Molecular Markers Improve Abiotic Stress Tolerance in Crops: A Review

Abstract

Plants endure many abiotic stresses, such as temperature (heat or frost), drought, and salt. Such factors are primary and frequent stressors that reduce agriculture crop yields. Often alterations in nutrient management and constituents, along with variations in biosynthetic capacity, ultimately reduce or halt plant growth. Genetically, stress is an environmental condition that interferes with complete genetic expression. A vast range of molecular genomic markers is available for the analysis of agricultural crops. These markers are classified into various groups based on how the markers are used: RAPD (Random amplified polymorphic DNA) markers serve to identify and screen hybrids based on salinity and drought stress tolerance, while simple sequence repeat (SSR) markers are excellent for the assessment of stress tolerance. Such markers also play an important role in the QTL (Quantitative trait loci) mapping of stress-related genes. Dehydrins for drought and saltol for salinity stresses are primitive genes which regulate responses to these conditions. Further, a focus on traits using single-gene single nucleotide polymorphisms (SNP) markers supports genetic mapping and the sequencing of stress-related traits in inbred lines. DNA markers facilitate marker-assisted breeding to enhance abiotic stress tolerance using advanced techniques and marker modification.

Identification of genetic diversity among some promising lines of rice under drought stress using SSR markers

“…For days to heading (day), the cultivar GZ8710 (Sakha107) gave the earliness value 82.22 day and 95.50 day for GZ9865-2-1-1-2 line. These findings are in agreement with those reported by [29,30] therefore, a strong indication the lines showing better performance for days to heading may perform better under drought stress condition. Concerning to leaf rolling which is a reflection of the pre-drought tolerance during the growth period, recorded the lowest values with significant differences by the line GZ9865-2-1-1-1 on the other hand the greatest one observed with GZ9865-2-1-1-2 (2.50), indicating that all lines had tolerance for water shortage stress.…”

Introgression of the Powdery Mildew Resistance Genes Pm60 and Pm60b from Triticum urartu to Common Wheat Using Durum as a ‘Bridge’

“…The incorporation of favorable traits from wild relatives into common wheat is regarded as a valuable way for breeders to increase the genetic diversity of wheat [35]. Molecular markers are now widely used for gene targeting, marker-assisted selection and other genetic studies, allowing tracking of the target gene through different generations of a breeding program, although independently of environmental conditions and growth stage [36]. In this study, the functional marker M-Pm60 for Pm60 was applied to test and track Pm60 alleles in the introgression of the target gene, and flanking markers linked to the Pm60 locus were used for the analysis of the size of the introduced fragments (Table 1 and Figure 3B).…”

Genome-wide identification and transcriptomic data exploring of the cytochrome P450 family in Chinese cabbage (Brassica rapa L. ssp. pekinensis)

“…Many plant breeders considered that SSRs are a more successful marker system for genetic diversity, identification of hybrids, classification and DNA fingerprinting of germplasm. SSRs have been extensively used for genetic analysis of many horticultural crops, including pear (Pyrus communis), grapes (Vitis vinifera), cucumber (Cucumis sativus), sugar beet (Beta vulgaris) and brassica species (Parthiban et al 2018;Taheri et al 2018;Wang et al 2018a;Ahmad et al 2020;Younis et al 2020).…”