Effects of UV Radiation on Germination, Growth, Chlorophyll Content, and Fresh and Dry Weights of Brassica rapa L. and Eruca sativa L.

Abstract

T he growth and development of plants depend upon energy obtained from the sunlight. A slight change in the wave length of light can alter the whole plant physiology and biochemistry (Schmitt and Wulff, 1993). Light waves of 400-700 nm wavelengths have greater effect on a plant's responses which cause Abstract | Due to the depletion in the ozone layer, solar UV radiation at the earth's surface is increasing, impacting economically important plants. The current study assesses the effects of UV radiation on germination, growth, chlorophyll content and fresh and dry weight of Brassica rapa L. and Eruca sativa L. Some seeds of Brassica rapa L. and Eruca sativa L. were placed in petri plates, and were exposed to UV light for 30, 60 and 120 mins daily. The source of UV light was a UV box having a UV Tube. The UV exposure on the seeds reduced the germination percentage in both species. The germination percentage in control was recorded as 19.35%, while it was 18.65% in 30min and 19.00% in 120min exposures. Root and shoot growth of the seedlings was markedly reduced by increasing UV radiation. The shoot length was 2.40mm in control, 2.75mm in 30min, 1.50mm in 60min and 1.60mm in 120min of exposure to the UV light. The root length in control was 1.38mm, 0.90mm in 30min, 1.00mm in 60min and 1.17mm in 120min exposure. The UV irradiations affected the chlorophyll contents positively, and therefore, the total quantity of chlorophyll content increased, compared to the control. The chlorophyll content in the control was 6.90 (µmol m-2) of leaf area while treatment showed 8.08 (µmol m-2) in 30min, 8.01 (µmol m-2) in 60min and 10.01 (µmol m-2) in 120min exposure. In both species, fresh and dry weights were decreased, as compared to the control set. The fresh weight of the control was 0.85g, 0.65g in 30min, 0.78g in 60min and 0.61g in 120min exposure. The dry weight of the control was recorded to be 0.70g, 0.60g in 30min, 0.62g in 60min and 0.50g in 120min exposure. It was concluded that ultraviolet radiation decreased the radicle and plumule lengths in Brassica rapa and Eruca sativa while increasing their chlorophyll content.

Heavy Metals Contaminants in Watercress (Nasturtium officinale R. BR.): Toxicity and Risk Assessment for Humans along the Swat River Basin, Khyber Pakhtunkhwa, Pakistan

“…The species has long been used for therapeutic purposes, since the Roman period, has a spicy or peppery taste, and is often used in salads, soups, and other foods, having a short shelf life of one week [29]. However, its shelf life may be extended by freezing and storing [30]. The plant is a nutritional food because it includes essential minerals such as calcium (Ca), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), vitamins A, C, E, and K, carotenoids (zeaxanthin and lutein), and glucosinolates [27].…”

Adventitious organogenesis and phytochemical composition of Madonna lily (Lilium candidum L.) in vitro modeled by different light quality

“…UV radiation induces the uncoupling of the chlorophyll molecules in the light-harvesting system that results in reduced photosynthesis in many plant species (Jovanić et al 2022). However, the response of chlorophyll to UV light may be different for different species and growing conditions (Begum et al 2021). Chlorophyll a and b may also have different sensitivity to UV light, which is related to their dissimilar pathways (Ranjbarfordoei et al 2009;Shaukat et al 2011).…”

Invasive Species as Rivals: Invasive Potential and Distribution Pattern of Xanthium strumarium L.

“…An invasive species may be able to invade and spread in a new habitat despite biotic and abiotic filters [15]. Environmental parameters of any area, notably temperature, relative humidity, day length, and geographical and topographic variables, operate as an abiotic filter for newly invading invaders [16]. The filter's efficiency is determined by how closely environmental conditions correspond to the species' native and invaded habitats [17].…”