Evaluation of cultivated and wild genotypes of Lens species under alkalinity stress and their molecular collocation using microsatellite markers

Abstract

In this study, 285 lentil genotypes were phenotyped under hydroponic and alkaline field conditions. Significant genotypic variation for alkalinity stress was observed among the six Lens species screened hydroponically and in the field having pH up to 9.1. The crucial parameters, like whole Na+ and K+ contents and the Na+/K+ ratio at 40 mM NaHCO3 were found significantly correlated with seedling survivability under hydroponics (r = -0.95, r = 0.93 and -0.97). Genotypes, ranked on the bases of seed yield, restricted uptake of Na+ with thick pith area, increased vascular bundles, less H2O2 production and low Na+/K+ ratio, were found important physio-anatomical traits for alkalinity stress tolerance. The proper regulation of Na+ uptake was found for maintaining higher K+. This relationship is probably the main factor responsible for a better mechanism for tolerance to high pH up to 9.1 in tolerant breeding lines PDL-1 and PSL-9 (cultivars) and ILWL-15, ILWL-192 and ILWL-20 (wild accessions). Based on UPGMA dendrogram, all the genotypes were clustered into four diverse groups. DMRT was implied within the group to differentiate genotypes based on phenotypic response under alkalinity stress. These results can be utilized for selecting diverse parents for developing alkalinity tolerant genotypes.

The Roles of Plant Growth Promoting Microbes in Enhancing Plant Tolerance to Acidity and Alkalinity Stresses

“…Most plants under alkalinity stress manifest stunted growth due to poor nutrient uptake and leaf chlorosis due to high and low uptake of Na + and Fe + , respectively (Zhang et al, 2012;Singh et al, 2018). High levels of Na + interfere with stomatal closure, which worsens the problem of water loss for plants (Bernstein, 1975), a common phenomenon under saline conditions, which can be similar under alkalinity conditions.…”

“…A range of plants have shown various mechanisms of tolerance to alkaline stress, most of them showing early seed germination and seedling establishment. Cultivars of lentil tolerant to alkalinity stress are known to have shoots with a thicker epidermis than sensitive cultivars (Singh et al, 2018). Similarly, tolerant lentils (Singh et al, 2018), finger millet (Krishnamurthy et al, 2014) and Lotus tenuis (Paz et al, 2012) minimize Na + uptake by having intact pericycle and stele regions.…”

“…Cultivars of lentil tolerant to alkalinity stress are known to have shoots with a thicker epidermis than sensitive cultivars (Singh et al, 2018). Similarly, tolerant lentils (Singh et al, 2018), finger millet (Krishnamurthy et al, 2014) and Lotus tenuis (Paz et al, 2012) minimize Na + uptake by having intact pericycle and stele regions. Despite the presence of tolerance mechanisms for alkalinity stress by plants much remains unknown in relation to other related stresses, such as salinity and drought.…”

Linking genome wide RNA sequencing with physio-biochemical and cytological responses to catalogue key genes and metabolic pathways for alkalinity stress tolerance in lentil (Lens culinaris Medikus)

“…Since third type of injury is not much prevalent in salinity stress, this contributes to higher alkalinity toxicity in plants as compared to the former. High concentrations of HCO 3 and NaHCO 3 in alkaline soils effects a wide array of metabolic activities in plants leading to stunted growth, leaf chlorosis and distorted anatomical structures [ 4 ]. These massive cyto-morphological disorders occur due to increased Na + uptake, nutritional deficiencies, organic acids imbalance, inorganic ions accumulation, disrupted cellular pH, together with decreased enzyme activities and photosynthetic carbon metabolism [ 5 , 6 ].…”

“…Lentil is moderately sensitive to both alkalinity and salinity stresses. However, two cultivars namely, PDL-1 and PSL-9 were found to be tolerant against both the stresses [ 4 , 14 ]. These cultivars have already been released in India to be cultivated under salt affected soils.…”