Maximum Inter-cluster Distance Research Articles

Study of genetic divergence in rice (Oryza sativa L.) genotypes with high grain zinc using Mahalanobis’ D2 analysis

The present investigation was conducted with twenty-two genotypes of rice during Kharif, 2018 in RBD with three replications in five different locations. The 22 rice genotypes were characterized based on 16 quantitative traits viz., days to first flowering, days to 50 per cent flowering, days to maturity, the total number of effective tillers per plant, plant height (cm), panicle length (cm), the number of spikelets per panicle, the number of grains per panicle, spikelet fertility percentage, grain weight per panicle (g), grain yield per plant (g) , 1000-grain weight (g), grain yield per plot (kg), grain yield per hectare (kg), grain L/B Ratio, grain zinc content (ppm or mg /kg) using Mahalanobis D2 statistic. D2 analysis distributed the 22 genotypes into six clusters, of which cluster I was the largest with 15 genotypes. Cluster II had maximum intra-cluster values of 5.16 and the maximum inter-cluster distance was observed between the clusters III and V (40.51) followed by cluster IV and V (28.39) indicating the importance of the genotypes present in these clusters for exploiting heterosis for the desirable traits of these clusters.

Mapping QTLs underpin nutrition components in aromatic rice germplasm

As rice is an important staple food globally, research for development and enhancement of its nutritional value it is an imperative task. Identification of nutrient enriched rice germplasm and exploiting them for breeding programme is the easiest way to develop better quality rice. In this study, we analyzed 113 aromatic rice germplasm in order to identify quantitative trait loci (QTL) underpinning nutrition components and determined by measuring the normal frequency distribution for Fe, Zn, amylose, and protein content in those rice germplasm. Comparatively, the germplasm Radhuni pagal, Kalobakri, Thakurbhog (26.6 ppm) and Hatisail exhibited the highest mean values for Fe (16.9 ppm), Zn (34.1 ppm), amylose (26.6 ppm) and protein content (11.0 ppm), respectively. Moreover, a significant linear relationship (R2 = 0.693) was observed between Fe and Zn contents. Cluster analysis based on Mahalanobis D2 distances revealed four major clusters of 113 rice germplasm, with cluster III containing a maximum 37 germplasm and a maximum inter-cluster distance between clusters III and IV. The 45 polymorphic SSRs and four trait associations exhibited eight significant quantitative trait loci (QTL) located on eight different chromosomes using composite interval mapping (CIM). The highly significant QTL (variance 7.89%, LOD 2.02) for protein content (QTL.pro.1) was observed on chromosome 1 at 94.9cM position. Also, four QTLs for amylose content were observed with the highly significant QTL.amy.8 located on chromosome 8 exhibiting 7.2% variance with LOD 1.83. Only one QTL (QTL.Fe.9) for Fe content was located on chromosome 9 (LOD 1.24), and two (QTL.Zn.4 and QTL.Zn.5) for Zn on chromosome 4 (LOD 1.71) and 5 (LOD 1.18), respectively. Overall, germplasm from clusters III and IV might offer higher heterotic response with the identified QTLs playing a significant role in any rice biofortification breeding program and released with development of new varieties.

Genetic divergence of blackgram genotypes (Vigna mungo (L.) Hepper)

Divergence analysis was carried out among hundred black gram genotypes using Mahalanobis D2 analysis. Among ten characters studied, seed yield per plant (g) contributes maximum to the genetic diversity (33.31%). Black gram genotypes were grouped into 14 clusters. Among this, cluster I had maximum number of genotypes. Maximum intra-cluster distance was found in cluster II and the maximum inter-cluster distance was observed between cluster IV and XI. Cluster XI (VBG 19-002) showed the highest cluster mean for seed yield per plant (g), the number of branches per plant and the total number of pods. Cluster IV (VBG 18-076) had superior mean for days to 50% flowering, plant height (cm) and pod length (cm). Hence, hybridization of genotypes VBG 18-076 (Cluster IV) and Mash 114 (Cluster XII) with VBG 19-002 (Cluster XI) could give wide range of variability in segregating population.

Studies on genetic diversity for yield, quality and yield attributing traits in cluster bean [Cyamopsis tetragonoloba (L.) Taub.] genotypes

The study was carried out to assess the genetic divergence among 56 cluster bean genotypes using Mahalanobis D2. Fifty-six genotypes were grouped into 8 clusters based on 11 characters. The intra-cluster distances were seen to be lower than the inter-cluster distances. The maximum inter-cluster distance was noticed between cluster VI and VII whereas, inter-cluster D2 value was least between cluster I and V. The maximum intra-cluster distance was observed in cluster IV. Clusters V, VII and VIII had only one genotype each and hence intra-cluster distance was 0.00. The per cent contribution towards genetic diversity was maximum in 100 seed weight (52.08%) followed by the protein content of pods (45.19%). On the basis of inter-cluster distances observed, the genotypes with specific characters can be utilized for the hybridization programme.

Genetic divergence studies in pearl millet (Pennisetum glaucum (L). R. Br)

The present investigation was conducted to evaluate the genetic divergence among fifty pearl millet germplasms using Mahalanobis D2 statistics for fourteen different traits. Analysis of variance indicated considerable diversity among genotypes showing significant variability for all the characters. D2 clustering grouped the genotypes into sixteen clusters. The maximum (191.2) inter-cluster distance was observed between cluster XV and XVI followed by clusters V and XV (144.9), clusters X and XV (139.7), clusters XIII and XV (137.8), clusters XI and XV (120.2) and clusters VI and XVI (117.3). The genotypes PPBI-04 from cluster XI, PPBI-34 from cluster V, PPBI-38 from cluster XVI and PPBI-39 from cluster IX were considered on the basis of higher inter-cluster distances and superior performance for yield and yield contributing characters. Though the inter-cluster distances of cluster I with other clusters were low, PPBI-31 and PPBI-44 from cluster I were selected based on high grain yield and important yield contributing characters. Hybridization among these genotypes produces heterotic combinations for improving grain yield per plant. Inclusion of genotypes, PPBI-34 and PPBI-44 in the crossing programme would produce drought-tolerant varieties as they were found superior for SPAD chlorophyll meter reading at 45 DAS.

Genetic divergence in advanced breeding lines and varieties of mungbean

The present investigation was carried out to study the genetic divergence of 100 mungbean genotypes using Mahalanobis D2 analysis. Among the traits studied, the number of branches contributed maximum percentage towards the total genetic divergence. The genotypes were grouped into fifteen clusters, with cluster I having the maximum number of genotypes. Maximum intra-cluster distance was recorded in cluster I indicating higher diversity among genotypes of this cluster. Cluster V and XV recorded maximum inter-cluster distance indicating wider divergence between genotypes of these clusters. Likewise, clusters III and XII also recorded wider divergence. Hybridization between genotypes of cluster V (VGG 16-035, VGG 17- 004) and cluster XV (VGG 17-009) followed by cluster III (VGG 18-012) and cluster XII (ADT 3) could yield better segregants. High mean performances for the number of clusters per plant, the number of pods per cluster, the total number of pods per plant and seed yield per plant was observed in cluster XIII (VGG 15-030). This genotype can be utilised for further crop improvement programmes in mungbean.

Estimation of genetic advance, heritability, genetic gain and genetic diversity of elite genotypes of grain cowpea [Vigna unguiculata (L.) walp.

The present investigation was conducted during kharif 2018 to evaluate forty-two genotypes including five checks, Pant Lobia 1, Pant Lobia 2, Pant Lobia 3, Pant Lobia 4 and Pant Lobia 5 of grain cowpea at Breeder Seed Production Centre to estimate genetic divergence, variability, heritability, genetic advance. Analysis of variance showed the presence of significant amount of variability in all the characters studied. Genetic divergence was performed by D-square statistics. Genotypes were divided into 8 clusters. Maximum inter-cluster distance was observed between cluster VI and VII while maximum intra-cluster distance was observed in cluster V. Mean values of different characters between different clusters was observed maximum for number of seeds per pod. Inter-cluster distance was higher than intra-cluster distance. High estimates phenotypic and genotypic variance was observed for yield per hectare. High estimate of PCV and GCV was observed for yield per plot. High heritability with high genetic advance was observed for plant height, yield per hectare and yield per plant. Moderate heritability and genetic advance were observed for days to 50% flowering while low heritability with low genetic advance was observed for leaf length. In the present investigation, on the basis of mean performance of genotypes PGCP 24, GCP 219 and GCP 378 were found superior of all the genotypes. Earliest 50% flowering was observed in Phule PCP 1124 and GCP-360 which is considered most important and desirable character in cowpea. Three genotypes namely, GCP 345 and GC 3 were identified as the most diversified and could be utilized in future crop improvement programmes.

Multivariate Analysis of Genetic Divergence and Character Association in Ethiopian Kale Accession(Brassica Carinata A)

Ethiopian kale is an important crop of Ethiopian origin and it has been grown in Ethiopia since antiquity both as a vegetable and oilseed crop. Cultivation of Ethiopian kale, as a vegetable, requires genetic improvement which relies on its genetic diversity and interrelationships among traits. The present study had objective, to assess the association among seed-yield and yield related traits. The experiment was carried out using 7x7 simple lattice design at Debre-zeit agricultural research center during the 2017/18 main cropping season. In this study, genetic diversity in 49 Ethiopian kale accessions, collected from the diverse agro-ecological area of the country were assessed using the techniques of cluster and principal component analyses based on 14 traits. Multivariate analyses of genetic divergence among accessions have resulted in the formation of three clusters, and have shown the presence variability for further selection and breeding. The largest and smallest numbers of accessions were found under cluster one and three respectively. The accessions subjected to divergence study fall in to different cluster showing the existence of significant difference (p<0.01) between all pairs of clusters. The maximum inter-cluster distance was found between cluster one and three which are better to use as a parent, while the minimum distance was showed between two and one. 75.8% of the variation was contributed by the fourth principal components among the accessions using agro-morphological traits. PC1 had 33.94% of total variation in agro morphological traits; PC2 depicted 21.45% of total morphological variability, while PC3 and PC4 accounted for 12.11% and 8.3 respectively, for the total variation.

Genetic diversity in Indian poppy (P. somniferum L.) germplasm using multivariate and SCoT marker analyses

The current study was undertaken to estimate the morphological and molecular diversity present among the 51 accessions of Indian opium poppy germplasm using Mahalanobis D2 and SCoT (Start Codon Targeted Polymorphism) marker analyses, respectively. A good range of morphological variations were observed among the accessions. The accessions were clumped into nine clusters and the morphological diversity recorded was 69%. Clusters VII and IX showed the maximum inter-cluster distance (117.97) whereas it was found to be minimum (21.53) in case of clusters II and III. The morphological trait, seed yield per capsule, contributed maximum (17.30%) towards the genetic divergence followed by thebaine content (14.56%) and papaverine content (14.06%). In contrast to the morphological diversity, genetic diversity at molecular level was found to be limited (33%), although successfully detected by utilizing DNA markers targeting coding regions of genome (SCoT markers). The outcome of the study has prospects in identification of lines with desirable traits to be utilized in future breeding programmes.

Fuzzy granularity neighborhood extreme clustering

Clustering is an important method for data analysis. Up to now, how to develop an efficient clustering algorithm is still a critical issue. Unsupervised extreme learning machine is an effective neural network learning method which has a fast training speed. In this paper, a fuzzy granularity neighborhood extreme clustering algorithm which is based on extreme learning machine is proposed. We use fuzzy neighborhood rough set to develop a new feature selection method to eliminate redundant attributes and introduce the adaptive adjustment mechanism to solve the parameters of unsupervised extreme learning machine. Different from the existing clustering algorithms, the proposed algorithm can obtain a clustering result with minimum intra-cluster distance and maximum inter-cluster distance. The proposed algorithm and comparison algorithms are executed on the synthetic data sets and real data sets. The experimental results show that the proposed algorithm outperforms the comparison algorithms on the most data sets and the proposed algorithm is effective for clustering task.

Clustering and Principal Component Analysis of Nerica Mutant Rice Lines Growing Under Rainfed Condition

A field experiment was conducted at subtropical region in Bangladesh to assess the contribution of morphological traits to variability in some NERICA mutant rice lines. The experiment was conducted following RCBD with three replications. Thirty-one NERICA rice genotypes (twenty-eight mutant lines along with three parents) of advanced generations were used. Data were collected on twelve morphological traits. The results of the principal component analysis showed that the first four components account for 80% of total variation giving a clear idea of the structure underlying the variables analyzed. This result was also supported by scree test. Cluster analysis using Ward's method classified the thirty-one genotypes into five distinct groups. The maximum inter-cluster distance was observed between clusters indicating the possibility of high heterosis if individuals from these clusters are cross-bred. The results of PCA were closely in line with those of the cluster analysis. These results can now be used by breeders to develop drought tolerant high yielding rice varieties and new breeding protocols for rice improvement.&#x0D; Int. J. Appl. Sci. Biotechnol. Vol 7(3): 327-334&#x0D;

Assessment of Genetic Variability and Diversity for Quantitative Characters in Naked Barley (Hordeum vulgare (L.) var. nudum Hk. f.)

Forty genotypes of hulless barley were studied to understand the extent of genetic variability and diversity based on 7 quantitative characters. A wide range of variation was observed for seed yield per plot followed by plant height, tillers per meter and 1000-grain weight. High heritability coupled with high genetic advance as percent of mean was registered for seed yield per plot and tillers per meter in genotypes indicating the predominance of additive gene action for these traits. Based on D2 statistics, 40 genotypes were grouped into 7 clusters in which cluster IV consisted of only single genotype (Geetanjali) while other six clusters involved multi-genotypes. The maximum inter-cluster distance was observed between cluster IV and VII (120.82) followed by cluster IV and V (107.43). Geetanjali of cluster IV exhibited highest seed yield per plot and tillers per meter along with early days to 50% heading. The genotypes involved in cluster IV and VII may be utilized in hybridization programme for improving the characters like early maturity, tillers/meter, short plant height and seed yield/plot.

Genetic Divergence Studies in Doubled Haploids of Ethiopian Mustard (Brassica carinata A. Braun)

The doubled haploids of Ethiopian mustard (Brassica carinata A. Braun) were evaluated along with mustard under two environments during rabi, 2010–11. Analysis of variance for different traits such as days to flower initiation, days to 50 per cent flowering, days to 75 per cent maturity, plant height, number of primary branches per plant, number of secondary branches per plant, siliquae per plant, length of main shoot, siliquae on main shoot, siliqua length, seeds per siliqua, 1000-seed weight, seed yield per plant, biological yield per plant, harvest index and per cent oil content revealed the presence of significant genetic variability for all characters except siliqua length and per cent oil content in Environment I (Env. I). On the other hand in Environment II (Env. II), the presence of significant genetic variability for most of the traits was observed. Pooled analysis over environments revealed the presence of g × e interactions for all characters except days to fl ower initiation and per cent oil content. All the 33 genotypes could be grouped into three clusters. Maximum genotypes were placed in cluster I. The cluster I exhibited maximum intra-cluster distance (1.12), while maximum inter-cluster distance was observed between cluster II and III (2.34). Maximum contribution towards genetic divergence was due to days to 75 per cent maturity.

Selection of promising genotypes of lentil (Lens culinaris Medik.) by deciphering genetic diversity and trait association

A panel of fifty diverse genotypes of lentil were evaluated to assess the genetic diversity for 11 morpho-physiological attributes. The results revealed wide range of variability among the genotypes for the examined characteristics. The mean performance demonstrated that the best genotype for more than one trait viz., plot yield, yield/plant, Leaf Area Index (LAI), Crop Growth Rate (CGR), biomass and plant height was LL1384. Traits association approximation witnessed a positive and significant relationship of seed yield with most of the studied traits. Cluster analysis distributed genotypes into seven distinct clusters. Cluster III happened to be the largest comprising of 20 genotypes, followed by Cluster VII comprising of 9 genotypes. The maximum inter-cluster distance was perceived between clusters II and IV which suggests the possibility of high heterotic effect if cross will be made between the individuals of these clusters. The principal component analysis developed 11 Eigen vectors and, of these three principal components had explained about 82.50% of variations. The characters that had the highest weight in component first were plot yield, yield/plant, pods/plant, CGR, biomass/plant, LAI and plant height, which explained 57.03% of the total variance. The biplot results were in accordance with correlation estimation, indicating that indirect selection based on component traits would help in improving the seed yield in lentil. Hybridization among genetically diverse genotypes of different clusters would be helpful in broadening the genetic base as well as in the creation of desirable recombinants for developing new improved lentil varieties.

Genetic diversity analysis and identification of promising lines for hybridization in Chickpea (Cicer arietinum L.)

Forty genotypes of chickpea were evaluated for assessing genetic divergence for different quantitative characters for improving yield potential of chickpea by using Mahalanobis D2 statistics. The genotypes were grouped into seven clusters suggesting considerable amount of genetic diversity in the material. The intra-cluster D2 value ranged from 0.00 to 9.06 while, intercluster D2 value ranged from 4.07 to 55.71. The maximum intra cluster distance was exhibited by cluster V followed by cluster II and cluster I. Cluster III had mono- genotype and emerged with contained highest cluster mean value grain yield per plot. Cluster II has highest mean value for number of pods per plant and lowest mean value for days to 50% flowering, days to maturity and plant height. Maximum contribution toward the total divergence was exhibited by 100-seed weight followed by number of pods per plant and minimum by days to maturity. Cluster IV and VI showing maximum inter cluster distance and crossing of genotypes Sabour chana-1 (BRC-1), GCP 105, PBC 503, DC 16-2, NBeG 776, RVSSG 42, G2016-43, GL 14042, IPC 2013-21, GNG 2338, GNG 2375 and KWR 108 from cluster VI suggested for improving grain yield per plot, 100-seed weight and earliness in flowering and ultimately enhancing the yield and chances of getting better recombinants in segregating generations.

D2 statistical analysis of yield contributing traits in maize (Zea mays L.) inbreds

Investigation was carried out to determine the genetic divergence in the 25 maize inbred lines. Analysis of variance revealed highly significant differences among all the inbreds. Inbreds were grouped into five clusters, indicating the presence of genetic diversity. The clusters I, IV and V had the highest number of inbreds (6). The maximum inter-cluster distance was observed between clusters I and III (19.279) and the highest intra-cluster distance was recorded in cluster III (0.243) and also wide range of variation was observed in cluster mean performance for the characters studied. Intercrossing among the inbreds belonging to clusters II and III was suggested to develop high yielding inbreds with desirable characters.

Genetic diversity studies for pod yield and nutrient uptake related traits in groundnut

Divergence analysis using Mahalanobis’s D2 statistics grouped 40 groundnut genotypes into eight clusters. The maximum inter-cluster distance was found between clusters II and VIII (D=183.23) followed by cluster VI and VIII indicating that the genotypes of these groups were highly divergent from each other. Among all the characters, pod yield per plant contributed the maximum to the diversity followed by leaf iron content (ppm) at 60 DAS, seed iron content (ppm) at maturity, seed calcium uptake (Kg ha-1) and seed calcium content (%) at maturity.The genotypes of above clusters revealed a substantial difference in the means for important yield contributing characters and form ideal parents for genetic improvement in groundnut.

Evaluation of sunflower (Helianthus annuus L.) germplasm using multivariate statistical techniques

Evaluation of sunflower hybrids using morphological data is necessary and essential in sunflower breeding programs. The aim of this paper was to evaluate the productive possibilities of some sunflower germplasm using multivariate technique. Fifty sunflower genotypes were characterized using eleven morphological traits. Among the traits studied, high coefficient of variation was observed for duration ofreproductive phase (11.73%), seed yield per plant (11.49%), 100-seedweight (8.98%) and head diameter (8.33%). Agglomerative hierarchical clusteringmethod classified the fifty genotypes into five clusters. A large number of genotypes were placed in cluster III (22) followed by cluster I (14), cluster II (6), cluster V (6) and cluster IV (2). The maximum inter-cluster distance of 47.83 was observed between clusters I and cluster IV indicating the possibility of high heterosis. The first four principal components showed 71.61% of the total variation. The genotype EC-512687 and EC-601746 had found top rank by both the methods. The results of PCA were closely in line with those of composite indices. These results can be used by breeders in sunflower breeding program.

Genetic divergence for yield and yield attributes in tomato (Solanum lycopersicum)

The research experiment was conducted to study genetic diversity for quantitative and qualitative traits in tomato (Solanum lycopersicum L.). The investigation was conducted during rabi, 2015-16 at Vegetable Research Farm, College of Horticulture, Rajendranagar, Hyderabad. Using Mahalanobis D2 statistic, the 30 genotypes were grouped into eight clusters, indicating the presence of diversity for different traits. The cluster I had the highest number containing 19 genotypes followed by cluster II containing five genotypes. However, the cluster III, IV, V, VI, VII and VIII were solitary. The maximum intra-cluster distance was recorded within cluster II (64.36) and the maximum inter-cluster distance between cluster VII and VI (220.70), indicating the existence of wide genetic variability. Based on mean performances, cluster III registered maximum plant height (134.40 cm). The genotypes included in clusters I took less number of days to first flowering (28.60), cluster III took less number of days to 50% flowering (35.33) and cluster I took less number of days to fruit set (38.33). The cluster VII registered high number of fruits per plant (326.00) and high fruit yield per plant (1.54 kg). The genotypes included in clusters I had maximum average fruit weight (51.23 g). The cluster V registered high TSS (9.07 oBrix). The cluster I registered high content of ascorbic acid (32.38 mg/100g) and beta carotene (2.33 mg/100g). Hence, these characters can be utilized in breeding programme for enhancing their respective characters. Based on cluster mean analysis, the superior and genetically divergent genotypes can be used in crop improvement programme in tomato.

Evaluation of genetic divergence in wheat (Triticum aestivum L.) germplasm

In the present study, twenty seven genotypes of wheat genotypes were evaluated for assessing genetic divergence for 14 different characters. The genetic diversity analysis revealed the formation of five clusters suggested the presence of wide genetic diversity among the 27 genotypes studied. The clustering pattern indicated that geographic diversity was not associated with genetic diversity. The maximum inter-cluster distance (D) was observed between clusters II and IV (D=43.62) followed by clusters IV and V (D=35.49) and II and III (D=34.68). The minimum inter-cluster distance (D=23.10) was found between clusters III and IV. Grains per spike, plant height, biological yield per plant, harvest index, days to heading and test weight contributed maximum towards total genetic divergence. Based on the maximum genetic distance, it is advisable to attempt crossing of the genotypes from cluster II with the genotypes of cluster IV, which may lead to the generation of broad spectrum of favorable genetic variability for yield improvement in bread wheat. Noteworthy is that cluster IV and V reflected high cluster means for days to heading, days to 50 % flowering, days to maturity, grains per spike, grain yield per plant, biological yield per plant, grain filling period, tiller per plant and plant height these clusters can be successfully utilized in hybridization programmes to get desirable transgressive segregants.