Euclidean Cluster Analysis Research Articles

Genetic Diversity of Rice Genotypes Screened under Normal and Flash Flooded Condition

The present investigation was undertaken to explore the extent of diversity in 30 rice genotypes under normal (E1) and flash flooded conditions (E2) during samba, 2020. Analysis of variance divulged significant variability with respect to all the nine traits viz., days to 50% flowering, plant height, number of productive tillers per plant, panicle length, number of grains per panicle, 1000 grain weight, grain length, grain breadth and grain yield per plant under study. Mahalanobis D2 values and non- hierarchical Euclidean cluster analysis categorized into seven clusters in E1 and three clusters in E2. The maximum intra cluster D2 was obtained in cluster V (80.618) in E1 and III (1626.542) in E2 and farthest inter cluster distance between III and cluster VI (129.797) in E1, cluster II and III (2743.060) in E2. The clusters VI and II exerted superior mean performance in E1 and cluster III and II had in E2. The characters viz., number of grains per panicles, panicle length, number of productive tillers per plant, grain breadth along with grain yield per plant were the major contributors for genetic divergence in E1. In the flash flood tolerance environment E2, the traits of plant height, grain breadth, and grain yield per plant contributed more toward the genetic divergence. Based on genetic diversity and performance of the genotypes Poongar, seeraga samba, CR 1009 sub1 and Swarna sub 1 are the superior parents for flash flood tolerance. Hence, these genotypes could be lucidly utilized for the flash flood genetic improvement program.

Multivariate Analysis to Study Genetic Diversity for Yield and its Attributing Traits in Rice (Oryza sativa L.)

The present investigation was carried out with 72 germplasm lines and three checks of rice (Oryza sativa L.) were grown at Crop Research Station, Masodha conducted in the GPB farm, Acharya Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya (U.P.) during Kharif June 2022- February 2023. Data on 10 characters, including grain yield per plant focused on diversity and PCA analysis. This investigation involved the analysis of 72 rice germplasm lines alongside three checks, showcasing extensive variation in agronomic and morphological traits. The study utilized Non-hierarchical Euclidean cluster analysis to assess genetic diversity. The pseudo F-test determined the optimal grouping of 75 genotypes into six distinct clusters. Cluster distribution revealed varying genotype compositions, with Cluster V comprising the highest entries (20), followed by Clusters I, VI, and II. Intra- and inter-cluster distances illustrated significant variability among clusters, emphasizing genetic diversity. Examining agronomic traits across these clusters revealed noteworthy variations in days to 50% flowering, days to maturity, plant height, and productive tillers. Panicle length, flag leaf area, biological yield, harvest index, 1000-grain weight, and grain yield per plant also exhibited cluster-specific variations. These findings provide valuable insights for rice breeding programs, facilitating targeted enhancements of specific agronomic traits within the rice population, thus contributing to the development of more resilient and productive rice varieties.

Variability Study Analysis for Half-sib Families under Control Environmental Conditions in Neolamarckia cadamba (Kadamb)

Neolamarckia cadamba is a widespread medium-sized deciduous forest tree over most of India, Bangladesh, and Sri Lanka. Twenty-half-sib progenies of kadamb (Neolamarckia cadamba) from various regions in Bihar, Rajasthan, and Uttar Pradesh were sown in a glasshouse in 2022 in order to assess the genetic diversity using non-hierarchical Euclidean cluster analysis. Significant variation was seen in the biomass and morphological traits of a few plus trees. Under greenhouse conditions, significant differences were seen in the growth parameters of plus tree progenies. Six clusters were formed from the twenty NPTs, according to the genetic divergence analysis. Clusters V and VI were found to have the greatest inter-cluster distance (5.530). The cluster (4.258) displayed the highest intra-cluster distance. As a result, there was a genetic divergence between clusters. Therefore, in order to obtain high-yielding genotypes in Neolamarckia cadamba, hybridization involving trees of clusters VI and V is advised. Collar diameter was a major factor in the creation of genetic diversity and contributed the most to the overall divergence. The superior plus trees of cluster V (NPT4, NPT5, NPT11, NPT12, NPT13, NPT17) and cluster VI (NPT18, NPT19, NPT20) may be taken into consideration as possible parents for a future tree improvement program in Neolamarckia cadamba due to their high cluster mean and large genetic distance.

Assessment of Yield Criteria in Bread Wheat through Correlation and Path Analysis

Path coefficient analysis was used by plant breeders to help identify traits that could be useful as a selection criterion for improving crop yield. The path coefficient divides correlation coefficients into direct and indirect effects within the correlation system of traits. When there is a genetic correlation between two traits, the selection for one of them will produce a change in the other trait. In other words, the response of the correlation to the act of selection will take place. The present investigation was conducted during rabi season of 2022-23 at Chamelti Agriculture Farm, MS Swaminathan School of Agriculture, Shoolini University, Solan, Himachal Pradesh. The experiment consisted of 75 genotypes of wheat with three check varieties viz., RAJ 3765, PBW 343 and HP 1633. The experimental field was divided into three blocks of equal size. Twenty-four entries including checks were accommodated in each block. Results indicated that grain yield per plant(g) have a positive and highly significant correlation with biological yield per plant (g), number of productive tillers per plant, harvest index (%), number of grains per spike. Path analysis identified biological yield per plant and number of productive tillers per plant as important direct components for grain yield per plant (g). As per the analysis of variance, variations due to blocks and checks were found to be significant for all the traits. Ten clusters were formed according to Non- hierarchical Euclidean cluster analysis and the maximum inter cluster was recorded between cluster 6 and 8 (86.478), followed by cluster 4 and 8 (83.180). Early maturing genotypes were contained in cluster 1 whereas cluster 4 contained the genotypes which gave the maximus grain yield per plant. High yielding genotypes identified were: DBW- 187, DBW-303, DBW-222, HD-3226 and HS-240. The identified superior can be further utilized in wheat improvement breeding programs.

An Empirical Analysis of Russian Regions’ Debt Sustainability

This paper investigates the impact of the moderate growth of government borrowing on debt sustainability in 11 Russian regions over about 10 years, starting in 2010. The current study aims to assess the debt sustainability of the Russian region’s budget by determining Euclidean distance budget constraints and cluster analysis. This study is based on the methodology of hierarchical cluster analysis, which makes it possible to isolate regions of accumulation of objects from the aggregate data and combine them into homogeneous segments. The central hypothesis of this study is that by using this method, it is possible to increase the accuracy of the values that limit budget constraints in a region’s financial system. This study, using open data from the Federal State Statistics Service, is based on a database of statistical, financial, and economic indicators of the Russian economy. The calculations include about 45 macroeconomic indicators, which reflect the ratios of socio-economic development of the region’s financial system. The methodology described in the paper for assessing the debt sustainability of budget policy proves the need to calculate six indicators and determine the debt limits for the regions of each cluster. It finds a need to reduce the high debt burden of 46% of the regions belonging to the Northwestern Federal District. Confidence intervals for the debt limit suggest that the negative growth effect of high debt may start from levels of around 5% of the debt-to-GDP ratio and about 43% of the debt-to-revenue ratio. The results indicate that regions with a high level of debt sustainability include St. Petersburg city, the Leningrad region, and the Kaliningrad region. From a state debt policy perspective, the results provide additional arguments for debt reduction for the Republic of Komi, the Republic of Karelia, the Arkhangelsk region, and the Pskov region. The general conclusion of the study boils down to the need to reduce the debt burden of the budgets of some regions of the SFZO, as well as to the need to change the upper limits of debt, which are equally set for all regions by the Budget Code of the Russian Federation, to differentiated values of public domestic debt, taking into account the results obtained in the study.

Pattern of genetic diversity in indigenous Ahu rice germplasm of Assam

The north-eastern part of India including Assam is one of the key centres of diversity of cultivated rice. Among the diverse varietal types, Ahu group of varieties with their evolutionary significance being intermediate between indica and japonica deserves attention for their detailed evaluation and utilisation in crop improvement programme. This work was attempted to elucidate the pattern of genetic variation and genetic diversity in a set of 147 indigenous Ahu rice genotypes of Assam grown under rainfed upland direct seeded condition. Among the 13 traits under study, the highest genotypic coefficient of variation was exhibited by primary branches per plant followed by secondary branches per plant and grain yield. Heritability in broad sense was the highest for grain L: B ratio followed by grain width and grain length. More than 90% heritability in broad sense was, observed for all the traits except effective tillers per plant, panicle length and grain yield. The highest genetic advance as per cent of mean was observed for primary branches per plant followed by secondary branches per plant and grain yield. Hence, selection for these traits would be most effective for further genetic improvement. At the intermediate linkage distance, four main and nine sub clusters were obtained by Euclidean cluster analysis. Cluster III b was the largest containing 35 entries, which was followed by cluster I c containing 32 entries. The variety Chidon Ahu remained distinct from all other entries and belonged to cluster I b. Based on per se performances of the genotypes and their inter se distance, promising genotypes were suggested for hybridization in order to obtain desirable segregants for further genetic improvement of Ahu rices. Keywords: Genetic variation, genetic divergence, Ahu rice, rainfed upland

Genetic Variability and G×E Interactions in a Diverse Set of Groundnut Accessions

Background: Knowledge of the genetic diversity for various agronomic traits and their interaction with the environment and subsequent classification of genotypes will be beneficial for identification of divergent and stable sources of agronomic traits. Methods: A set of 96 groundnut germplasm accessions belonging to four botanical groups were evaluated for three years (2017 to 2019) for pod yield and component traits using AMMI analysis and subsequently accessions were classified based Euclidean cluster analysis. Result: Among different botanical groups, Virginia genotypes matured late and possessed high SPAD chlorophyll meter readings (SCMR) and pod yield compared to Spanish types. The component traits of pod maturity like days to flowering (first and 50%) showed low heritability and high genotype × environment interaction (GEI) and significant negatively affected sound mature kernel (SMK) and shelling per centage (SP). The cumulative contribution of environment and GEI component to the total variance was the highest in the expression of SP (67%) followed by days to maturity (54%) and days to 50% flowering (52%). Euclidean distance-based cluster analysis grouped the 96 accessions into five major clusters. Cluster I had accessions with higher pod yield, whereas cluster V contained accessions with low SLA, high SCMR and moderate pod yield. High yielding as well as stable accessions identified based on AMMI stability value (ASV) are NRCG 17332, 10076, 17268, 17197, 17108, 10106, 10089 and 17165. Trait specific as well as stable accessions identified in the present study can be useful donors for groundnut breeding programme.

Is chiropterophily an evolutionary dead end? A phylogenetic test in the pantropical genus Parkia (Leguminosae, Caesalpinioideae, mimosoid clade)

Background and aims – Pollination systems often reflect adaptations to specific groups of pollinators, and these morphological specialisations have been important in the diversification of the angiosperms. Here, we study the evolution of the capitulum and pollination system in the pantropical genus Parkia, which comprises 35 species of trees distributed largely in the forests of South and Central America, Africa, Madagascar, and the Indo-Pacific. The flowers are grouped into capitula that are composed of one, two, or three distinct morphological types, and are principally pollinated either by insects or by bats. Material and methods – Using BEAST, we estimated the ages of nodes in a phylogeny based on four chloroplast regions (matK, trnL, psbA-trnH, and rps16-trnQ) and the nuclear region ITS/18S/26S. This analysis also enabled us to reconstruct the ancestral state of the capitulum and hence infer the ancestral pollination system. Euclidean distance-based cluster analysis was performed to determine which characters are consistently related to a specific pollination system.Key results – Our results indicate that the ancestral capitulum in the genus had three types of flowers and a morphology associated with bat-pollination in both the Paleotropics and Neotropics. In one derived Neotropical clade, the number of floral types in each capitulum was reduced to two (capitulum also bat-pollinated) or one (insect-pollinated). Thus, entomophily, as seen in some Neotropical species of Parkia, has been derived from a bat-pollinated ancestor. Cluster analysis showed that the floral characters were mostly consistent with pollination systems.Conclusion – Chiropterophily is not an evolutionary dead end in Parkia because during the evolutionary history of the genus there has been at least one transition to entomophily. Parkia provides a unique example of evolutionary transitions from chiropterophily to entomophily in a pantropical genus of trees.

Characterization of Oilseed Crop Noug (Guizotia abyssinica) Using Agro-Morphological Traits

Noug (Guizotia abyssinica) is an outcrossing oilseed crop that serves as a source of edible oil and other nutrients although its seed yield is generally low. The analysis of agro-morphological traits in relation to seed and oil yields is important for improving the productivity of this crop. The present study aimed at assessing the variation and heritability of quantitative (10) and qualitative (6) traits in noug based on 60 landrace accessions collected from wide geographic area in Ethiopia. The field trial was conducted at two sites in Ethiopia using a square lattice design. The analysis of variance revealed significant variation (p < 0.05) among these accessions. The highest broad-sense heritability (H2) was recorded for days to 10% flowering (DTF10; 85.4%), whereas number of capitula per plant (NCPP) and number of seeds per capitulum (NSPC) showed medium heritability (H2 = 38.5% and 31.6%, respectively). NCPP and NSPC showed a highly significant (p < 0.01) positive and negative genotypic correlation with days to flowering, respectively. These three traits showed very low genotypic coefficient of variation (<1%). In the case of qualitative traits, small capitulum, large flower, green leaf, green stem and course leaf margin showed significant association with higher number of seeds per plant (NSPP). Euclidean distance-based cluster analysis revealed that the clustering pattern of the accessions poorly correlates with the geographic distance between sample collecting sites. Similarly, no clear clustering pattern of accessions was revealed by principal component analysis (PCA) that explained 66.3% and 53.6% of the total variation of quantitative traits and qualitative traits, respectively. The oil content of these accessions was previously investigated and accessions with high oil content show large differences in terms of days to flowering, NSPP and thousand seed weight (TSW). Among the accessions included in this research, Hr_B21; Gj_C17, Sh_I4 and Gr_F15 Gj_G18 and Tg-R13 are top ranking, as they have at least one the following highly desirable traits: early maturity, high oil content, NSPP and TSW. Hence, crossbreeding of their selected genotypes would lead to the development of new cultivars that combine early maturity and both high seed and oil yields.

Responses and screening of white jute (Corchorus capsularis L.) genotypes against salinity stresses

Soil salinity, a serious threat to jute cultivation in saline areas (southern parts) of Bangladesh. Bangladesh Jute Research Institute (BJRI) has developed a moderately salt tolerant White Jute variety (BJRI Deshi pat-8; BJC 2197) in 2013 which can’t grow well in saline areas having more than 8.0 dSm-1 salinity stress. Hence, 23 whitejute accessions and one control variety (BJC 2197) were tested to isolate the salt tolerant accession(s) for hybridization purpose followed by augmented design in farmers’ field having nearly 8.0-9.0 dSm-1 salinity at Patuakhali district during mid-March to mid-August 2019. The experimental plot size was 3.0 m2 (3 m × 1 m) for each genotype having 3 lines of 1.0 m length, plant-plant: 10-15 cm and line- line: 30 cm distance. Soil salinity was recorded during sowing, vegetative and plant maturity stages. In this study, the highest plant height 2.84 m was recorded in Acc. 2750 followed by Acc. 2589 (2.76 m) and Acc. 1779 (2.69 m). The highest fiber yield (9.0 g plant-1) was observed in Acc. 1779 followed by Acc. 2589 (8.40 g plant-1) and Acc. 2750 (8.0 g plant-1). The lowest plant mortality rate (2.5%) was found in Acc.2750 followed by Acc.1779 (6.24%), Acc. 1780 (7.50), Acc. 3556 (11.10%), Acc. 2589 (11.20%) and BJC 2197 (16.5%). Few seeds were germinated in Acc. 3020 and Acc. 3658 but plants were died after 20 days of sowing. Six genotypes of cluster I showed higher diversity in Euclidean cluster analysis. The Acc. 2750, Acc. 1779, Acc. 2589 of cluster I having relative salinity tolerance and good fiber yield capacity would be grown in next year for confirmation as well as hybridization with the existing salinity susceptible variety to develop high yielding white jute variety for saline areas.

Genetic divergence analysis in rice (Oryza sativa L.) under sodic soil condition

Genetic divergence and variability was assessed among eighty eight (88) diverse rice genotypes including three checks (Narendra Usar Dhan 3, Jaya and CSR-36) which were evaluated in augmented deign under sodic soil using non-hierarchical Euclidean cluster analysis. The genotypes were grouped into ten clusters which indicate presence of high degree of genetic diversity in germplasm collections. Among the different clusters, cluster V with eighteen (18) entries got the highest number of genotypes followed by thirteen (13) entries in both cluster I and II. Although the least number of genotypes was observed in Cluster X but the highest intra-cluster distance was identified in cluster X (25.00), followed by cluster VIII (14.62) and VII (13.76). In case of inter-cluster distance maximum value was found between cluster X and III (46.19). So the genotypes present in the diverse clusters may serve as parental materials for hybridization programme which will leads to isolation of desirable segregants for developing high yielding rice varieties in sodic soil.

Statistical classification of South African seasonal divisions on the basis of daily temperature data

Across South Africa, a wide range of activities is influenced by differences in seasonality. In a South African context, there is little consensus on the timing of seasonal boundaries. Inconsistency exists through the use of ad-hoc approaches to define seasonal boundaries across South Africa. In this paper, we present one of the very first uniform statistical classifications of South African seasonal divisions on the basis of daily temperature data. Daily maximum and minimum temperature data were obtained from 35 selected South African Weather Service meteorological stations that had sufficiently complete data sets and homogeneous time series, spanning the period 1980–2015. An Euclidean cluster analysis was performed using Ward’s D method. We found that the majority of the stations can be classified into four distinct seasons, with the remaining 12 stations’ data best classified into three seasons, using Tavg as the classifier. The statistically classified seasonal brackets include summer (October/November/December/ January/February/March), early autumn (April) and late autumn (May), winter (June/July/August), and spring (September). Exploring the boundaries of seasons, the start of summer and end of winter months follow a southwest to northeastwards spatial pattern across the country. Summers start later and winters end later in the southwestern parts of the country, whereas in the northeast, summers start earlier and winters end earlier.
 Significance:
 
 The findings contribute to the common knowledge of seasonality in South Africa.
 New seasonal divisions in South Africa are proposed.

Genetic Diversity Assessment in Chickpea (Cicer arietinum L.) through Agro-morphological and ISSR Molecular Markers

Background: Chickpea (Cicer arietinum L.), commonly known as gram or Bengal gram, is a self-pollinated diploid plant (2n= 2x= 16) ranked third after common bean and field pea. Genetic diversity assessment is the fundamental of any breeding programme, conservation of genetic resources and as a general guide for the choice of parents in hybrid breeding. The present investigation aimed to study the genetic diversity among 45 elite chickpea genotypes using agro-morphological traits and ISSR molecular markers.Methods: The experimental material comprised of 45 elite chickpea genotypes, grown in Randomized Block Design (RBD) with three replications under natural field conditions at Research Farm of Pulses Section, CCSHAU, Hisar during Rabi 2014-15. Genetic divergence was studied using 11 agro-morphological traits by Non-hierarchical Euclidean cluster analysis and 25 ISSR primers using UPGMA based method.Result: Genetic divergence study based on agro-morphological traits and molecular markers showed ample amount of genetic variation among elite chickpea genotypes which were discussed and compared their diversity analysis as well. The present study confirmed the importance of agro-morphological traits and ISSR markers for detecting tremendous amount of genetic diversity in chickpea which may be used to select good parental material in chickpea breeding programmes for further improvement.

Genetic divergence for qualitative traits of fruit yield and its components in custard apple (Annona squamosa L.). Indigenous accessions from northern Bastar of Chhattisgarh

The field experiment was conducted at Research cum Instructional Farm, College of Agriculture and Research Station, Singarbhat, Kanker, Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.) during Kharif 2013-14. The experiment was laid out in Randomized Block Complete Design with four replication, in-situ sixty genotypes of about 10 year age were selected for investigation, which were found as wild seedling plants on forest land and rice bunds in Kanker District-(C.G.). The treatments comprised of sixty genotypes for with different qualitative character viz total soluble solid, total sugar, reducing sugar, non-reducing sugar, titration acetic acid, keeping days, pulp ratio, pulp seed ratio, peel percentage and fruit yield per plant. The D2 analysis classifies the genotypes into relatively homogeneous groups in such a way that within cluster diversity is minimized and between clusters diversity is maximized. The respective genotypes from diverse clusters can be utilized in breeding programme. Cluster analysis for qualitative traits showed that all genotypes were grouped into 8 clusters using non-hierarchical Euclidean cluster analysis (Table 4.15 and Fig. 4.5). For qualitative parameter, maximum number of genotypes were grouped into cluster VIII (14) followed by cluster III (12). Intra and Inter-Cluster distances among 8 clusters for qualitative traits in custard apple are presented in Table 4.16. The highest intra-cluster distance was recorded for cluster VI (48.65) followed by cluster II (46.79) and the smallest intra cluster distance was recorded in cluster III (0.00) followed by cluster V (8.15) for qualitative traits. Custard apple is a predominantly cross-pollinated (protogyny) crop and no information is available suggesting a change in its breeding behavior under varied environmental conditions. Discrimination of desirable parents for a successful hybridization programme is a difficult task for a plant breeder. Generally, geographical diversity has been considered as a measure of genetic diversity. However, this is an inferential criterion and it may not be so effective in quantifying or differentiating among populations.

Genetic diversity and variability analysis in oats (Avena sp) genotypes

Fifty oat genotypes belonging to eight different Avena species were evaluated to assess the genetic diversity and genetic divergence. The observations were recorded on five randomly selected plants in each genotype for quantitative traits. The Non-hierarchical Euclidean cluster analysis grouped oat genotypes into six clusters indicating presence of substantial genetic diversity in the evaluated germplasm. The highest intra-cluster distance which was observed in cluster VI followed by cluster I, cluster II, cluster V, cluster IV and cluster III. A maximum inter cluster distance showed between cluster II and cluster III followed by between cluster III and cluster IV. The minimum inter cluster distance was noticed between cluster V and cluster IV. Cluster II and III had better cluster means for many characters, so genotypes from these clusters can be used as parents for future breeding programmes. A total of eight principal components were extracted on the basis of eigen values (>1) and these components explained total of 75% variability. Varimax rotation enabled loading of all the traits on different principal factors. The first principal factor (PF) showed high loading for flag leaf length, dry fodder yield per plant and green fodder yield per plant. The second factor was composed of some of trait like high dry fodder yield, dry matter per cent, leaf length and leaf width. It is clear that both of the first three factors which would express the combined effect of flag leaf length, leaf length, leaf width, high dry matter per cent, high green fodder yield per plant were most closely associated with dry fodder yield per plant whereas, last three factors were associated with seed yield.

Torque waveform analysis and fastening method on invalid thread of track bolt

Aiming at the problem of bolt fastening failure identification during bolt maintenance, the qualitative analysis of the mechanical mechanism of the track bolts was carried out, torque sensor was used to collect the data of the torque in different failure modes, three kinds of mathematic models, such as curve Euclidean distance, cluster analysis and regression statistical analysis, were established for the collected data. The failure forms of thread were analyzed one by one, and the analysis data was compared with the actual construction results. The experimental results show that the discriminant analysis results of the mathematical model are consistent with the actual construction results, which proves the accuracy and feasibility of the model to judge the failure form of the sample data.

Catchment tracers reveal discharge, recharge and sources of groundwater-borne pollutants in a novel lake modelling approach

Abstract. Groundwater-borne contaminants such as nutrients, dissolved organic carbon (DOC), coloured dissolved organic matter (CDOM) and pesticides can have an impact the biological quality of lakes. The sources of pollutants can, however, be difficult to identify due to high heterogeneity in groundwater flow patterns. This study presents a novel approach for fast hydrological surveys of small groundwater-fed lakes using multiple groundwater-borne tracers. Water samples were collected from the lake and temporary groundwater wells, installed every 50 m within a distance of 5–45 m to the shore, were analysed for tracer concentrations of CDOM, DOC, total dissolved nitrogen (TDN, groundwater only), total nitrogen (TN, lake only), total dissolved phosphorus (TDP, groundwater only), total phosphorus (TP, lake only), δ18O ∕ δ16O isotope ratios and fluorescent dissolved organic matter (FDOM) components derived from parallel factor analysis (PARAFAC). The isolation of groundwater recharge areas was based on δ18O measurements and areas with a high groundwater recharge rate were identified using a microbially influenced FDOM component. Groundwater discharge sites and the fractions of water delivered from the individual sites were isolated with the Community Assembly via Trait Selection model (CATS). The CATS model utilized tracer measurements of TDP, TDN, DOC and CDOM from the groundwater samples and related these to the tracer measurements of TN, TP, DOC and CDOM in the lake. A direct comparison between the lake and the inflowing groundwater was possible as degradation rates of the tracers in the lake were taken into account and related to a range of water retention times (WRTs) of the lake (0.25–3.5 years in 0.25-year increments). These estimations showed that WRTs above 2 years required a higher tracer concentration of inflowing water than found in any of the groundwater wells around the lake. From the estimations of inflowing tracer concentration, the CATS model isolated groundwater discharge sites located mainly in the eastern part of the lake with a single site in the southern part. Observations from the eastern part of the lake revealed an impermeable clay layer that promotes discharge during heavy precipitation events, which would otherwise be difficult to identify using traditional hydrological methods. In comparison to the lake concentrations, high tracer concentrations in the southern part showed that only a smaller fraction of water could originate from this area, thereby confirming the model results. A Euclidean cluster analysis of δ18O isotopes identified recharge sites corresponding to areas adjacent to drainage channels, and a cluster analysis of the microbially influenced FDOM component C4 further identified five sites that showed a tendency towards high groundwater recharge rate. In conclusion, it was found that this methodology can be applied to smaller lakes within a short time frame, providing useful information regarding the WRT of the lake and more importantly the groundwater recharge and discharge sites around the lake. Thus, it is a tool for specific management of the catchment.

Determination of genetic divergence in pointed gourd by principal component and non-hierarchical euclidean cluster analysis

The present investigation was carried out at Vegetable Research Centre, Pantnagar to estimate the ge-netic divergence using Mahalanobis D2 statistics for twelve characters on 35 genotypes of pointed gourd. Cluster analysis and principal component analysis (PCA) were used to identify the most discerning trait responsible for greater variability in the lines and on the basis of mean performance, genotypes were classified into different groups. Five principal components (PC) have been extracted using the mean performance of the genotypes and 83.23 per cent variation is yielded by the first five principal components, among them high mean positive value or higher weight age was obtained was obtained for days to first female flower anthesis and days to first fruit harvest among all the vectors, indicates that these traits are important component of genetic divergence in pointed gourd. Non- hierarchical Euclidean cluster analysis grouped the genotypes into seven clusters and the highest number of genotypes were found in cluster number IV i.e. eleven whereas maximum inter-cluster distance was found between the cluster III and VI i.e. 74.250, it indicates that a wide range of genetic divergence is present between the genotypes present among these two clusters. And as per contribution toward total divergence, traits like fruit yield per hectare and number of fruit per plant contributed 92.64% toward total divergence. The high diversity found in the genotypes showed its great potential for improving qualitative as well as quantitative traits in pointed gourd.

Genetic divergence analysis in Ailanthus excelsa based on morphological traits

Knowledge about the extent of source variation in relation to growth and fodder yield characters is very useful for improvement of multipurpose tree species (MPTs). The present studies were conducted to assess the variability among 23 progenies of Ailanthus excelsa for its further improvement. Morphological and genetic analyses were used to identify the elite progeny and record the variations in different progenies of A. excelsa. Significant differences (P >0.05) were recorded among the progenies of A. excelsa for growth and fodder yield characters. Maximum diameter 15.33 and 86.11 mm was recorded in progeny P23 after 6 and 12 months of planting. The genotypic coefficient of variation was much less than the phenotypic coefficient of variation for growth characters, i.e. height, diameter and volume index indicating the influence of environment on growth. Maximum phenotypic coefficient of variation (53.98) and genotypic coefficient of variation (31.16) were observed for volume index. High heritability values for leaf fodder yield (67.00%) and height (64.00%) was observed, while low heritability was observed for height and diameter. The genetic advance as per cent of mean varied from 4.63 to 47 .31 % (leaf fodder). Plant height and diameter after 12 months of planting showed positive correlation with each other and fodder yield. Progeny P23 showed consistency in terms of growth and found superior over others. Non Hierarchical Euclidean cluster analysis (D2), of 23 progenies grouped the progenies into 4 clusters. The intra and inter-cluster distance indicated the presence of wider genetic distance between A. excelsa progenies. Maximum inter-cluster distance between cluster II and IV (3.93) followed by cluster III and IV indicates greater divergence between genotypes belonging to these clusters and an attempt to cross the genotypes in these clusters should bring out desirable gene combinations. Among the growth attributes, volume index contributed maximum to genetic divergence.

Assessment of genetic diversity using morphological traits in pigeonpea [Cajanus cajan (L.) Millsp.

The nature and magnitude of genetic diversity was assessed among 120 genotypes of pigeonpea along with three checks in augmented design during Kharif, 2011-12. The Non-hierarchical Euclidean cluster analysis grouped all the genotypes into twelve distinct non-overlapping clusters indicated existence of high degree of genetic diversity in the materials. The crossings between the members of diverse clusters separated by high inter-cluster distances are likely to throw desirable segregants. In this context, very high inter cluster distances were recorded between cluster VI and XII, cluster V and XII, cluster II and IX, cluster VI and XI, cluster II and VI and cluster V and IX. Considering the mean performance for different characters of genotypes belonging to diverse clusters, the promising genotypes for exploitation as parents in breeding programme were NDAGC 2011-4, NDAGC 2011-42 and NDAGC 2011-2 of cluster II; NDAGC 2011-18, NDAGC 2011-58, NDAGC 2011-34 and NDAGC 2011-27 of cluster V; NDAGC 2011-16, NDAGC 2011-41, NDAGC 2011-88, NDAGC 2011-104 and NDAGC 2011-103 of cluster VI; IC 525504 and Pusa 33 of cluster IX and IC 525456, IC 525408 and IC 525463 of cluster XII. It may be concluded that crosses between diverse genotypes belonging to clusters separated by high inter-cluster distances with desired means are likely to produce transgressive segregants may be advocated for developing high yielding pigeonpea varieties.