/plant depicted the presenceof high amount of variation. High heritability coupled with high genetic advance for seed yield suggesting that it could be improved through direct selection due to predominant additive variation. High heritability with moderate genetic advance as 5% of mean were observed for plant height and 1000 seed weight indicating the influence of non-additive gene action in the expression ofthese traits. Correlation coefficient analysis showed that seed yield had significant positive association with number of capsules/plant followed by 1000 seed weight and oil content at both genotypic and phenotypic level. Path coefficient analysis revealed that number of capsules/plant possess the highest positive direct effect (0.473) followed by 1000 seed weight (0.432) and plant height (0.313) on seed yield, whichsuggested that during selection more emphasis should be given to these characters to develop a desirable plant type. In the diversity study, the maximum intra-cluster distance was estimated in cluster-VIII (11.77) followed by cluster-VI (10.74), cluster-I (8.94), cluster-II (8.76), cluster-III (7.11) and cluster-IV (5.12) indicating wide genetic variability within the genotypes of these six clusters. The maximum inter-cluster distance was estimated between cluster-III and VIII (69.10) followed by cluster-III and IV (62.33) and cluster-III and VI (62.24), suggesting wide diversity between genotypes of these clusters.