Genetic diversity of yield related traits in a large subset of exotic and indigenous rice germplasm collection maintained at Tamil Nadu Agricultural University gene bank

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.

Consistent Clustering Pattern of Prokaryotic Genes Based on Base Frequency at the Second Codon Position and its Association with Functional Category Preference

In 2002, our research group observed a gene clustering pattern based on the base frequency of A versus T at the second codon position in the genome of Vibrio cholera and found that the functional category distribution of genes in the two clusters was different. With the availability of a large number of sequenced genomes, we performed a systematic investigation of A2–T2 distribution and found that 2694 out of 2764 prokaryotic genomes have an optimal clustering number of two, indicating a consistent pattern. Analysis of the functional categories of the coding genes in each cluster in 1483 prokaryotic genomes indicated, that 99.33% of the genomes exhibited a significant difference (p < 0.01) in function distribution between the two clusters. Specifically, functional category P was overrepresented in the small cluster of 98.65% of genomes, whereas categories J, K, and L were overrepresented in the larger cluster of over 98.52% of genomes. Lineage analysis uncovered that these preferences appear consistently across all phyla. Overall, our work revealed an almost universal clustering pattern based on the relative frequency of A2 versus T2 and its role in functional category preference. These findings will promote the understanding of the rationality of theoretical prediction of functional classes of genes from their nucleotide sequences and how protein function is determined by DNA sequence. Graphical abstract

Stability and transformation of metabolic syndrome in adolescents A prospective assessment in relation to the change of metabolic risk factors

Background Underlying pathophysiological mechanisms drive excessive clustering of cardiometabolic risk factors, causing metabolic syndrome (MetS). However, MetS status may transform as adolescents transition to young adulthood. This study evaluated the latent clustering structure and its stability for MetS during adolescence and investigated the determinants for MetS transformation over 2 years of follow-up. Methods A community-based representative adolescent cohort (n=1516) was evaluated for MetS using four diagnostic criteria and followed for 2.2 years to identify new-onset MetS. Factor analysis and polytomous logistic regression were separately applied to investigate the latent clustering structure for MetS and the relationship between changes in metabolic risk factors and transformations in MetS status. Results The clustering pattern of cardiometabolic parameters was comparable at baseline and follow-up surveys; both comprised a fat‒blood pressure‒glucose three-factor structure (total variance explained: 68.8% and 69.7%, respectively). Among adolescents who were MetS-negative at baseline, 3.2%‒4.4% had incident MetS after 2 years. Among adolescents who were MetS-positive at baseline, 52.0%‒61.9% experienced MetS remission, and 38.1%‒48.0% experienced MetS persistence. Increased systolic blood pressure (SBP) was associated with a higher risk of MetS incidence, and decreased SBP, triglycerides, and glucose levels were associated with MetS remission. Compared with adolescents with a normal metabolic status at baseline, those having an initial abnormal status in the five MetS components all had greater risks for persistent metabolic abnormality 2 years later, with abdominal obesity and increased triglycerides rendering a 15.0- and 5.7-fold risk, respectively. Conclusions The structure of cardiometabolic parameter clustering for MetS is stable during adolescence. Changes in metabolic risk factors affect typological transformation of adolescent MetS. Abnormal MetS components have a high probability of persisting. Early identification of each abnormal component and attendant intervention are vital in adolescents to minimize the future risk of cardiometabolic disorders.

Morpho-agronomic and genetic variation among Phaseolus vulgaris landraces from selected provinces of South Africa

Key message The morpho-agronomic and genetic studies recorded variations in vegetative and reproductive traits, and in molecular information through population structure and clustering approaches among South African Phaseolus vulgaris landraces. Abstract Phaseolus vulgaris L., commonly known as common beans, is widely used for its edible leaves, immature pods, and dry seeds. Studies on variation in morphology and genetics among P. vulgaris landraces are limited in South Africa. Therefore, the current study aimed to determine the morpho-agronomic and genetic variations among P. vulgaris landraces. Thirty-eight landraces from different agro-ecological origins, planted in a randomized complete block design, had their variation in vegetative and reproductive traits determined. These landraces were studied for their genetic diversity using simple sequence repeat (SSR) markers. The landraces were clustered in a biplot and dendrogram based on their seed coats, shape, similar morpho-agronomic traits, and their areas of origin. A total of 57 alleles were produced with a mean of 3.64 per SSR locus. The polymorphism information content ranged from 0.00 to 0.58. The population structure had the highest delta value K = 2, thus the 38 landraces were divided into two subpopulations based on the Bayesian approach. The population structure showed an overlap among the landraces as several from the Mesoamerican carried some seed traits or genes from the Andean gene pool, and showed a high level of admixtures. The principal coordinate analysis and the dendrogram had a similar clustering pattern as the population structure. This study revealed the potential markers with high diversity that can be used to determine genetically homogenous/heterogeneous landraces. Therefore, the use of PV-ctt001, PV-ag001, and PV-at003 could be beneficial in future breeding, conservation, and marker-assisted selection studies.

Evaluation of Genetic Diversity in Bottle Gourd Germplasm Based on Phenotypic Characters for Yield and Yield Associated Traits

The experiment was conducted during Kharif season 2018 at Horticulture Research Centre, Sardar Vallabhbhai Patel University of Agriculture & Technology; Modipuram, Meerut (U.P.) assess the genetic diversity among fifteen genotypes of bottle gourd [Lagenaria siceraria (Mol.) Standl.]. The genetic diversity analysis according to that the formation of five clusters suggesting the presence of wide genetic diversity. The clustering pattern showed that geographical diversity wasn't related to genetic diversity. The analysis of % contribution of assorted characters toward the expression of total genetic divergence showed that the Days to 50% flowering (14.48%) followed Days of fruit set (12.95%), Vine length (m) (11.67%), Number of fruits per plant (10.93%), Number of the primary branches (10.37%), Days to first fruit harvest (10.16%), Average fruit weight (g) (9.44%), Fruit diameter (cm) (6.63%) contributed maximum towards total genetic divergence. Based on the maximum genetic distance. It is advisable to attempt a crossing of the genotype from cluster II (GP-7) with the genotype of cluster I (GP-5), cluster IV (GP-2) and cluster III (GP-1), which may cause to the generation of a broad spectrum of favorable genetic variability for yield improvement in bottle gourd.

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.

Assessment of Genetic Diversity in Morphological Traits of Mango Genotypes Using D2 Statistics

An experiment was conducted during 2018-2020 to study the genetic diversity in 24 morphological traits using D2 statistics in mango genotypes of eastern tropical region of India. Present study reveals that the clustering pattern based on D2 statistics grouped 40 genotypes of mango into 7 clusters, out of which cluster VI (7397.45) shows the highest intracluster value followed by cluster III (5346.99) and cluster V (4130.4), indicating considerable genetic divergence among the accessions of this cluster. While maximum inter- cluster distance was observed between the cluster VI and VII (300180) followed by cluster II and VI (289267.7) and cluster I and VI (214380.5) indicated that the accessions belonging to these groups were genetically most diverse and can be used as a parent in hybridization programme. Wide range of genetic diversity observed among cluster VI and cluster VII, can either be utilized for breeding programmes for genetic improvement in mango or directly adopted as a variety. Fruit yield exhibited significant contribution towards the genetic divergence (60.77%) followed by fruit weight (26.79%), stone percentage (4.74%), peel percentage (2.31%) and pulp percentage (2.05%).

Cytological Spectrum of Pulmonary Histoplasmosis Diagnosed by Bronchoalveolar Lavage: 12 Years of Experience in French Guiana

Disseminated histoplasmosis is a major cause of mortality in HIV-infected patients. Rapid and efficient diagnosis of Histoplasma capsulatum is crucial. Cytopathology is available in most hospitals and represents a rapid diagnostic alternative. In this study, we reviewed 12 years of experience to describe the cytology of histoplasmosis diagnosed by bronchoalveolar lavage (BAL) in relation to patient characteristics. BAL-diagnosed pulmonary histoplasmosis concerned 17 patients (14 HIV+). BAL cellularity ranged from 76,000 to 125,000 cells/mL in HIV patients, and 117,000 to 160,000 cells/mL in non-HIV patients. Macrophages predominated in all HIV patients (from 60% to 88%), lymphocytic infiltrates ranged from 5% to 15%, and neutrophils were very heterogeneous (from 2% to 32%). The number of H. capsulatum at hot spots seemed greater in HIV-infected than in immunocompetent patients (9 to 375 vs. 4 to 10) and were inversely proportional to the CD4 counts. Yeasts were both intracellular and extracellular in 85.7% of the HIV patients. This is the most comprehensive series detailing the cytological aspects of BAL in the diagnosis of H. capsulatum, focusing on the number of yeasts and their clustering pattern. The cytological examination of the Gomori-Grocott-stained BAL allows a reliable diagnosis of histoplasmosis.

​​Genetic Divergence in Leafy Mustard (Brassica juncea var. rugosa) Germplasm Grown under Tarai Condition of Uttarakhand

Background: Mustard represents a rich diversity and widely cultivated in 23 states and union territories of India. However, much of this diversity is concentrated in the Indo-Gangetic plains and the sub-mountain Himalayas. Genetic diversity plays a significant role in plant improvement because a hybrid between the lines of diverse origin usually display a greater heterosis than those between closely related ones which permit the selection of genetically divergent plants to obtain the desirable recombination of segregating generation. Therefore, the present study was undertaken to assess “Genetic Divergence in Leafy Mustard (Brassica juncea. var. rugosa) germplasm grown under Tarai condition of Uttarakhand” and to identify divergent parents for hybridization program, which would provide superior transgressive segregants from collected germplasm. Methods: The present investigation consisted of thirty-two genotypes of leafy mustard and the research was carried out at Vegetable Research Centre (VRC), G.B. Pant University of Agriculture and Technology, Pantnagar, U.S. Nagar (Uttarakhand) in rabi season of 2015-2016. Mustard genotypes were sown in randomized block design with three replications in field and data were observed for seventeen quantitative and qualitative characters. The estimation of genetic divergence was done with the help of Mahalonobis D2 statistic as suggested by Rao (1952). Cluster analysis by Tocher method for all the traits was done. Result: Thirty two germplasm of leafy mustard for different characters and grouped them into six clusters using Mahalanobis D2 statistic. The analysis revealed the maximum inter cluster distance was (20534.12) between cluster V and cluster VI so, we can create variation by inter mating genotypes from these two clusters to each other and the maximum intra cluster distance in cluster III (441.91) with six germplasm. It means we can intermate genotypes of this cluster with each other (2014/MGVAR-2, FS-13-1, FS-13-4, 2014/MGVAR-4, PRHC-12-9-1, PRHC-12-7-2, FS-13-3 and Pusa Sag 1) to create variation in next generations. The clustering pattern could be utilized in selection of parents for crossing and deciding the best cross combinations which may generate the highest possible variability for various traits.