Publications

Additional file 5: Supplementary Table 5. Marker-trait association identified with GLM analysis in diverse panel I phenotypic data measured under water stress.

The growth of chickpea (Cicer arietinum L.) is very sensitive to salinity, with the most susceptible genotypes dying in just 25 mm NaCl and resistant genotypes unlikely to survive 100 mm NaCl in hydroponics; germination is more tolerant with some genotypes tolerating 320 mm NaCl. When growing in a saline medium, Cl(-), which is secreted from glandular hairs on leaves, stems and pods, is present in higher concentrations in shoots than Na(+). Salinity reduces the amount of water extractable from soil by a chickpea crop and induces osmotic adjustment, which is greater in nodules than in leaves or roots. Chickpea rhizobia show a higher 'free-living' salt resistance than chickpea plants, and salinity can cause large reductions in nodulation, nodule size and N(2)-fixation capacity. Recent screenings of diverse germplasm suggest significant variation of seed yield under saline conditions. Both dominance and additive gene effects have been identified in the effects of salinity on chickpea and there appears to be sufficient genetic variation to enable improvement in yield under saline conditions via breeding. Selections are required across the entire life cycle with a range of rhizobial strains under salt-affected, preferably field, conditions.

A high and stable apple yield is critical for rainfed hilly apple orchards; however, many factors threaten apple yield and sustainable apple production, including water shortage, soil erosion, and chemical fertilizer overuse. Therefore, we undertook a field trial with three treatments— (1) organic and inorganic fertilizer combining a water-saving technique (OIWS), (2) inorganic fertilizer combining a water-saving technique (IWS), and (3) inorganic fertilizer alone (CK)—to determine how to alleviate these yield-limiting factors and improve soil fertility. Averaged across five years (2016–2020), the OIWS treatment increased apple yield the most, by 24.87% and 67.34% relative to IWS and CK, respectively. The OIWS treatment also had the highest apple yield stability, despite no significant differences between treatments, indicating OIWS treatment could produce higher apple yield year by year relative to IWS and CK. In comparison to IWS and CK, OIWS treatment showed greater 0–1 m by 12.21% and 26.08% and 0–3 m soil water storage (SWS) by 14.81% and 19.12%, as well as the highest abundance of 0–1 m soil microaggregates (0.053–0.2 mm) and macroaggregates (0.2–2 mm). Moreover, relative to IWS and CK averaged across the five years and 0–2 m soil layers, OIWS treatment substantially enhanced soil organic carbon (SOC) by 4.23 and 3.93 g kg−1 and total nitrogen (TN) by 0.09 and 0.11 g kg−1, respectively. Furthermore, Changes in apple production were positively linked with variations in 0–1 m SWS, soil microaggregate and macroaggregate abundance, and SOC and TN. And the most relevant factor to apple yield is 0–1 m SWS. Overall, on the Loess Plateau, OIWS system is a sustainable approach for increasing apple productivity and soil fertilities in rainfed hilly orchards.

Asbestos is a silicate mineral that occurs naturally and is made up of flexible fibres that are resistant to heat, fire, and chemicals and do not conduct electricity. Both anthropogenic disturbance and natural weathering of asbestos-containing waste materials (ACWMs) can result in the emission of asbestos fibre dust, which when breathed, can cause asbestosis, a chronic lung illness that happens due to prolonged exposure of such fibre dust, and can cause ‘mesothelioma’ cancer. Although asbestos mining and its utilisation had been banned in many countries, there is still a significant issue of ACWMs disposal in the built environment and abandoned sites. It is neither practical nor economical to safely eliminate ACWMs from the built environment, and it is estimated that globally, 4 billion metric tonnes of ACWMs require safe management strategies. The toxicity of inhaled asbestos fibre relies on its surface properties, and in particular the distribution of iron, which serves a critical role in pathogenicity by forming reactive free radicals that damage DNA, thereby trigging cancer. Examining the usefulness of higher plants and microbes in the bioremediation of soil contaminated with ACWMs is the prime aim of the review. Higher plants and microorganisms such as lichens, fungi, and bacteria often play a major role in the remediation of soil contaminated with ACWMs by facilitating the bioweathering of asbestos and the removal of iron to mitigate the toxicity of asbestos.

Metabolic regulation is the key mechanism implicated in plants maintaining cell osmotic potential under drought stress. Understanding drought stress tolerance in plants will have a significant impact on food security in the face of increasingly harsh climatic conditions. Plant primary and secondary metabolites and metabolic genes are key factors in drought tolerance through their involvement in diverse metabolic pathways. Physio-biochemical and molecular strategies involved in plant tolerance mechanisms could be exploited to increase plant survival under drought stress. This review summarizes the most updated findings on primary and secondary metabolites involved in drought stress. We also examine the application of useful metabolic genes and their molecular responses to drought tolerance in plants and discuss possible strategies to help plants to counteract unfavorable drought periods.

In the Australian grainbelt, early winter rainfall has declined during the last 30 years, and farmers sow their crops dry, increasing the risk of early season drought. This study aimed to examine whether differences in the root systems were associated with tolerance to early season drought. Three wheat cultivars with different root systems were grown in 1 m columns in a glasshouse. Immediately after sowing in dry soil, 440 mL water (equivalent to 25 mm rainfall) was supplied to each column, and no water was added to induce the early-season drought for the next 30 days. Shoot and root traits were measured at the end of the early season drought, anthesis and at maturity, respectively. The restricted water supply reduced Ψ_leaf, stomatal conductance, leaf photosynthetic rate, shoot and root biomass. Early season drought delayed phenology in all cultivars, but there was recovery of root and shoot biomass at anthesis in all three cultivars. Leaf area and shoot biomass at anthesis in Bahatans-87 (large root system) recovered better than Tincurrin (small root system). At maturity, early season drought reduced grain yield more in Tincurrin than Bahatans-87. The slow phenology of Bahatans-87 allowed greater recovery after the drought in leaf area and shoot biomass, which may explain the smaller reduction in grain yield after early season drought.