cluster distance
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2021 ◽  
Vol 58 (4) ◽  
pp. 487-495
Author(s):  
K Amudha ◽  
G Ariharasutharsan

The present investigation was carried out to explore the extent of genetic divergence in 95 rice germplasm accessions for twelve characters during kharif, 2018. In D2 analysis, the 95 genotypes were grouped into fifteen clusters. The clustering pattern indicated that there was no parallelism between genetic diversity and geographical origin as the genotypes from same origin were included in different clusters and vice versa. The highest intra cluster distance was registered in cluster V (215.183) followed by cluster IX (209.831), cluster VIII (204.057) and cluster XIV (202.623).The maximum inter cluster distance was observed between cluster II and cluster III (991.049) followed by cluster II and cluster X (974.960), cluster III and cluster XI (963.826), cluster II and XII (962.013), cluster X and cluster XI (932.469) and cluster XI and cluster XII (919.151). Genetically distant parents from those clusters could be able to produce higher heterosis in progenies on hybridization. Grain yield per plant, 100 grain weight and days to 50% flowering were the major contributors towards the total genetic divergence among the genotypes studied. Thus selection could be made based on grain yield per plant, hundred grain weight and days to 50%flowering for the progenies identified.


Author(s):  
В.П. Бессчетнов ◽  
Н.Н. Бессчетнова ◽  
А.Ю. Щербаков

Изучали содержание и соотношение пластидных пигментов в хвое представителей разных популяций ели европейской, введенных в состав географических культур на территории Нижегородской области. Применяли спектрофотометрический метод выявления количественных оценок пигментного состава листового аппарата с обеспечением принципа единственного логического различия и основных требований к организации опыта. Проведены натурные обследования насаждений и лабораторные анализы биологических проб. Выявлены различия между представителями удаленных друг от друга популяций ели европейской при их совместном выращивании в составе географических культур по комплексу показателей пигментного состава однолетней хвои. Наибольшее содержание хлорофилла-а (3,25±0,06 мг/г) отмечено у семенного потомства популяций из Псковской области, что в 1,26 раза превосходит соответствующий минимум (2,57±0,04 мг/г), зафиксированный у представителей популяций из Калининградской области. Зафиксированы сходные масштабы соотношения оценок содержания хлорофилла-b, притом что максимальные значения (1,37±0,05 мг/г и 1,37±0,06 мг/г) наблюдались у происхождений из Костромской и Карельской областей, а минимальные (1,07±0,03 мг/г и 1,09±0,03 мг/г) – у представителей популяций из Архангельской и Калининградской областей. Подтверждена существенность различий между популяциями ели европейской по всем рассматриваемым показателям пигментного состава. Обнаружено сходство в сложении трех группировок популяций, возникших при выполнении факторного и кластерного анализа. Коэффициенты плотности кластера (средняя евклидова дистанция его сложения) каждой их них составили: 6,258 единиц евклидовой дистанции (у первой); 4,374 ед. (у второй); 7,818 ед. (у третьей) и 6,150 ед. (общая средняя дистанция). Среднее межкластерное расстояние при этом достигло 20,414 ед., что принципиально больше величин внутрикластерных дистанций и позволяет признать корректным выделение кластеров. Обоснован устойчивый характер соотношения популяций ели европейской, имеющих различное географическое происхождение, по пигментному составу хвои. The content and ratio of plastid pigments in the conifers of representatives of different populations of Norway spruce introduced into the geographic test-cultures in the Nizhny Novgorod region were studied. A spectrophotometric method was used to identify quantitative estimates of the pigment composition of the leaf apparatus, ensuring the principle of a single logical difference and the basic requirements for the organization of the experiment. Field surveys of plantings and laboratory analyses of biological samples were carried out. The differences between representatives of Norway spruce populations that are remote from each other were revealed when they were grown together as part of geographical crops according to the complex of indicators of the pigment composition of annual needles. The highest content of chlorophyll-a (3.25±0.06 mg/g) was observed in the seed offspring of populations from the Pskov region, which is 1.26 times higher than the corresponding minimum (2.57±0.04 mg/g) recorded in representatives of populations from the Kaliningrad region. Similar scales of the ratio of estimates of the content of chlorophyll-b were recorded, despite the fact that the maximum values (1.37±0.05 mg/g and 1.37±0.06 mg/g) were observed in the origin from the Kostroma and Karelian regions, and the minimum values (1.07±0.03 mg/g and 1.09±0.03 mg/g) were observed in representatives of populations from the Arkhangelsk and Kaliningrad regions. The significance of differences between the populations of Norway spruce in all the considered indicators of pigment composition was confirmed. A similarity was found in the addition of three groups of populations that arose during factor and cluster analysis. The cluster density coefficients (the average Euclidean distance of its addition) of each of them were: 6,258 units of the Euclidean distance (for the first one); 4,374 units. (in the second); 7,818 units. (at the third) and 6,150 units. (total average distance). The average inter-cluster distance at the same time reached 20,414 units, which is fundamentally greater than the values of intra-cluster distances and allows us to recognize the correct allocation of clusters. The stable nature of the ratio of populations of Norway spruce with different geographical origin, according to the pigment composition of needles, is justified.


Author(s):  
Juan-Luis García-Mendoza ◽  
Luis Villaseñor-Pineda ◽  
Felipe Orihuela-Espina ◽  
Lázaro Bustio-Martínez

Distant Supervision is an approach that allows automatic labeling of instances. This approach has been used in Relation Extraction. Still, the main challenge of this task is handling instances with noisy labels (e.g., when two entities in a sentence are automatically labeled with an invalid relation). The approaches reported in the literature addressed this problem by employing noise-tolerant classifiers. However, if a noise reduction stage is introduced before the classification step, this increases the macro precision values. This paper proposes an Adversarial Autoencoders-based approach for obtaining a new representation that allows noise reduction in Distant Supervision. The representation obtained using Adversarial Autoencoders minimize the intra-cluster distance concerning pre-trained embeddings and classic Autoencoders. Experiments demonstrated that in the noise-reduced datasets, the macro precision values obtained over the original dataset are similar using fewer instances considering the same classifier. For example, in one of the noise-reduced datasets, the macro precision was improved approximately 2.32% using 77% of the original instances. This suggests the validity of using Adversarial Autoencoders to obtain well-suited representations for noise reduction. Also, the proposed approach maintains the macro precision values concerning the original dataset and reduces the total instances needed for classification.


Author(s):  
M A Madobe ◽  
M S Raihan ◽  
M Hasan ◽  
M S Biswas

Characterization of genetic diversity is the foundation step for crop improvement, which provides a basis for analyzing combining ability and heterosis of inbred genotypes during a hybridization program. An investigation was carried out at the field laboratory of the Genetics and Plant Breeding department in Bangabandhu Sheikh Mujibur Rahman Agricultural University, to elucidate the genetic architecture by evaluating 12 morphological and 4 molecular (SSR) markers within 52 diverse S1 genotypes, and to assess the relationship of molecular and morphological GD. An almost equal amount of PCV and GCV coupled with high heritability and genetic advance for the traits cob weight (gm), NKPC, and NKPR lead to the selection of promising genotypes based on these characters. Correlation coefficient and scatter plot matrix established a positive and strong relationship of KL (mm), KW (mm), and KT (mm) with 100 kernel weight (gm) suggesting the importance of kernel morphology. Mahalanobis D2 statistics revealed the highest inter-cluster distance between I and II. The percentages of molecular variance within the population and among the population were 76% and 14 %, respectively. The optimum K-value was 5. Heatmap relying on molecular GD exposed MMIL-28, MMIL-54, and MMIL-96 as the most diverse lines. SHE analysis hypothesized the increase of richness and diversity over time. Less correlation between the divergence generated from morphological traits and molecular markers suggested that the morphological variation may be determined by environmental factors and also by genetic factors. A strategy for the effective selection of predicting parental lines for a future hybridization program was developed.


2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Bojan Papić ◽  
Majda Golob ◽  
Irena Zdovc ◽  
Jana Avberšek ◽  
Metka Pislak Ocepek ◽  
...  

The spore-forming bacterium Paenibacillus larvae is the causative agent of American foulbrood (AFB), a devastating disease of honeybees (Apis mellifera). In the present study, we used whole-genome sequencing (WGS) to investigate an extensive outbreak of AFB in northwestern Slovenia in 2019. A total of 59 P . larvae isolates underwent WGS, of which 40 originated from a single beekeeping operation, to assess the diversity of P. larvae within the beekeeping operation, apiary and colony. By applying a case-specific single-linkage threshold of 34 allele differences (AD), whole-genome multilocus sequence typing (wgMLST) identified two outbreak clusters represented by ERIC II-ST11 clones. All isolates from a single beekeeping operation fell within cluster 1 and the median pairwise AD between them was 10 (range=1–22). The median pairwise AD for apiaries of the same beekeeping operation ranged from 8 to 11 (min.=1, max.=22). For colonies of the same apiary and honey samples from these colonies, the median pairwise AD ranged from 8 to 14 (min.=1, max.=20). The maximum within-cluster distance was 33 pairwise AD for cluster 1 and 44 for cluster 2 isolates. The minimum distance between the outbreak-related and non-related isolates was 37 AD, confirming the importance of associated epidemiological data for delineating outbreak clusters. The observed transmission events could be explained by the activities of honeybees and beekeepers. The present study provides insight into the genetic diversity of P. larvae at different levels and thus provides information for future AFB surveillance.


Author(s):  
Anuradha Sinha ◽  
Paramveer Singh ◽  
Randhir Kumar ◽  
Ajay Bhardwaj ◽  
Swapnil .

Background: Tomato plant has high yield potential, although the yield is very low because of non-availability of superior cultivars for protected cultivation. Presence of diversity is an important for variety development. Hybridization among divergent parents is probably produce ample variability and helps to isolate superior recombinants. So, the study was carried out to assess of genetic diversity in tomato for choosing promising and genetically diverse parents for improvement in yield for protected cultivation. Methods: Fourteen genotypes of tomato were planted inside naturally ventilated polyhouse during September 2018 to May 2019. The data were recorded for twenty-one characters from randomly five tagged plants from each genotype and genetic diversity was computed by utilizing Mahalanobis D2 analysis. Result: All genotypes were arranged into five highly divergent clusters in which cluster I contain maximum genotypes followed by cluster II. The intra cluster distance was highest in cluster I and inter-cluster distance was highest among cluster-II and V. Cluster means indicated that cluster II had high mean values for maximum traits. The highest contribution towards genetic diversity was shown by fruit yield/plant followed by number of fruits per plant. Based on breeding objectives, potential lines are selected as parents for utilization in hybridization programme.


Author(s):  
Ritu R. Saxena ◽  
Kanushree Nandedkar ◽  
Suman Rawte ◽  
S.S. Porte ◽  
Mary S. Xalxo ◽  
...  

Background: In an effort to develop micronutrient-rich chickpea lines, a study to examine the variability in yield and nutritional traits was conducted. Methods: 99 genotypes were studied, the data was recorded and analyzed on yield traits, protein, iron and zinc content in Rabi 2019-20. Result: Maximum variability was recorded in plant yield followed by iron concentration (mg/kg), hundred seed weight and number of pods per plant. Of the total entries, nine entries namely, RGH4, RGH56, RG2016-84, ICC251762, RGH53, IPC98-12, RG2016-03, ICC1053 and RGH58 recorded high protein content ( greater than 20%). All these entries possessing high protein had pink flower. One chickpea accession (RGH53) accumulated the highest concentration for both protein and zinc, with an average of 21.86% and 73.00 ppm, respectively, but it showed low iron concentration (20.77 ppm). The first six principal components provided a reasonable summary of the data and explained 80.19% of the total variation. Ninety nine genotypes were grouped into ten clusters. Maximum inter cluster distance was observed between clusters VI and IX; VI and VII and IV and VI. The genotypes of these clusters are suggested for utilization in the crossing programs to breed varieties of chickpea for high yield with amenability to nutrients.


2021 ◽  
Author(s):  
SUMANT PRATAP SINGH ◽  
N. A. Khan ◽  
Reeshu Singh ◽  
Lalit Pal ◽  
Baudh Bharati ◽  
...  

Abstract Disease screening against Alternaria blight under field condition showed that, none was free from disease only 13 genotypes were found MR and 152 genotypes were found MS, 252 S and 3HS. The high estimate of phenotypic and genotypic coefficient of variation was recorded for YPP and SB., high estimate of broad sense heritability was recorded all characters except YPP. The genetics advance in per cent of mean was found high for PB, high heritability along with high genetic advance was observed for HPF. At phenotypic and genotypic level both YPP shoes highly significant and positive correlation. At phenotypic and genotypic level path coefficient reveled that in HPF, PL. The genotypes were grouped into eight different non overlapping cluster (five 115, three 100, six 84, one 78, seven 37 and three, two and four 1, eight 36 genotypes). The maximum and minimum inter cluster distance was between six, eight and one, three. One highest cluster mean for PH, MAT, and HPF and two (MAT, PH, HPF). Three (MAT, PH, HPF) four (MAT, PH, HPF) five (PH, MAT, HPF) six (MAT, PH, HPF) seven (MAT, HPF. PH), eight had no values due to reason no geminated or un survived plant and GWAS analysis of identified six significant association for Alternaria blight resistance on chromosome (A07, A09, A03, B07, B04, B03) respectively, This study showed that the diversity panel of Indian mustard identified QTLs for controlling of disease resistance against Alternaria blight in Indian mustard.


Author(s):  
V. Netam S. K. Sinha ◽  
K. Tigga V. K. Singh ◽  
N. Chouksey

The present investigation on “Diversity analysis by D2 analysis in fine scented genotypes of rice (Oryza sativa L.)” was used to investigate the diversity among 40 fine scented genotypes obtained from the Indira Gandhi Krishi Vishwavidyalaya in Raipur. The current studies was conducted at research cum instructional farm, IGKV, RMD Ambikapur, Chhattisgarh. The experiment was conducted in RBD with purpose to characterized 40 genotypes of rice along with 4 checks viz. CG Sugandhitbhog, CG Devbhog, Indira Sugandhit Dhan-1 and Dubrajsel 1 for diversity. Based on cluster analysis, the genotypes were grouped into 5 clusters in which cluster I was the largest consistin of 29 genotypes. While cluster IV & V were the smallest with only a single genotypes; each. Maximum intra cluster distance was found in the cluster II, Which comprises only 5 genotypes. The most divergent clusters observed were cluster III & V. The minimum cluster distance was recorded between cluster I & III.


Author(s):  
Reshmi Jahan Mohammed L. Prasanthi ◽  
Lakshminarayana R. Vemireddy

An investigation was carried out to estimate the genetic divergence for twenty characters in 50 genotypes of greengram [Vigna radiata (L.) Wilczek] using Mahalanobis's D2 statistic and total of eight clusters were formed. The highest number of genotypes were found in cluster II containing sixteen genotypes followed by cluster I with thirteen genotypes, cluster IV with ten genotypes, cluster VI with five genotypes, cluster VIII with three genotypes and clusters III, V and VII with only one genotype. Highest intra-cluster distance was observed for cluster IV (87.54) and lowest intra cluster distance was observed for clusters III, V and VII. The highest inter-cluster distance was observed between cluster IV and VIII (285.11),while the lowest inter cluster distance was observed between cluster VI and VII (251.29). Among the characters studied, phenols content contributed the maximum (32.57 %) towards the diversity. The genotypes present in the clusters V (COGG-13-19) and VII (LGG-544) showed high seed yield performance so, cross obtained between these genotypes will give better performance for yield. The genotypes in the cluster VI (GGG-1, GGG-1-1, IPM-2-14, WGG-42, EC-396117) and cluster III (AGG-35) exhibited resistance to YMV. Hence, the crosses among cluster V, VII, VI and III would give high seed yield along with YMV disease resistance.


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