Salinity is one of the major constraints reducing plant growth and yield.Irrigation with poor quality and brackish water to orchards is a major cause of stunted growth and low yield.The salt tolerance mechanism is one...Salinity is one of the major constraints reducing plant growth and yield.Irrigation with poor quality and brackish water to orchards is a major cause of stunted growth and low yield.The salt tolerance mechanism is one of the complicated genomic characters that is very problematic to develop in fruit trees and becomes much more severe at any growth and developmental stage.Osmotic stress and hormonal imbalances are major constraints causing low biomass production.Fruit tree tolerance/sensitivity is chiefly based on the activation of a defense system comprised of super-oxidase dismutase(SOD),peroxidase(POD)and catalases(CAT),non-enzymatic compounds including ascorbic acid,phenolics,flavonoids,stress indicators[i.e.,hydrogen peroxide(H2O2),lipid peroxidation,malondialdehyde(MDA),reactive oxygen species(ROS)and osmolytes containing proline,glycine-betaine(GB),ascorbates(APX),glutathione peroxidase(GPX)and glutathione reductase(GR)].Tolerant genotypes must have higher antioxidant assays to cope with the adverse effects of salinity stress because their defense system had the potential to scavenge toxic ROS and protect from membrane leakage.Some work is conducted on agronomic and horticultural crops;however,underutilized fruit crops are still neglected and need serious consideration from plant researchers.Minor fruit crops especially Zizyphus had excellent nutritional aspects.The current study provides detailed insights into the physiological and biochemical mechanisms of Zizyphus species to cope with the adverse effects of salinity by improving their plant defense system.The development of salt-tolerant germplasm is a requisite and can be developed by utilization of physiological,biochemical,and molecular mechanisms.Application of different molecular approaches(i.e.,genome mapping,genome editing,genetic transformation,proteomics,transcriptomics,and metabolites)are effective for higher yield by improving tolerance mechanisms.展开更多
Selection and use of molecular markers for evaluation of DNA polymorphism in plants are couple of the most important approaches in the field of molecular genetics.The assessment of genetic diversity using morphologica...Selection and use of molecular markers for evaluation of DNA polymorphism in plants are couple of the most important approaches in the field of molecular genetics.The assessment of genetic diversity using morphological markers is not sufficient due to little differentiating traits among the species,genera or their individuals.Morphological markers are not only highly influenced by environmental factors but skilled assessment is also prerequisite to find the variations in plant genetic resources.Therefore,molecular markers are considered as efficient tools for detailed DNA based characterization of fruit crops.Molecular markers provide new directions to the efforts of plant breeders particularly in genetic variability,gene tags,gene localization,taxonomy,genetic diversity,phylogenetic analysis and also play an important role to decrease the time required for development of new and excellent cultivars.The success of molecular markers technology in genetic improvement programs depends on the close relationship among the plant breeders,biotechnologists,skilled manpower and good financial support.The present review describes application and success of molecular markers technology used for genetic improvement in different fruit crops.展开更多
文摘Salinity is one of the major constraints reducing plant growth and yield.Irrigation with poor quality and brackish water to orchards is a major cause of stunted growth and low yield.The salt tolerance mechanism is one of the complicated genomic characters that is very problematic to develop in fruit trees and becomes much more severe at any growth and developmental stage.Osmotic stress and hormonal imbalances are major constraints causing low biomass production.Fruit tree tolerance/sensitivity is chiefly based on the activation of a defense system comprised of super-oxidase dismutase(SOD),peroxidase(POD)and catalases(CAT),non-enzymatic compounds including ascorbic acid,phenolics,flavonoids,stress indicators[i.e.,hydrogen peroxide(H2O2),lipid peroxidation,malondialdehyde(MDA),reactive oxygen species(ROS)and osmolytes containing proline,glycine-betaine(GB),ascorbates(APX),glutathione peroxidase(GPX)and glutathione reductase(GR)].Tolerant genotypes must have higher antioxidant assays to cope with the adverse effects of salinity stress because their defense system had the potential to scavenge toxic ROS and protect from membrane leakage.Some work is conducted on agronomic and horticultural crops;however,underutilized fruit crops are still neglected and need serious consideration from plant researchers.Minor fruit crops especially Zizyphus had excellent nutritional aspects.The current study provides detailed insights into the physiological and biochemical mechanisms of Zizyphus species to cope with the adverse effects of salinity by improving their plant defense system.The development of salt-tolerant germplasm is a requisite and can be developed by utilization of physiological,biochemical,and molecular mechanisms.Application of different molecular approaches(i.e.,genome mapping,genome editing,genetic transformation,proteomics,transcriptomics,and metabolites)are effective for higher yield by improving tolerance mechanisms.
文摘Selection and use of molecular markers for evaluation of DNA polymorphism in plants are couple of the most important approaches in the field of molecular genetics.The assessment of genetic diversity using morphological markers is not sufficient due to little differentiating traits among the species,genera or their individuals.Morphological markers are not only highly influenced by environmental factors but skilled assessment is also prerequisite to find the variations in plant genetic resources.Therefore,molecular markers are considered as efficient tools for detailed DNA based characterization of fruit crops.Molecular markers provide new directions to the efforts of plant breeders particularly in genetic variability,gene tags,gene localization,taxonomy,genetic diversity,phylogenetic analysis and also play an important role to decrease the time required for development of new and excellent cultivars.The success of molecular markers technology in genetic improvement programs depends on the close relationship among the plant breeders,biotechnologists,skilled manpower and good financial support.The present review describes application and success of molecular markers technology used for genetic improvement in different fruit crops.
