جستجوی مقالات مرتبط با کلیدواژه "کیفیت نور" در نشریات گروه "زیست شناسی"

Microgreens are considered a functional food that can be so useful for increasing the health level of society. This experiment was conducted in factorial format based on a completely randomized design with two factors. The first factor, light spectrum, was investigated at four levels, and the second factor, sulfur nutrition, at two levels (0 and 60 mg/liter). The light treatments included different ratios of red (R) and blue (B) light (R1B2, R1B1, R2B1, and R3B1). The highest leaf length was recorded in the R3B1 treatment without sulfur feeding, which was significantly higher than all other treatments used. The length of the stem in the combined treatment of R3B1 with sulfur feeding showed the highest figure. The highest amount of total chlorophyll was obtained in R1B2 treatment with sulfur feeding, although their difference with R3B1 treatment with sulfur feeding and R2B1 without sulfur feeding was not statistically significant. In carotenoid pigment, the highest amount was seen in R2B1 treatment without sulfur, which did not show a significant difference with R1B2 without sulfur feeding. The total antioxidant activity showed the highest value in R3B1 treatment without sulfur, and its difference was not significant between R1B1 treatment without sulfur and R1B1 with sulfur feeding. The maximum calculated phenol was recorded in R2B1 treatment without sulfur, which was not significantly different from R1B2 treatment without sulfur and R3B1 with sulfur feeding. The most flavonoids were obtained in the R1B2 treatment without sulfur feeding, which was significantly more than all other treatments. Since the high proportion of red light in conditions without sulfur nutrition caused proper morphological growth and also increased the antioxidant capacity of the plant, therefore the mentioned treatment is recommended for the production of broccoli microgreens under artificial light.

Zamofilia is one the most valuable foliage plants which is commonly propagated using vegetative methods. This technique requires a great number of mother plants to provide adequate cuttings for commercial propagation which hardly seem to meet the most economical expectations. However, due to the slow growth habit of this plant, even under ideal growing conditions, its commercial and mass production are limited by some species-related characteristics. Therefore, developing an improved method of micropropagation which lead to a fast and reliable mass propagation technique may overcome most of these limitations especially at commercial scale. In this regard, this research was conducted and aimed to introduce an efficient micropropagation method in in-vitro condition for rapid propagation of this plant. Two different concentrations of BAP (1 and 2 mg L-1) and NAA (0 and 0.1 2 mg L-1 ) were applied on the explants taken from one of the three different positions of the leaflets (i.e., lower, middle and upper parts) cultured in MS medium and treated with blue (460 nm) or red (660 nm) light supplied by LED luminaries The results showed that the best treatment for callus and protocorm formation with the maximum stimulation (93.75%) and (66.66%) was the application of 2 mg/L BAP along with 0.1 mg/L NAA in The light was red. Callus production occurred in cut surfaces by 90% under blue and 85% under red light, while these lights induced protocorm indirectly by 80% and 90% respectively, leaving the rest to be regenerated by directly. Blue and red light induced protocorm emergence by 95% and 97% respectively from the cut surface and the parts around the cut location were responsible for the emergence of the remained protocorms. The highest rate of regeneration of protocorms (95%) in the treatment of 0.1 mg/liter NAA .

Phalaenopsis (the moth orchid; Phalaenopsis spp.) is currently the most sold indoor potted crop in the world’s major floriculture markets. The effects of light quality in night interruption (NI) and NPK fertilizers were examined on the vegetative growth and flowering of Phalaenopsis, an Evolution cultivar, in a factorial experiment as a completely randomized design. Young 6-old months plants from the last days of August to October when the length of flower buds was about 5 cm, were grown under ambient light/dark of greenhouse (control), ambient light plus night interruption (23:00–03:00 h) with light intensity at 20 µmol m−2 s−1 with three spectra light including white (400-700 nm), blue (450 nm) and red (680 nm) LED lights. Also, three water-soluble NPK fertilizers including 19N-6P-20k, 12N-12P-36K and 20N-20P-20K were applied to plants at concentrations of 1/1000. The tallest plants (25 cm) at flowering were in the control group in the 20N-20P-20K fertilizer treatment. NI with white LED + 19N-6P-20k or control + 20N-20P-20K effectively increased floret number. To obtain early flowering using 12N-12P-36K (without NI) and NI treatment with white light + 20N-20P-20K and blue light + 12N-12P-36K during their reproductive stage could be suggested. Plants fertigated with 12N-12P-36K and NI with red LED, showed the highest amount of chlorophyll a (0.36 mg/FW) and b (0.17 mg/FW). The highest amount of K and P in all three light treatments were obtained in 12N-12P-36K fertilizer. The experimental results suggested that NI treatment can be used effectively to promote flower induction with an increased growth rate. To obtain high-quality plants, however, NI with red and white LEDs should be considered.

In this study, some of the growth parameters and biochemical composition of Chaetoceros muelleri were investigated under blue, white, and red light. Different treatments of lights applied to Chaetoceros muelleri cultures (salinity 25 ppt, temperature 23 ± 1°C, light intensity 1500 ± 200 lux, Light/Dark 12/12, mild aeration, alkalinity 7.5-8.5( for 12 days in divided Indoor chambers. The microalgae under blue light showed the highest cell density, specific growth rate, chlorophyll a, dry weight, protein, omega-3 fatty acids, palmitoleic acid (C16:1), and the shortest doubling time, low fat and omega-6 were observed. The lowest cell density, dry weight, chlorophyll a, protein, omega-3 fatty acids, oleic acid (C18: 1), and more than 25% palmitic acid (C16: 0) were observed under red light. The highest doubling time of the population, the highest amount of omega-6 fatty acids and oleic acid (C18: 1), was observed in white light. The total fat content was not significantly different between the three light ones (p <0.05). Red light accounted for more than 41% of the SFA value, white light more than 16% of PUFA, and light blue 46% of MUFA. Blue light clearly showed better performance and had a significant difference (0.05 pp) compared to white and red while there was no significant difference between white and red.