Publications

A wide range of indigenous varieties of different legume crops has been available in Oman since time immemorial, as these crops are preferred by farmers for their cooking quality and affinity. This paper focuses on the outputs of a collecting expeditions of indigenous legume germplasm for their conservation to avoid extinction due to new emerging edaphic (temperature, salinity, drought etc.) and biotic (insects, pests, diseases etc.) stresses being faced as a result of climate change and to ensure food security of the country. In all, 303 seed samples of land races/accessions in nine legume crops were collected from seven governorates, 187 of which were from seven food legume crops collected from 110 sites. The highest number of accessions was found in cowpea (Vigna unguiculata subsp. unguiculata) (64) followed by faba bean or broad bean (Vicia faba) (41), field peas (Pisum sativum) (27), mung bean (Vigna aureus) (25), chickpea (Cicer arietinum) (13), lentil (Lens culinaris) (11) and pigeon pea (Cajanus cajan) (6). South Batinah had the most legume accessions collected (70), mainly from wilayat Rustaq, followed by Interior (66), Sharqiya (63) Dhahira and Buraimi (46), Dhofar governate (23) and North Batinah (15). In alfalfa (Medicago sativa), 67 seed samples/accessions were collected from 62 sites, with the most (25) from Sharqiya, 20 from Interior, 8 each from North Batinah and Dhahira and Buraimi, 6 from South Batinah and none from Dhofar. In fenugreek (Trigonella foenum-graecum), 49 seed samples/accessions were collected from 43 sites, with the most from Batinah South (14) represented mostly by Rustaq, followed by Interior (13), Sharqiya (12) and Dhahira and Buraimi (10). The seed accessions were diverse with respect to the seed characters studied i.e., seed length (cm) and width (cm), 100-seed weight (g) and seed color. The diverse nature of the legume seed accessions and their genetic erosion are discussed. © 2014 Friends Science Publishers.

Relative changes of turgor pressure of leafy higher plants and trees can be measured by the non-invasive leaf patch clamp pressure probe (so-called ZIMprobe) with high sensitivity. The ZIM-probe is characterised by operating convenience and robustness and, therefore, allows long-term measurements under field conditions. Probe data are sent by wireless telemetry and mobile network to an internet server from which the data can be downloaded, viewed and analysed in real time. Drought effects on the water supply of leaves can clearly be distinguished from those induced by climate factors (such as temperature or light irradiation). The temporal and spatial dynamics of plant water relations can be revealed on the scale of a single leaf but also at the whole plant (tree) level by simultaneous multiple probe readings at different heights and orientations. Furthermore, concomitant ZIMprobe, dendrometer and sap flow measurements have given intriguing insight into the complex non-linear sap flow-leaf turgor pressure pattern within tree canopies indicating possible roles of water storage compartments and complex adaptations to drought in maintaining water supply of leaves. © ISHS 2013.

High temperature and water deficit are the most critical yield-limiting environmental factors for wheat in rainfed environments. It is important to understand the heat avoidance mechanisms and their associations with leaf morpho-physiological traits that allow crops to stay cool and retain high biomass under warm and dry conditions. We examined 20 morpho-physiologically diverse wheat genotypes under ambient and elevated temperatures (T_air) to investigate whether increased water use leads to high biomass retention due to increased leaf cooling. An experiment was conducted under well-watered conditions in two partially controlled glasshouses. We measured plant transpiration (T_r), leaf temperature (T_leaf), vapor pressure deficit (VPD), and associated leaf morpho-physiological characteristics. High water use and leaf cooling increased biomass retention under high temperatures, but increased use did not always increase biomass retention. Some genotypes maintained biomass, irrespective of water use, possibly through mechanisms other than leaf cooling, indicating their adaptation under water shortage. Genotypic differences in leaf cooling capacity did not always correlate with T_r (VPD) response. In summary, the contribution of high water use or the leaf cooling effect on biomass retention under high temperature is genotype-dependent and possibly due to variations in leaf morpho-physiological traits. These findings are useful for breeding programs to develop climate resilient wheat cultivars.

Abstract Earth's water resources are critical for supporting livelihoods and food security but are being increasingly overexploited to support global agriculture. Diversifying cropping systems could potentially resolve unsustainable water use but trade‐offs with other aspects of sustainability and food security have not yet been assessed. We performed a detailed analysis of 31 different field crop rotations conducted during 1990–2019 in the North China Plain, to assess the potential impact of crop diversification on actual evapotranspiration ( ET a ), changes in regional groundwater table, grain yield, economic output, and water use efficiency (WUE) and to identify configurations that can achieve co‐benefits across multiple dimensions. We found that a combination of lowering the cropping index (i.e., harvest frequency), incorporating fallow periods, and introducing higher‐value crops into the currently dominant winter wheat–summer maize double cropping system can reduce growing season ET a by as much as 31%, mitigate groundwater decline by 19% or more, and increased economic output and economic WUE by more than 11% and 3%, respectively. We also found that multiple diversified wheat‐maize–based rotations—all with rotation lengths greater than 2 years—achieve co‐benefits across all evaluated dimensions. This study provides new empirical evidence of the opportunities for diversified crop rotations to balance the multiple objectives of food production, sustainable groundwater use, and farmer profitability. Extending this solution to other water‐stressed agricultural regions could be an effective strategy in achieving more sustainable food production system globally.

Traditional rice systems are holistic systems, resilient, eco-friendly and a key to nutrition security but unfortunately, in decline. Traditional cultivation that uses local rice varieties appears to withstand the impacts of climate change. Many agencies in rice producing countries are working towards the revival of traditional rice varieties. This study explored the traditional rice farming scenario in Kerala, India. We looked at the farmers who cultivated traditional rice varieties, their satisfaction levels and what factors will possibly lead to the sustainability of traditional rice cultivation. The study found some emerging types of new rice farmers who were more satisfied with traditional rice cultivation. Marketed surplus, education, area and institutional support were identified as the key factors that lead to successful farm enterprises. While there were positive indicators for the sustainability of traditional rice, how far they will endure in the future is unclear.

Zero hunger and good health could be realized by 2030 through effective conservation, characterization and utilization of germplasm resources¹. So far, few chickpea (Cicer arietinum) germplasm accessions have been characterized at the genome sequence level². Here we present a detailed map of variation in 3,171 cultivated and 195 wild accessions to provide publicly available resources for chickpea genomics research and breeding. We constructed a chickpea pan-genome to describe genomic diversity across cultivated chickpea and its wild progenitor accessions. A divergence tree using genes present in around 80% of individuals in one species allowed us to estimate the divergence of Cicer over the last 21 million years. Our analysis found chromosomal segments and genes that show signatures of selection during domestication, migration and improvement. The chromosomal locations of deleterious mutations responsible for limited genetic diversity and decreased fitness were identified in elite germplasm. We identified superior haplotypes for improvement-related traits in landraces that can be introgressed into elite breeding lines through haplotype-based breeding, and found targets for purging deleterious alleles through genomics-assisted breeding and/or gene editing. Finally, we propose three crop breeding strategies based on genomic prediction to enhance crop productivity for 16 traits while avoiding the erosion of genetic diversity through optimal contribution selection (OCS)-based pre-breeding. The predicted performance for 100-seed weight, an important yield-related trait, increased by up to 23% and 12% with OCS- and haplotype-based genomic approaches, respectively.

Abstract Microplastics (MPs) reach the soil environment through the application of recycled water, biosolids, and compost and the in‐situ weathering of plastic mulch used in agriculture. This review provides an overview of the sources of MP input to soil and their interactions with soil biota, thereby impacting soil biological health. MPs contain various chemical additives and can be ingested by soil biota, thereby impacting their activity and function. MPs also serve as a vector for inorganic and organic contaminants. These chemical additives and environmental contaminants can be released into soil porewater during the weathering of MPs in soil and impact soil biota. Overall, MPs can also alter soil's physical and chemical properties thereby impacting the habitat for soil microorganisms. Soil microorganisms can use MPs as a carbon source and porous habitat for proliferation. Future research needs to focus on the genomic and functional diversity of soil microbes as impacted by MP contamination, thereby enabling us to develop strategies to mitigate the impacts of MP on soil biological health.