INTRODUCTION Vegetables are vital dietary ingredients, and are important sources of carbohydrates, proteins, minerals, vitamins, dietary fibres and various bioactive compounds like antioxidants, making them effective protective foods (Sharma et al., 2021). Due to the buzzing lifestyle and hustled behavior of the 21st century, dietary supplements, which are imperative for combating certain deficiency diseases and chronic health problems, may be absorbed poorly, because of which people have started resorting to chemical derivatives rather than the natural sources of these supplements (Kader et al., 2000). In this light, the idea of raising microgreens to meet all the dietary and nutritional requirements of the people and supplementing the already existing staple diet with this nutrient boost can be very well explored. Microgreens are an innovative concept in the field of micro-scale horticulture (Elbert, 2012). These are emerging foods consisting of young edible vegetables and herbs, which are harvested when cotyledonary leaves have fully developed and the first true leaves have emerged, which is usually 7–21 days after germination (Allegretta et al., 2019). Microgreen production is on the rise among homemade food preparations and ready-to-eat market and the dietary supplements industry (Galieni et al., 2020). Microgreens may contain 4-40 times the amount of nutritional compounds as the mature vegetable plant would produce. Microgreens are valuable nutritional supplement to human diet as they require very little space, growth-time and chemical inputs and offer a lucrative solution to health-conscious consumers. Microgreens are considered as “Functional foods” which means the food products that possess particular health promoting or disease preventing properties that are additional to their normal nutritional values (Janovska et al., 2010). Researchers have provided a lot of information and reviews on the nutritional traits of microgreens, because they are affected by different cultivars or landraces, plant growth stages and environmental conditions (Kyriacou et al., 2016). All of these compositionally-positive aspects are coupled with a relatively easy production process, as they only need water, light, and a substrate to grow on (Marchioni et al., 2021). They can be grown in greenhouses, high tunnels, shade structures or indoors. Microgreens are generally grown in a standard, sterile, loose, soil, and many mixes have been used successfully with peat, vermiculite, perlite, and bark (Kou et al., 2013). Microgreens have a short growing cycle and may be produced hydroponically or semi-hydroponically (Tamilselvi and Arumugam 2018). The present study aims to apprehend the relationship of various growth and developmental traits of microgreens with the media in which they grow. MATERIALS AND METHODS The present investigation was carried out in the Department of Seed Science and Technology as well as the Department of Vegetable Science and Floriculture, College of Agriculture, Chaudhary Sarwan Kumar Himachal Pradesh Krishi Vishvavidyalaya, Palampur during March- April, 2021. Technical programme of work. All the vegetable microgreens viz; kale, broccoli, lettuce and turnip were raised in trays (45cm × 35cm × 7.5cm) using mixture of cocopeat, vermiculte and perlite as the first growing media and vermicompost as the second growing media. Seeds were broadcasted at the rate of 10g seed/tray. Shallow sowing of the seeds was done and the trays were watered daily for maintaining the optimum moisture level in the substrates. The experiment was conducted in completely randomized design (CRD) and the effect of interaction of different media and varieties on various growth and developmental traits of microgreens were studied. Table 1 describes the the source of various crop varieties which were used during the course of research work. Before sowing the seeds into trays with the mentioned growth media, the germination percentage was calculated using top of paper method as per the procedure given by the International Seed Testing Association (Anonymous, 2019), where the seeds were germinated on the top of one layer paper enclosed in transparent petri dishes, with the addition of appropriate quantity of water in the beginning of the test. These petri plates were then kept in the germinator at 20±1°C. Readings were taken twice (4 DAS and 8 DAS). Germination % age was calculated using the formula: Germination (%) = 100 × (No. of normal seedlings)/ (No. of seeds kept for germination) The root length, shoot length, leaf length and leaf breadth were measured using centimeter scale. 100 seedling weight was computed using digital electronic balance and yield was calculated in kilograms per metre square of the area of trays in which microgreens were sown. All data was taken on four harvest intervals, i.e., 7 DAS, 14 DAS, 21 DAS and 28 DAS in replications of three and displayed as averages, with a clear distinction between the two media used for cultivating the microgreens under study. Statistical analysis. All data obtained was analysed based on simple ANOVA as three factor factorial and comparison of CDs was done using the software OPSTAT (Sheoran et al., 1998). RESULTS AND DISCUSSIONS Seeds of turnip varieties Pusa Swarnima and Pusa Chandrima had the highest germination percentage (99%), followed by Pusa Kale- 64 and local kale varieties of kale (98%) and then Palam Samridhi (97%), Palam Vichitra (96%) and Palam Kanchan (96%) varieties of broccoli seeds. Similar observations were made in Indian mustard varieties, cotton, sunflower and peralmillet (Rai et al., 2017; Chritiansen and Rowland 1981; Pallavi et al., 2003; Gupta et al., 2005). Lettuce seeds germinated the slowest, with the Great Lakes variety having 30% germination percentage. Results in a study on six different lettuce varieties also revealed low germination percentages like in the present research (Penaloza et al., 2005).From Fig. 1, it was inferred that for all the morphological traits for microgreens under study, the best media was cocopeat, vermiculite and perlite mixed in the ratio of 3:1:1 (media 1), owing to its greater porosity which meant higher root and shoot length, thus greater seedling height and improved visual characters. A significant impact of growth media has been reported on the growth characteristics of microgreens in literature (Di Gioia et al., 2017). A similar trend in mustard, leaf mustard, radish and cabbage microgreens grown in four different growing media has been reported, with highest values obtained in soil plus cowdung media (Efendi et al., 2020). These results were attributed to the chemical properties of the soil (pH, cation exchange capacity, total N and available P) and physical properties of the soil media viz., bulk density, porosity and water holding capacity (Di Gioia et al., 2019). Wild cosmos microgreens grown in two different planting media also exhibited similar observations, where plant height, leaf area and root length showed significantly different values in various media, with highest plant height in biochar grown microgreens. However, yield was found to be greater in the media containing vermicompost as the growth substrate (media 2). This may be due to more number of seedlings in media 1, that resulted in more intraspecific competition for growth and development which eventually led to lesser yield in comparison to media 2 where a proper crop stand was obtained. Substrate biofortification also plays an imperative role in the morphometry of microgreens (Lee et al., 2004), thus proving that the media in which the microgreens are grown not only alters the nutritional composition but also the visual characteristics of the microgreens. Plant morphology largely depends on its genetics. Many species germinate easily and grow promptly while others are slow and perform poor in comparison (Paradiso et al., 2018). The morphological characters measured in the present study revealed that in general, kale microgreens (Pusa Kale- 64 and local kale) performed better morphologically than the other microgreens and Purple Top White Globe turnip gave poor results for most of the morphological parameters under observation (Table 3). Highest shoot length (11.68 cm) and leaf length (38.92 mm) was calculated in Chinese Yellow lettuce, maximum seedling length (16.34 cm) was obtained in Pusa Swarnima variety of turnip microgreens and highest root length (5.16 cm) was measured in Palam Vichitra broccoli. However, maximum value of leaf breadth (21.25 mm) and 100 seedling weight (29.64 g) was measured in local kale microgreens. Palam Samridhi gave the highest yield (7.30 kg/m2) among all the microgreens under study. This revealed that different microgreen varieties performed significantly different in the two growth media. Similar observations have been made by various scientists in other microgreens (Efendi et al., 2020; Lenzi et al., 2019; Sinha and Thilakavathya 2021; Ghoora et al., 2020; Sharma et al., 2013). These observations may be reasoned with germination related traits and vigor index which is inherent for different varieties of microgreens under study (Di Bella et al., 2021). Apart from the growth media, genotypes significantly affected the growth related traits of the microgreens, as revealed by our study. This observation was supported by another research on three microgreens belonging to Brassicaceae, where the genotype had significant impact on the leaf length, leaf breadth, weight and yield of microgreens.