Reactive oxygen species turnover, phenolics metabolism, and some key gene expressions modulate postharvest physiological deterioration in cassava tubers.

Rapid postharvest physiological deterioration (PPD) in cassava (Manihot esculenta Crantz) tuber is a significant concern during storage. The freshly harvested tubers start spoiling within 24 to 72 h. Accumulation of H2O2 is one of the earliest biochemical events that occurred during PPD, which was detected using the 3,3 diaminobenzidine (DAB) in two contrast cassava genotypes, MNP Local A (29-57 µg g-1) and Sree Prakash (64-141 µg g-1). Accumulating the fluorescence hydroxycoumarin compounds emitted by the cassava tubers observed under an ultraviolet (UV) lamp showed significant variations at 0, 3, 6, 9, 12, and 15 days of storage. The total phenolics and carotenoids significantly and negatively correlated with PPD progression; however, the anthocyanin and flavonoids positively correlated with the PPD-anchored ROS accumulation. The primary compound, Phthalic acid, di(2-propylpentyl) ester, was identified in both the cassava tubers, Sree Prakash (57.21 and 35.21%), and MNP Local A (75.58 and 60.21%) at 0, and 72 h of PPD, respectively. The expression of PPD-associated genes APX-2, APX-3, PAL, and AP was higher at 6-12 days of PPD, which signified the synthesis of ROS turnover and phenylpropanoid biosynthesis. A significant, strong, and positive correlation was established between the secondary metabolites and PPD signaling gene expression, which was inversely correlated with hydroxycoumarin and H2O2 accumulation. MNP Local A tubers exhibited longer storage life of 15 days with a low PPD score, higher metabolites synthesis, and gene expression. The PPD-resistant lines may be used to augment cassava breeding strategies for large-scale commercial and industrial use.

Orphan legumes: harnessing their potential for food, nutritional and health security through genetic approaches.

Legumes, being angiosperm's third-largest family as well as the second major crop family, contributes beyond 33% of human dietary proteins. The advent of the global food crisis owing to major climatic concerns leads to nutritional deprivation, hunger and hidden hunger especially in developing and underdeveloped nations. Hence, in the wake of promoting sustainable agriculture and nutritional security, apart from the popular legumes, the inclusion of lesser-known and understudied local crop legumes called orphan legumes in the farming systems of various tropical and sub-tropical parts of the world is indeed a need of the hour. Despite possessing tremendous potentialities, wide adaptability under diverse environmental conditions, and rich in nutritional and nutraceutical values, these species are still in a neglected and devalued state. Therefore, a major re-focusing of legume genetics, genomics, and biology is much crucial in pursuance of understanding the yield constraints, and endorsing underutilized legume breeding programs. Varying degrees of importance to these crops do exist among researchers of developing countries in establishing the role of orphan legumes as future crops. Under such circumstances, this article assembles a comprehensive note on the necessity of promoting these crops for further investigations and sustainable legume production, the exploitation of various orphan legume species and their potencies. In addition, an attempt has been made to highlight various novel genetic, molecular, and omics approaches for the improvement of such legumes for enhancing yield, minimizing the level of several anti-nutritional factors, and imparting biotic and abiotic stress tolerance. A significant genetic enhancement through extensive research in 'omics' areas is the absolute necessity to transform them into befitting candidates for large-scale popularization around the globe.

Assessment of heavy metal status and identification of source in soils under intensive vegetable growing areas of Brahmaputra valley, North East India.

This study investigated the content of Cd, Pb, Cr, and Ni in the soils of intensive vegetable growing areas of the Brahmaputra valley, North East India, to assess their status and detect any buildup of metals due to long-term and continuous application of agrochemicals and organic manures. The content of heavy metals was determined in eighty composite surface soil samples (0-20 cm) collected from eight different locations of the valley having a history of more than forty years of vegetable production. This finding is novel as no comprehensive investigation has been done till date in respect of the content of heavy metals in the intensive vegetable growing areas of Brahmaputra valley. The locations are considered free from any pollution caused by industrial effluent or urbanization processes. The investigational data showed that the content of Cd, Pb, Cr, and Ni in the soils ranged from 0.43 to 3.24, 6.00 to 22.90, 3.00 to 15.24, and 3.30 to 14.30 mg kg-1, respectively. The overall mean values of the heavy metals showed a decreasing order of Pb (14.79 mg kg-1) > Cr (8.87 mg kg-1) > Ni (8.37 mg kg-1) > Cd (1.43 mg kg-1). The findings of the study indicated significant enrichment of the metals in the surface soils over the local background values of the elements measured in the C horizon. Though the concentrations of Pb, Cr, and Ni of the soils were well below the reference levels used in different countries, Cd showed distinctly higher value with maximum enrichment level. The soils were categorized as slightly to moderately polluted based on different pollution indices. Based on the ecological risk index, soils were in the low-risk category, but in respect of Cd, most of the soils fell under the moderately risky category. Multivariate analysis suggested the predominance of lithogenic influence on the content of Pb, Ni, and Cr while Cd content bears a distinct signature of the anthropogenic source. The buildup of Cd in the studied soils is a matter of critical concern and needs proper monitoring and management strategies to avoid any potential detrimental effect on soil, crop, and human health.

Planning rainwater conservation measures using geospatial and multi-criteria decision making tools.

The assessment of rainwater-harvesting demand (RWHD) map and the identification of appropriate priority-based locations for rainwater-harvesting (RWH) and groundwater recharge structures are very crucial for the water managers, particularly in irrigation commands. This study addresses this challenge by using multi-criteria decision-making (MCDM) and geospatial techniques to present a novel and robust approach for generating RWHD map and identifying sites/zones for distinct RWH and groundwater recharge on a priority basis. Primary thematic layers such as existing irrigation water supply, irrigation demand, and groundwater potential were considered in this study for delineating RWHD zones. Further, sites suitable for RWH and groundwater recharge were identified using soil, slope, drainage network, and lineament thematic layers of the study area and they were prioritized. Four zones of rainwater demand were identified for the prioritization of RWH and groundwater structures: (a) "low" rainwater-harvesting demand zone (covering 3% of the total study area), (b) "moderate" rainwater-harvesting demand zone (40%), (c) "high" rainwater-harvesting demand zone (42%), and (d) "very high" rainwater-harvesting demand zone (15%). Moreover, 46 sites for check dams and 145 suitable sites for percolation tanks were identified, together with 253 ha area for groundwater recharge based on the priority of rainwater-harvesting demand. Integration of geospatial and MCDM techniques in conjunction with suitable thematic layers provides a helpful and realistic tool for large-scale planning and management of rainwater conservation measures.

Examining the effects of green revolution led agricultural expansion on net ecosystem service values in India using multiple valuation approaches.

Ecosystem Services (ESs) are bundles of natural processes and functions that are essential for human well-being, subsistence, and livelihoods. The 'Green Revolution' (GR) has substantial impact on the agricultural landscape and ESs in India. However, the effects of GR on ESs have not been adequately documented and analyzed. This leads to the main hypothesis of this work - 'the incremental trend of ESs in India is mainly prompted by GR led agricultural innovations that took place during 1960 - 1970'. The analysis was carried out through five successive steps. First, the spatiotemporal Ecosystem Service Values (ESVs) in Billion US$ for 1985, 1995, and 2005 were estimated using several value transfer approaches. Second, the sensitivity and elasticity of different ESs to land conversion were carried out using coefficient of sensitivity and coefficient of elasticity. Third, the Geographically Weighted Regression model was performed using five explanatory factors, i.e., total crop area, crop production, crop yield, net irrigated area, and cropping intensity, to explore the cumulative and individual effects of these driving factors on ESVs. Fourth, Multi-Layer Perceptron based Artificial Neural Network was employed to estimate the normalized importance of these explanatory factors. Fifth, simple and multiple linear regression modeling was done to assess the linear associations between the driving factors and the ESs. During the observation periods, cropland, forestland and water bodies contributed to 80%-90% of ESVs, followed by grassland, mangrove, wetland and urban built-up. In all three evaluation years, the highest estimated ESVs among the nine ES categories was provided by water regulation, followed by soil formation and soil-water retention, biodiversity maintenance, waste treatment, climate regulation, and greenhouse gas regulation. Among the five explanatory factors, total crop area, crop production, and net irrigated area showed strong positive associations with ESVs, while cropping intensity exhibited a negative association. Therefore, the study reveals a strong association between GR led agricultural expansion and ESVs in India. This study suggests that there should be an urgent need for formulation of rigorous ecosystem management strategies and policies to preserve ecological integrity and flow of uninterrupted ESs and to sustain human well-being.