Biofortification of Six Varieties of Lettuce (Lactuca sativa L.) With Iodine and Selenium in Combination With the Application of Salicylic Acid

Abstract

The agrotechnical methods of biofortification of plants, i.e., enriching them in iodine (I) and selenium (Se) could be effective methods to enrich food products in these elements. The advantage of agrotechnical methods of biofortification is the incorporation of elements in organic compounds in plants; therefore, they have better health-promoting properties than pure technical salts. Two-year studies were conducted in a greenhouse with hydroponic cultivation of three botanical varieties of lettuce in an NFT (nutrient film technique) system: two cultivars butterhead lettuces (abb. BUTL) ‘Cud Voorburgu’ and ‘Zimująca,’ two cultivars iceberg lettuces (abb. ICEL) ‘Maugli’ and ‘Królowa lata’ (all this four cultivars are classified as Lactuca sativa L. var. capitata ) as well two cultivars Lactuca sativa L. var. crispa L. cultivars (abb. REDL) ‘Lollo rossa’ and ‘Redin’ having little red leaves. The study included the application of I (as KIO 3 ), Se (as Na 2 SeO 3 ), and SA into the nutrient solution. The tested treatments were as follows: (1) control, (2) I+Se, (3) I+Se+0.1 mg SA dm −3 , (4) I+Se+1.0 mg SA dm −3 , and (5) I+Se+10.0 mg SA dm −3 . KIO 3 was used at a dose of 5 mg I dm −3 , while Na 2 SeO 3 was 0.5 mg Se dm −3 . Regardless of the kind of the applied compound, the highest biomass of heads was produced by the REDL ‘Redin’ variety. Furthermore, this variety, as the only one in six varieties tested, reacted with the decrease in yield to the application of I+Se and I+Se+three concentrations of SA. In the heads of all cultivars, the level of I accumulation was 10–30 times higher than of Se. The level of I accumulation formed the following order: REDL ‘Lollo rossa’ > REDL ‘Redin’ = BUTL ‘Cud Voorburgu’ > BUTL ‘Zimująca’ > ICEL ‘Maugli’ > ICEL ‘Królowa lata’. The order of Se content in leaves was as follows: REDL ‘Redin’ = BUTL ‘Cud Voorburgu’ > REDL ‘Lollo rossa’ > ICEL ‘Maugli’ > BUTL ‘Zimująca’ > ICEL ‘Królowa lata’. The obtained results indicate that the introduction of SA to the nutrient solutions in hydroponic systems may allow an improve the effectiveness of – biofortification.

Combating Micronutrient Deficiency and Enhancing Food Functional Quality Through Selenium Fortification of Select Lettuce Genotypes Grown in a Closed Soilless System

“…Consequently, the RDA-Se varies with the same trend reaching a peak at 40 µM dose in both cultivars (685 and 646%, respectively for the green and red Salanova, respectively). Our RDA-Se values observed at the lowest Se dose (8 µM), were comparable with those found by Smoleń et al (2019) on six varieties of lettuce biofortified with selenium combined with iodine at the 6.3 µM Se dose. Particularly, the iceberg varieties Krolowa and Maugli showed the lowest values (23.8 and 27.1%, respectively), while the green butterhead Cud Voorburgu and the red lettuce Lollo rossa reached the highest percentage (44.7 and 44.8%, respectively) which were comparable with the values found in green and red Salanova at the 8 µM Se dose (57 and 45%, respectively).…”

Joint Biofortification of Plants with Selenium and Iodine: New Field of Discoveries

“…Hydroponics or soilless is another technological approach providing strict control of crop growing conditions and minimizing the effect of environmental factors. Four studies of joint Se–I biofortification in soilless conditions [ 38 , 39 , 40 , 41 ] demonstrated the stimulating effect of salicylic acid on I accumulation. Furthermore, in conditions of joint Se–I hydroponics application, the activation of Se organic forms biosynthesis (SeMet, SeCys) reportedly takes place [ 38 , 41 ].…”

New Aspects of Uptake and Metabolism of Non-organic and Organic Iodine Compounds—The Role of Vanadium and Plant-Derived Thyroid Hormone Analogs in Lettuce

“…In the NFT hydroponic system, target replanting was preceded by thorough rinsing of the substrate between the seedlings' The type of nutrient solution, its preparation (content of macro-and microelements), regulation of pH and EC, and type of fertilizers in the NFT were the same as in our previous studies with lettuce in the same hydroponic system (Smoleń et al, 2019b). The I used in the base nutrient solutions (control) was iodide I − (25.52 µg I•dm −3 ) and iodate IO 3 − (0.29 µg I•dm −3 ).…”