scholarly journals Genetic Diversity in Wheat Genotypes under Early Heat Stress in Bangladesh

2020 ◽  
pp. 1
Author(s):  
Md Siddquie
Keyword(s):  
Genetic Diversity ◽  
Heat Stress ◽  
Wheat Genotypes

Assessing genetic variation for heat stress tolerance in Indian bread wheat genotypes using morpho-physiological traits and molecular markers

2016 ◽  
Vol 15 (6) ◽  
pp. 539-547 ◽  
Author(s):  
P. Sharma ◽  
S. Sareen ◽  
M. Saini ◽  
Shefali
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Heat Stress ◽  
Molecular Markers ◽  
Heat Tolerance ◽  
Polymorphic Information Content ◽  
Physiological Traits ◽  
Phenotypic Traits ◽  
Phenotypic Data ◽  
Wheat Genotypes

AbstractHeat stress greatly limits the productivity of wheat in many regions. Knowledge on the degree of genetic diversity of wheat varieties along with their selective traits will facilitate the development of high yielding, stress-tolerant wheat cultivar. The objective of this study were to determine genetic variation in morpho-physiological traits associated with heat tolerance in 30 diverse wheat genotypes and to examine genetic diversity and relationship among the genotypes varying heat tolerance using molecular markers. Phenotypic data of 15 traits were evaluated for heat tolerance under non-stress and stress conditions for two consecutive years. A positive and significant correlation among cell membrane stability, canopy temperature depression, biomass, susceptibility index and grain yield was shown. Genetic diversity assessed by 41 polymorphic simple sequence repeat (SSR) markers was compared with diversity evaluated for 15 phenotypic traits averaged over stress and non-stress field conditions. The mean polymorphic information content for SSR value was 0.38 with range of 0.12–0.75. Based on morpho-physiological traits and genotypic data, three groups were obtained based on their tolerance (HHT, MHT and LHT) levels. Analysis of molecular variance explained 91.7% of the total variation could be due to variance within the heat tolerance genotypes. Genetic diversity among HHT was higher than LHT genotypes and HHT genotypes were distributed among all cluster implied that genetic basis of heat tolerance in these genotypes was different thereby enabling the wheat breeders to combine these diverse sources of genetic variation to improve heat tolerance in wheat breeding programme.

scholarly journals Discovery of miRNAs and Development of Heat-Responsive miRNA-SSR Markers for Characterization of Wheat Germplasm for Terminal Heat Tolerance Breeding

2021 ◽  
Vol 12 ◽  
Author(s):  
Pooja Sihag ◽  
Vijeta Sagwal ◽  
Anuj Kumar ◽  
Priyanka Balyan ◽  
Reyazul Rouf Mir ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Heat Stress ◽  
Ssr Markers ◽  
Heat Tolerance ◽  
Wheat Varieties ◽  
Wheat Genotypes ◽  
Wheat Germplasm ◽  
Heat Tolerant

A large proportion of the Asian population fulfills their energy requirements from wheat (Triticum aestivum L.). Wheat quality and yield are critically affected by the terminal heat stress across the globe. It affects approximately 40% of the wheat-cultivating regions of the world. Therefore, there is a critical need to develop improved terminal heat-tolerant wheat varieties. Marker-assisted breeding with genic simple sequence repeats (SSR) markers have been used for developing terminal heat-tolerant wheat varieties; however, only few studies involved the use of microRNA (miRNA)-based SSR markers (miRNA-SSRs) in wheat, which were found as key players in various abiotic stresses. In the present study, we identified 104 heat-stress-responsive miRNAs reported in various crops. Out of these, 70 miRNA-SSR markers have been validated on a set of 20 terminal heat-tolerant and heat-susceptible wheat genotypes. Among these, only 19 miRNA-SSR markers were found to be polymorphic, which were further used to study the genetic diversity and population structure. The polymorphic miRNA-SSRs amplified 61 SSR loci with an average of 2.9 alleles per locus. The polymorphic information content (PIC) value of polymorphic miRNA-SSRs ranged from 0.10 to 0.87 with a mean value of 0.48. The dendrogram constructed using unweighted neighbor-joining method and population structure analysis clustered these 20 wheat genotypes into 3 clusters. The target genes of these miRNAs are involved either directly or indirectly in providing tolerance to heat stress. Furthermore, two polymorphic markers miR159c and miR165b were declared as very promising diagnostic markers, since these markers showed specific alleles and discriminated terminal heat-tolerant genotypes from the susceptible genotypes. Thus, these identified miRNA-SSR markers will prove useful in the characterization of wheat germplasm through the study of genetic diversity and population structural analysis and in wheat molecular breeding programs aimed at terminal heat tolerance of wheat varieties.

scholarly journals Development and use of miRNA-derived SSR markers for the study of genetic diversity, population structure, and characterization of genotypes for breeding heat tolerant wheat varieties

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0231063
Author(s):  
Sandhya Tyagi ◽  
Anuj Kumar ◽  
Tinku Gautam ◽  
Renu Pandey ◽  
Sachin Rustgi ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Heat Stress ◽  
Ssr Markers ◽  
Allelic Diversity ◽  
Abiotic Factor ◽  
Wheat Genotypes ◽  
Mirna Genes ◽  
Heat Tolerant

Heat stress is an important abiotic factor that limits wheat production globally, including south-east Asia. The importance of micro (mi) RNAs in gene expression under various biotic and abiotic stresses is well documented. Molecular markers, specifically simple sequence repeats (SSRs), play an important role in the wheat improvement breeding programs. Given the role of miRNAs in heat stress-induced transcriptional regulation and acclimatization, the development of miRNA-derived SSRs would prove useful in studying the allelic diversity at the heat-responsive miRNA-genes in wheat. In the present study, efforts have been made to identify SSRs from 96 wheat heat-responsive miRNA-genes and their characterization using a panel of wheat genotypes with contrasting reactions (tolerance/susceptible) to heat stress. A set of 13 miRNA-derived SSR markers were successfully developed as an outcome. These miRNA-SSRs are located on 11 different common wheat chromosomes (2A, 3A, 3B, 3D, 4D, 5A, 5B, 5D, 6A, 6D, and 7A). Among 13 miRNA-SSRs, seven were polymorphic on a set of 37 selected wheat genotypes. Within these polymorphic SSRs, three makers, namely HT-169j, HT-160a, and HT-160b, were found promising as they could discriminate heat-tolerant and heat-susceptible genotypes. This is the first report of miRNA-SSR development in wheat and their deployment in genetic diversity and population structure studies and characterization of trait-specific germplasm. The study suggests that this new class of molecular makers has great potential in the marker-assisted breeding (MAB) programs targeted at improving heat tolerance and other adaptability or developmental traits in wheat and other crops.

Genetic diversity of durum wheat genotypes using morpho-protein analysis

2014 ◽  
Vol 42 (4) ◽  
pp. 677-686
Author(s):  
M. Rajabi Hashjin ◽  
M.H. Fotokian ◽  
M. Agahee Sarbrzeh ◽  
M. Mohammadi ◽  
D. Talei
Keyword(s):  
Genetic Diversity ◽  
Durum Wheat ◽  
Protein Analysis ◽  
Wheat Genotypes

scholarly journals Molecular and Physiological Responses of Rice and Weedy Rice to Heat and Drought Stress

Agriculture ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 9
Author(s):  
Leonard Bonilha Piveta ◽  
Nilda Roma-Burgos ◽  
José Alberto Noldin ◽  
Vívian Ebeling Viana ◽  
Claudia de Oliveira ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Heat Stress ◽  
Drought Stress ◽  
Intercellular Co2 Concentration ◽  
Tiller Number ◽  
Weedy Rice ◽  
Photosynthetic Parameters ◽  
World Population ◽  
Rice Grain ◽  
Rice Cultivars

Rice is the staple food for about half of the world population. Rice grain yield and quality are affected by climatic changes. Arguably, rice cultivars’ genetic diversity is diminished from decades of breeding using narrow germplasm, requiring introgressions from other Oryza species, weedy or wild. Weedy rice has high genetic diversity, which is an essential resource for rice crop improvement. Here, we analyzed the phenotypic, physiological, and molecular profiles of two rice cultivars (IRGA 424 and SCS119 Rubi) and five weedy rice (WR), from five different Brazilian regions, in response to heat and drought stress. Drought and heat stress affected the phenotype and photosynthetic parameters in different ways in rice and WR genotypes. A WR from Northern Brazil yielded better under heat stress than the non-stressed check. Drought stress upregulated HSF7A while heat stress upregulated HSF2a. HSP74.8, HSP80.2, and HSP24.1 were upregulated in both conditions. Based on all evaluated traits, we hypothesized that in drought conditions increasing HSFA7 expression is related to tiller number and that increase WUE (water use efficiency) and HSFA2a expression are associated with yield. In heat conditions, Gs (stomatal conductance) and E’s increases may be related to plant height; tiller number is inversely associated with HSPs expression, and chlorophyll content and Ci (intercellular CO2 concentration) may be related to yield. Based on morphology, physiology, and gene regulation in heat and drought stress, we can discriminate genotypes that perform well under these stress conditions and utilize such genotypes as a source of genetic diversity for rice breeding.

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