Resistance of Sweet Pepper Genotypes to Abiotic Stresses in Grpwing Conditions of Low-Capacity Hydroponics

Abstract

The modern trend of vegetable crop breeding is a development of new cultivars and hybrids resistant to abiotic and biotic stresses and suitable for fully mechanized agriculture. It can provide the maximal commercial output and high profitability of vegetable growing. Pre-breeding is based on knowledge of impact of various abiotic factors on the yield and productivity of certain genotype in specific growing conditions. Traditionally the pepper plants are cultivated in greenhouses on low-volume soil or artificial medium with drop irrigation. Main advantage of low-volume technologies is a labor saving and improved phytosanitary conditions. In the present paper, the response of different sweet pepper (Capsicum annuum L.) genotypes to various abiotic factors has been studied aiming at development of initial breeding material for new varieties and hybrids under the hydroponic system conditions. The investigation has been conducted in 2008-2014 in the All-Russian Research Institute for vegetable breeding and seed production (Moscow Province). The breeding and collection samples of sweet pepper as well as F 1 hybrid Raisa (standard) were used in the present study. Plants were grown in a greenhouse on sphagnum peat mixed with calcified substance as a potting substrate and mineral fertilizers. The concentration of nutrient solution for irrigation of seedlings conforms to the recommended standard. The growth conditions were partially controlled. The parameters of outside environment were recorded during growing period using an automated climate control system KISTOCK KH-100 (France). The soil temperature was also controlled. Yield sample characteristics and assessment were done by UPOV system (Union Internationale pour la protection des obtentions végétales, France). The most adverse factores were recorded in the beginning (February-May) and the end (September-October) of growing season regardless of year of investigation, that resulted in decreasing marketability of the yield. The unmarketable part of yield was represented by fruits with excessive growth, deformation, and affected by blossom-end rot. Long-term screening of pepper genotypes on responsiveness to unfavorable factors of environment allowed to divide the cultivars into the following groups: susceptible (cv. Agapovskii), low-susceptible (cv. Elisa), and tolerant (cv. Zheltiyi buket). At hydroponics, productivity of the susceptible cultivar Agapovskiy was decreased up to 40 % as compared with the tolerant cultivar Zheltiyi buket. It was shown that adaptability of sweet pepper varieties to the conditions of lowcapacity hydroponics is defined by the norm of reaction to changes of environmental factors such as daily temperature, difference of night and day temperatures, humidity, and its combinations. Changes of the light intensity are not so crucial for cultivars productivity; it may have negative impact on varieties with low adaptability when combined with other environment parameters. The correlation between the rate of non-standard part of yield, the damage of f...

Yield of different onion varieties depending on the level of mineral nutrition and growth regulators in the conditions of the Southern Forest-steppe of the Republic of Bashkortostan

“…Factors such as mean daily temperature, day-night temperature difference, relative humidity and their combination are important and affect the standard production in vegetable production. Light intensity has a less significant effect on the reduction of marketability and may act as an additional negative factor in combination with other environmental parameters in varieties with low adaptive capacity [12].…”

Role of Exogenous Application of Alpha-Tocopherol in Reducing Low Temperature Stress in Bell Pepper

“…Under low temperatures, reactive oxygen species (ROS) increase in plants that damage the cell membranes, and plants die due to oxidative stress (Li et al, 2004;Wang and Liu, 2010;Zhai et al, 2016). Capsicum is highly temperature sensitive crop and low temperature (14C) severely disturbs its physiology that results in decreased growth of leaves, buds, and flower, reduced metabolism and cell function, irregular shedding of vegetative and reproductive parts, accumulation of ROS that lead to lipid and protein degradation, abnormal sex organ and feasible pollen grain, swollen and enlarged ovaries, parthenocarpic and abnormal fruit size and poor yield (Mateos et al, 2013;Pyshnaya et al, 2016). Application of antioxidants is one of the leading remedies to reduce stress, improve quality, growth, and yield.…”

Do AMF and Irrigation Regimes Affect Sweet Pepper Fruit Quality under Open Field Conditions?

“…Sweet pepper is now grown across the world as a vegetable, spice, and medicinal plant in order to obtain fresh and dried peppers as well as processed products. Pepper cultivars differ in many morphological characters and the content of biologically active substances [4], but also in their resistance to environmental stress [5,6] and to diseases caused by fungi, bacteria, and viruses [7]. Sweet peppers are characterized by a high content of vitamin C [165.4 mg 100 g −1 ] as well as of sugars, carotenoids, tocopherols, polyphenols, and minerals [2].…”