Combined study on genetic diversity of wheat genotypes using SNP marker and phenotypic reaction to Heterodera filipjevi

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.

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Genetic Diversity in Wheat Genotypes under Early Heat Stress in Bangladesh

Fundamental and Applied Agriculture ◽

10.5455/faa.131857 ◽

2020 ◽

pp. 1

Author(s):

Md Siddquie

Keyword(s):

Genetic Diversity ◽

Heat Stress ◽

Wheat Genotypes

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Heat stress impact and genetic diversity among some bread wheat genotypes

Egyptian Journal of Agronomy ◽

10.21608/agro.2016.1276 ◽

2016 ◽

Vol 38 (3) ◽

pp. 389-412

Author(s):

Alhosein Hamada ◽

Khalid Ibrahim

Keyword(s):

Genetic Diversity ◽

Heat Stress ◽

Bread Wheat ◽

Wheat Genotypes

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Identification and Validation of a Core Single-Nucleotide Polymorphism Marker Set for Genetic Diversity Assessment, Fingerprinting Identification, and Core Collection Development in Bottle Gourd

Frontiers in Plant Science ◽

10.3389/fpls.2021.747940 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ying Wang ◽

Xiaohua Wu ◽

Yanwei Li ◽

Zishan Feng ◽

Zihan Mu ◽

...

Keyword(s):

Genetic Diversity ◽

Single Nucleotide Polymorphism ◽

Snp Markers ◽

Bottle Gourd ◽

Snp Marker ◽

Nucleotide Polymorphism ◽

Single Nucleotide ◽

The Core ◽

Germplasm Collections ◽

Diversity Assessment

Germplasm collections are indispensable resources for the mining of important genes and variety improvement. To preserve and utilize germplasm collections in bottle gourd, we identified and validated a highly informative core single-nucleotide polymorphism (SNP) marker set from 1,100 SNPs. This marker set consisted of 22 uniformly distributed core SNPs with abundant polymorphisms, which were established to have strong representativeness and discriminatory power based on analyses of 206 bottle gourd germplasm collections and a multiparent advanced generation inter-cross (MAGIC) population. The core SNP markers were used to assess genetic diversity and population structure, and to fingerprint important accessions, which could provide an optimized procedure for seed authentication. Furthermore, using the core SNP marker set, we developed an accessible core population of 150 accessions that represents 100% of the genetic variation in bottle gourds. This core population will make an important contribution to the preservation and utilization of bottle gourd germplasm collections, cultivar identification, and marker-assisted breeding.

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

Frontiers in Genetics ◽

10.3389/fgene.2021.699420 ◽

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.

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