Vegetables play a key role in food security and nutrition as the food system shifts from food quantity to dietary quality and health benefits. One of the main reasons for the low production and declining average yields of most vegetable crops is climate change. Important limiting factors in maintaining and increasing vegetable crop yields are rising temperatures, reduced water availability for irrigation, flooding and salinity. Under changing climatic conditions, crop failures, declining quality and increasing pest and disease problems are becoming commonplace and making vegetable production unprofitable. Since many physiological processes and enzyme activity are temperature dependent, they will be greatly affected. Drought and salinity are two important effects of rising temperatures that reduce vegetable crop yields. These impacts of climate change also affect the emergence of pests and diseases, host-pathogen interactions, distribution and ecology of insects, timing of emergence, migration to new locations, and their ability to overwinter, all of which become a major barrier to vegetable production. To mitigate the adverse effects of climate change on the productivity and quality of vegetable crops, sound adaptation strategies need to be developed. Emphasis should be placed on the development of production systems that improve water efficiency and are adapted to hot and dry conditions. Technological practices, such as mulching with crop residues and plastic materials, help maintain soil moisture. Excessive soil moisture due to heavy rains becomes a serious problem that can be solved by growing crops in raised beds. An effective way to solve these problems is to create genotypes that are resistant to high temperatures, moisture, salinity and resistance to climatic conditions, using traditional and non-traditional breeding methods, genomics, biotechnology, etc.

At the first stage of breeding, the new source material was created to obtain a variety of daikon resistant to abiotic factors with high productivity and commercial qualities, better taste, and biochemical properties. Eighteen samples from Russia, Ukraine, Belarus, China, Korea, and Japan were in the nursery of the original forms. The following breeding types were used in the hybrid nursery: 1) crossing of several morphologically close samples originating from geographically remote areas; 2) paired crosses of morphologically and biologically different samples. Breeding was carried out on an accelerated scheme: before harvesting, samples were evaluated for resistance to bolting, shape and color of the roots, taste qualities, and affection with diseases; in February, the roots were planted in temporary greenhouses in pairs for hybridization; seeds were threshed in mid-July; the hybrid seeds were sown on the roots in early August; the roots were harvested and evaluated 60-65 days after the moment of sprouting. Then, the 1.5-year cycle was repeated until the constant lines were obtained. Yield fluctuations were determined by taking into account the sum of effective temperatures and precipitation for the period “sprouting – harvest” [4]. Slight variability in the yield at high agronomic stability was observed for the varieties Sokol, Gulliver, and hybrid No. 41. The standard (variety Klyk slona) differed from other varieties by high variability in the yield and insufficiently high agronomic stability (66%). We found that there was the fluctuation of the yield of modern varieties: Klyk slona by 22 t/ha, Gulliver by 9 t/ha, Sokol by 14 t/ha, and hybrid No. 41 by 15 t/ha. It was estimated that for every 1 degree Celsius rise in the amounts of effective temperatures the yield of the aforementioned varieties decreased: 9.7; 38; 7.4 and 66 kg/ha, respectively. And, vice versa, if the amount of precipitation increased by 1 mm, the yield of Klyk slona would increase by 17 kg/ha, Gulliver - by 10 kg/ha, Sokol - by 11 kg/ha, and hybrid No. 41 – by 6 kg/ha. The technology and method for initial seed production of daikon have been developed with the preserved economic and biological characteristics. The daikon variety Sokol was created and included in the State Register.

The breeding program for daikon in Crimea was carried out according to the following plan: the seed sowing in the third decade of July, and root selection for economically valuable traits after 58-70 days; storage during the winter; planting in the short warm periods of February, under temporary tunnel coverage for parental lines used for hybridization; seed production in second decade of July; seed sowing in third decade of July; assessment of progenies in 58-70 days. The annual cycle was repeated until the constant lines were obtained. As result of that, the middle-maturing variety was developed, the periods from shoots to root formation, to root harvesting, to seed maturation were 26 days, 63 days and 90 days, respectively. Variety ‘Solol’ had 3% less of dry matter than standard variety ‘Klyck Slona’ and 10% higher than standard variety ‘Guliver’. The variety ‘Sokol’ had 6-14% more total sugar than both standard varieties. The variety was characterized by high ultrastability and agrochemical stability (86%), average value of yield variation V=13.6%, whereas correlation with sum of effective temperature, r = -0.34 and sum of rainfall, r = +0.58. The yield of daikon root in the variety ‘Sokol’ was 47 t/ha that was 27-31% higher than yield in the standard variety.