RETRACTED ARTICLE: Characterization and Evaluation of Mango Germplasm Through Morphological, Biochemical, and Molecular Markers Focusing on Fruit Production: An Overview

Genetic diversity among local mango (Mangifera indica L.) germplasm using morphological, biochemical and chloroplast DNA barcodes analyses

BACKGROUND

In this study, the genetic diversity of local mango (Mangifera indica L.) germplasm including 14 genotypes were evaluated by using morphological, biochemical markers and DNA barcoding technique. Morphological characterization is the first step towards utilizing these germplasm in crop improvement studies. The advanced chloroplast based DNA barcode method can be utilized to assess the genetic diversity and phylogenetic structure in such populations.

METHODS

The study was carried out during 2018-2019 years to evaluate local mango germplasm including 14 diverse genotypes based on a number of morphological and biochemical traits and chloroplast DNA barcoding as well. The experiment was laid out in one way ANOVA design with fourteen germplasm indicated with indigenous collection number.

RESULTS

Among local mango germplasm, IC 589756 was found to be the most promising with respect to high magnitudes of fruit length, fruit width, fruit weight, pulp weight, soluble solid content (SSC)/Acidity ratio, pH and low acidity followed by IC 589746 exhibiting the highest pulp percentage and SSC accompanied with lowest stone weight and stone percent as compared to the other genotypes. Further, the dendrogram and cluster analyses based on sequencing of chloroplast marker i.e., trnH- psbA and trnCD depicted the relationship among mango genotypes and clearly clustered them into two main clusters at a similarity coefficient 0.035 and 0.150, respectively. The first cluster includes only one genotype and cluster-II contains 13 genotypes.

CONCLUSIONS

Particularly results revealed that DNA barcoding of local mango germplasm can assist not only in molecular identification but also help in elucidation of their phylogenetic relationship and thus important in maintaining biodiversity inventories.

Induced in vitro adaptation for salt tolerance in date palm (Phoenix dactylifera L.) cultivar Khalas

BACKGROUND

Soil salinity causes huge economic losses to agriculture productivity in arid and semiarid areas worldwide. The affected plants face disturbances in osmotic adjustment, nutrient transport, ionic toxicity and reduced photosynthesis. Conventional breeding approaches produce little success in combating various stresses in plants. However, non-conventional approaches, such as in vitro tissue culturing, produce genetic variability in the development of salt-tolerant plants, particularly in woody trees.

RESULTS

Embryogenic callus cultures of the date palm cultivar Khalas were subjected to various salt levels ranging from 0 to 300 mM in eight subcultures. The regenerants obtained from the salt-treated cultures were regenerated and evaluated using the same concentration of NaCl with which the calli were treated. All the salt-adapted (SA) regenerants showed improved growth characteristics, physiological performance, ion concentrations and K+/Na+ ratios than the salt non-adapted (SNA) regenerants and the control. Regression between the leaf Na+ concentration and net photosynthesis revealed an inverse nonlinear correlation in the SNA regenerants. Leaf K+ contents and stomatal conductance showed a strong linear relationship in SA regenerants compared with the inverse linear correlation, and a very poor coefficient of determination in SNA regenerants. The genetic fidelity of the selected SA regenerants was also tested using 36 random amplified polymorphic DNA (RAPD) primers, of which 26 produced scorable bands. The primers generated 1-10 bands, with an average of 5.4 bands per RAPD primer; there was no variation between SA regenerants and the negative control.

CONCLUSION

This is the first report of the variants generated from salt-stressed cultures and their potential adaptation to salinity in date palm cv. Khalas. The massive production of salt stress-adapted date palm plants may be much easier using the salt adaptation approach. Such plants can perform better during exposure to salt stress compared to the non-treated date palm plants.