2.5 KiB
Executable file
2.5 KiB
Executable file
Basil's growth, yield, and chemical composition are significantly influenced by environmental and nutritional stress.
- Water Stress (Drought): Inhibits overall plant growth and significantly reduces dry herb yield.
- Drought Effects: Leads to a decrease in total sugar and carotenoid concentrations.
- Biomass: Drought stress reduces dry herb yield, which can be attributed to a smaller leaf area index and reduced photosynthesis.
- Photosynthesis: Drought stress leads to a significant decrease in the net assimilation rate and stomatal conductance.
- Essential Oils: Water stress can have a positive or negative effect on essential oil content, depending on the cultivar and stress severity.
- Heat Stress: High temperatures inhibit plant growth and significantly decrease total chlorophyll levels.
- Oxidative Stress: Both high temperature and water stress can cause oxidative stress, indicated by increased malondialdehyde (MDA) levels.
- Phenolic Compounds: The concentration of total phenolic compounds increases in response to water and heat stress.
- Flavonoids: Flavonoid content increases under high-temperature stress but may decrease under water stress.
- Proline and Glycine Betaine: Under severe stress, basil plants accumulate proline and glycine betaine, which aid in cellular osmoregulation.
- Salt Stress: Basil is considered moderately tolerant to salinity.
- Salinity Effects: High salt levels can cause stunted growth, leaf yellowing, and reduced essential oil yield.
- Genotype Variation: The response to salt stress is genotype-dependent; some cultivars may see a reduction in fresh yield while others are unaffected.
- Carotenoids under Salinity: Salt stress can either increase or decrease lutein and β-carotene concentrations depending on the cultivar.
- Volatile Organic Compounds (VOCs): The composition of VOCs, which contribute to the aroma, is significantly affected by salinity, with compounds like linalool being negatively impacted.
- Nutritional Stress: Nitrogen content in the plant can be increased by salt stress in some cultivars.
- Flooding Stress: Reduces photosynthetic rates and stomatal conductance.
- Combined Flooding and Drought: This sequence of stress has a more significant negative impact on photosynthetic pigments and flavonoid content than single stress events.
- Pigment Reduction: Chlorophyll a, chlorophyll b, and β-carotene levels all decrease under combined flooding and drought stress.